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de6f4b1d TL |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
2 | From: Boris Ostrovsky <boris.ostrovsky@oracle.com> | |
3 | Date: Fri, 31 Jan 2020 08:06:41 -0300 | |
4 | Subject: [PATCH] x86/kvm: Introduce kvm_(un)map_gfn() | |
5 | ||
6 | CVE-2019-3016 | |
7 | CVE-2020-3016 | |
8 | ||
9 | kvm_vcpu_(un)map operates on gfns from any current address space. | |
10 | In certain cases we want to make sure we are not mapping SMRAM | |
11 | and for that we can use kvm_(un)map_gfn() that we are introducing | |
12 | in this patch. | |
13 | ||
14 | This is part of CVE-2019-3016. | |
15 | ||
16 | Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> | |
17 | Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> | |
18 | Reviewed-by: Joao Martins <joao.m.martins@oracle.com> | |
19 | Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> | |
20 | Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com> | |
21 | --- | |
22 | include/linux/kvm_host.h | 2 ++ | |
23 | virt/kvm/kvm_main.c | 29 ++++++++++++++++++++++++----- | |
24 | 2 files changed, 26 insertions(+), 5 deletions(-) | |
25 | ||
26 | diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h | |
27 | index d41c521a39da..df4cc0ead363 100644 | |
28 | --- a/include/linux/kvm_host.h | |
29 | +++ b/include/linux/kvm_host.h | |
30 | @@ -758,8 +758,10 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn | |
31 | kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn); | |
32 | kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn); | |
33 | int kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_host_map *map); | |
34 | +int kvm_map_gfn(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map); | |
35 | struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn); | |
36 | void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty); | |
37 | +int kvm_unmap_gfn(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty); | |
38 | unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn); | |
39 | unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable); | |
40 | int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset, | |
41 | diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c | |
42 | index 91e56a9b0661..6614e030ae75 100644 | |
43 | --- a/virt/kvm/kvm_main.c | |
44 | +++ b/virt/kvm/kvm_main.c | |
45 | @@ -1792,12 +1792,13 @@ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) | |
46 | } | |
47 | EXPORT_SYMBOL_GPL(gfn_to_page); | |
48 | ||
49 | -static int __kvm_map_gfn(struct kvm_memory_slot *slot, gfn_t gfn, | |
50 | +static int __kvm_map_gfn(struct kvm_memslots *slots, gfn_t gfn, | |
51 | struct kvm_host_map *map) | |
52 | { | |
53 | kvm_pfn_t pfn; | |
54 | void *hva = NULL; | |
55 | struct page *page = KVM_UNMAPPED_PAGE; | |
56 | + struct kvm_memory_slot *slot = __gfn_to_memslot(slots, gfn); | |
57 | ||
58 | if (!map) | |
59 | return -EINVAL; | |
60 | @@ -1826,14 +1827,20 @@ static int __kvm_map_gfn(struct kvm_memory_slot *slot, gfn_t gfn, | |
61 | return 0; | |
62 | } | |
63 | ||
64 | +int kvm_map_gfn(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) | |
65 | +{ | |
66 | + return __kvm_map_gfn(kvm_memslots(vcpu->kvm), gfn, map); | |
67 | +} | |
68 | +EXPORT_SYMBOL_GPL(kvm_map_gfn); | |
69 | + | |
70 | int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) | |
71 | { | |
72 | - return __kvm_map_gfn(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, map); | |
73 | + return __kvm_map_gfn(kvm_vcpu_memslots(vcpu), gfn, map); | |
74 | } | |
75 | EXPORT_SYMBOL_GPL(kvm_vcpu_map); | |
76 | ||
77 | -void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, | |
78 | - bool dirty) | |
79 | +static void __kvm_unmap_gfn(struct kvm_memory_slot *memslot, | |
80 | + struct kvm_host_map *map, bool dirty) | |
81 | { | |
82 | if (!map) | |
83 | return; | |
84 | @@ -1849,7 +1856,7 @@ void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, | |
85 | #endif | |
86 | ||
87 | if (dirty) { | |
88 | - kvm_vcpu_mark_page_dirty(vcpu, map->gfn); | |
89 | + mark_page_dirty_in_slot(memslot, map->gfn); | |
90 | kvm_release_pfn_dirty(map->pfn); | |
91 | } else { | |
92 | kvm_release_pfn_clean(map->pfn); | |
93 | @@ -1858,6 +1865,18 @@ void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, | |
94 | map->hva = NULL; | |
95 | map->page = NULL; | |
96 | } | |
97 | + | |
98 | +int kvm_unmap_gfn(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) | |
99 | +{ | |
100 | + __kvm_unmap_gfn(gfn_to_memslot(vcpu->kvm, map->gfn), map, dirty); | |
101 | + return 0; | |
102 | +} | |
103 | +EXPORT_SYMBOL_GPL(kvm_unmap_gfn); | |
104 | + | |
105 | +void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) | |
106 | +{ | |
107 | + __kvm_unmap_gfn(kvm_vcpu_gfn_to_memslot(vcpu, map->gfn), map, dirty); | |
108 | +} | |
109 | EXPORT_SYMBOL_GPL(kvm_vcpu_unmap); | |
110 | ||
111 | struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn) |