/****************************************************************************** * arch/x86/mm.c * * Copyright (c) 2002-2005 K A Fraser * Copyright (c) 2004 Christian Limpach * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; If not, see . */ /* * A description of the x86 page table API: * * Domains trap to do_mmu_update with a list of update requests. * This is a list of (ptr, val) pairs, where the requested operation * is *ptr = val. * * Reference counting of pages: * ---------------------------- * Each page has two refcounts: tot_count and type_count. * * TOT_COUNT is the obvious reference count. It counts all uses of a * physical page frame by a domain, including uses as a page directory, * a page table, or simple mappings via a PTE. This count prevents a * domain from releasing a frame back to the free pool when it still holds * a reference to it. * * TYPE_COUNT is more subtle. A frame can be put to one of three * mutually-exclusive uses: it might be used as a page directory, or a * page table, or it may be mapped writable by the domain [of course, a * frame may not be used in any of these three ways!]. * So, type_count is a count of the number of times a frame is being * referred to in its current incarnation. Therefore, a page can only * change its type when its type count is zero. * * Pinning the page type: * ---------------------- * The type of a page can be pinned/unpinned with the commands * MMUEXT_[UN]PIN_L?_TABLE. Each page can be pinned exactly once (that is, * pinning is not reference counted, so it can't be nested). * This is useful to prevent a page's type count falling to zero, at which * point safety checks would need to be carried out next time the count * is increased again. * * A further note on writable page mappings: * ----------------------------------------- * For simplicity, the count of writable mappings for a page may not * correspond to reality. The 'writable count' is incremented for every * PTE which maps the page with the _PAGE_RW flag set. However, for * write access to be possible the page directory entry must also have * its _PAGE_RW bit set. We do not check this as it complicates the * reference counting considerably [consider the case of multiple * directory entries referencing a single page table, some with the RW * bit set, others not -- it starts getting a bit messy]. * In normal use, this simplification shouldn't be a problem. * However, the logic can be added if required. * * One more note on read-only page mappings: * ----------------------------------------- * We want domains to be able to map pages for read-only access. The * main reason is that page tables and directories should be readable * by a domain, but it would not be safe for them to be writable. * However, domains have free access to rings 1 & 2 of the Intel * privilege model. In terms of page protection, these are considered * to be part of 'supervisor mode'. The WP bit in CR0 controls whether * read-only restrictions are respected in supervisor mode -- if the * bit is clear then any mapped page is writable. * * We get round this by always setting the WP bit and disallowing * updates to it. This is very unlikely to cause a problem for guest * OS's, which will generally use the WP bit to simplify copy-on-write * implementation (in that case, OS wants a fault when it writes to * an application-supplied buffer). */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pv/mm.h" /* Override macros from asm/page.h to make them work with mfn_t */ #undef mfn_to_page #define mfn_to_page(mfn) __mfn_to_page(mfn_x(mfn)) #undef page_to_mfn #define page_to_mfn(pg) _mfn(__page_to_mfn(pg)) /* Mapping of the fixmap space needed early. */ l1_pgentry_t __section(".bss.page_aligned") __aligned(PAGE_SIZE) l1_fixmap[L1_PAGETABLE_ENTRIES]; paddr_t __read_mostly mem_hotplug; /* Private domain structs for DOMID_XEN and DOMID_IO. */ struct domain *dom_xen, *dom_io, *dom_cow; /* Frame table size in pages. */ unsigned long max_page; unsigned long total_pages; bool __read_mostly machine_to_phys_mapping_valid; struct rangeset *__read_mostly mmio_ro_ranges; static uint32_t base_disallow_mask; /* Global bit is allowed to be set on L1 PTEs. Intended for user mappings. */ #define L1_DISALLOW_MASK ((base_disallow_mask | _PAGE_GNTTAB) & ~_PAGE_GLOBAL) #define L2_DISALLOW_MASK base_disallow_mask #define l3_disallow_mask(d) (!is_pv_32bit_domain(d) ? \ base_disallow_mask : 0xFFFFF198U) #define L4_DISALLOW_MASK (base_disallow_mask) #define l1_disallow_mask(d) \ ((d != dom_io) && \ (rangeset_is_empty((d)->iomem_caps) && \ rangeset_is_empty((d)->arch.ioport_caps) && \ !has_arch_pdevs(d) && \ is_pv_domain(d)) ? \ L1_DISALLOW_MASK : (L1_DISALLOW_MASK & ~PAGE_CACHE_ATTRS)) static s8 __read_mostly opt_mmio_relax; static int __init parse_mmio_relax(const char *s) { if ( !*s ) opt_mmio_relax = 1; else opt_mmio_relax = parse_bool(s, NULL); if ( opt_mmio_relax < 0 && strcmp(s, "all") ) { opt_mmio_relax = 0; return -EINVAL; } return 0; } custom_param("mmio-relax", parse_mmio_relax); static void __init init_frametable_chunk(void *start, void *end) { unsigned long s = (unsigned long)start; unsigned long e = (unsigned long)end; unsigned long step; mfn_t mfn; ASSERT(!(s & ((1 << L2_PAGETABLE_SHIFT) - 1))); for ( ; s < e; s += step << PAGE_SHIFT ) { step = 1UL << (cpu_has_page1gb && !(s & ((1UL << L3_PAGETABLE_SHIFT) - 1)) ? L3_PAGETABLE_SHIFT - PAGE_SHIFT : L2_PAGETABLE_SHIFT - PAGE_SHIFT); /* * The hardcoded 4 below is arbitrary - just pick whatever you think * is reasonable to waste as a trade-off for using a large page. */ while ( step && s + (step << PAGE_SHIFT) > e + (4 << PAGE_SHIFT) ) step >>= PAGETABLE_ORDER; mfn = alloc_boot_pages(step, step); map_pages_to_xen(s, mfn_x(mfn), step, PAGE_HYPERVISOR); } memset(start, 0, end - start); memset(end, -1, s - e); } void __init init_frametable(void) { unsigned int sidx, eidx, nidx; unsigned int max_idx = (max_pdx + PDX_GROUP_COUNT - 1) / PDX_GROUP_COUNT; struct page_info *end_pg, *top_pg; BUILD_BUG_ON(XEN_VIRT_END > FRAMETABLE_VIRT_START); BUILD_BUG_ON(FRAMETABLE_VIRT_START & ((1UL << L2_PAGETABLE_SHIFT) - 1)); for ( sidx = 0; ; sidx = nidx ) { eidx = find_next_zero_bit(pdx_group_valid, max_idx, sidx); nidx = find_next_bit(pdx_group_valid, max_idx, eidx); if ( nidx >= max_idx ) break; init_frametable_chunk(pdx_to_page(sidx * PDX_GROUP_COUNT), pdx_to_page(eidx * PDX_GROUP_COUNT)); } end_pg = pdx_to_page(max_pdx - 1) + 1; top_pg = mem_hotplug ? pdx_to_page(max_idx * PDX_GROUP_COUNT - 1) + 1 : end_pg; init_frametable_chunk(pdx_to_page(sidx * PDX_GROUP_COUNT), top_pg); memset(end_pg, -1, (unsigned long)top_pg - (unsigned long)end_pg); } #ifndef NDEBUG static unsigned int __read_mostly root_pgt_pv_xen_slots = ROOT_PAGETABLE_PV_XEN_SLOTS; static l4_pgentry_t __read_mostly split_l4e; #else #define root_pgt_pv_xen_slots ROOT_PAGETABLE_PV_XEN_SLOTS #endif void __init arch_init_memory(void) { unsigned long i, pfn, rstart_pfn, rend_pfn, iostart_pfn, ioend_pfn; /* * Basic guest-accessible flags: * PRESENT, R/W, USER, A/D, AVAIL[0,1,2], AVAIL_HIGH, NX (if available). */ base_disallow_mask = ~(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_AVAIL | _PAGE_AVAIL_HIGH | _PAGE_NX); /* * Initialise our DOMID_XEN domain. * Any Xen-heap pages that we will allow to be mapped will have * their domain field set to dom_xen. * Hidden PCI devices will also be associated with this domain * (but be [partly] controlled by Dom0 nevertheless). */ dom_xen = domain_create(DOMID_XEN, DOMCRF_dummy, 0, NULL); BUG_ON(IS_ERR(dom_xen)); INIT_LIST_HEAD(&dom_xen->arch.pdev_list); /* * Initialise our DOMID_IO domain. * This domain owns I/O pages that are within the range of the page_info * array. Mappings occur at the priv of the caller. */ dom_io = domain_create(DOMID_IO, DOMCRF_dummy, 0, NULL); BUG_ON(IS_ERR(dom_io)); /* * Initialise our COW domain. * This domain owns sharable pages. */ dom_cow = domain_create(DOMID_COW, DOMCRF_dummy, 0, NULL); BUG_ON(IS_ERR(dom_cow)); /* * First 1MB of RAM is historically marked as I/O. If we booted PVH, * reclaim the space. Irrespective, leave MFN 0 as special for the sake * of 0 being a very common default value. Also reserve page 0x1 which is * used by the trampoline code on PVH. */ BUG_ON(pvh_boot && trampoline_phys != 0x1000); for ( i = 0; i < (pvh_boot ? (1 + PFN_UP(trampoline_end - trampoline_start)) : 0x100); i++ ) share_xen_page_with_guest(mfn_to_page(_mfn(i)), dom_io, XENSHARE_writable); /* Any areas not specified as RAM by the e820 map are considered I/O. */ for ( i = 0, pfn = 0; pfn < max_page; i++ ) { while ( (i < e820.nr_map) && (e820.map[i].type != E820_RAM) && (e820.map[i].type != E820_UNUSABLE) ) i++; if ( i >= e820.nr_map ) { /* No more RAM regions: mark as I/O right to end of memory map. */ rstart_pfn = rend_pfn = max_page; } else { /* Mark as I/O just up as far as next RAM region. */ rstart_pfn = min_t(unsigned long, max_page, PFN_UP(e820.map[i].addr)); rend_pfn = max_t(unsigned long, rstart_pfn, PFN_DOWN(e820.map[i].addr + e820.map[i].size)); } /* * Make sure any Xen mappings of RAM holes above 1MB are blown away. * In particular this ensures that RAM holes are respected even in * the statically-initialised 1-16MB mapping area. */ iostart_pfn = max_t(unsigned long, pfn, 1UL << (20 - PAGE_SHIFT)); ioend_pfn = min(rstart_pfn, 16UL << (20 - PAGE_SHIFT)); if ( iostart_pfn < ioend_pfn ) destroy_xen_mappings((unsigned long)mfn_to_virt(iostart_pfn), (unsigned long)mfn_to_virt(ioend_pfn)); /* Mark as I/O up to next RAM region. */ for ( ; pfn < rstart_pfn; pfn++ ) { if ( !mfn_valid(_mfn(pfn)) ) continue; share_xen_page_with_guest( mfn_to_page(_mfn(pfn)), dom_io, XENSHARE_writable); } /* Skip the RAM region. */ pfn = rend_pfn; } subarch_init_memory(); efi_init_memory(); mem_sharing_init(); #ifndef NDEBUG if ( highmem_start ) { unsigned long split_va = (unsigned long)__va(highmem_start); if ( split_va < HYPERVISOR_VIRT_END && split_va - 1 == (unsigned long)__va(highmem_start - 1) ) { root_pgt_pv_xen_slots = l4_table_offset(split_va) - ROOT_PAGETABLE_FIRST_XEN_SLOT; ASSERT(root_pgt_pv_xen_slots < ROOT_PAGETABLE_PV_XEN_SLOTS); if ( l4_table_offset(split_va) == l4_table_offset(split_va - 1) ) { l3_pgentry_t *l3tab = alloc_xen_pagetable(); if ( l3tab ) { const l3_pgentry_t *l3idle = l4e_to_l3e(idle_pg_table[l4_table_offset(split_va)]); for ( i = 0; i < l3_table_offset(split_va); ++i ) l3tab[i] = l3idle[i]; for ( ; i < L3_PAGETABLE_ENTRIES; ++i ) l3tab[i] = l3e_empty(); split_l4e = l4e_from_pfn(virt_to_mfn(l3tab), __PAGE_HYPERVISOR_RW); } else ++root_pgt_pv_xen_slots; } } } #endif } int page_is_ram_type(unsigned long mfn, unsigned long mem_type) { uint64_t maddr = pfn_to_paddr(mfn); int i; for ( i = 0; i < e820.nr_map; i++ ) { switch ( e820.map[i].type ) { case E820_RAM: if ( mem_type & RAM_TYPE_CONVENTIONAL ) break; continue; case E820_RESERVED: if ( mem_type & RAM_TYPE_RESERVED ) break; continue; case E820_UNUSABLE: if ( mem_type & RAM_TYPE_UNUSABLE ) break; continue; case E820_ACPI: case E820_NVS: if ( mem_type & RAM_TYPE_ACPI ) break; continue; default: /* unknown */ continue; } /* Test the range. */ if ( (e820.map[i].addr <= maddr) && ((e820.map[i].addr + e820.map[i].size) >= (maddr + PAGE_SIZE)) ) return 1; } return 0; } unsigned long domain_get_maximum_gpfn(struct domain *d) { if ( is_hvm_domain(d) ) return p2m_get_hostp2m(d)->max_mapped_pfn; /* NB. PV guests specify nr_pfns rather than max_pfn so we adjust here. */ return (arch_get_max_pfn(d) ?: 1) - 1; } void share_xen_page_with_guest( struct page_info *page, struct domain *d, int readonly) { if ( page_get_owner(page) == d ) return; set_gpfn_from_mfn(mfn_x(page_to_mfn(page)), INVALID_M2P_ENTRY); spin_lock(&d->page_alloc_lock); /* The incremented type count pins as writable or read-only. */ page->u.inuse.type_info = (readonly ? PGT_none : PGT_writable_page); page->u.inuse.type_info |= PGT_validated | 1; page_set_owner(page, d); smp_wmb(); /* install valid domain ptr before updating refcnt. */ ASSERT((page->count_info & ~PGC_xen_heap) == 0); /* Only add to the allocation list if the domain isn't dying. */ if ( !d->is_dying ) { page->count_info |= PGC_xen_heap | PGC_allocated | 1; if ( unlikely(d->xenheap_pages++ == 0) ) get_knownalive_domain(d); page_list_add_tail(page, &d->xenpage_list); } spin_unlock(&d->page_alloc_lock); } int __init unshare_xen_page_with_guest(struct page_info *page, struct domain *d) { if ( page_get_owner(page) != d || !is_xen_heap_page(page) ) return -EINVAL; if ( test_and_clear_bit(_PGC_allocated, &page->count_info) ) put_page(page); /* Remove the owner and clear the flags. */ page->u.inuse.type_info = 0; page_set_owner(page, NULL); return 0; } void share_xen_page_with_privileged_guests( struct page_info *page, int readonly) { share_xen_page_with_guest(page, dom_xen, readonly); } void free_shared_domheap_page(struct page_info *page) { if ( test_and_clear_bit(_PGC_allocated, &page->count_info) ) put_page(page); if ( !test_and_clear_bit(_PGC_xen_heap, &page->count_info) ) ASSERT_UNREACHABLE(); page->u.inuse.type_info = 0; page_set_owner(page, NULL); free_domheap_page(page); } void make_cr3(struct vcpu *v, mfn_t mfn) { v->arch.cr3 = mfn_x(mfn) << PAGE_SHIFT; } void write_ptbase(struct vcpu *v) { write_cr3(v->arch.cr3); } /* * Should be called after CR3 is updated. * * Uses values found in vcpu->arch.(guest_table and guest_table_user), and * for HVM guests, arch.monitor_table and hvm's guest CR3. * * Update ref counts to shadow tables appropriately. */ void update_cr3(struct vcpu *v) { mfn_t cr3_mfn; if ( paging_mode_enabled(v->domain) ) { paging_update_cr3(v); return; } if ( !(v->arch.flags & TF_kernel_mode) ) cr3_mfn = pagetable_get_mfn(v->arch.guest_table_user); else cr3_mfn = pagetable_get_mfn(v->arch.guest_table); make_cr3(v, cr3_mfn); } static inline void set_tlbflush_timestamp(struct page_info *page) { /* * Record TLB information for flush later. We do not stamp page tables * when running in shadow mode: * 1. Pointless, since it's the shadow pt's which must be tracked. * 2. Shadow mode reuses this field for shadowed page tables to store * flags info -- we don't want to conflict with that. */ if ( !(page->count_info & PGC_page_table) || !shadow_mode_enabled(page_get_owner(page)) ) page_set_tlbflush_timestamp(page); } const char __section(".bss.page_aligned.const") __aligned(PAGE_SIZE) zero_page[PAGE_SIZE]; static void invalidate_shadow_ldt(struct vcpu *v, int flush) { l1_pgentry_t *pl1e; unsigned int i; struct page_info *page; BUG_ON(unlikely(in_irq())); spin_lock(&v->arch.pv_vcpu.shadow_ldt_lock); if ( v->arch.pv_vcpu.shadow_ldt_mapcnt == 0 ) goto out; v->arch.pv_vcpu.shadow_ldt_mapcnt = 0; pl1e = pv_ldt_ptes(v); for ( i = 0; i < 16; i++ ) { if ( !(l1e_get_flags(pl1e[i]) & _PAGE_PRESENT) ) continue; page = l1e_get_page(pl1e[i]); l1e_write(&pl1e[i], l1e_empty()); ASSERT_PAGE_IS_TYPE(page, PGT_seg_desc_page); ASSERT_PAGE_IS_DOMAIN(page, v->domain); put_page_and_type(page); } /* Rid TLBs of stale mappings (guest mappings and shadow mappings). */ if ( flush ) flush_tlb_mask(v->vcpu_dirty_cpumask); out: spin_unlock(&v->arch.pv_vcpu.shadow_ldt_lock); } static int alloc_segdesc_page(struct page_info *page) { const struct domain *owner = page_get_owner(page); struct desc_struct *descs = __map_domain_page(page); unsigned i; for ( i = 0; i < 512; i++ ) if ( unlikely(!check_descriptor(owner, &descs[i])) ) break; unmap_domain_page(descs); return i == 512 ? 