1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /******************************************************************************
3 * arch/x86/hvm/grant_table.c
4 *
5 * Grant table interfaces for HVM guests
6 *
7 * Copyright (C) 2017 Wei Liu <wei.liu2@citrix.com>
8 */
9
10 #include <xen/types.h>
11
12 #include <asm/hvm/grant_table.h>
13 #include <asm/p2m.h>
14
create_grant_p2m_mapping(uint64_t addr,mfn_t frame,unsigned int flags,unsigned int cache_flags)15 int create_grant_p2m_mapping(uint64_t addr, mfn_t frame,
16 unsigned int flags,
17 unsigned int cache_flags)
18 {
19 p2m_type_t p2mt;
20 int rc;
21
22 if ( cache_flags || (flags & ~GNTMAP_readonly) != GNTMAP_host_map )
23 return GNTST_general_error;
24
25 if ( flags & GNTMAP_readonly )
26 p2mt = p2m_grant_map_ro;
27 else
28 p2mt = p2m_grant_map_rw;
29 rc = p2m_add_page(current->domain, _gfn(addr >> PAGE_SHIFT),
30 frame, PAGE_ORDER_4K, p2mt);
31 if ( rc )
32 return GNTST_general_error;
33 else
34 return GNTST_okay;
35 }
36
replace_grant_p2m_mapping(uint64_t addr,mfn_t frame,uint64_t new_addr,unsigned int flags)37 int replace_grant_p2m_mapping(uint64_t addr, mfn_t frame,
38 uint64_t new_addr, unsigned int flags)
39 {
40 unsigned long gfn = (unsigned long)(addr >> PAGE_SHIFT);
41 p2m_type_t type;
42 mfn_t old_mfn;
43 struct domain *d = current->domain;
44
45 if ( new_addr != 0 || (flags & GNTMAP_contains_pte) )
46 return GNTST_general_error;
47
48 old_mfn = get_gfn_query(d, gfn, &type);
49 if ( !p2m_is_grant(type) || !mfn_eq(old_mfn, frame) )
50 {
51 put_gfn(d, gfn);
52 gdprintk(XENLOG_WARNING,
53 "old mapping invalid (type %d, mfn %" PRI_mfn ", frame %"PRI_mfn")\n",
54 type, mfn_x(old_mfn), mfn_x(frame));
55 return GNTST_general_error;
56 }
57 if ( p2m_remove_page(d, _gfn(gfn), frame, PAGE_ORDER_4K) )
58 {
59 put_gfn(d, gfn);
60 return GNTST_general_error;
61 }
62
63 put_gfn(d, gfn);
64 return GNTST_okay;
65 }
66
67 /*
68 * Local variables:
69 * mode: C
70 * c-file-style: "BSD"
71 * c-basic-offset: 4
72 * tab-width: 4
73 * indent-tabs-mode: nil
74 * End:
75 */
76