diff options
| author | Avi Kivity <avi@redhat.com> | 2010-05-12 11:48:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-07-05 11:16:14 -0700 |
| commit | e5085dda9c31aada430b3b57ce78ec102e934e9c (patch) | |
| tree | 63f11aaebfde81e9901868185845e0149ba55fc2 | |
| parent | 22d962cf52f77eef04d635caba46ae54e30723c5 (diff) | |
KVM: MMU: Segregate shadow pages with different cr0.wp
When cr0.wp=0, we may shadow a gpte having u/s=1 and r/w=0 with an spte
having u/s=0 and r/w=1. This allows excessive access if the guest sets
cr0.wp=1 and accesses through this spte.
Fix by making cr0.wp part of the base role; we'll have different sptes for
the two cases and the problem disappears.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
(cherry picked from commit 3dbe141595faa48a067add3e47bba3205b79d33c)
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 3 |
2 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index ca9e97f51b4..e62b4b9696a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -193,6 +193,7 @@ union kvm_mmu_page_role { unsigned invalid:1; unsigned cr4_pge:1; unsigned nxe:1; + unsigned cr0_wp:1; }; }; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 28c3d814c09..db2611b904b 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -227,7 +227,7 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, } EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes); -static int is_write_protection(struct kvm_vcpu *vcpu) +static bool is_write_protection(struct kvm_vcpu *vcpu) { return vcpu->arch.cr0 & X86_CR0_WP; } @@ -2448,6 +2448,7 @@ static int init_kvm_softmmu(struct kvm_vcpu *vcpu) r = paging32_init_context(vcpu); vcpu->arch.mmu.base_role.glevels = vcpu->arch.mmu.root_level; + vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu); return r; } |