0 : -EINVAL; } static int get_page_and_type_from_mfn( mfn_t mfn, unsigned long type, struct domain *d, int partial, int preemptible) { struct page_info *page = mfn_to_page(mfn); int rc; if ( likely(partial >= 0) && unlikely(!get_page_from_mfn(mfn, d)) ) return -EINVAL; rc = (preemptible ? get_page_type_preemptible(page, type) : (get_page_type(page, type) ? 0 : -EINVAL)); if ( unlikely(rc) && partial >= 0 && (!preemptible || page != current->arch.old_guest_table) ) put_page(page); return rc; } static void put_data_page( struct page_info *page, int writeable) { if ( writeable ) put_page_and_type(page); else put_page(page); } #ifdef CONFIG_PV_LINEAR_PT static bool inc_linear_entries(struct page_info *pg) { typeof(pg->linear_pt_count) nc = read_atomic(&pg->linear_pt_count), oc; do { /* * The check below checks for the "linear use" count being non-zero * as well as overflow. Signed integer overflow is undefined behavior * according to the C spec. However, as long as linear_pt_count is * smaller in size than 'int', the arithmetic operation of the * increment below won't overflow; rather the result will be truncated * when stored. Ensure that this is always true. */ BUILD_BUG_ON(sizeof(nc) >= sizeof(int)); oc = nc++; if ( nc <= 0 ) return false; nc = cmpxchg(&pg->linear_pt_count, oc, nc); } while ( oc != nc ); return true; } static void dec_linear_entries(struct page_info *pg) { typeof(pg->linear_pt_count) oc; oc = arch_fetch_and_add(&pg->linear_pt_count, -1); ASSERT(oc > 0); } static bool inc_linear_uses(struct page_info *pg) { typeof(pg->linear_pt_count) nc = read_atomic(&pg->linear_pt_count), oc; do { /* See the respective comment in inc_linear_entries(). */ BUILD_BUG_ON(sizeof(nc) >= sizeof(int)); oc = nc--; if ( nc >= 0 ) return false; nc = cmpxchg(&pg->linear_pt_count, oc, nc); } while ( oc != nc ); return true; } static void dec_linear_uses(struct page_info *pg) { typeof(pg->linear_pt_count) oc; oc = arch_fetch_and_add(&pg->linear_pt_count, 1); ASSERT(oc < 0); } /* * We allow root tables to map each other (a.k.a. linear page tables). It * needs some special care with reference counts and access permissions: * 1. The mapping entry must be read-only, or the guest may get write access * to its own PTEs. * 2. We must only bump the reference counts for an *already validated* * L2 table, or we can end up in a deadlock in get_page_type() by waiting * on a validation that is required to complete that validation. * 3. We only need to increment the reference counts for the mapped page * frame if it is mapped by a different root table. This is sufficient and * also necessary to allow validation of a root table mapping itself. */ static bool __read_mostly opt_pv_linear_pt = true; boolean_param("pv-linear-pt", opt_pv_linear_pt); #define define_get_linear_pagetable(level) \ static int \ get_##level##_linear_pagetable( \ level##_pgentry_t pde, unsigned long pde_pfn, struct domain *d) \ { \ unsigned long x, y; \ struct page_info *page; \ unsigned long pfn; \ \ if ( !opt_pv_linear_pt ) \ { \ gdprintk(XENLOG_WARNING, \ "Attempt to create linear p.t. (feature disabled)\n"); \ return 0; \ } \ \ if ( (level##e_get_flags(pde) & _PAGE_RW) ) \ { \ gdprintk(XENLOG_WARNING, \ "Attempt to create linear p.t. with write perms\n"); \ return 0; \ } \ \ if ( (pfn = level##e_get_pfn(pde)) != pde_pfn ) \ { \ struct page_info *ptpg = mfn_to_page(_mfn(pde_pfn)); \ \ /* Make sure the page table belongs to the correct domain. */ \ if ( unlikely(page_get_owner(ptpg) != d) ) \ return 0; \ \ /* Make sure the mapped frame belongs to the correct domain. */ \ if ( unlikely(!get_page_from_mfn(_mfn(pfn), d)) ) \ return 0; \ \ /* \ * Ensure that the mapped frame is an already-validated page table \ * and is not itself having linear entries, as well as that the \ * containing page table is not iself in use as a linear page table \ * elsewhere. \ * If so, atomically increment the count (checking for overflow). \ */ \ page = mfn_to_page(_mfn(pfn)); \ if ( !inc_linear_entries(ptpg) ) \ { \ put_page(page); \ return 0; \ } \ if ( !inc_linear_uses(page) ) \ { \ dec_linear_entries(ptpg); \ put_page(page); \ return 0; \ } \ y = page->u.inuse.type_info; \ do { \ x = y; \ if ( unlikely((x & PGT_count_mask) == PGT_count_mask) || \ unlikely((x & (PGT_type_mask|PGT_validated)) != \ (PGT_##level##_page_table|PGT_validated)) ) \ { \ dec_linear_uses(page); \ dec_linear_entries(ptpg); \ put_page(page); \ return 0; \ } \ } \ while ( (y = cmpxchg(&page->u.inuse.type_info, x, x + 1)) != x ); \ } \ \ return 1; \ } #else /* CONFIG_PV_LINEAR_PT */ #define define_get_linear_pagetable(level) \ static int \ get_##level##_linear_pagetable( \ level##_pgentry_t pde, unsigned long pde_pfn, struct domain *d) \ { \ return 0; \ } static void dec_linear_uses(struct page_info *pg) { ASSERT(pg->linear_pt_count == 0); } static void dec_linear_entries(struct page_info *pg) { ASSERT(pg->linear_pt_count == 0); } #endif /* CONFIG_PV_LINEAR_PT */ bool is_iomem_page(mfn_t mfn) { struct page_info *page; if ( !mfn_valid(mfn) ) return true; /* Caller must know that it is an iomem page, or a reference is held. */ page = mfn_to_page(mfn); ASSERT((page->count_info & PGC_count_mask) != 0); return (page_get_owner(page) == dom_io); } static int update_xen_mappings(unsigned long mfn, unsigned int cacheattr) { int err = 0; bool alias = mfn >= PFN_DOWN(xen_phys_start) && mfn < PFN_UP(xen_phys_start + xen_virt_end - XEN_VIRT_START); unsigned long xen_va = XEN_VIRT_START + ((mfn - PFN_DOWN(xen_phys_start)) << PAGE_SHIFT); if ( unlikely(alias) && cacheattr ) err = map_pages_to_xen(xen_va, mfn, 1, 0); if ( !err ) err = map_pages_to_xen((unsigned long)mfn_to_virt(mfn), mfn, 1, PAGE_HYPERVISOR | cacheattr_to_pte_flags(cacheattr)); if ( unlikely(alias) && !cacheattr && !err ) err = map_pages_to_xen(xen_va, mfn, 1, PAGE_HYPERVISOR); return err; } #ifndef NDEBUG struct mmio_emul_range_ctxt { const struct domain *d; unsigned long mfn; }; static int print_mmio_emul_range(unsigned long s, unsigned long e, void *arg) { const struct mmio_emul_range_ctxt *ctxt = arg; if ( ctxt->mfn > e ) return 0; if ( ctxt->mfn >= s ) { static DEFINE_SPINLOCK(last_lock); static const struct domain *last_d; static unsigned long last_s = ~0UL, last_e; bool print = false; spin_lock(&last_lock); if ( last_d != ctxt->d || last_s != s || last_e != e ) { last_d = ctxt->d; last_s = s; last_e = e; print = true; } spin_unlock(&last_lock); if ( print ) printk(XENLOG_G_INFO "d%d: Forcing write emulation on MFNs %lx-%lx\n", ctxt->d->domain_id, s, e); } return 1; } #endif /* * get_page_from_l1e returns: * 0 => success (page not present also counts as such) * <0 => error code * >0 => the page flags to be flipped */ int get_page_from_l1e( l1_pgentry_t l1e, struct domain *l1e_owner, struct domain *pg_owner) { unsigned long mfn = l1e_get_pfn(l1e); struct page_info *page = mfn_to_page(_mfn(mfn)); uint32_t l1f = l1e_get_flags(l1e); struct vcpu *curr = current; struct domain *real_pg_owner; bool write; if ( !(l1f & _PAGE_PRESENT) ) return 0; if ( unlikely(l1f & l1_disallow_mask(l1e_owner)) ) { gdprintk(XENLOG_WARNING, "Bad L1 flags %x\n", l1f & l1_disallow_mask(l1e_owner)); return -EINVAL; } if ( !mfn_valid(_mfn(mfn)) || (real_pg_owner = page_get_owner_and_reference(page)) == dom_io ) { int flip = 0; /* Only needed the reference to confirm dom_io ownership. */ if ( mfn_valid(_mfn(mfn)) ) put_page(page); /* DOMID_IO reverts to caller for privilege checks. */ if ( pg_owner == dom_io ) pg_owner = curr->domain; if ( !iomem_access_permitted(pg_owner, mfn, mfn) ) { if ( mfn != (PADDR_MASK >> PAGE_SHIFT) ) /* INVALID_MFN? */ { gdprintk(XENLOG_WARNING, "d%d non-privileged attempt to map MMIO space %"PRI_mfn"\n", pg_owner->domain_id, mfn); return -EPERM; } return -EINVAL; } if ( pg_owner != l1e_owner && !iomem_access_permitted(l1e_owner, mfn, mfn) ) { if ( mfn != (PADDR_MASK >> PAGE_SHIFT) ) /* INVALID_MFN? */ { gdprintk(XENLOG_WARNING, "d%d attempted to map MMIO space %"PRI_mfn" in d%d to d%d\n", curr->domain->domain_id, mfn, pg_owner->domain_id, l1e_owner->domain_id); return -EPERM; } return -EINVAL; } if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn) ) { /* MMIO pages must not be mapped cachable unless requested so. */ switch ( opt_mmio_relax ) { case 0: break; case 1: if ( !is_hardware_domain(l1e_owner) ) break; /* fallthrough */ case -1: return 0; default: ASSERT_UNREACHABLE(); } } else if ( l1f & _PAGE_RW ) { #ifndef NDEBUG const unsigned long *ro_map; unsigned int seg, bdf; if ( !pci_mmcfg_decode(mfn, &seg, &bdf) || ((ro_map = pci_get_ro_map(seg)) != NULL && test_bit(bdf, ro_map)) ) printk(XENLOG_G_WARNING "d%d: Forcing read-only access to MFN %lx\n", l1e_owner->domain_id, mfn); else rangeset_report_ranges(mmio_ro_ranges, 0, ~0UL, print_mmio_emul_range, &(struct mmio_emul_range_ctxt){ .d = l1e_owner, .mfn = mfn }); #endif flip = _PAGE_RW; } switch ( l1f & PAGE_CACHE_ATTRS ) { case 0: /* WB */ flip |= _PAGE_PWT | _PAGE_PCD; break; case _PAGE_PWT: /* WT */ case _PAGE_PWT | _PAGE_PAT: /* WP */ flip |= _PAGE_PCD | (l1f & _PAGE_PAT); break; } return flip; } if ( unlikely( (real_pg_owner != pg_owner) && (real_pg_owner != dom_cow) ) ) { /* * Let privileged domains transfer the right to map their target * domain's pages. This is used to allow stub-domain pvfb export to * dom0, until pvfb supports granted mappings. At that time this * minor hack can go away. */ if ( (real_pg_owner == NULL) || (pg_owner == l1e_owner) || xsm_priv_mapping(XSM_TARGET, pg_owner, real_pg_owner) ) { gdprintk(XENLOG_WARNING, "pg_owner d%d l1e_owner d%d, but real_pg_owner d%d\n", pg_owner->domain_id, l1e_owner->domain_id, real_pg_owner ? real_pg_owner->domain_id : -1); goto could_not_pin; } pg_owner = real_pg_owner; } /* * Extra paranoid check for shared memory. Writable mappings * disallowed (unshare first!) */ if ( (l1f & _PAGE_RW) && (real_pg_owner == dom_cow) ) goto could_not_pin; /* * Foreign mappings into guests in shadow external mode don't * contribute to writeable mapping refcounts. (This allows the * qemu-dm helper process in dom0 to map the domain's memory without * messing up the count of "real" writable mappings.) */ write = (l1f & _PAGE_RW) && ((l1e_owner == pg_owner) || !paging_mode_external(pg_owner)); if ( write && !get_page_type(page, PGT_writable_page) ) { gdprintk(XENLOG_WARNING, "Could not get page type PGT_writable_page\n"); goto could_not_pin; } if ( pte_flags_to_cacheattr(l1f) != ((page->count_info & PGC_cacheattr_mask) >> PGC_cacheattr_base) ) { unsigned long x, nx, y = page->count_info; unsigned long cacheattr = pte_flags_to_cacheattr(l1f); int err; if ( is_xen_heap_page(page) ) { if ( write ) put_page_type(page); put_page(page); gdprintk(XENLOG_WARNING, "Attempt to change cache attributes of Xen heap page\n"); return -EACCES; } do { x = y; nx = (x & ~PGC_cacheattr_mask) | (cacheattr << PGC_cacheattr_base); } while ( (y = cmpxchg(&page->count_info, x, nx)) != x ); err = update_xen_mappings(mfn, cacheattr); if ( unlikely(err) ) { cacheattr = y & PGC_cacheattr_mask; do { x = y; nx = (x & ~PGC_cacheattr_mask) | cacheattr; } while ( (y = cmpxchg(&page->count_info, x, nx)) != x ); if ( write ) put_page_type(page); put_page(page); gdprintk(XENLOG_WARNING, "Error updating mappings for mfn %" PRI_mfn " (pfn %" PRI_pfn ", from L1 entry %" PRIpte ") for d%d\n", mfn, get_gpfn_from_mfn(mfn), l1e_get_intpte(l1e), l1e_owner->domain_id); return err; } } return 0; could_not_pin: gdprintk(XENLOG_WARNING, "Error getting mfn %" PRI_mfn " (pfn %" PRI_pfn ") from L1 entry %" PRIpte " for l1e_owner d%d, pg_owner d%d\n", mfn, get_gpfn_from_mfn(mfn), l1e_get_intpte(l1e), l1e_owner->domain_id, pg_owner->domain_id); if ( real_pg_owner != NULL ) put_page(page); return -EBUSY; } /* NB. Virtual address 'l2e' maps to a machine address within frame 'pfn'. */ /* * get_page_from_l2e returns: * 1 => page not present * 0 => success * <0 => error code */ define_get_linear_pagetable(l2); static int get_page_from_l2e( l2_pgentry_t l2e, unsigned long pfn, struct domain *d) { unsigned long mfn = l2e_get_pfn(l2e); int rc; if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) ) return 1; if ( unlikely((l2e_get_flags(l2e) & L2_DISALLOW_MASK)) ) { gdprintk(XENLOG_WARNING, "Bad L2 flags %x\n", l2e_get_flags(l2e) & L2_DISALLOW_MASK); return -EINVAL; } if ( !(l2e_get_flags(l2e) & _PAGE_PSE) ) { rc = get_page_and_type_from_mfn(_mfn(mfn), PGT_l1_page_table, d, 0, 0); if ( unlikely(rc == -EINVAL) && get_l2_linear_pagetable(l2e, pfn, d) ) rc = 0; return rc; } return -EINVAL; } /* * get_page_from_l3e returns: * 1 => page not present * 0 => success * <0 => error code */ define_get_linear_pagetable(l3); static int get_page_from_l3e( l3_pgentry_t l3e, unsigned long pfn, struct domain *d, int partial) { int rc; if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) ) return 1; if ( unlikely((l3e_get_flags(l3e) & l3_disallow_mask(d))) ) { gdprintk(XENLOG_WARNING, "Bad L3 flags %x\n", l3e_get_flags(l3e) & l3_disallow_mask(d)); return -EINVAL; } rc = get_page_and_type_from_mfn( l3e_get_mfn(l3e), PGT_l2_page_table, d, partial, 1); if ( unlikely(rc == -EINVAL) && !is_pv_32bit_domain(d) && get_l3_linear_pagetable(l3e, pfn, d) ) rc = 0; return rc; } /* * get_page_from_l4e returns: * 1 => page not present * 0 => success * <0 => error code */ define_get_linear_pagetable(l4); static int get_page_from_l4e( l4_pgentry_t l4e, unsigned long pfn, struct domain *d, int partial) { int rc; if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) ) return 1; if ( unlikely((l4e_get_flags(l4e) & L4_DISALLOW_MASK)) ) { gdprintk(XENLOG_WARNING, "Bad L4 flags %x\n", l4e_get_flags(l4e) & L4_DISALLOW_MASK); return -EINVAL; } rc = get_page_and_type_from_mfn( l4e_get_mfn(l4e), PGT_l3_page_table, d, partial, 1); if ( unlikely(rc == -EINVAL) && get_l4_linear_pagetable(l4e, pfn, d) ) rc = 0; return rc; } static int _put_page_type(struct page_info *page, bool preemptible, struct page_info *ptpg); void put_page_from_l1e(l1_pgentry_t l1e, struct domain *l1e_owner) { unsigned long pfn = l1e_get_pfn(l1e); struct page_info *page; struct domain *pg_owner; struct vcpu *v; if ( !(l1e_get_flags(l1e) & _PAGE_PRESENT) || is_iomem_page(_mfn(pfn)) ) return; page = mfn_to_page(_mfn(pfn)); pg_owner = page_get_owner(page); /* * Check if this is a mapping that was established via a grant reference. * If it was then we should not be here: we require that such mappings are * explicitly destroyed via the grant-table interface. * * The upshot of this is that the guest can end up with active grants that * it cannot destroy (because it no longer has a PTE to present to the * grant-table interface). This can lead to subtle hard-to-catch bugs, * hence a special grant PTE flag can be enabled to catch the bug early. * * (Note that the undestroyable active grants are not a security hole in * Xen. All active grants can safely be cleaned up when the domain dies.) */ if ( (l1e_get_flags(l1e) & _PAGE_GNTTAB) && !l1e_owner->is_shutting_down && !l1e_owner->is_dying ) { gdprintk(XENLOG_WARNING, "Attempt to implicitly unmap a granted PTE %" PRIpte "\n", l1e_get_intpte(l1e)); domain_crash(l1e_owner); } /* * Remember we didn't take a type-count of foreign writable mappings * to paging-external domains. */ if ( (l1e_get_flags(l1e) & _PAGE_RW) && ((l1e_owner == pg_owner) || !paging_mode_external(pg_owner)) ) { put_page_and_type(page); } else { /* We expect this is rare so we blow the entire shadow LDT. */ if ( unlikely(((page->u.inuse.type_info & PGT_type_mask) == PGT_seg_desc_page)) && unlikely(((page->u.inuse.type_info & PGT_count_mask) != 0)) && (l1e_owner == pg_owner) ) { for_each_vcpu ( pg_owner, v ) invalidate_shadow_ldt(v, 1); } put_page(page); } } /* * NB. Virtual address 'l2e' maps to a machine address within frame 'pfn'. * Note also that this automatically deals correctly with linear p.t.'s. */ static int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn) { if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) || (l2e_get_pfn(l2e) == pfn) ) return 1; if ( l2e_get_flags(l2e) & _PAGE_PSE ) { struct page_info *page = l2e_get_page(l2e); unsigned int i; for ( i = 0; i < (1u << PAGETABLE_ORDER); i++, page++ ) put_page_and_type(page); } else { struct page_info *pg = l2e_get_page(l2e); int rc = _put_page_type(pg, false, mfn_to_page(_mfn(pfn))); ASSERT(!rc); put_page(pg); } return 0; } static int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, int partial, bool defer) { struct page_info *pg; int rc; if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || (l3e_get_pfn(l3e) == pfn) ) return 1; if ( unlikely(l3e_get_flags(l3e) & _PAGE_PSE) ) { unsigned long mfn = l3e_get_pfn(l3e); int writeable = l3e_get_flags(l3e) & _PAGE_RW; ASSERT(!