From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 2 Apr 2015 09:04:05 +0000 (+0200)
Subject: KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages
X-Git-Tag: firefly_0821_release~3679^2~427
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0b93bc9d1b0ca52d58a2015809b69ad188d0866c;p=firefly-linux-kernel-4.4.55.git

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e14b1f8667bb..5a75ebf3d69f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3975,7 +3975,7 @@ 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) {
 		if (detect_write_misaligned(sp, gpa, bytes) ||
 		      detect_write_flooding(sp)) {