1 // Copyright 2017 The Fuchsia Authors
2 //
3 // Use of this source code is governed by a MIT-style
4 // license that can be found in the LICENSE file or at
5 // https://opensource.org/licenses/MIT
6
7 #include <arch/x86/apic.h>
8 #include <arch/x86/feature.h>
9 #include <zircon/syscalls/hypervisor.h>
10
11 #include "vmx_cpu_state_priv.h"
12
ignore_msr(VmxPage * msr_bitmaps_page,bool ignore_writes,uint32_t msr)13 static void ignore_msr(VmxPage* msr_bitmaps_page, bool ignore_writes, uint32_t msr) {
14 // From Volume 3, Section 24.6.9.
15 uint8_t* msr_bitmaps = msr_bitmaps_page->VirtualAddress<uint8_t>();
16 if (msr >= 0xc0000000) {
17 msr_bitmaps += 1 << 10;
18 }
19
20 uint16_t msr_low = msr & 0x1fff;
21 uint16_t msr_byte = msr_low / 8;
22 uint8_t msr_bit = msr_low % 8;
23
24 // Ignore reads to the MSR.
25 msr_bitmaps[msr_byte] &= (uint8_t) ~(1 << msr_bit);
26
27 if (ignore_writes) {
28 // Ignore writes to the MSR.
29 msr_bitmaps += 2 << 10;
30 msr_bitmaps[msr_byte] &= (uint8_t) ~(1 << msr_bit);
31 }
32 }
33
34 // static
Create(ktl::unique_ptr<Guest> * out)35 zx_status_t Guest::Create(ktl::unique_ptr<Guest>* out) {
36 // Check that the CPU supports VMX.
37 if (!x86_feature_test(X86_FEATURE_VMX)) {
38 return ZX_ERR_NOT_SUPPORTED;
39 }
40
41 zx_status_t status = alloc_vmx_state();
42 if (status != ZX_OK) {
43 return status;
44 }
45
46 fbl::AllocChecker ac;
47 ktl::unique_ptr<Guest> guest(new (&ac) Guest);
48 if (!ac.check()) {
49 return ZX_ERR_NO_MEMORY;
50 }
51
52 status = hypervisor::GuestPhysicalAddressSpace::Create(&guest->gpas_);
53 if (status != ZX_OK) {
54 return status;
55 }
56
57 // Setup common MSR bitmaps.
58 VmxInfo vmx_info;
59 status = guest->msr_bitmaps_page_.Alloc(vmx_info, UINT8_MAX);
60 if (status != ZX_OK) {
61 return status;
62 }
63
64 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_PAT);
65 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_EFER);
66 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_FS_BASE);
67 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_GS_BASE);
68 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_KERNEL_GS_BASE);
69 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_STAR);
70 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_LSTAR);
71 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_FMASK);
72 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_TSC_ADJUST);
73 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_TSC_AUX);
74 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_SYSENTER_CS);
75 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_SYSENTER_ESP);
76 ignore_msr(&guest->msr_bitmaps_page_, true, X86_MSR_IA32_SYSENTER_EIP);
77
78 // Setup VPID allocator
79 fbl::AutoLock lock(&guest->vcpu_mutex_);
80 status = guest->vpid_allocator_.Init();
81 if (status != ZX_OK) {
82 return status;
83 }
84
85 *out = ktl::move(guest);
86 return ZX_OK;
87 }
88
~Guest()89 Guest::~Guest() {
90 free_vmx_state();
91 }
92
SetTrap(uint32_t kind,zx_vaddr_t addr,size_t len,fbl::RefPtr<PortDispatcher> port,uint64_t key)93 zx_status_t Guest::SetTrap(uint32_t kind, zx_vaddr_t addr, size_t len,
94 fbl::RefPtr<PortDispatcher> port, uint64_t key) {
95 if (len == 0) {
96 return ZX_ERR_INVALID_ARGS;
97 } else if (SIZE_MAX - len < addr) {
98 return ZX_ERR_OUT_OF_RANGE;
99 }
100
101 switch (kind) {
102 case ZX_GUEST_TRAP_MEM:
103 if (port) {
104 return ZX_ERR_INVALID_ARGS;
105 }
106 break;
107 case ZX_GUEST_TRAP_BELL:
108 if (!port) {
109 return ZX_ERR_INVALID_ARGS;
110 }
111 break;
112 case ZX_GUEST_TRAP_IO:
113 if (port) {
114 return ZX_ERR_INVALID_ARGS;
115 } else if (addr + len > UINT16_MAX) {
116 return ZX_ERR_OUT_OF_RANGE;
117 }
118 return traps_.InsertTrap(kind, addr, len, ktl::move(port), key);
119 default:
120 return ZX_ERR_INVALID_ARGS;
121 }
122
123 // Common logic for memory-based traps.
124 if (!IS_PAGE_ALIGNED(addr) || !IS_PAGE_ALIGNED(len)) {
125 return ZX_ERR_INVALID_ARGS;
126 }
127 zx_status_t status = gpas_->UnmapRange(addr, len);
128 if (status != ZX_OK) {
129 return status;
130 }
131 return traps_.InsertTrap(kind, addr, len, ktl::move(port), key);
132 }
133
AllocVpid(uint16_t * vpid)134 zx_status_t Guest::AllocVpid(uint16_t* vpid) {
135 fbl::AutoLock lock(&vcpu_mutex_);
136 return vpid_allocator_.AllocId(vpid);
137 }
138
FreeVpid(uint16_t vpid)139 zx_status_t Guest::FreeVpid(uint16_t vpid) {
140 fbl::AutoLock lock(&vcpu_mutex_);
141 return vpid_allocator_.FreeId(vpid);
142 }
143