(mfn & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1))); do { put_data_page(mfn_to_page(_mfn(mfn)), writeable); } while ( ++mfn & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1) ); return 0; } pg = l3e_get_page(l3e); if ( unlikely(partial > 0) ) { ASSERT(!defer); return _put_page_type(pg, true, mfn_to_page(_mfn(pfn))); } if ( defer ) { current->arch.old_guest_ptpg = mfn_to_page(_mfn(pfn)); current->arch.old_guest_table = pg; return 0; } rc = _put_page_type(pg, true, mfn_to_page(_mfn(pfn))); if ( likely(!rc) ) put_page(pg); return rc; } static int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, int partial, bool defer) { int rc = 1; if ( (l4e_get_flags(l4e) & _PAGE_PRESENT) && (l4e_get_pfn(l4e) != pfn) ) { struct page_info *pg = l4e_get_page(l4e); if ( unlikely(partial > 0) ) { ASSERT(!defer); return _put_page_type(pg, true, mfn_to_page(_mfn(pfn))); } if ( defer ) { current->arch.old_guest_ptpg = mfn_to_page(_mfn(pfn)); current->arch.old_guest_table = pg; return 0; } rc = _put_page_type(pg, true, mfn_to_page(_mfn(pfn))); if ( likely(!rc) ) put_page(pg); } return rc; } static int alloc_l1_table(struct page_info *page) { struct domain *d = page_get_owner(page); l1_pgentry_t *pl1e; unsigned int i; int ret = 0; pl1e = __map_domain_page(page); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) { switch ( ret = get_page_from_l1e(pl1e[i], d, d) ) { default: goto fail; case 0: break; case _PAGE_RW ... _PAGE_RW | PAGE_CACHE_ATTRS: ASSERT(!(ret & ~(_PAGE_RW | PAGE_CACHE_ATTRS))); l1e_flip_flags(pl1e[i], ret); break; } pl1e[i] = adjust_guest_l1e(pl1e[i], d); } unmap_domain_page(pl1e); return 0; fail: gdprintk(XENLOG_WARNING, "Failure in alloc_l1_table: slot %#x\n", i); while ( i-- > 0 ) put_page_from_l1e(pl1e[i], d); unmap_domain_page(pl1e); return ret; } static int create_pae_xen_mappings(struct domain *d, l3_pgentry_t *pl3e) { struct page_info *page; l3_pgentry_t l3e3; if ( !is_pv_32bit_domain(d) ) return 1; pl3e = (l3_pgentry_t *)((unsigned long)pl3e & PAGE_MASK); /* 3rd L3 slot contains L2 with Xen-private mappings. It *must* exist. */ l3e3 = pl3e[3]; if ( !(l3e_get_flags(l3e3) & _PAGE_PRESENT) ) { gdprintk(XENLOG_WARNING, "PAE L3 3rd slot is empty\n"); return 0; } /* * The Xen-private mappings include linear mappings. The L2 thus cannot * be shared by multiple L3 tables. The test here is adequate because: * 1. Cannot appear in slots != 3 because get_page_type() checks the * PGT_pae_xen_l2 flag, which is asserted iff the L2 appears in slot 3 * 2. Cannot appear in another page table's L3: * a. alloc_l3_table() calls this function and this check will fail * b. mod_l3_entry() disallows updates to slot 3 in an existing table */ page = l3e_get_page(l3e3); BUG_ON(page->u.inuse.type_info & PGT_pinned); BUG_ON((page->u.inuse.type_info & PGT_count_mask) == 0); BUG_ON(!(page->u.inuse.type_info & PGT_pae_xen_l2)); if ( (page->u.inuse.type_info & PGT_count_mask) != 1 ) { gdprintk(XENLOG_WARNING, "PAE L3 3rd slot is shared\n"); return 0; } return 1; } static int alloc_l2_table(struct page_info *page, unsigned long type, int preemptible) { struct domain *d = page_get_owner(page); unsigned long pfn = mfn_x(page_to_mfn(page)); l2_pgentry_t *pl2e; unsigned int i; int rc = 0; pl2e = map_domain_page(_mfn(pfn)); for ( i = page->nr_validated_ptes; i < L2_PAGETABLE_ENTRIES; i++ ) { if ( preemptible && i > page->nr_validated_ptes && hypercall_preempt_check() ) { page->nr_validated_ptes = i; rc = -ERESTART; break; } if ( !is_guest_l2_slot(d, type, i) || (rc = get_page_from_l2e(pl2e[i], pfn, d)) > 0 ) continue; if ( rc < 0 ) { gdprintk(XENLOG_WARNING, "Failure in alloc_l2_table: slot %#x\n", i); while ( i-- > 0 ) if ( is_guest_l2_slot(d, type, i) ) put_page_from_l2e(pl2e[i], pfn); break; } pl2e[i] = adjust_guest_l2e(pl2e[i], d); } if ( rc >= 0 && (type & PGT_pae_xen_l2) ) init_xen_pae_l2_slots(pl2e, d); unmap_domain_page(pl2e); return rc > 0 ? 0 : rc; } static int alloc_l3_table(struct page_info *page) { struct domain *d = page_get_owner(page); unsigned long pfn = mfn_x(page_to_mfn(page)); l3_pgentry_t *pl3e; unsigned int i; int rc = 0, partial = page->partial_pte; pl3e = map_domain_page(_mfn(pfn)); /* * PAE guests allocate full pages, but aren't required to initialize * more than the first four entries; when running in compatibility * mode, however, the full page is visible to the MMU, and hence all * 512 entries must be valid/verified, which is most easily achieved * by clearing them out. */ if ( is_pv_32bit_domain(d) ) memset(pl3e + 4, 0, (L3_PAGETABLE_ENTRIES - 4) * sizeof(*pl3e)); for ( i = page->nr_validated_ptes; i < L3_PAGETABLE_ENTRIES; i++, partial = 0 ) { if ( is_pv_32bit_domain(d) && (i == 3) ) { if ( !(l3e_get_flags(pl3e[i]) & _PAGE_PRESENT) || (l3e_get_flags(pl3e[i]) & l3_disallow_mask(d)) ) rc = -EINVAL; else rc = get_page_and_type_from_mfn( l3e_get_mfn(pl3e[i]), PGT_l2_page_table | PGT_pae_xen_l2, d, partial, 1); } else if ( (rc = get_page_from_l3e(pl3e[i], pfn, d, partial)) > 0 ) continue; if ( rc == -ERESTART ) { page->nr_validated_ptes = i; page->partial_pte = partial ?: 1; } else if ( rc == -EINTR && i ) { page->nr_validated_ptes = i; page->partial_pte = 0; rc = -ERESTART; } if ( rc < 0 ) break; pl3e[i] = adjust_guest_l3e(pl3e[i], d); } if ( rc >= 0 && !create_pae_xen_mappings(d, pl3e) ) rc = -EINVAL; if ( rc < 0 && rc != -ERESTART && rc != -EINTR ) { gdprintk(XENLOG_WARNING, "Failure in alloc_l3_table: slot %#x\n", i); if ( i ) { page->nr_validated_ptes = i; page->partial_pte = 0; current->arch.old_guest_ptpg = NULL; current->arch.old_guest_table = page; } while ( i-- > 0 ) pl3e[i] = unadjust_guest_l3e(pl3e[i], d); } unmap_domain_page(pl3e); return rc > 0 ? 0 : rc; } void init_xen_pae_l2_slots(l2_pgentry_t *l2t, const struct domain *d) { memcpy(&l2t[COMPAT_L2_PAGETABLE_FIRST_XEN_SLOT(d)], &compat_idle_pg_table_l2[ l2_table_offset(HIRO_COMPAT_MPT_VIRT_START)], COMPAT_L2_PAGETABLE_XEN_SLOTS(d) * sizeof(*l2t)); } /* * Fill an L4 with Xen entries. * * This function must write all ROOT_PAGETABLE_PV_XEN_SLOTS, to clobber any * values a guest may have left there from alloc_l4_table(). * * l4t and l4mfn are mandatory, but l4mfn doesn't need to be the mfn under * *l4t. All other parameters are optional and will either fill or zero the * appropriate slots. Pagetables not shared with guests will gain the * extended directmap. */ void init_xen_l4_slots(l4_pgentry_t *l4t, mfn_t l4mfn, const struct domain *d, mfn_t sl4mfn, bool ro_mpt) { /* * PV vcpus need a shortened directmap. HVM and Idle vcpus get the full * directmap. */ bool short_directmap = d && !paging_mode_external(d); /* Slot 256: RO M2P (if applicable). */ l4t[l4_table_offset(RO_MPT_VIRT_START)] = ro_mpt ? idle_pg_table[l4_table_offset(RO_MPT_VIRT_START)] : l4e_empty(); /* Slot 257: PCI MMCFG. */ l4t[l4_table_offset(PCI_MCFG_VIRT_START)] = idle_pg_table[l4_table_offset(PCI_MCFG_VIRT_START)]; /* Slot 258: Self linear mappings. */ ASSERT(!mfn_eq(l4mfn, INVALID_MFN)); l4t[l4_table_offset(LINEAR_PT_VIRT_START)] = l4e_from_mfn(l4mfn, __PAGE_HYPERVISOR_RW); /* Slot 259: Shadow linear mappings (if applicable) .*/ l4t[l4_table_offset(SH_LINEAR_PT_VIRT_START)] = mfn_eq(sl4mfn, INVALID_MFN) ? l4e_empty() : l4e_from_mfn(sl4mfn, __PAGE_HYPERVISOR_RW); /* Slot 260: Per-domain mappings (if applicable). */ l4t[l4_table_offset(PERDOMAIN_VIRT_START)] = d ? l4e_from_page(d->arch.perdomain_l3_pg, __PAGE_HYPERVISOR_RW) : l4e_empty(); /* Slot 261-: text/data/bss, RW M2P, vmap, frametable, directmap. */ #ifndef NDEBUG if ( short_directmap && unlikely(root_pgt_pv_xen_slots < ROOT_PAGETABLE_PV_XEN_SLOTS) ) { /* * If using highmem-start=, artificially shorten the directmap to * simulate very large machines. */ l4_pgentry_t *next; memcpy(&l4t[l4_table_offset(XEN_VIRT_START)], &idle_pg_table[l4_table_offset(XEN_VIRT_START)], (ROOT_PAGETABLE_FIRST_XEN_SLOT + root_pgt_pv_xen_slots - l4_table_offset(XEN_VIRT_START)) * sizeof(*l4t)); next = &l4t[ROOT_PAGETABLE_FIRST_XEN_SLOT + root_pgt_pv_xen_slots]; if ( l4e_get_intpte(split_l4e) ) *next++ = split_l4e; memset(next, 0, _p(&l4t[ROOT_PAGETABLE_LAST_XEN_SLOT + 1]) - _p(next)); } else #endif { unsigned int slots = (short_directmap ? ROOT_PAGETABLE_PV_XEN_SLOTS : ROOT_PAGETABLE_XEN_SLOTS); memcpy(&l4t[l4_table_offset(XEN_VIRT_START)], &idle_pg_table[l4_table_offset(XEN_VIRT_START)], (ROOT_PAGETABLE_FIRST_XEN_SLOT + slots - l4_table_offset(XEN_VIRT_START)) * sizeof(*l4t)); } } bool fill_ro_mpt(mfn_t mfn) { l4_pgentry_t *l4tab = map_domain_page(mfn); bool ret = false; if ( !l4e_get_intpte(l4tab[l4_table_offset(RO_MPT_VIRT_START)]) ) { l4tab[l4_table_offset(RO_MPT_VIRT_START)] = idle_pg_table[l4_table_offset(RO_MPT_VIRT_START)]; ret = true; } unmap_domain_page(l4tab); return ret; } void zap_ro_mpt(mfn_t mfn) { l4_pgentry_t *l4tab = map_domain_page(mfn); l4tab[l4_table_offset(RO_MPT_VIRT_START)] = l4e_empty(); unmap_domain_page(l4tab); } static int alloc_l4_table(struct page_info *page) { struct domain *d = page_get_owner(page); unsigned long pfn = mfn_x(page_to_mfn(page)); l4_pgentry_t *pl4e = map_domain_page(_mfn(pfn)); unsigned int i; int rc = 0, partial = page->partial_pte; for ( i = page->nr_validated_ptes; i < L4_PAGETABLE_ENTRIES; i++, partial = 0 ) { if ( !is_guest_l4_slot(d, i) || (rc = get_page_from_l4e(pl4e[i], pfn, d, partial)) > 0 ) continue; if ( rc == -ERESTART ) { page->nr_validated_ptes = i; page->partial_pte = partial ?: 1; } else if ( rc < 0 ) { if ( rc != -EINTR ) gdprintk(XENLOG_WARNING, "Failure in alloc_l4_table: slot %#x\n", i); if ( i ) { page->nr_validated_ptes = i; page->partial_pte = 0; if ( rc == -EINTR ) rc = -ERESTART; else { if ( current->arch.old_guest_table ) page->nr_validated_ptes++; current->arch.old_guest_ptpg = NULL; current->arch.old_guest_table = page; } } } if ( rc < 0 ) { unmap_domain_page(pl4e); return rc; } pl4e[i] = adjust_guest_l4e(pl4e[i], d); } if ( rc >= 0 ) { init_xen_l4_slots(pl4e, _mfn(pfn), d, INVALID_MFN, VM_ASSIST(d, m2p_strict)); atomic_inc(&d->arch.pv_domain.nr_l4_pages); rc = 0; } unmap_domain_page(pl4e); return rc; } static void free_l1_table(struct page_info *page) { struct domain *d = page_get_owner(page); l1_pgentry_t *pl1e; unsigned int i; pl1e = __map_domain_page(page); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) put_page_from_l1e(pl1e[i], d); unmap_domain_page(pl1e); } static int free_l2_table(struct page_info *page, int preemptible) { struct domain *d = page_get_owner(page); unsigned long pfn = mfn_x(page_to_mfn(page)); l2_pgentry_t *pl2e; unsigned int i = page->nr_validated_ptes - 1; int err = 0; pl2e = map_domain_page(_mfn(pfn)); ASSERT(page->nr_validated_ptes); do { if ( is_guest_l2_slot(d, page->u.inuse.type_info, i) && put_page_from_l2e(pl2e[i], pfn) == 0 && preemptible && i && hypercall_preempt_check() ) { page->nr_validated_ptes = i; err = -ERESTART; } } while ( !err && i-- ); unmap_domain_page(pl2e); if ( !err ) page->u.inuse.type_info &= ~PGT_pae_xen_l2; return err; } static int free_l3_table(struct page_info *page) { struct domain *d = page_get_owner(page); unsigned long pfn = mfn_x(page_to_mfn(page)); l3_pgentry_t *pl3e; int rc = 0, partial = page->partial_pte; unsigned int i = page->nr_validated_ptes - !partial; pl3e = map_domain_page(_mfn(pfn)); do { rc = put_page_from_l3e(pl3e[i], pfn, partial, 0); if ( rc < 0 ) break; partial = 0; if ( rc > 0 ) continue; pl3e[i] = unadjust_guest_l3e(pl3e[i], d); } while ( i-- ); unmap_domain_page(pl3e); if ( rc == -ERESTART ) { page->nr_validated_ptes = i; page->partial_pte = partial ?: -1; } else if ( rc == -EINTR && i < L3_PAGETABLE_ENTRIES - 1 ) { page->nr_validated_ptes = i + 1; page->partial_pte = 0; rc = -ERESTART; } return rc > 0 ? 0 : rc; } static int free_l4_table(struct page_info *page) { struct domain *d = page_get_owner(page); unsigned long pfn = mfn_x(page_to_mfn(page)); l4_pgentry_t *pl4e = map_domain_page(_mfn(pfn)); int rc = 0, partial = page->partial_pte; unsigned int i = page->nr_validated_ptes - !partial; do { if ( is_guest_l4_slot(d, i) ) rc = put_page_from_l4e(pl4e[i], pfn, partial, 0); if ( rc < 0 ) break; partial = 0; } while ( i-- ); if ( rc == -ERESTART ) { page->nr_validated_ptes = i; page->partial_pte = partial ?: -1; } else if ( rc == -EINTR && i < L4_PAGETABLE_ENTRIES - 1 ) { page->nr_validated_ptes = i + 1; page->partial_pte = 0; rc = -ERESTART; } unmap_domain_page(pl4e); if ( rc >= 0 ) { atomic_dec(&d->arch.pv_domain.nr_l4_pages); rc = 0; } return rc; } int page_lock(struct page_info *page) { unsigned long x, nx; do { while ( (x = page->u.inuse.type_info) & PGT_locked ) cpu_relax(); nx = x + (1 | PGT_locked); if ( !(x & PGT_validated) || !(x & PGT_count_mask) || !(nx & PGT_count_mask) ) return 0; } while ( cmpxchg(&page->u.inuse.type_info, x, nx) != x ); return 1; } void page_unlock(struct page_info *page) { unsigned long x, nx, y = page->u.inuse.type_info; do { x = y; ASSERT((x & PGT_count_mask) && (x & PGT_locked)); nx = x - (1 | PGT_locked); /* We must not drop the last reference here. */ ASSERT(nx & PGT_count_mask); } while ( (y = cmpxchg(&page->u.inuse.type_info, x, nx)) != x ); } /* * PTE flags that a guest may change without re-validating the PTE. * All other bits affect translation, caching, or Xen's safety. */ #define FASTPATH_FLAG_WHITELIST \ (_PAGE_NX_BIT | _PAGE_AVAIL_HIGH | _PAGE_AVAIL | _PAGE_GLOBAL | \ _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_USER) /* Update the L1 entry at pl1e to new value nl1e. */ static int mod_l1_entry(l1_pgentry_t *pl1e, l1_pgentry_t nl1e, unsigned long gl1mfn, int preserve_ad, struct vcpu *pt_vcpu, struct domain *pg_dom) { l1_pgentry_t ol1e; struct domain *pt_dom = pt_vcpu->domain; int rc = 0; if ( unlikely(__copy_from_user(&ol1e, pl1e, sizeof(ol1e)) != 0) ) return -EFAULT; ASSERT(!paging_mode_refcounts(pt_dom)); if ( l1e_get_flags(nl1e) & _PAGE_PRESENT ) { struct page_info *page = NULL; if ( unlikely(l1e_get_flags(nl1e) & l1_disallow_mask(pt_dom)) ) { gdprintk(XENLOG_WARNING, "Bad L1 flags %x\n", l1e_get_flags(nl1e) & l1_disallow_mask(pt_dom)); return -EINVAL; } /* Translate foreign guest address. */ if ( paging_mode_translate(pg_dom) ) { p2m_type_t p2mt; p2m_query_t q = l1e_get_flags(nl1e) & _PAGE_RW ? P2M_ALLOC | P2M_UNSHARE : P2M_ALLOC; page = get_page_from_gfn(pg_dom, l1e_get_pfn(nl1e), &p2mt, q); if ( p2m_is_paged(p2mt) ) { if ( page ) put_page(page); p2m_mem_paging_populate(pg_dom, l1e_get_pfn(nl1e)); return -ENOENT; } if ( p2mt == p2m_ram_paging_in && !page ) return -ENOENT; /* Did our attempt to unshare fail? */ if ( (q & P2M_UNSHARE) && p2m_is_shared(p2mt) ) { /* We could not have obtained a page ref. */ ASSERT(!page); /* And mem_sharing_notify has already been called. */ return -ENOMEM; } if ( !page ) return -EINVAL; nl1e = l1e_from_page(page, l1e_get_flags(nl1e)); } /* Fast path for sufficiently-similar mappings. */ if ( !l1e_has_changed(ol1e, nl1e, ~FASTPATH_FLAG_WHITELIST) ) { nl1e = adjust_guest_l1e(nl1e, pt_dom); rc = UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, pt_vcpu, preserve_ad); if ( page ) put_page(page); return rc ? 