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 11:23:02 -0700 |
| commit | 7bf8439befd355aa60d8448ba238b555f0242482 (patch) | |
| tree | 66b6d42f035c161817ca66d384d2eae9c5603ea8 | |
| parent | 6809d9686bf751235b9acc8869fa5793f9fe912d (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 c5e834ed68a5..63400e6bb4eb 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -180,6 +180,7 @@ 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 19a8906bcaa2..01b3c33437f1 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -223,7 +223,7 @@ 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 kvm_read_cr0_bits(vcpu, X86_CR0_WP); } @@ -2439,6 +2439,7 @@ 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; } |