KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages

commit 898761158be7682082955e3efa4ad24725305fc7 upstream.

smep_andnot_wp is initialized in kvm_init_shadow_mmu and shadow pages
should not be reused for different values of it.  Thus, it has to be
added to the mask in kvm_mmu_pte_write.

Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 84f4bca0ca2c97582d9ca00ff7a4dfe1532d4a6a..2da1a8c9173ea4f62cf0769e6dfb5578f9795d7d 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3658,7 +3658,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        ++vcpu->kvm->stat.mmu_pte_write;
        kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE);
 
-       mask.cr0_wp = mask.cr4_pae = mask.nxe = 1;
+       mask.cr0_wp = mask.cr4_pae = mask.nxe = mask.smep_andnot_wp = 1;
        for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node) {
                if (detect_write_misaligned(sp, gpa, bytes) ||
                      detect_write_flooding(sp)) {