0 : -EBUSY; } switch ( rc = get_page_from_l1e(nl1e, pt_dom, pg_dom) ) { default: if ( page ) put_page(page); return rc; case 0: break; case _PAGE_RW ... _PAGE_RW | PAGE_CACHE_ATTRS: ASSERT(!(rc & ~(_PAGE_RW | PAGE_CACHE_ATTRS))); l1e_flip_flags(nl1e, rc); rc = 0; break; } if ( page ) put_page(page); nl1e = adjust_guest_l1e(nl1e, pt_dom); if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, pt_vcpu, preserve_ad)) ) { ol1e = nl1e; rc = -EBUSY; } } else if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, pt_vcpu, preserve_ad)) ) { return -EBUSY; } put_page_from_l1e(ol1e, pt_dom); return rc; } /* Update the L2 entry at pl2e to new value nl2e. pl2e is within frame pfn. */ static int mod_l2_entry(l2_pgentry_t *pl2e, l2_pgentry_t nl2e, unsigned long pfn, int preserve_ad, struct vcpu *vcpu) { l2_pgentry_t ol2e; struct domain *d = vcpu->domain; struct page_info *l2pg = mfn_to_page(_mfn(pfn)); unsigned long type = l2pg->u.inuse.type_info; int rc = 0; if ( unlikely(!is_guest_l2_slot(d, type, pgentry_ptr_to_slot(pl2e))) ) { gdprintk(XENLOG_WARNING, "L2 update in Xen-private area, slot %#lx\n", pgentry_ptr_to_slot(pl2e)); return -EPERM; } if ( unlikely(__copy_from_user(&ol2e, pl2e, sizeof(ol2e)) != 0) ) return -EFAULT; if ( l2e_get_flags(nl2e) & _PAGE_PRESENT ) { if ( unlikely(l2e_get_flags(nl2e) & L2_DISALLOW_MASK) ) { gdprintk(XENLOG_WARNING, "Bad L2 flags %x\n", l2e_get_flags(nl2e) & L2_DISALLOW_MASK); return -EINVAL; } /* Fast path for sufficiently-similar mappings. */ if ( !l2e_has_changed(ol2e, nl2e, ~FASTPATH_FLAG_WHITELIST) ) { nl2e = adjust_guest_l2e(nl2e, d); if ( UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, vcpu, preserve_ad) ) return 0; return -EBUSY; } if ( unlikely((rc = get_page_from_l2e(nl2e, pfn, d)) < 0) ) return rc; nl2e = adjust_guest_l2e(nl2e, d); if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, vcpu, preserve_ad)) ) { ol2e = nl2e; rc = -EBUSY; } } else if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, vcpu, preserve_ad)) ) { return -EBUSY; } put_page_from_l2e(ol2e, pfn); return rc; } /* Update the L3 entry at pl3e to new value nl3e. pl3e is within frame pfn. */ static int mod_l3_entry(l3_pgentry_t *pl3e, l3_pgentry_t nl3e, unsigned long pfn, int preserve_ad, struct vcpu *vcpu) { l3_pgentry_t ol3e; struct domain *d = vcpu->domain; int rc = 0; /* * Disallow updates to final L3 slot. It contains Xen mappings, and it * would be a pain to ensure they remain continuously valid throughout. */ if ( is_pv_32bit_domain(d) && (pgentry_ptr_to_slot(pl3e) >= 3) ) return -EINVAL; if ( unlikely(__copy_from_user(&ol3e, pl3e, sizeof(ol3e)) != 0) ) return -EFAULT; if ( l3e_get_flags(nl3e) & _PAGE_PRESENT ) { if ( unlikely(l3e_get_flags(nl3e) & l3_disallow_mask(d)) ) { gdprintk(XENLOG_WARNING, "Bad L3 flags %x\n", l3e_get_flags(nl3e) & l3_disallow_mask(d)); return -EINVAL; } /* Fast path for sufficiently-similar mappings. */ if ( !l3e_has_changed(ol3e, nl3e, ~FASTPATH_FLAG_WHITELIST) ) { nl3e = adjust_guest_l3e(nl3e, d); rc = UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, vcpu, preserve_ad); return rc ? 0 : -EFAULT; } rc = get_page_from_l3e(nl3e, pfn, d, 0); if ( unlikely(rc < 0) ) return rc; rc = 0; nl3e = adjust_guest_l3e(nl3e, d); if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, vcpu, preserve_ad)) ) { ol3e = nl3e; rc = -EFAULT; } } else if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, vcpu, preserve_ad)) ) { return -EFAULT; } if ( likely(rc == 0) ) if ( !create_pae_xen_mappings(d, pl3e) ) BUG(); put_page_from_l3e(ol3e, pfn, 0, 1); return rc; } /* Update the L4 entry at pl4e to new value nl4e. pl4e is within frame pfn. */ static int mod_l4_entry(l4_pgentry_t *pl4e, l4_pgentry_t nl4e, unsigned long pfn, int preserve_ad, struct vcpu *vcpu) { struct domain *d = vcpu->domain; l4_pgentry_t ol4e; int rc = 0; if ( unlikely(!is_guest_l4_slot(d, pgentry_ptr_to_slot(pl4e))) ) { gdprintk(XENLOG_WARNING, "L4 update in Xen-private area, slot %#lx\n", pgentry_ptr_to_slot(pl4e)); return -EINVAL; } if ( unlikely(__copy_from_user(&ol4e, pl4e, sizeof(ol4e)) != 0) ) return -EFAULT; if ( l4e_get_flags(nl4e) & _PAGE_PRESENT ) { if ( unlikely(l4e_get_flags(nl4e) & L4_DISALLOW_MASK) ) { gdprintk(XENLOG_WARNING, "Bad L4 flags %x\n", l4e_get_flags(nl4e) & L4_DISALLOW_MASK); return -EINVAL; } /* Fast path for sufficiently-similar mappings. */ if ( !l4e_has_changed(ol4e, nl4e, ~FASTPATH_FLAG_WHITELIST) ) { nl4e = adjust_guest_l4e(nl4e, d); rc = UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, vcpu, preserve_ad); return rc ? 0 : -EFAULT; } rc = get_page_from_l4e(nl4e, pfn, d, 0); if ( unlikely(rc < 0) ) return rc; rc = 0; nl4e = adjust_guest_l4e(nl4e, d); if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, vcpu, preserve_ad)) ) { ol4e = nl4e; rc = -EFAULT; } } else if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, vcpu, preserve_ad)) ) { return -EFAULT; } put_page_from_l4e(ol4e, pfn, 0, 1); return rc; } static int cleanup_page_cacheattr(struct page_info *page) { unsigned int cacheattr = (page->count_info & PGC_cacheattr_mask) >> PGC_cacheattr_base; if ( likely(cacheattr == 0) ) return 0; page->count_info &= ~PGC_cacheattr_mask; BUG_ON(is_xen_heap_page(page)); return update_xen_mappings(mfn_x(page_to_mfn(page)), 0); } void put_page(struct page_info *page) { unsigned long nx, x, y = page->count_info; do { ASSERT((y & PGC_count_mask) != 0); x = y; nx = x - 1; } while ( unlikely((y = cmpxchg(&page->count_info, x, nx)) != x) ); if ( unlikely((nx & PGC_count_mask) == 0) ) { if ( cleanup_page_cacheattr(page) == 0 ) free_domheap_page(page); else gdprintk(XENLOG_WARNING, "Leaking mfn %" PRI_mfn "\n", mfn_x(page_to_mfn(page))); } } struct domain *page_get_owner_and_reference(struct page_info *page) { unsigned long x, y = page->count_info; struct domain *owner; do { x = y; /* * Count == 0: Page is not allocated, so we cannot take a reference. * Count == -1: Reference count would wrap, which is invalid. * Count == -2: Remaining unused ref is reserved for get_page_light(). */ if ( unlikely(((x + 2) & PGC_count_mask) <= 2) ) return NULL; } while ( (y = cmpxchg(&page->count_info, x, x + 1)) != x ); owner = page_get_owner(page); ASSERT(owner); return owner; } int get_page(struct page_info *page, struct domain *domain) { struct domain *owner = page_get_owner_and_reference(page); if ( likely(owner == domain) ) return 1; if ( !paging_mode_refcounts(domain) && !domain->is_dying ) gprintk(XENLOG_INFO, "Error mfn %"PRI_mfn": rd=%d od=%d caf=%08lx taf=%" PRtype_info "\n", mfn_x(page_to_mfn(page)), domain->domain_id, owner ? owner->domain_id : DOMID_INVALID, page->count_info - !!owner, page->u.inuse.type_info); if ( owner ) put_page(page); return 0; } /* * Special version of get_page() to be used exclusively when * - a page is known to already have a non-zero reference count * - the page does not need its owner to be checked * - it will not be called more than once without dropping the thus * acquired reference again. * Due to get_page() reserving one reference, this call cannot fail. */ static void get_page_light(struct page_info *page) { unsigned long x, nx, y = page->count_info; do { x = y; nx = x + 1; BUG_ON(!(x & PGC_count_mask)); /* Not allocated? */ BUG_ON(!(nx & PGC_count_mask)); /* Overflow? */ y = cmpxchg(&page->count_info, x, nx); } while ( unlikely(y != x) ); } static int alloc_page_type(struct page_info *page, unsigned long type, int preemptible) { struct domain *owner = page_get_owner(page); int rc; /* A page table is dirtied when its type count becomes non-zero. */ if ( likely(owner != NULL) ) paging_mark_dirty(owner, page_to_mfn(page)); switch ( type & PGT_type_mask ) { case PGT_l1_page_table: rc = alloc_l1_table(page); break; case PGT_l2_page_table: rc = alloc_l2_table(page, type, preemptible); break; case PGT_l3_page_table: ASSERT(preemptible); rc = alloc_l3_table(page); break; case PGT_l4_page_table: ASSERT(preemptible); rc = alloc_l4_table(page); break; case PGT_seg_desc_page: rc = alloc_segdesc_page(page); break; default: printk("Bad type in alloc_page_type %lx t=%" PRtype_info " c=%lx\n", type, page->u.inuse.type_info, page->count_info); rc = -EINVAL; BUG(); } /* No need for atomic update of type_info here: noone else updates it. */ smp_wmb(); switch ( rc ) { case 0: page->u.inuse.type_info |= PGT_validated; break; case -EINTR: ASSERT((page->u.inuse.type_info & (PGT_count_mask|PGT_validated|PGT_partial)) == 1); page->u.inuse.type_info &= ~PGT_count_mask; break; default: ASSERT(rc < 0); gdprintk(XENLOG_WARNING, "Error while validating mfn %" PRI_mfn " (pfn %" PRI_pfn ") for type %" PRtype_info ": caf=%08lx taf=%" PRtype_info "\n", mfn_x(page_to_mfn(page)), get_gpfn_from_mfn(mfn_x(page_to_mfn(page))), type, page->count_info, page->u.inuse.type_info); if ( page != current->arch.old_guest_table ) page->u.inuse.type_info = 0; else { ASSERT((page->u.inuse.type_info & (PGT_count_mask | PGT_validated)) == 1); case -ERESTART: get_page_light(page); page->u.inuse.type_info |= PGT_partial; } break; } return rc; } int free_page_type(struct page_info *page, unsigned long type, int preemptible) { struct domain *owner = page_get_owner(page); unsigned long gmfn; int rc; if ( likely(owner != NULL) && unlikely(paging_mode_enabled(owner)) ) { /* A page table is dirtied when its type count becomes zero. */ paging_mark_dirty(owner, page_to_mfn(page)); ASSERT(!shadow_mode_refcounts(owner)); gmfn = mfn_to_gmfn(owner, mfn_x(page_to_mfn(page))); ASSERT(VALID_M2P(gmfn)); /* Page sharing not supported for shadowed domains */ if(!SHARED_M2P(gmfn)) shadow_remove_all_shadows(owner, _mfn(gmfn)); } if ( !(type & PGT_partial) ) { page->nr_validated_ptes = 1U << PAGETABLE_ORDER; page->partial_pte = 0; } switch ( type & PGT_type_mask ) { case PGT_l1_page_table: free_l1_table(page); rc = 0; break; case PGT_l2_page_table: rc = free_l2_table(page, preemptible); break; case PGT_l3_page_table: ASSERT(preemptible); rc = free_l3_table(page); break; case PGT_l4_page_table: ASSERT(preemptible); rc = free_l4_table(page); break; default: gdprintk(XENLOG_WARNING, "type %" PRtype_info " mfn %" PRI_mfn "\n", type, mfn_x(page_to_mfn(page))); rc = -EINVAL; BUG(); } return rc; } static int _put_final_page_type(struct page_info *page, unsigned long type, bool preemptible, struct page_info *ptpg) { int rc = free_page_type(page, type, preemptible); /* No need for atomic update of type_info here: noone else updates it. */ if ( rc == 0 ) { if ( ptpg && PGT_type_equal(type, ptpg->u.inuse.type_info) ) { dec_linear_uses(page); dec_linear_entries(ptpg); } ASSERT(!page->linear_pt_count || page_get_owner(page)->is_dying); set_tlbflush_timestamp(page); smp_wmb(); page->u.inuse.type_info--; } else if ( rc == -EINTR ) { ASSERT((page->u.inuse.type_info & (PGT_count_mask|PGT_validated|PGT_partial)) == 1); smp_wmb(); page->u.inuse.type_info |= PGT_validated; } else { BUG_ON(rc != -ERESTART); smp_wmb(); get_page_light(page); page->u.inuse.type_info |= PGT_partial; } return rc; } static int _put_page_type(struct page_info *page, bool preemptible, struct page_info *ptpg) { unsigned long nx, x, y = page->u.inuse.type_info; int rc = 0; for ( ; ; ) { x = y; nx = x - 1; ASSERT((x & PGT_count_mask) != 0); if ( unlikely((nx & PGT_count_mask) == 0) ) { if ( unlikely((nx & PGT_type_mask) <= PGT_l4_page_table) && likely(nx & (PGT_validated|PGT_partial)) ) { /* * Page-table pages must be unvalidated when count is zero. The * 'free' is safe because the refcnt is non-zero and validated * bit is clear => other ops will spin or fail. */ nx = x & ~(PGT_validated|PGT_partial); if ( unlikely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) != x) ) continue; /* We cleared the 'valid bit' so we do the clean up. */ rc = _put_final_page_type(page, x, preemptible, ptpg); ptpg = NULL; if ( x & PGT_partial ) put_page(page); break; } if ( !ptpg || !PGT_type_equal(x, ptpg->u.inuse.type_info) ) { /* * set_tlbflush_timestamp() accesses the same union * linear_pt_count lives in. Pages (including page table ones), * however, don't need their flush time stamp set except when * the last reference is being dropped. For page table pages * this happens in _put_final_page_type(). */ set_tlbflush_timestamp(page); } else BUG_ON(!IS_ENABLED(CONFIG_PV_LINEAR_PT)); } else if ( unlikely((nx & (PGT_locked | PGT_count_mask)) == (PGT_locked | 1)) ) { /* * We must not drop the second to last reference when the page is * locked, as page_unlock() doesn't do any cleanup of the type. */ cpu_relax(); y = page->u.inuse.type_info; continue; } if ( likely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) == x) ) break; if ( preemptible && hypercall_preempt_check() ) return -EINTR; } if ( ptpg && PGT_type_equal(x, ptpg->u.inuse.type_info) ) { ASSERT(!rc); dec_linear_uses(page); dec_linear_entries(ptpg); } return rc; } static int __get_page_type(struct page_info *page, unsigned long type, int preemptible) { unsigned long nx, x, y = page->u.inuse.type_info; int rc = 0, iommu_ret = 0; ASSERT(!(type & ~(PGT_type_mask | PGT_pae_xen_l2))); ASSERT(!in_irq()); for ( ; ; ) { x = y; nx = x + 1; if ( unlikely((nx & PGT_count_mask) == 0) ) { gdprintk(XENLOG_WARNING, "Type count overflow on mfn %"PRI_mfn"\n", mfn_x(page_to_mfn(page))); return -EINVAL; } else if ( unlikely((x & PGT_count_mask) == 0) ) { struct domain *d = page_get_owner(page); /* * Normally we should never let a page go from type count 0 * to type count 1 when it is shadowed. One exception: * out-of-sync shadowed pages are allowed to become * writeable. */ if ( d && shadow_mode_enabled(d) && (page->count_info & PGC_page_table) && !((page->shadow_flags & (1u<<29)) && type == PGT_writable_page) ) shadow_remove_all_shadows(d, page_to_mfn(page)); ASSERT(!(x & PGT_pae_xen_l2)); if ( (x & PGT_type_mask) != type ) { /* * On type change we check to flush stale TLB entries. This * may be unnecessary (e.g., page was GDT/LDT) but those * circumstances should be very rare. */ cpumask_t *mask = this_cpu(scratch_cpumask); BUG_ON(in_irq()); cpumask_copy(mask, d->domain_dirty_cpumask); /* Don't flush if the timestamp is old enough */ tlbflush_filter(mask, page->tlbflush_timestamp); if ( unlikely(!cpumask_empty(mask)) && /* Shadow mode: track only writable pages. */ (!shadow_mode_enabled(page_get_owner(page)) || ((nx & PGT_type_mask) == PGT_writable_page)) ) { perfc_incr(need_flush_tlb_flush); flush_tlb_mask(mask); } /* We lose existing type and validity. */ nx &= ~(PGT_type_mask | PGT_validated); nx |= type; /* * No special validation needed for writable pages. * Page tables and GDT/LDT need to be scanned for validity. */ if ( type == PGT_writable_page || type == PGT_shared_page ) nx |= PGT_validated; } } else if ( unlikely((x & (PGT_type_mask|PGT_pae_xen_l2)) != type) ) { /* Don't log failure if it could be a recursive-mapping attempt. */ if ( ((x & PGT_type_mask) == PGT_l2_page_table) && (type == PGT_l1_page_table) ) return -EINVAL; if ( ((x & PGT_type_mask) == PGT_l3_page_table) && (type == PGT_l2_page_table) ) return -EINVAL; if ( ((x & PGT_type_mask) == PGT_l4_page_table) && (type == PGT_l3_page_table) ) return -EINVAL; gdprintk(XENLOG_WARNING, "Bad type (saw %" PRtype_info " != exp %" PRtype_info ") " "for mfn %" PRI_mfn " (pfn %" PRI_pfn ")\n", x, type, mfn_x(page_to_mfn(page)), get_gpfn_from_mfn(mfn_x(page_to_mfn(page)))); return -EINVAL; } else if ( unlikely(!