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KVM: x86: check for cr3 validity in mmu_alloc_roots

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Verify the cr3 address stored in vcpu->arch.cr3 points to an existant
memslot. If not, inject a triple fault.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Marcelo Tosatti 2009-05-12 18:55:45 -03:00 committed by Avi Kivity
parent b43b1901ad
commit 8986ecc0ef
2 changed files with 24 additions and 4 deletions
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27
arch/x86/kvm/mmu.c
View File

@ -1912,7 +1912,19 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
}
static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn)
{
int ret = 0;
if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) {
set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
ret = 1;
}
return ret;
}
static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
{
int i;
gfn_t root_gfn;
@ -1927,13 +1939,15 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
ASSERT(!VALID_PAGE(root));
if (tdp_enabled)
direct = 1;
if (mmu_check_root(vcpu, root_gfn))
return 1;
sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
PT64_ROOT_LEVEL, direct,
ACC_ALL, NULL);
root = __pa(sp->spt);
++sp->root_count;
vcpu->arch.mmu.root_hpa = root;
return;
return 0;
}
direct = !is_paging(vcpu);
if (tdp_enabled)
@ -1950,6 +1964,8 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
} else if (vcpu->arch.mmu.root_level == 0)
root_gfn = 0;
if (mmu_check_root(vcpu, root_gfn))
return 1;
sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
PT32_ROOT_LEVEL, direct,
ACC_ALL, NULL);
@ -1958,6 +1974,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
}
vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
return 0;
}
static void mmu_sync_roots(struct kvm_vcpu *vcpu)
@ -1976,7 +1993,7 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu)
for (i = 0; i < 4; ++i) {
hpa_t root = vcpu->arch.mmu.pae_root[i];
if (root) {
if (root && VALID_PAGE(root)) {
root &= PT64_BASE_ADDR_MASK;
sp = page_header(root);
mmu_sync_children(vcpu, sp);
@ -2311,9 +2328,11 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
goto out;
spin_lock(&vcpu->kvm->mmu_lock);
kvm_mmu_free_some_pages(vcpu);
mmu_alloc_roots(vcpu);
r = mmu_alloc_roots(vcpu);
mmu_sync_roots(vcpu);
spin_unlock(&vcpu->kvm->mmu_lock);
if (r)
goto out;
kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
kvm_mmu_flush_tlb(vcpu);
out:

1
arch/x86/kvm/x86.c
View File

@ -4568,6 +4568,7 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
void kvm_arch_flush_shadow(struct kvm *kvm)
{
kvm_mmu_zap_all(kvm);
kvm_reload_remote_mmus(kvm);
}
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)