KVM: MMU: Adjust shadow paging to work when SMEP=1 and CR0.WP=0

When CR0.WP=0, we sometimes map user pages as kernel pages (to allow
the kernel to write to them).  Unfortunately this also allows the kernel
to fetch from these pages, even if CR4.SMEP is set.

Adjust for this by also setting NX on the spte in these circumstances.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 554be456f11e..da6bbee878ca 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -205,6 +205,7 @@ union kvm_mmu_page_role {
                 unsigned invalid:1;
                 unsigned nxe:1;
                 unsigned cr0_wp:1;
+                unsigned smep_andnot_wp:1;
         };
 };