(x & PGT_validated)) ) { if ( !(x & PGT_partial) ) { /* Someone else is updating validation of this page. Wait... */ while ( (y = page->u.inuse.type_info) == x ) { if ( preemptible && hypercall_preempt_check() ) return -EINTR; cpu_relax(); } continue; } /* Type ref count was left at 1 when PGT_partial got set. */ ASSERT((x & PGT_count_mask) == 1); nx = x & ~PGT_partial; } if ( likely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) == x) ) break; if ( preemptible && hypercall_preempt_check() ) return -EINTR; } if ( unlikely((x & PGT_type_mask) != type) ) { /* Special pages should not be accessible from devices. */ struct domain *d = page_get_owner(page); if ( d && is_pv_domain(d) && unlikely(need_iommu(d)) ) { gfn_t gfn = _gfn(mfn_to_gmfn(d, mfn_x(page_to_mfn(page)))); if ( (x & PGT_type_mask) == PGT_writable_page ) iommu_ret = iommu_unmap_page(d, gfn_x(gfn)); else if ( type == PGT_writable_page ) iommu_ret = iommu_map_page(d, gfn_x(gfn), mfn_x(page_to_mfn(page)), IOMMUF_readable|IOMMUF_writable); } } if ( unlikely(!(nx & PGT_validated)) ) { if ( !(x & PGT_partial) ) { page->nr_validated_ptes = 0; page->partial_pte = 0; } page->linear_pt_count = 0; rc = alloc_page_type(page, type, preemptible); } if ( (x & PGT_partial) && !(nx & PGT_partial) ) put_page(page); if ( !rc ) rc = iommu_ret; return rc; } void put_page_type(struct page_info *page) { int rc = _put_page_type(page, false, NULL); ASSERT(rc == 0); (void)rc; } int get_page_type(struct page_info *page, unsigned long type) { int rc = __get_page_type(page, type, 0); if ( likely(rc == 0) ) return 1; ASSERT(rc != -EINTR && rc != -ERESTART); return 0; } int put_page_type_preemptible(struct page_info *page) { return _put_page_type(page, true, NULL); } int get_page_type_preemptible(struct page_info *page, unsigned long type) { ASSERT(!current->arch.old_guest_table); return __get_page_type(page, type, 1); } int put_old_guest_table(struct vcpu *v) { int rc; if ( !v->arch.old_guest_table ) return 0; switch ( rc = _put_page_type(v->arch.old_guest_table, true, v->arch.old_guest_ptpg) ) { case -EINTR: case -ERESTART: return -ERESTART; case 0: put_page(v->arch.old_guest_table); } v->arch.old_guest_table = NULL; return rc; } int vcpu_destroy_pagetables(struct vcpu *v) { unsigned long mfn = pagetable_get_pfn(v->arch.guest_table); struct page_info *page; l4_pgentry_t *l4tab = NULL; int rc = put_old_guest_table(v); if ( rc ) return rc; if ( is_pv_32bit_vcpu(v) ) { l4tab = map_domain_page(_mfn(mfn)); mfn = l4e_get_pfn(*l4tab); } if ( mfn ) { page = mfn_to_page(_mfn(mfn)); if ( paging_mode_refcounts(v->domain) ) put_page(page); else rc = put_page_and_type_preemptible(page); } if ( l4tab ) { if ( !rc ) l4e_write(l4tab, l4e_empty()); unmap_domain_page(l4tab); } else if ( !rc ) { v->arch.guest_table = pagetable_null(); /* Drop ref to guest_table_user (from MMUEXT_NEW_USER_BASEPTR) */ mfn = pagetable_get_pfn(v->arch.guest_table_user); if ( mfn ) { page = mfn_to_page(_mfn(mfn)); if ( paging_mode_refcounts(v->domain) ) put_page(page); else rc = put_page_and_type_preemptible(page); } if ( !rc ) v->arch.guest_table_user = pagetable_null(); } v->arch.cr3 = 0; /* * put_page_and_type_preemptible() is liable to return -EINTR. The * callers of us expect -ERESTART so convert it over. */ return rc != -EINTR ? rc : -ERESTART; } int new_guest_cr3(mfn_t mfn) { struct vcpu *curr = current; struct domain *d = curr->domain; int rc; mfn_t old_base_mfn; if ( is_pv_32bit_domain(d) ) { mfn_t gt_mfn = pagetable_get_mfn(curr->arch.guest_table); l4_pgentry_t *pl4e = map_domain_page(gt_mfn); rc = mod_l4_entry(pl4e, l4e_from_mfn(mfn, (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)), mfn_x(gt_mfn), 0, curr); unmap_domain_page(pl4e); switch ( rc ) { case 0: break; case -EINTR: case -ERESTART: return -ERESTART; default: gdprintk(XENLOG_WARNING, "Error while installing new compat baseptr %" PRI_mfn "\n", mfn_x(mfn)); return rc; } invalidate_shadow_ldt(curr, 0); write_ptbase(curr); return 0; } rc = put_old_guest_table(curr); if ( unlikely(rc) ) return rc; old_base_mfn = pagetable_get_mfn(curr->arch.guest_table); /* * This is particularly important when getting restarted after the * previous attempt got preempted in the put-old-MFN phase. */ if ( mfn_eq(old_base_mfn, mfn) ) { write_ptbase(curr); return 0; } rc = paging_mode_refcounts(d) ? (get_page_from_mfn(mfn, d) ? 0 : -EINVAL) : get_page_and_type_from_mfn(mfn, PGT_root_page_table, d, 0, 1); switch ( rc ) { case 0: break; case -EINTR: case -ERESTART: return -ERESTART; default: gdprintk(XENLOG_WARNING, "Error while installing new baseptr %" PRI_mfn "\n", mfn_x(mfn)); return rc; } invalidate_shadow_ldt(curr, 0); if ( !VM_ASSIST(d, m2p_strict) && !paging_mode_refcounts(d) ) fill_ro_mpt(mfn); curr->arch.guest_table = pagetable_from_mfn(mfn); update_cr3(curr); write_ptbase(curr); if ( likely(mfn_x(old_base_mfn) != 0) ) { struct page_info *page = mfn_to_page(old_base_mfn); if ( paging_mode_refcounts(d) ) put_page(page); else switch ( rc = put_page_and_type_preemptible(page) ) { case -EINTR: rc = -ERESTART; /* fallthrough */ case -ERESTART: curr->arch.old_guest_ptpg = NULL; curr->arch.old_guest_table = page; break; default: BUG_ON(rc); break; } } return rc; } static struct domain *get_pg_owner(domid_t domid) { struct domain *pg_owner = NULL, *curr = current->domain; if ( likely(domid == DOMID_SELF) ) { pg_owner = rcu_lock_current_domain(); goto out; } if ( unlikely(domid == curr->domain_id) ) { gdprintk(XENLOG_WARNING, "Cannot specify itself as foreign domain\n"); goto out; } switch ( domid ) { case DOMID_IO: pg_owner = rcu_lock_domain(dom_io); break; case DOMID_XEN: pg_owner = rcu_lock_domain(dom_xen); break; default: if ( (pg_owner = rcu_lock_domain_by_id(domid)) == NULL ) { gdprintk(XENLOG_WARNING, "Unknown domain d%d\n", domid); break; } break; } out: return pg_owner; } static void put_pg_owner(struct domain *pg_owner) { rcu_unlock_domain(pg_owner); } static inline int vcpumask_to_pcpumask( struct domain *d, XEN_GUEST_HANDLE_PARAM(const_void) bmap, cpumask_t *pmask) { unsigned int vcpu_id, vcpu_bias, offs; unsigned long vmask; struct vcpu *v; bool is_native = !is_pv_32bit_domain(d); cpumask_clear(pmask); for ( vmask = 0, offs = 0; ; ++offs ) { vcpu_bias = offs * (is_native ? BITS_PER_LONG : 32); if ( vcpu_bias >= d->max_vcpus ) return 0; if ( unlikely(is_native ? copy_from_guest_offset(&vmask, bmap, offs, 1) : copy_from_guest_offset((unsigned int *)&vmask, bmap, offs, 1)) ) { cpumask_clear(pmask); return -EFAULT; } while ( vmask ) { vcpu_id = find_first_set_bit(vmask); vmask &= ~(1UL << vcpu_id); vcpu_id += vcpu_bias; if ( (vcpu_id >= d->max_vcpus) ) return 0; if ( ((v = d->vcpu[vcpu_id]) != NULL) ) cpumask_or(pmask, pmask, v->vcpu_dirty_cpumask); } } } long do_mmuext_op( XEN_GUEST_HANDLE_PARAM(mmuext_op_t) uops, unsigned int count, XEN_GUEST_HANDLE_PARAM(uint) pdone, unsigned int foreigndom) { struct mmuext_op op; unsigned long type; unsigned int i, done = 0; struct vcpu *curr = current; struct domain *currd = curr->domain; struct domain *pg_owner; int rc = put_old_guest_table(curr); if ( unlikely(rc) ) { if ( likely(rc == -ERESTART) ) rc = hypercall_create_continuation( __HYPERVISOR_mmuext_op, "hihi", uops, count, pdone, foreigndom); return rc; } if ( unlikely(count == MMU_UPDATE_PREEMPTED) && likely(guest_handle_is_null(uops)) ) { /* * See the curr->arch.old_guest_table related * hypercall_create_continuation() below. */ return (int)foreigndom; } if ( unlikely(count & MMU_UPDATE_PREEMPTED) ) { count &= ~MMU_UPDATE_PREEMPTED; if ( unlikely(!guest_handle_is_null(pdone)) ) (void)copy_from_guest(&done, pdone, 1); } else perfc_incr(calls_to_mmuext_op); if ( unlikely(!guest_handle_okay(uops, count)) ) return -EFAULT; if ( (pg_owner = get_pg_owner(foreigndom)) == NULL ) return -ESRCH; if ( !is_pv_domain(pg_owner) ) { put_pg_owner(pg_owner); return -EINVAL; } rc = xsm_mmuext_op(XSM_TARGET, currd, pg_owner); if ( rc ) { put_pg_owner(pg_owner); return rc; } for ( i = 0; i < count; i++ ) { if ( curr->arch.old_guest_table || (i && hypercall_preempt_check()) ) { rc = -ERESTART; break; } if ( unlikely(__copy_from_guest(&op, uops, 1) != 0) ) { rc = -EFAULT; break; } if ( is_hvm_domain(currd) ) { switch ( op.cmd ) { case MMUEXT_PIN_L1_TABLE: case MMUEXT_PIN_L2_TABLE: case MMUEXT_PIN_L3_TABLE: case MMUEXT_PIN_L4_TABLE: case MMUEXT_UNPIN_TABLE: break; default: rc = -EOPNOTSUPP; goto done; } } rc = 0; switch ( op.cmd ) { struct page_info *page; p2m_type_t p2mt; case MMUEXT_PIN_L1_TABLE: type = PGT_l1_page_table; goto pin_page; case MMUEXT_PIN_L2_TABLE: type = PGT_l2_page_table; goto pin_page; case MMUEXT_PIN_L3_TABLE: type = PGT_l3_page_table; goto pin_page; case MMUEXT_PIN_L4_TABLE: if ( is_pv_32bit_domain(pg_owner) ) break; type = PGT_l4_page_table; pin_page: /* Ignore pinning of invalid paging levels. */ if ( (op.cmd - MMUEXT_PIN_L1_TABLE) > (CONFIG_PAGING_LEVELS - 1) ) break; if ( paging_mode_refcounts(pg_owner) ) break; page = get_page_from_gfn(pg_owner, op.arg1.mfn, NULL, P2M_ALLOC); if ( unlikely(!page) ) { rc = -EINVAL; break; } rc = get_page_type_preemptible(page, type); if ( unlikely(rc) ) { if ( rc == -EINTR ) rc = -ERESTART; else if ( rc != -ERESTART ) gdprintk(XENLOG_WARNING, "Error %d while pinning mfn %" PRI_mfn "\n", rc, mfn_x(page_to_mfn(page))); if ( page != curr->arch.old_guest_table ) put_page(page); break; } rc = xsm_memory_pin_page(XSM_HOOK, currd, pg_owner, page); if ( !rc && unlikely(test_and_set_bit(_PGT_pinned, &page->u.inuse.type_info)) ) { gdprintk(XENLOG_WARNING, "mfn %" PRI_mfn " already pinned\n", mfn_x(page_to_mfn(page))); rc = -EINVAL; } if ( unlikely(rc) ) goto pin_drop; /* A page is dirtied when its pin status is set. */ paging_mark_dirty(pg_owner, page_to_mfn(page)); /* We can race domain destruction (domain_relinquish_resources). */ if ( unlikely(pg_owner != currd) ) { bool drop_ref; spin_lock(&pg_owner->page_alloc_lock); drop_ref = (pg_owner->is_dying && test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info)); spin_unlock(&pg_owner->page_alloc_lock); if ( drop_ref ) { pin_drop: if ( type == PGT_l1_page_table ) put_page_and_type(page); else { curr->arch.old_guest_ptpg = NULL; curr->arch.old_guest_table = page; } } } break; case MMUEXT_UNPIN_TABLE: if ( paging_mode_refcounts(pg_owner) ) break; page = get_page_from_gfn(pg_owner, op.arg1.mfn, NULL, P2M_ALLOC); if ( unlikely(!page) ) { gdprintk(XENLOG_WARNING, "mfn %" PRI_mfn " bad, or bad owner d%d\n", op.arg1.mfn, pg_owner->domain_id); rc = -EINVAL; break; } if ( !test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info) ) { put_page(page); gdprintk(XENLOG_WARNING, "mfn %" PRI_mfn " not pinned\n", op.arg1.mfn); rc = -EINVAL; break; } switch ( rc = put_page_and_type_preemptible(page) ) { case -EINTR: case -ERESTART: curr->arch.old_guest_ptpg = NULL; curr->arch.old_guest_table = page; rc = 0; break; default: BUG_ON(rc); break; } put_page(page); /* A page is dirtied when its pin status is cleared. */ paging_mark_dirty(pg_owner, page_to_mfn(page)); break; case MMUEXT_NEW_BASEPTR: if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( unlikely(paging_mode_translate(currd)) ) rc = -EINVAL; else rc = new_guest_cr3(_mfn(op.arg1.mfn)); break; case MMUEXT_NEW_USER_BASEPTR: { unsigned long old_mfn; if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( unlikely(paging_mode_translate(currd)) ) rc = -EINVAL; if ( unlikely(rc) ) break; old_mfn = pagetable_get_pfn(curr->arch.guest_table_user); /* * This is particularly important when getting restarted after the * previous attempt got preempted in the put-old-MFN phase. */ if ( old_mfn == op.arg1.mfn ) break; if ( op.arg1.mfn != 0 ) { rc = get_page_and_type_from_mfn( _mfn(op.arg1.mfn), PGT_root_page_table, currd, 0, 1); if ( unlikely(rc) ) { if ( rc == -EINTR ) rc = -ERESTART; else if ( rc != -ERESTART ) gdprintk(XENLOG_WARNING, "Error %d installing new mfn %" PRI_mfn "\n", rc, op.arg1.mfn); break; } if ( VM_ASSIST(currd, m2p_strict) ) zap_ro_mpt(_mfn(op.arg1.mfn)); } curr->arch.guest_table_user = pagetable_from_pfn(op.arg1.mfn); if ( old_mfn != 0 ) { page = mfn_to_page(_mfn(old_mfn)); switch ( rc = put_page_and_type_preemptible(page) ) { case -EINTR: rc = -ERESTART; /* fallthrough */ case -ERESTART: curr->arch.old_guest_ptpg = NULL; curr->arch.old_guest_table = page; break; default: BUG_ON(rc); break; } } break; } case MMUEXT_TLB_FLUSH_LOCAL: if ( likely(currd == pg_owner) ) flush_tlb_local(); else rc = -EPERM; break; case MMUEXT_INVLPG_LOCAL: if ( unlikely(currd != pg_owner) ) rc = -EPERM; else paging_invlpg(curr, op.arg1.linear_addr); break; case MMUEXT_TLB_FLUSH_MULTI: case MMUEXT_INVLPG_MULTI: { cpumask_t *mask = this_cpu(scratch_cpumask); if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( unlikely(vcpumask_to_pcpumask(currd, guest_handle_to_param(op.arg2.vcpumask, const_void), mask)) ) rc = -EINVAL; if ( unlikely(rc) ) break; if ( op.cmd == MMUEXT_TLB_FLUSH_MULTI ) flush_tlb_mask(mask); else if ( __addr_ok(op.arg1.linear_addr) ) flush_tlb_one_mask(mask, op.arg1.linear_addr); break; } case MMUEXT_TLB_FLUSH_ALL: if ( likely(currd == pg_owner) ) flush_tlb_mask(currd->domain_dirty_cpumask); else rc = -EPERM; break; case MMUEXT_INVLPG_ALL: if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( __addr_ok(op.arg1.linear_addr) ) flush_tlb_one_mask(currd->domain_dirty_cpumask, op.arg1.linear_addr); break; case MMUEXT_FLUSH_CACHE: if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( unlikely(!cache_flush_permitted(currd)) ) rc = -EACCES; else wbinvd(); break; case MMUEXT_FLUSH_CACHE_GLOBAL: if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( likely(cache_flush_permitted(currd)) ) { unsigned int cpu; cpumask_t *mask = this_cpu(scratch_cpumask); cpumask_clear(mask); for_each_online_cpu(cpu) if ( !cpumask_intersects(mask, per_cpu(cpu_sibling_mask, cpu)) ) __cpumask_set_cpu(cpu, mask); flush_mask(mask, FLUSH_CACHE); } else rc = -EINVAL; break; case MMUEXT_SET_LDT: { unsigned int ents = op.arg2.nr_ents; unsigned long ptr = ents ? op.arg1.linear_addr : 0; if ( unlikely(currd != pg_owner) ) rc = -EPERM; else if ( paging_mode_external(currd) ) rc = -EINVAL; else if ( ((ptr & (PAGE_SIZE - 1)) != 0) || !__addr_ok(ptr) || (ents > 8192) ) { gdprintk(XENLOG_WARNING, "Bad args to SET_LDT: ptr=%lx, ents=%x\n", ptr, ents); rc = -EINVAL; } else if ( (curr->arch.pv_vcpu.ldt_ents != ents) || (curr->arch.pv_vcpu.ldt_base != ptr) ) { invalidate_shadow_ldt(curr, 0); flush_tlb_local(); curr->arch.pv_vcpu.ldt_base = ptr; curr->arch.pv_vcpu.ldt_ents = ents; load_LDT(curr); } break; } case MMUEXT_CLEAR_PAGE: page = get_page_from_gfn(pg_owner, op.arg1.mfn, &p2mt, P2M_ALLOC); if ( unlikely(p2mt != p2m_ram_rw) && page ) { put_page(page); page = NULL; } if ( !page || !get_page_type(page, PGT_writable_page) ) { if ( page ) put_page(page); gdprintk(XENLOG_WARNING, "Error clearing mfn %" PRI_mfn "\n", op.arg1.mfn); rc = -EINVAL; break; } /* A page is dirtied when it's being cleared. */ paging_mark_dirty(pg_owner, page_to_mfn(page)); clear_domain_page(page_to_mfn(page)); put_page_and_type(page); break; case MMUEXT_COPY_PAGE: { struct page_info *src_page, *dst_page; src_page = get_page_from_gfn(pg_owner, op.arg2.src_mfn, &p2mt, P2M_ALLOC); if ( unlikely(p2mt != p2m_ram_rw) && src_page ) { put_page(src_page); src_page = NULL; } if ( unlikely(!src_page) ) { gdprintk(XENLOG_WARNING, "Error copying from mfn %" PRI_mfn "\n", op.arg2.src_mfn); rc = -EINVAL; break; } dst_page = get_page_from_gfn(pg_owner, op.arg1.mfn, &p2mt, P2M_ALLOC); if ( unlikely(p2mt != p2m_ram_rw) && dst_page ) { put_page(dst_page); dst_page = NULL; } rc = (dst_page && get_page_type(dst_page, PGT_writable_page)) ? 0 : -EINVAL; if ( unlikely(rc) ) { put_page(src_page); if ( dst_page ) put_page(dst_page); gdprintk(XENLOG_WARNING, "Error copying to mfn %" PRI_mfn "\n", op.arg1.mfn); break; } /* A page is dirtied when it's being copied to. */ paging_mark_dirty(pg_owner, page_to_mfn(dst_page)); copy_domain_page(page_to_mfn(dst_page), page_to_mfn(src_page)); put_page_and_type(dst_page); put_page(src_page); break; } case MMUEXT_MARK_SUPER: case MMUEXT_UNMARK_SUPER: rc = -EOPNOTSUPP; break; default: rc = -ENOSYS; break; } done: if ( unlikely(rc) ) break; guest_handle_add_offset(uops, 1); } if ( rc == -ERESTART ) { ASSERT(i < count); rc = hypercall_create_continuation( __HYPERVISOR_mmuext_op, "hihi", uops, (count - i) | MMU_UPDATE_PREEMPTED, pdone, foreigndom); } else if ( curr->arch.old_guest_table ) { XEN_GUEST_HANDLE_PARAM(void) null; ASSERT(rc || i == count); set_xen_guest_handle(null, NULL); /* * In order to have a way to communicate the final return value to * our continuation, we pass this in place of "foreigndom", building * on the fact that this argument isn't needed anymore. */ rc = hypercall_create_continuation( __HYPERVISOR_mmuext_op, "hihi", null, MMU_UPDATE_PREEMPTED, null, rc); } put_pg_owner(pg_owner); perfc_add(num_mmuext_ops, i); /* Add incremental work we have done to the @done output parameter. */ if ( unlikely(!guest_handle_is_null(pdone)) ) { done += i; copy_to_guest(pdone, &done, 1); } return rc; } long do_mmu_update( XEN_GUEST_HANDLE_PARAM(mmu_update_t) ureqs, unsigned int count, XEN_GUEST_HANDLE_PARAM(uint) pdone, unsigned int foreigndom) { struct mmu_update req; void *va = NULL; unsigned long gpfn, gmfn, mfn; struct page_info *page; unsigned int cmd, i = 0, done = 0, pt_dom; struct vcpu *curr = current, *v = curr; struct domain *d = v->domain, *pt_owner = d, *pg_owner; mfn_t map_mfn = INVALID_MFN; uint32_t xsm_needed = 0; uint32_t xsm_checked = 0; int rc = put_old_guest_table(curr); if ( unlikely(rc) ) { if ( likely(rc == -ERESTART) ) rc = hypercall_create_continuation( __HYPERVISOR_mmu_update, "hihi", ureqs, count, pdone, foreigndom); return rc; } if ( unlikely(count == MMU_UPDATE_PREEMPTED) && likely(guest_handle_is_null(ureqs)) ) { /* * See the curr->arch.old_guest_table related * hypercall_create_continuation() below. */ return (int)foreigndom; } if ( unlikely(count & MMU_UPDATE_PREEMPTED) ) { count &= ~MMU_UPDATE_PREEMPTED; if ( unlikely(!guest_handle_is_null(pdone)) ) (void)copy_from_guest(&done, pdone, 1); } else perfc_incr(calls_to_mmu_update); if ( unlikely(!guest_handle_okay(ureqs, count)) ) return -EFAULT; if ( (pt_dom = foreigndom >> 16) != 0 ) { /* Pagetables belong to a foreign domain (PFD). */ if ( (pt_owner = rcu_lock_domain_by_id(pt_dom - 1)) == NULL ) return -ESRCH; if ( pt_owner == d ) rcu_unlock_domain(pt_owner); else if ( !pt_owner->vcpu || (v = pt_owner->vcpu[0]) == NULL ) { rc = -EINVAL; goto out; } } if ( (pg_owner = get_pg_owner((uint16_t)foreigndom)) == NULL ) { rc = -ESRCH; goto out; } for ( i = 0; i < count; i++ ) { if ( curr->arch.old_guest_table || (i && hypercall_preempt_check()) ) { rc = -ERESTART; break; } if ( unlikely(__copy_from_guest(&req, ureqs, 1) != 0) ) { rc = -EFAULT; break; } cmd = req.ptr & (sizeof(l1_pgentry_t)-1); switch ( cmd ) { /* * MMU_NORMAL_PT_UPDATE: Normal update to any level of page table. * MMU_UPDATE_PT_PRESERVE_AD: As above but also preserve (OR) * current A/D bits. */ case MMU_NORMAL_PT_UPDATE: case MMU_PT_UPDATE_PRESERVE_AD: { p2m_type_t p2mt; rc = -EOPNOTSUPP; if ( unlikely(paging_mode_refcounts(pt_owner)) ) break; xsm_needed |= XSM_MMU_NORMAL_UPDATE; if ( get_pte_flags(req.val) & _PAGE_PRESENT ) { xsm_needed |= XSM_MMU_UPDATE_READ; if ( get_pte_flags(req.val) & _PAGE_RW ) xsm_needed |= XSM_MMU_UPDATE_WRITE; } if ( xsm_needed != xsm_checked ) { rc = xsm_mmu_update(XSM_TARGET, d, pt_owner, pg_owner, xsm_needed); if ( rc ) break; xsm_checked = xsm_needed; } rc = -EINVAL; req.ptr -= cmd; gmfn = req.ptr >> PAGE_SHIFT; page = get_page_from_gfn(pt_owner, gmfn, &p2mt, P2M_ALLOC); if ( p2m_is_paged(p2mt) ) { ASSERT(!page); p2m_mem_paging_populate(pt_owner, gmfn); rc = -ENOENT; break; } if ( unlikely(!page) ) { gdprintk(XENLOG_WARNING, "Could not get page for normal update\n"); break; } mfn = mfn_x(page_to_mfn(page)); if ( !mfn_eq(_mfn(mfn), map_mfn) ) { if ( va ) unmap_domain_page(va); va = map_domain_page(_mfn(mfn)); map_mfn = _mfn(mfn); } va = _p(((unsigned long)va & PAGE_MASK) + (req.ptr & ~PAGE_MASK)); if ( page_lock(page) ) { switch ( page->u.inuse.type_info & PGT_type_mask ) { case PGT_l1_page_table: rc = mod_l1_entry(va, l1e_from_intpte(req.val), mfn, cmd == MMU_PT_UPDATE_PRESERVE_AD, v, pg_owner); break; case PGT_l2_page_table: rc = mod_l2_entry(va, l2e_from_intpte(req.val), mfn, cmd == MMU_PT_UPDATE_PRESERVE_AD, v); break; case PGT_l3_page_table: rc = mod_l3_entry(va, l3e_from_intpte(req.val), mfn, cmd == MMU_PT_UPDATE_PRESERVE_AD, v); break; case PGT_l4_page_table: rc = mod_l4_entry(va, l4e_from_intpte(req.val), mfn, cmd == MMU_PT_UPDATE_PRESERVE_AD, v); break; case PGT_writable_page: perfc_incr(writable_mmu_updates); if ( paging_write_guest_entry(v, va, req.val, _mfn(mfn)) ) rc = 0; break; } page_unlock(page); if ( rc == -EINTR ) rc = -ERESTART; } else if ( get_page_type(page, PGT_writable_page) ) { perfc_incr(writable_mmu_updates); if ( paging_write_guest_entry(v, va, req.val, _mfn(mfn)) ) rc = 0; put_page_type(page); } put_page(page); } break; case MMU_MACHPHYS_UPDATE: if ( unlikely(d != pt_owner) ) { rc = -EPERM; break; } if ( unlikely(paging_mode_translate(pg_owner)) ) { rc = -EINVAL; break; } mfn = req.ptr >> PAGE_SHIFT; gpfn = req.val; xsm_needed |= XSM_MMU_MACHPHYS_UPDATE; if ( xsm_needed != xsm_checked ) { rc = xsm_mmu_update(XSM_TARGET, d, NULL, pg_owner, xsm_needed); if ( rc ) break; xsm_checked = xsm_needed; } if ( unlikely(!get_page_from_mfn(_mfn(mfn), pg_owner)) ) { gdprintk(XENLOG_WARNING, "Could not get page for mach->phys update\n"); rc = -EINVAL; break; } set_gpfn_from_mfn(mfn, gpfn); paging_mark_dirty(pg_owner, _mfn(mfn)); put_page(mfn_to_page(_mfn(mfn))); break; default: rc = -ENOSYS; break; } if ( unlikely(rc) ) break; guest_handle_add_offset(ureqs, 1); } if ( rc == -ERESTART ) { ASSERT(i < count); rc = hypercall_create_continuation( __HYPERVISOR_mmu_update, "hihi", ureqs, (count - i) | MMU_UPDATE_PREEMPTED, pdone, foreigndom); } else if ( curr->arch.old_guest_table ) { XEN_GUEST_HANDLE_PARAM(void) null; ASSERT(rc || i == count); set_xen_guest_handle(null, NULL); /* * In order to have a way to communicate the final return value to * our continuation, we pass this in place of "foreigndom", building * on the fact that this argument isn't needed anymore. */ rc = hypercall_create_continuation( __HYPERVISOR_mmu_update, "hihi", null, MMU_UPDATE_PREEMPTED, null, rc); } put_pg_owner(pg_owner); if ( va ) unmap_domain_page(va); perfc_add(num_page_updates, i); out: if ( pt_owner != d ) rcu_unlock_domain(pt_owner); /* Add incremental work we have done to the @done output parameter. */ if ( unlikely(!guest_handle_is_null(pdone)) ) { done += i; copy_to_guest(pdone, &done, 1); } return rc; } int donate_page( struct domain *d, struct page_info *page, unsigned int memflags) { const struct domain *owner = dom_xen; spin_lock(&d->page_alloc_lock); if ( is_xen_heap_page(page) || ((owner = page_get_owner(page)) != NULL) ) goto fail; if ( d->is_dying ) goto fail; if ( page->count_info & ~(PGC_allocated | 1) ) goto fail; if ( !(memflags & MEMF_no_refcount) ) { if ( d->tot_pages >= d->max_pages ) goto fail; domain_adjust_tot_pages(d, 1); } page->count_info = PGC_allocated | 1; page_set_owner(page, d); page_list_add_tail(page,&d->page_list); spin_unlock(&d->page_alloc_lock); return 0; fail: spin_unlock(&d->page_alloc_lock); gdprintk(XENLOG_WARNING, "Bad donate mfn %" PRI_mfn " to d%d (owner d%d) caf=%08lx taf=%" PRtype_info "\n", mfn_x(page_to_mfn(page)), d->domain_id, owner ? owner->domain_id : DOMID_INVALID, page->count_info, page->u.inuse.type_info); return -EINVAL; } int steal_page( struct domain *d, struct page_info *page, unsigned int memflags) { unsigned long x, y; bool drop_dom_ref = false; const struct domain *owner = dom_xen; if ( paging_mode_external(d) ) return -EOPNOTSUPP; spin_lock(&d->page_alloc_lock); if ( is_xen_heap_page(page) || ((owner = page_get_owner(page)) != d) ) goto fail; /* * We require there is just one reference (PGC_allocated). We temporarily * drop this reference now so that we can safely swizzle the owner. */ y = page->count_info; do { x = y; if ( (x & (PGC_count_mask|PGC_allocated)) != (1 | PGC_allocated) ) goto fail; y = cmpxchg(&page->count_info, x, x & ~PGC_count_mask); } while ( y != x ); /* * With the sole reference dropped temporarily, no-one can update type * information. Type count also needs to be zero in this case, but e.g. * PGT_seg_desc_page may still have PGT_validated set, which we need to * clear before transferring ownership (as validation criteria vary * depending on domain type). */ BUG_ON(page->u.inuse.type_info & (PGT_count_mask | PGT_locked | PGT_pinned)); page->u.inuse.type_info = 0; /* Swizzle the owner then reinstate the PGC_allocated reference. */ page_set_owner(page, NULL); y = page->count_info; do { x = y; BUG_ON((x & (PGC_count_mask|PGC_allocated)) != PGC_allocated); } while ( (y = cmpxchg(&page->count_info, x, x | 1)) != x ); /* Unlink from original owner. */ if ( !(memflags & MEMF_no_refcount) && !domain_adjust_tot_pages(d, -1) ) drop_dom_ref = true; page_list_del(page, &d->page_list); spin_unlock(&d->page_alloc_lock); if ( unlikely(drop_dom_ref) ) put_domain(d); return 0; fail: spin_unlock(&d->page_alloc_lock); gdprintk(XENLOG_WARNING, "Bad steal mfn %" PRI_mfn " from d%d (owner d%d) caf=%08lx taf=%" PRtype_info "\n", mfn_x(page_to_mfn(page)), d->domain_id, owner ? owner->domain_id : DOMID_INVALID, page->count_info, page->u.inuse.type_info); return -EINVAL; } static int __do_update_va_mapping( unsigned long va, u64 val64, unsigned long flags, struct domain *pg_owner) { l1_pgentry_t val = l1e_from_intpte(val64); struct vcpu *v = current; struct domain *d = v->domain; struct page_info *gl1pg; l1_pgentry_t *pl1e; unsigned long bmap_ptr; mfn_t gl1mfn; cpumask_t *mask = NULL; int rc; perfc_incr(calls_to_update_va); rc = xsm_update_va_mapping(XSM_TARGET, d, pg_owner, val); if ( rc ) return rc; rc = -EINVAL; pl1e = map_guest_l1e(va, &gl1mfn); if ( unlikely(!pl1e || !get_page_from_mfn(gl1mfn, d)) ) goto out; gl1pg = mfn_to_page(gl1mfn); if ( !page_lock(gl1pg) ) { put_page(gl1pg); goto out; } if ( (gl1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table ) { page_unlock(gl1pg); put_page(gl1pg); goto out; } rc = mod_l1_entry(pl1e, val, mfn_x(gl1mfn), 0, v, pg_owner); page_unlock(gl1pg); put_page(gl1pg); out: if ( pl1e ) unmap_domain_page(pl1e); switch ( flags & UVMF_FLUSHTYPE_MASK ) { case UVMF_TLB_FLUSH: switch ( (bmap_ptr = flags & ~UVMF_FLUSHTYPE_MASK) ) { case UVMF_LOCAL: flush_tlb_local(); break; case UVMF_ALL: mask = d->domain_dirty_cpumask; break; default: mask = this_cpu(scratch_cpumask); rc = vcpumask_to_pcpumask(d, const_guest_handle_from_ptr(bmap_ptr, void), mask); break; } if ( mask ) flush_tlb_mask(mask); break; case UVMF_INVLPG: switch ( (bmap_ptr = flags & ~UVMF_FLUSHTYPE_MASK) ) { case UVMF_LOCAL: paging_invlpg(v, va); break; case UVMF_ALL: mask = d->domain_dirty_cpumask; break; default: mask = this_cpu(scratch_cpumask); rc = vcpumask_to_pcpumask(d, const_guest_handle_from_ptr(bmap_ptr, void), mask); break; } if ( mask ) flush_tlb_one_mask(mask, va); break; } return rc; } long do_update_va_mapping(unsigned long va, u64 val64, unsigned long flags) { return __do_update_va_mapping(va, val64, flags, current->domain); } long do_update_va_mapping_otherdomain(unsigned long va, u64 val64, unsigned long flags, domid_t domid) { struct domain *pg_owner; int rc; if ( (pg_owner = get_pg_owner(domid)) == NULL ) return -ESRCH; rc = __do_update_va_mapping(va, val64, flags, pg_owner); put_pg_owner(pg_owner); return rc; } typedef struct e820entry e820entry_t; DEFINE_XEN_GUEST_HANDLE(e820entry_t); struct memory_map_context { unsigned int n; unsigned long s; struct xen_memory_map map; }; static int _handle_iomem_range(unsigned long s, unsigned long e, struct memory_map_context *ctxt) { if ( s > ctxt->s && !(s >> (paddr_bits - PAGE_SHIFT)) ) { e820entry_t ent; XEN_GUEST_HANDLE_PARAM(e820entry_t) buffer_param; XEN_GUEST_HANDLE(e820entry_t) buffer; if ( !guest_handle_is_null(ctxt->map.buffer) ) { if ( ctxt->n + 1 >= ctxt->map.nr_entries ) return -EINVAL; ent.addr = (uint64_t)ctxt->s << PAGE_SHIFT; ent.size = (uint64_t)(s - ctxt->s) << PAGE_SHIFT; ent.type = E820_RESERVED; buffer_param = guest_handle_cast(ctxt->map.buffer, e820entry_t); buffer = guest_handle_from_param(buffer_param, e820entry_t); if ( __copy_to_guest_offset(buffer, ctxt->n, &ent, 1) ) return -EFAULT; } ctxt->n++; } ctxt->s = e + 1; return 0; } static int handle_iomem_range(unsigned long s, unsigned long e, void *p) { int err = 0; do { unsigned long low = -1UL; unsigned int i; for ( i = 0; i < nr_ioapics; ++i ) { unsigned long mfn = paddr_to_pfn(mp_ioapics[i].mpc_apicaddr); if ( mfn >= s && mfn <= e && mfn < low ) low = mfn; } if ( !(low + 1) ) break; if ( s < low ) err = _handle_iomem_range(s, low - 1, p); s = low + 1; } while ( !err ); return err || s > e ? err : _handle_iomem_range(s, e, p); } int xenmem_add_to_physmap_one( struct domain *d, unsigned int space, union xen_add_to_physmap_batch_extra extra, unsigned long idx, gfn_t gpfn) { struct page_info *page = NULL; unsigned long gfn = 0; /* gcc ... */ unsigned long prev_mfn, old_gpfn; int rc = 0; mfn_t mfn = INVALID_MFN; p2m_type_t p2mt; if ( !paging_mode_translate(d) ) return -EACCES; switch ( space ) { case XENMAPSPACE_shared_info: if ( idx == 0 ) mfn = _mfn(virt_to_mfn(d->shared_info)); break; case XENMAPSPACE_grant_table: rc = gnttab_map_frame(d, idx, gpfn, &mfn); if ( rc ) return rc; break; case XENMAPSPACE_gmfn_range: case XENMAPSPACE_gmfn: { p2m_type_t p2mt; gfn = idx; idx = mfn_x(get_gfn_unshare(d, idx, &p2mt)); /* If the page is still shared, exit early */ if ( p2m_is_shared(p2mt) ) { put_gfn(d, gfn); return -ENOMEM; } if ( !get_page_from_mfn(_mfn(idx), d) ) break; mfn = _mfn(idx); page = mfn_to_page(mfn); break; } case XENMAPSPACE_gmfn_foreign: return p2m_add_foreign(d, idx, gfn_x(gpfn), extra.foreign_domid); default: break; } if ( mfn_eq(mfn, INVALID_MFN) ) { rc = -EINVAL; goto put_both; } /* Remove previously mapped page if it was present. */ prev_mfn = mfn_x(get_gfn(d, gfn_x(gpfn), &p2mt)); if ( mfn_valid(_mfn(prev_mfn)) ) { if ( is_xen_heap_mfn(prev_mfn) ) /* Xen heap frames are simply unhooked from this phys slot. */ rc = guest_physmap_remove_page(d, gpfn, _mfn(prev_mfn), PAGE_ORDER_4K); else /* Normal domain memory is freed, to avoid leaking memory. */ rc = guest_remove_page(d, gfn_x(gpfn)); } /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */ put_gfn(d, gfn_x(gpfn)); if ( rc ) goto put_both; /* Unmap from old location, if any. */ old_gpfn = get_gpfn_from_mfn(mfn_x(mfn)); ASSERT( old_gpfn != SHARED_M2P_ENTRY ); if ( (space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range) && old_gpfn != gfn ) { rc = -EXDEV; goto put_both; } if ( old_gpfn != INVALID_M2P_ENTRY ) rc = guest_physmap_remove_page(d, _gfn(old_gpfn), mfn, PAGE_ORDER_4K); /* Map at new location. */ if ( !rc ) rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K); put_both: /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */ if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range ) put_gfn(d, gfn); if ( page ) put_page(page); return rc; } long arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg) { int rc; switch ( cmd ) { case XENMEM_set_memory_map: { struct xen_foreign_memory_map fmap; struct domain *d; struct e820entry *e820; if ( copy_from_guest(&fmap, arg, 1) ) return -EFAULT; if ( fmap.map.nr_entries > E820MAX ) return -EINVAL; d = rcu_lock_domain_by_any_id(fmap.domid); if ( d == NULL ) return -ESRCH; rc = xsm_domain_memory_map(XSM_TARGET, d); if ( rc ) { rcu_unlock_domain(d); return rc; } e820 = xmalloc_array(e820entry_t, fmap.map.nr_entries); if ( e820 == NULL ) { rcu_unlock_domain(d); return -ENOMEM; } if ( copy_from_guest(e820, fmap.map.buffer, fmap.map.nr_entries) ) { xfree(e820); rcu_unlock_domain(d); return -EFAULT; } spin_lock(&d->arch.e820_lock); xfree(d->arch.e820); d->arch.e820 = e820; d->arch.nr_e820 = fmap.map.nr_entries; spin_unlock(&d->arch.e820_lock); rcu_unlock_domain(d); return rc; } case XENMEM_memory_map: { struct xen_memory_map map; struct domain *d = current->domain; if ( copy_from_guest(&map, arg, 1) ) return -EFAULT; spin_lock(&d->arch.e820_lock); /* Backwards compatibility. */ if ( (d->arch.nr_e820 == 0) || (d->arch.e820 == NULL) ) { spin_unlock(&d->arch.e820_lock); return -ENOSYS; } map.nr_entries = min(map.nr_entries, d->arch.nr_e820); if ( copy_to_guest(map.buffer, d->arch.e820, map.nr_entries) || __copy_to_guest(arg, &map, 1) ) { spin_unlock(&d->arch.e820_lock); return -EFAULT; } spin_unlock(&d->arch.e820_lock); return 0; } case XENMEM_machine_memory_map: { struct memory_map_context ctxt; XEN_GUEST_HANDLE(e820entry_t) buffer; XEN_GUEST_HANDLE_PARAM(e820entry_t) buffer_param; unsigned int i; bool store; rc = xsm_machine_memory_map(XSM_PRIV); if ( rc ) return rc; if ( copy_from_guest(&ctxt.map, arg, 1) ) return -EFAULT; store = !guest_handle_is_null(ctxt.map.buffer); if ( store && ctxt.map.nr_entries < e820.nr_map + 1 ) return -EINVAL; buffer_param = guest_handle_cast(ctxt.map.buffer, e820entry_t); buffer = guest_handle_from_param(buffer_param, e820entry_t); if ( store && !guest_handle_okay(buffer, ctxt.map.nr_entries) ) return -EFAULT; for ( i = 0, ctxt.n = 0, ctxt.s = 0; i < e820.nr_map; ++i, ++ctxt.n ) { unsigned long s = PFN_DOWN(e820.map[i].addr); if ( s > ctxt.s ) { rc = rangeset_report_ranges(current->domain->iomem_caps, ctxt.s, s - 1, handle_iomem_range, &ctxt); if ( !rc ) rc = handle_iomem_range(s, s, &ctxt); if ( rc ) return rc; } if ( store ) { if ( ctxt.map.nr_entries <= ctxt.n + (e820.nr_map - i) ) return -EINVAL; if ( __copy_to_guest_offset(buffer, ctxt.n, e820.map + i, 1) ) return -EFAULT; } ctxt.s = PFN_UP(e820.map[i].addr + e820.map[i].size); } if ( ctxt.s ) { rc = rangeset_report_ranges(current->domain->iomem_caps, ctxt.s, ~0UL, handle_iomem_range, &ctxt); if ( !rc && ctxt.s ) rc = handle_iomem_range(~0UL, ~0UL, &ctxt); if ( rc ) return rc; } ctxt.map.nr_entries = ctxt.n; if ( __copy_to_guest(arg, &ctxt.map, 1) ) return -EFAULT; return 0; } case XENMEM_machphys_mapping: { struct xen_machphys_mapping mapping = { .v_start = MACH2PHYS_VIRT_START, .v_end = MACH2PHYS_VIRT_END, .max_mfn = MACH2PHYS_NR_ENTRIES - 1 }; if ( !mem_hotplug && is_hardware_domain(current->domain) ) mapping.max_mfn = max_page - 1; if ( copy_to_guest(arg, &mapping, 1) ) return -EFAULT; return 0; } case XENMEM_set_pod_target: case XENMEM_get_pod_target: { xen_pod_target_t target; struct domain *d; struct p2m_domain *p2m; if ( copy_from_guest(&target, arg, 1) ) return -EFAULT; d = rcu_lock_domain_by_any_id(target.domid); if ( d == NULL ) return -ESRCH; if ( cmd == XENMEM_set_pod_target ) rc = xsm_set_pod_target(XSM_PRIV, d); else rc = xsm_get_pod_target(XSM_PRIV, d); if ( rc != 0 ) goto pod_target_out_unlock; if ( cmd == XENMEM_set_pod_target ) { if ( target.target_pages > d->max_pages ) { rc = -EINVAL; goto pod_target_out_unlock; } rc = p2m_pod_set_mem_target(d, target.target_pages); } if ( rc == -ERESTART ) { rc = hypercall_create_continuation( __HYPERVISOR_memory_op, "lh", cmd, arg); } else if ( rc >= 0 ) { p2m = p2m_get_hostp2m(d); target.tot_pages = d->tot_pages; target.pod_cache_pages = p2m->pod.count; target.pod_entries = p2m->pod.entry_count; if ( __copy_to_guest(arg, &target, 1) ) { rc= -EFAULT; goto pod_target_out_unlock; } } pod_target_out_unlock: rcu_unlock_domain(d); return rc; } default: return subarch_memory_op(cmd, arg); } return 0; } int mmio_ro_emulated_write( enum x86_segment seg, unsigned long offset, void *p_data, unsigned int bytes, struct x86_emulate_ctxt *ctxt) { struct mmio_ro_emulate_ctxt *mmio_ro_ctxt = ctxt->data; /* Only allow naturally-aligned stores at the original %cr2 address. */ if ( ((bytes | offset) & (bytes - 1)) || !bytes || offset != mmio_ro_ctxt->cr2 ) { gdprintk(XENLOG_WARNING, "bad access (cr2=%lx, addr=%lx, bytes=%u)\n", mmio_ro_ctxt->cr2, offset, bytes); return X86EMUL_UNHANDLEABLE; } return X86EMUL_OKAY; } int mmcfg_intercept_write( enum x86_segment seg, unsigned long offset, void *p_data, unsigned int bytes, struct x86_emulate_ctxt *ctxt) { struct mmio_ro_emulate_ctxt *mmio_ctxt = ctxt->data; /* * Only allow naturally-aligned stores no wider than 4 bytes to the * original %cr2 address. */ if ( ((bytes | offset) & (bytes - 1)) || bytes > 4 || !bytes || offset != mmio_ctxt->cr2 ) { gdprintk(XENLOG_WARNING, "bad write (cr2=%lx, addr=%lx, bytes=%u)\n", mmio_ctxt->cr2, offset, bytes); return X86EMUL_UNHANDLEABLE; } offset &= 0xfff; if ( pci_conf_write_intercept(mmio_ctxt->seg, mmio_ctxt->bdf, offset, bytes, p_data) >= 0 ) pci_mmcfg_write(mmio_ctxt->seg, PCI_BUS(mmio_ctxt->bdf), PCI_DEVFN2(mmio_ctxt->bdf), offset, bytes, *(uint32_t *)p_data); return X86EMUL_OKAY; } void *alloc_xen_pagetable(void) { if ( system_state != SYS_STATE_early_boot ) { void *ptr = alloc_xenheap_page(); BUG_ON(!hardware_domain && !ptr); return ptr; } return mfn_to_virt(mfn_x(alloc_boot_pages(1, 1))); } void free_xen_pagetable(void *v) { if ( system_state != SYS_STATE_early_boot ) free_xenheap_page(v); } static DEFINE_SPINLOCK(map_pgdir_lock); static l3_pgentry_t *virt_to_xen_l3e(unsigned long v) { l4_pgentry_t *pl4e; pl4e = &idle_pg_table[l4_table_offset(v)]; if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) ) { bool locking = system_state > SYS_STATE_boot; l3_pgentry_t *pl3e = alloc_xen_pagetable(); if ( !pl3e ) return NULL; clear_page(pl3e); if ( locking ) spin_lock(&map_pgdir_lock); if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) ) { l4_pgentry_t l4e = l4e_from_paddr(__pa(pl3e), __PAGE_HYPERVISOR); l4e_write(pl4e, l4e); efi_update_l4_pgtable(l4_table_offset(v), l4e); pl3e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); if ( pl3e ) free_xen_pagetable(pl3e); } return l4e_to_l3e(*pl4e) + l3_table_offset(v); } static l2_pgentry_t *virt_to_xen_l2e(unsigned long v) { l3_pgentry_t *pl3e; pl3e = virt_to_xen_l3e(v); if ( !pl3e ) return NULL; if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) { bool locking = system_state > SYS_STATE_boot; l2_pgentry_t *pl2e = alloc_xen_pagetable(); if ( !pl2e ) return NULL; clear_page(pl2e); if ( locking ) spin_lock(&map_pgdir_lock); if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) { l3e_write(pl3e, l3e_from_paddr(__pa(pl2e), __PAGE_HYPERVISOR)); pl2e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); if ( pl2e ) free_xen_pagetable(pl2e); } BUG_ON(l3e_get_flags(*pl3e) & _PAGE_PSE); return l3e_to_l2e(*pl3e) + l2_table_offset(v); } l1_pgentry_t *virt_to_xen_l1e(unsigned long v) { l2_pgentry_t *pl2e; pl2e = virt_to_xen_l2e(v); if ( !pl2e ) return NULL; if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { bool locking = system_state > SYS_STATE_boot; l1_pgentry_t *pl1e = alloc_xen_pagetable(); if ( !pl1e ) return NULL; clear_page(pl1e); if ( locking ) spin_lock(&map_pgdir_lock); if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { l2e_write(pl2e, l2e_from_paddr(__pa(pl1e), __PAGE_HYPERVISOR)); pl1e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); if ( pl1e ) free_xen_pagetable(pl1e); } BUG_ON(l2e_get_flags(*pl2e) & _PAGE_PSE); return l2e_to_l1e(*pl2e) + l1_table_offset(v); } /* Convert to from superpage-mapping flags for map_pages_to_xen(). */ #define l1f_to_lNf(f) (((f) & _PAGE_PRESENT) ? ((f) | _PAGE_PSE) : (f)) #define lNf_to_l1f(f) (((f) & _PAGE_PRESENT) ? ((f) & ~_PAGE_PSE) : (f)) /* * map_pages_to_xen() can be called with interrupts disabled during * early bootstrap. In this case it is safe to use flush_area_local() * and avoid locking because only the local CPU is online. */ #define flush_area(v,f) (!local_irq_is_enabled() ? \ flush_area_local((const void *)v, f) : \ flush_area_all((const void *)v, f)) int map_pages_to_xen( unsigned long virt, unsigned long mfn, unsigned long nr_mfns, unsigned int flags) { bool locking = system_state > SYS_STATE_boot; l2_pgentry_t *pl2e, ol2e; l1_pgentry_t *pl1e, ol1e; unsigned int i; #define flush_flags(oldf) do { \ unsigned int o_ = (oldf); \ if ( (o_) & _PAGE_GLOBAL ) \ flush_flags |= FLUSH_TLB_GLOBAL; \ if ( (flags & _PAGE_PRESENT) && \ (((o_) ^ flags) & PAGE_CACHE_ATTRS) ) \ { \ flush_flags |= FLUSH_CACHE; \ if ( virt >= DIRECTMAP_VIRT_START && \ virt < HYPERVISOR_VIRT_END ) \ flush_flags |= FLUSH_VA_VALID; \ } \ } while (0) while ( nr_mfns != 0 ) { l3_pgentry_t ol3e, *pl3e = virt_to_xen_l3e(virt); if ( !pl3e ) return -ENOMEM; ol3e = *pl3e; if ( cpu_has_page1gb && !(((virt >> PAGE_SHIFT) | mfn) & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1)) && nr_mfns >= (1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) && !(flags & (_PAGE_PAT | MAP_SMALL_PAGES)) ) { /* 1GB-page mapping. */ l3e_write_atomic(pl3e, l3e_from_pfn(mfn, l1f_to_lNf(flags))); if ( (l3e_get_flags(ol3e) & _PAGE_PRESENT) ) { unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(2 * PAGETABLE_ORDER); if ( l3e_get_flags(ol3e) & _PAGE_PSE ) { flush_flags(lNf_to_l1f(l3e_get_flags(ol3e))); flush_area(virt, flush_flags); } else { pl2e = l3e_to_l2e(ol3e); for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) { ol2e = pl2e[i]; if ( !(l2e_get_flags(ol2e) & _PAGE_PRESENT) ) continue; if ( l2e_get_flags(ol2e) & _PAGE_PSE ) flush_flags(lNf_to_l1f(l2e_get_flags(ol2e))); else { unsigned int j; pl1e = l2e_to_l1e(ol2e); for ( j = 0; j < L1_PAGETABLE_ENTRIES; j++ ) flush_flags(l1e_get_flags(pl1e[j])); } } flush_area(virt, flush_flags); for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) { ol2e = pl2e[i]; if ( (l2e_get_flags(ol2e) & _PAGE_PRESENT) && !(l2e_get_flags(ol2e) & _PAGE_PSE) ) free_xen_pagetable(l2e_to_l1e(ol2e)); } free_xen_pagetable(pl2e); } } virt += 1UL << L3_PAGETABLE_SHIFT; mfn += 1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT); nr_mfns -= 1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT); continue; } if ( (l3e_get_flags(ol3e) & _PAGE_PRESENT) && (l3e_get_flags(ol3e) & _PAGE_PSE) ) { unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(2 * PAGETABLE_ORDER); /* Skip this PTE if there is no change. */ if ( ((l3e_get_pfn(ol3e) & ~(L2_PAGETABLE_ENTRIES * L1_PAGETABLE_ENTRIES - 1)) + (l2_table_offset(virt) << PAGETABLE_ORDER) + l1_table_offset(virt) == mfn) && ((lNf_to_l1f(l3e_get_flags(ol3e)) ^ flags) & ~(_PAGE_ACCESSED|_PAGE_DIRTY)) == 0 ) { /* We can skip to end of L3 superpage if we got a match. */ i = (1u << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - (mfn & ((1 << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1)); if ( i > nr_mfns ) i = nr_mfns; virt += i << PAGE_SHIFT; mfn += i; nr_mfns -= i; continue; } pl2e = alloc_xen_pagetable(); if ( pl2e == NULL ) return -ENOMEM; for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) l2e_write(pl2e + i, l2e_from_pfn(l3e_get_pfn(ol3e) + (i << PAGETABLE_ORDER), l3e_get_flags(ol3e))); if ( l3e_get_flags(ol3e) & _PAGE_GLOBAL ) flush_flags |= FLUSH_TLB_GLOBAL; if ( locking ) spin_lock(&map_pgdir_lock); if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) && (l3e_get_flags(*pl3e) & _PAGE_PSE) ) { l3e_write_atomic(pl3e, l3e_from_pfn(virt_to_mfn(pl2e), __PAGE_HYPERVISOR)); pl2e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(virt, flush_flags); if ( pl2e ) free_xen_pagetable(pl2e); } pl2e = virt_to_xen_l2e(virt); if ( !pl2e ) return -ENOMEM; if ( ((((virt >> PAGE_SHIFT) | mfn) & ((1u << PAGETABLE_ORDER) - 1)) == 0) && (nr_mfns >= (1u << PAGETABLE_ORDER)) && !(flags & (_PAGE_PAT|MAP_SMALL_PAGES)) ) { /* Super-page mapping. */ ol2e = *pl2e; l2e_write_atomic(pl2e, l2e_from_pfn(mfn, l1f_to_lNf(flags))); if ( (l2e_get_flags(ol2e) & _PAGE_PRESENT) ) { unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(PAGETABLE_ORDER); if ( l2e_get_flags(ol2e) & _PAGE_PSE ) { flush_flags(lNf_to_l1f(l2e_get_flags(ol2e))); flush_area(virt, flush_flags); } else { pl1e = l2e_to_l1e(ol2e); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) flush_flags(l1e_get_flags(pl1e[i])); flush_area(virt, flush_flags); free_xen_pagetable(pl1e); } } virt += 1UL << L2_PAGETABLE_SHIFT; mfn += 1UL << PAGETABLE_ORDER; nr_mfns -= 1UL << PAGETABLE_ORDER; } else { /* Normal page mapping. */ if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { pl1e = virt_to_xen_l1e(virt); if ( pl1e == NULL ) return -ENOMEM; } else if ( l2e_get_flags(*pl2e) & _PAGE_PSE ) { unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(PAGETABLE_ORDER); /* Skip this PTE if there is no change. */ if ( (((l2e_get_pfn(*pl2e) & ~(L1_PAGETABLE_ENTRIES - 1)) + l1_table_offset(virt)) == mfn) && (((lNf_to_l1f(l2e_get_flags(*pl2e)) ^ flags) & ~(_PAGE_ACCESSED|_PAGE_DIRTY)) == 0) ) { /* We can skip to end of L2 superpage if we got a match. */ i = (1u << (L2_PAGETABLE_SHIFT - PAGE_SHIFT)) - (mfn & ((1u << (L2_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1)); if ( i > nr_mfns ) i = nr_mfns; virt += i << L1_PAGETABLE_SHIFT; mfn += i; nr_mfns -= i; goto check_l3; } pl1e = alloc_xen_pagetable(); if ( pl1e == NULL ) return -ENOMEM; for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) l1e_write(&pl1e[i], l1e_from_pfn(l2e_get_pfn(*pl2e) + i, lNf_to_l1f(l2e_get_flags(*pl2e)))); if ( l2e_get_flags(*pl2e) & _PAGE_GLOBAL ) flush_flags |= FLUSH_TLB_GLOBAL; if ( locking ) spin_lock(&map_pgdir_lock); if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) && (l2e_get_flags(*pl2e) & _PAGE_PSE) ) { l2e_write_atomic(pl2e, l2e_from_pfn(virt_to_mfn(pl1e), __PAGE_HYPERVISOR)); pl1e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(virt, flush_flags); if ( pl1e ) free_xen_pagetable(pl1e); } pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(virt); ol1e = *pl1e; l1e_write_atomic(pl1e, l1e_from_pfn(mfn, flags)); if ( (l1e_get_flags(ol1e) & _PAGE_PRESENT) ) { unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(0); flush_flags(l1e_get_flags(ol1e)); flush_area(virt, flush_flags); } virt += 1UL << L1_PAGETABLE_SHIFT; mfn += 1UL; nr_mfns -= 1UL; if ( (flags == PAGE_HYPERVISOR) && ((nr_mfns == 0) || ((((virt >> PAGE_SHIFT) | mfn) & ((1u << PAGETABLE_ORDER) - 1)) == 0)) ) { unsigned long base_mfn; if ( locking ) spin_lock(&map_pgdir_lock); ol2e = *pl2e; /* * L2E may be already cleared, or set to a superpage, by * concurrent paging structure modifications on other CPUs. */ if ( !(l2e_get_flags(ol2e) & _PAGE_PRESENT) ) { if ( locking ) spin_unlock(&map_pgdir_lock); continue; } if ( l2e_get_flags(ol2e) & _PAGE_PSE ) { if ( locking ) spin_unlock(&map_pgdir_lock); goto check_l3; } pl1e = l2e_to_l1e(ol2e); base_mfn = l1e_get_pfn(*pl1e) & ~(L1_PAGETABLE_ENTRIES - 1); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++, pl1e++ ) if ( (l1e_get_pfn(*pl1e) != (base_mfn + i)) || (l1e_get_flags(*pl1e) != flags) ) break; if ( i == L1_PAGETABLE_ENTRIES ) { l2e_write_atomic(pl2e, l2e_from_pfn(base_mfn, l1f_to_lNf(flags))); if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(virt - PAGE_SIZE, FLUSH_TLB_GLOBAL | FLUSH_ORDER(PAGETABLE_ORDER)); free_xen_pagetable(l2e_to_l1e(ol2e)); } else if ( locking ) spin_unlock(&map_pgdir_lock); } } check_l3: if ( cpu_has_page1gb && (flags == PAGE_HYPERVISOR) && ((nr_mfns == 0) || !(((virt >> PAGE_SHIFT) | mfn) & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1))) ) { unsigned long base_mfn; if ( locking ) spin_lock(&map_pgdir_lock); ol3e = *pl3e; /* * L3E may be already cleared, or set to a superpage, by * concurrent paging structure modifications on other CPUs. */ if ( !(l3e_get_flags(ol3e) & _PAGE_PRESENT) || (l3e_get_flags(ol3e) & _PAGE_PSE) ) { if ( locking ) spin_unlock(&map_pgdir_lock); continue; } pl2e = l3e_to_l2e(ol3e); base_mfn = l2e_get_pfn(*pl2e) & ~(L2_PAGETABLE_ENTRIES * L1_PAGETABLE_ENTRIES - 1); for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++, pl2e++ ) if ( (l2e_get_pfn(*pl2e) != (base_mfn + (i << PAGETABLE_ORDER))) || (l2e_get_flags(*pl2e) != l1f_to_lNf(flags)) ) break; if ( i == L2_PAGETABLE_ENTRIES ) { l3e_write_atomic(pl3e, l3e_from_pfn(base_mfn, l1f_to_lNf(flags))); if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(virt - PAGE_SIZE, FLUSH_TLB_GLOBAL | FLUSH_ORDER(2*PAGETABLE_ORDER)); free_xen_pagetable(l3e_to_l2e(ol3e)); } else if ( locking ) spin_unlock(&map_pgdir_lock); } } #undef flush_flags return 0; } int populate_pt_range(unsigned long virt, unsigned long mfn, unsigned long nr_mfns) { return map_pages_to_xen(virt, mfn, nr_mfns, MAP_SMALL_PAGES); } /* * Alter the permissions of a range of Xen virtual address space. * * Does not create new mappings, and does not modify the mfn in existing * mappings, but will shatter superpages if necessary, and will destroy * mappings if not passed _PAGE_PRESENT. * * The only flags considered are NX, RW and PRESENT. All other input flags * are ignored. * * It is an error to call with present flags over an unpopulated range. */ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) { bool locking = system_state > SYS_STATE_boot; l2_pgentry_t *pl2e; l1_pgentry_t *pl1e; unsigned int i; unsigned long v = s; /* Set of valid PTE bits which may be altered. */ #define FLAGS_MASK (_PAGE_NX|_PAGE_RW|_PAGE_PRESENT) nf &= FLAGS_MASK; ASSERT(IS_ALIGNED(s, PAGE_SIZE)); ASSERT(IS_ALIGNED(e, PAGE_SIZE)); while ( v < e ) { l3_pgentry_t *pl3e = virt_to_xen_l3e(v); if ( !pl3e || !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) { /* Confirm the caller isn't trying to create new mappings. */ ASSERT(!(nf & _PAGE_PRESENT)); v += 1UL << L3_PAGETABLE_SHIFT; v &= ~((1UL << L3_PAGETABLE_SHIFT) - 1); continue; } if ( l3e_get_flags(*pl3e) & _PAGE_PSE ) { if ( l2_table_offset(v) == 0 && l1_table_offset(v) == 0 && ((e - v) >= (1UL << L3_PAGETABLE_SHIFT)) ) { /* PAGE1GB: whole superpage is modified. */ l3_pgentry_t nl3e = !(nf & _PAGE_PRESENT) ? l3e_empty() : l3e_from_pfn(l3e_get_pfn(*pl3e), (l3e_get_flags(*pl3e) & ~FLAGS_MASK) | nf); l3e_write_atomic(pl3e, nl3e); v += 1UL << L3_PAGETABLE_SHIFT; continue; } /* PAGE1GB: shatter the superpage and fall through. */ pl2e = alloc_xen_pagetable(); if ( !pl2e ) return -ENOMEM; for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) l2e_write(pl2e + i, l2e_from_pfn(l3e_get_pfn(*pl3e) + (i << PAGETABLE_ORDER), l3e_get_flags(*pl3e))); if ( locking ) spin_lock(&map_pgdir_lock); if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) && (l3e_get_flags(*pl3e) & _PAGE_PSE) ) { l3e_write_atomic(pl3e, l3e_from_pfn(virt_to_mfn(pl2e), __PAGE_HYPERVISOR)); pl2e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); if ( pl2e ) free_xen_pagetable(pl2e); } /* * The L3 entry has been verified to be present, and we've dealt with * 1G pages as well, so the L2 table cannot require allocation. */ pl2e = l3e_to_l2e(*pl3e) + l2_table_offset(v); if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { /* Confirm the caller isn't trying to create new mappings. */ ASSERT(!(nf & _PAGE_PRESENT)); v += 1UL << L2_PAGETABLE_SHIFT; v &= ~((1UL << L2_PAGETABLE_SHIFT) - 1); continue; } if ( l2e_get_flags(*pl2e) & _PAGE_PSE ) { if ( (l1_table_offset(v) == 0) && ((e-v) >= (1UL << L2_PAGETABLE_SHIFT)) ) { /* PSE: whole superpage is modified. */ l2_pgentry_t nl2e = !(nf & _PAGE_PRESENT) ? l2e_empty() : l2e_from_pfn(l2e_get_pfn(*pl2e), (l2e_get_flags(*pl2e) & ~FLAGS_MASK) | nf); l2e_write_atomic(pl2e, nl2e); v += 1UL << L2_PAGETABLE_SHIFT; } else { /* PSE: shatter the superpage and try again. */ pl1e = alloc_xen_pagetable(); if ( !pl1e ) return -ENOMEM; for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) l1e_write(&pl1e[i], l1e_from_pfn(l2e_get_pfn(*pl2e) + i, l2e_get_flags(*pl2e) & ~_PAGE_PSE)); if ( locking ) spin_lock(&map_pgdir_lock); if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) && (l2e_get_flags(*pl2e) & _PAGE_PSE) ) { l2e_write_atomic(pl2e, l2e_from_pfn(virt_to_mfn(pl1e), __PAGE_HYPERVISOR)); pl1e = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); if ( pl1e ) free_xen_pagetable(pl1e); } } else { l1_pgentry_t nl1e; /* * Ordinary 4kB mapping: The L2 entry has been verified to be * present, and we've dealt with 2M pages as well, so the L1 table * cannot require allocation. */ pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(v); /* Confirm the caller isn't trying to create new mappings. */ if ( !(l1e_get_flags(*pl1e) & _PAGE_PRESENT) ) ASSERT(!(nf & _PAGE_PRESENT)); nl1e = !(nf & _PAGE_PRESENT) ? l1e_empty() : l1e_from_pfn(l1e_get_pfn(*pl1e), (l1e_get_flags(*pl1e) & ~FLAGS_MASK) | nf); l1e_write_atomic(pl1e, nl1e); v += PAGE_SIZE; /* * If we are not destroying mappings, or not done with the L2E, * skip the empty&free check. */ if ( (nf & _PAGE_PRESENT) || ((v != e) && (l1_table_offset(v) != 0)) ) continue; if ( locking ) spin_lock(&map_pgdir_lock); /* * L2E may be already cleared, or set to a superpage, by * concurrent paging structure modifications on other CPUs. */ if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { if ( locking ) spin_unlock(&map_pgdir_lock); goto check_l3; } if ( l2e_get_flags(*pl2e) & _PAGE_PSE ) { if ( locking ) spin_unlock(&map_pgdir_lock); continue; } pl1e = l2e_to_l1e(*pl2e); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) if ( l1e_get_intpte(pl1e[i]) != 0 ) break; if ( i == L1_PAGETABLE_ENTRIES ) { /* Empty: zap the L2E and free the L1 page. */ l2e_write_atomic(pl2e, l2e_empty()); if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(NULL, FLUSH_TLB_GLOBAL); /* flush before free */ free_xen_pagetable(pl1e); } else if ( locking ) spin_unlock(&map_pgdir_lock); } check_l3: /* * If we are not destroying mappings, or not done with the L3E, * skip the empty&free check. */ if ( (nf & _PAGE_PRESENT) || ((v != e) && (l2_table_offset(v) + l1_table_offset(v) != 0)) ) continue; if ( locking ) spin_lock(&map_pgdir_lock); /* * L3E may be already cleared, or set to a superpage, by * concurrent paging structure modifications on other CPUs. */ if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) || (l3e_get_flags(*pl3e) & _PAGE_PSE) ) { if ( locking ) spin_unlock(&map_pgdir_lock); continue; } pl2e = l3e_to_l2e(*pl3e); for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) if ( l2e_get_intpte(pl2e[i]) != 0 ) break; if ( i == L2_PAGETABLE_ENTRIES ) { /* Empty: zap the L3E and free the L2 page. */ l3e_write_atomic(pl3e, l3e_empty()); if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(NULL, FLUSH_TLB_GLOBAL); /* flush before free */ free_xen_pagetable(pl2e); } else if ( locking ) spin_unlock(&map_pgdir_lock); } flush_area(NULL, FLUSH_TLB_GLOBAL); #undef FLAGS_MASK return 0; } #undef flush_area int destroy_xen_mappings(unsigned long s, unsigned long e) { return modify_xen_mappings(s, e, _PAGE_NONE); } void __set_fixmap( enum fixed_addresses idx, unsigned long mfn, unsigned long flags) { BUG_ON(idx >= __end_of_fixed_addresses); map_pages_to_xen(__fix_to_virt(idx), mfn, 1, flags); } void *__init arch_vmap_virt_end(void) { return fix_to_virt(__end_of_fixed_addresses); } void __iomem *ioremap(paddr_t pa, size_t len) { mfn_t mfn = _mfn(PFN_DOWN(pa)); void *va; WARN_ON(page_is_ram_type(mfn_x(mfn), RAM_TYPE_CONVENTIONAL)); /* The low first Mb is always mapped. */ if ( !((pa + len - 1) >> 20) ) va = __va(pa); else { unsigned int offs = pa & (PAGE_SIZE - 1); unsigned int nr = PFN_UP(offs + len); va = __vmap(&mfn, nr, 1, 1, PAGE_HYPERVISOR_UCMINUS, VMAP_DEFAULT) + offs; } return (void __force __iomem *)va; } int create_perdomain_mapping(struct domain *d, unsigned long va, unsigned int nr, l1_pgentry_t **pl1tab, struct page_info **ppg) { struct page_info *pg; l3_pgentry_t *l3tab; l2_pgentry_t *l2tab; l1_pgentry_t *l1tab; int rc = 0; ASSERT(va >= PERDOMAIN_VIRT_START && va < PERDOMAIN_VIRT_SLOT(PERDOMAIN_SLOTS)); if ( !d->arch.perdomain_l3_pg ) { pg = alloc_domheap_page(d, MEMF_no_owner); if ( !pg ) return -ENOMEM; l3tab = __map_domain_page(pg); clear_page(l3tab); d->arch.perdomain_l3_pg = pg; if ( !nr ) { unmap_domain_page(l3tab); return 0; } } else if ( !nr ) return 0; else l3tab = __map_domain_page(d->arch.perdomain_l3_pg); ASSERT(!l3_table_offset(va ^ (va + nr * PAGE_SIZE - 1))); if ( !(l3e_get_flags(l3tab[l3_table_offset(va)]) & _PAGE_PRESENT) ) { pg = alloc_domheap_page(d, MEMF_no_owner); if ( !pg ) { unmap_domain_page(l3tab); return -ENOMEM; } l2tab = __map_domain_page(pg); clear_page(l2tab); l3tab[l3_table_offset(va)] = l3e_from_page(pg, __PAGE_HYPERVISOR_RW); } else l2tab = map_l2t_from_l3e(l3tab[l3_table_offset(va)]); unmap_domain_page(l3tab); if ( !pl1tab && !ppg ) { unmap_domain_page(l2tab); return 0; } for ( l1tab = NULL; !rc && nr--; ) { l2_pgentry_t *pl2e = l2tab + l2_table_offset(va); if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { if ( pl1tab && !IS_NIL(pl1tab) ) { l1tab = alloc_xenheap_pages(0, MEMF_node(domain_to_node(d))); if ( !l1tab ) { rc = -ENOMEM; break; } ASSERT(!pl1tab[l2_table_offset(va)]); pl1tab[l2_table_offset(va)] = l1tab; pg = virt_to_page(l1tab); } else { pg = alloc_domheap_page(d, MEMF_no_owner); if ( !pg ) { rc = -ENOMEM; break; } l1tab = __map_domain_page(pg); } clear_page(l1tab); *pl2e = l2e_from_page(pg, __PAGE_HYPERVISOR_RW); } else if ( !l1tab ) l1tab = map_l1t_from_l2e(*pl2e); if ( ppg && !(l1e_get_flags(l1tab[l1_table_offset(va)]) & _PAGE_PRESENT) ) { pg = alloc_domheap_page(d, MEMF_no_owner); if ( pg ) { clear_domain_page(page_to_mfn(pg)); if ( !IS_NIL(ppg) ) *ppg++ = pg; l1tab[l1_table_offset(va)] = l1e_from_page(pg, __PAGE_HYPERVISOR_RW | _PAGE_AVAIL0); l2e_add_flags(*pl2e, _PAGE_AVAIL0); } else rc = -ENOMEM; } va += PAGE_SIZE; if ( rc || !nr || !l1_table_offset(va) ) { /* Note that this is a no-op for the alloc_xenheap_page() case. */ unmap_domain_page(l1tab); l1tab = NULL; } } ASSERT(!l1tab); unmap_domain_page(l2tab); return rc; } void destroy_perdomain_mapping(struct domain *d, unsigned long va, unsigned int nr) { const l3_pgentry_t *l3tab, *pl3e; ASSERT(va >= PERDOMAIN_VIRT_START && va < PERDOMAIN_VIRT_SLOT(PERDOMAIN_SLOTS)); ASSERT(!l3_table_offset(va ^ (va + nr * PAGE_SIZE - 1))); if ( !d->arch.perdomain_l3_pg ) return; l3tab = __map_domain_page(d->arch.perdomain_l3_pg); pl3e = l3tab + l3_table_offset(va); if ( l3e_get_flags(*pl3e) & _PAGE_PRESENT ) { const l2_pgentry_t *l2tab = map_l2t_from_l3e(*pl3e); const l2_pgentry_t *pl2e = l2tab + l2_table_offset(va); unsigned int i = l1_table_offset(va); while ( nr ) { if ( l2e_get_flags(*pl2e) & _PAGE_PRESENT ) { l1_pgentry_t *l1tab = map_l1t_from_l2e(*pl2e); for ( ; nr && i < L1_PAGETABLE_ENTRIES; --nr, ++i ) { if ( (l1e_get_flags(l1tab[i]) & (_PAGE_PRESENT | _PAGE_AVAIL0)) == (_PAGE_PRESENT | _PAGE_AVAIL0) ) free_domheap_page(l1e_get_page(l1tab[i])); l1tab[i] = l1e_empty(); } unmap_domain_page(l1tab); } else if ( nr + i < L1_PAGETABLE_ENTRIES ) break; else nr -= L1_PAGETABLE_ENTRIES - i; ++pl2e; i = 0; } unmap_domain_page(l2tab); } unmap_domain_page(l3tab); } void free_perdomain_mappings(struct domain *d) { l3_pgentry_t *l3tab; unsigned int i; if ( !d->arch.perdomain_l3_pg ) return; l3tab = __map_domain_page(d->arch.perdomain_l3_pg); for ( i = 0; i < PERDOMAIN_SLOTS; ++i) if ( l3e_get_flags(l3tab[i]) & _PAGE_PRESENT ) { struct page_info *l2pg = l3e_get_page(l3tab[i]); l2_pgentry_t *l2tab = __map_domain_page(l2pg); unsigned int j; for ( j = 0; j < L2_PAGETABLE_ENTRIES; ++j ) if ( l2e_get_flags(l2tab[j]) & _PAGE_PRESENT ) { struct page_info *l1pg = l2e_get_page(l2tab[j]); if ( l2e_get_flags(l2tab[j]) & _PAGE_AVAIL0 ) { l1_pgentry_t *l1tab = __map_domain_page(l1pg); unsigned int k; for ( k = 0; k < L1_PAGETABLE_ENTRIES; ++k ) if ( (l1e_get_flags(l1tab[k]) & (_PAGE_PRESENT | _PAGE_AVAIL0)) == (_PAGE_PRESENT | _PAGE_AVAIL0) ) free_domheap_page(l1e_get_page(l1tab[k])); unmap_domain_page(l1tab); } if ( is_xen_heap_page(l1pg) ) free_xenheap_page(page_to_virt(l1pg)); else free_domheap_page(l1pg); } unmap_domain_page(l2tab); free_domheap_page(l2pg); } unmap_domain_page(l3tab); free_domheap_page(d->arch.perdomain_l3_pg); d->arch.perdomain_l3_pg = NULL; } #ifdef MEMORY_GUARD static void __memguard_change_range(void *p, unsigned long l, int guard) { unsigned long _p = (unsigned long)p; unsigned long _l = (unsigned long)l; unsigned int flags = __PAGE_HYPERVISOR_RW | MAP_SMALL_PAGES; /* Ensure we are dealing with a page-aligned whole number of pages. */ ASSERT(IS_ALIGNED(_p, PAGE_SIZE)); ASSERT(IS_ALIGNED(_l, PAGE_SIZE)); if ( guard ) flags &= ~_PAGE_PRESENT; map_pages_to_xen( _p, virt_to_maddr(p) >> PAGE_SHIFT, _l >> PAGE_SHIFT, flags); } void memguard_guard_range(void *p, unsigned long l) { __memguard_change_range(p, l, 1); } void memguard_unguard_range(void *p, unsigned long l) { __memguard_change_range(p, l, 0); } #endif void memguard_guard_stack(void *p) { BUILD_BUG_ON((PRIMARY_STACK_SIZE + PAGE_SIZE) > STACK_SIZE); p = (void *)((unsigned long)p + STACK_SIZE - PRIMARY_STACK_SIZE - PAGE_SIZE); memguard_guard_range(p, PAGE_SIZE); } void memguard_unguard_stack(void *p) { p = (void *)((unsigned long)p + STACK_SIZE - PRIMARY_STACK_SIZE - PAGE_SIZE); memguard_unguard_range(p, PAGE_SIZE); } void arch_dump_shared_mem_info(void) { printk("Shared frames %u -- Saved frames %u\n", mem_sharing_get_nr_shared_mfns(), mem_sharing_get_nr_saved_mfns()); } const unsigned long *__init get_platform_badpages(unsigned int *array_size) { u32 igd_id; static unsigned long __initdata bad_pages[] = { 0x20050000, 0x20110000, 0x20130000, 0x20138000, 0x40004000, }; *array_size = ARRAY_SIZE(bad_pages); igd_id = pci_conf_read32(0, 0, 2, 0, 0); if ( !IS_SNB_GFX(igd_id) ) return NULL; return bad_pages; } void paging_invlpg(struct vcpu *v, unsigned long va) { if ( !is_canonical_address(va) ) return; if ( paging_mode_enabled(v->domain) && !paging_get_hostmode(v)->invlpg(v, va) ) return; if ( is_pv_vcpu(v) ) flush_tlb_one_local(va); else hvm_funcs.invlpg(v, va); } /* Build a 32bit PSE page table using 4MB pages. */ void write_32bit_pse_identmap(uint32_t *l2) { unsigned int i; for ( i = 0; i < PAGE_SIZE / sizeof(*l2); i++ ) l2[i] = ((i << 22) | _PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_PSE); } unsigned long get_upper_mfn_bound(void) { unsigned long max_mfn; max_mfn = mem_hotplug ? PFN_DOWN(mem_hotplug) : max_page; #ifndef CONFIG_BIGMEM max_mfn = min(max_mfn, 1UL << 32); #endif return min(max_mfn, 1UL << (paddr_bits - PAGE_SHIFT)) - 1; } /* * Local variables: * mode: C * c-file-style: "BSD" * c-basic-offset: 4 * tab-width: 4 * indent-tabs-mode: nil * End: */