diff mbox

[v4,3/4] KVM: Disable SMAP for guests in EPT realmode and EPT unpaging mode

Message ID 1396345596-25682-4-git-send-email-feng.wu@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wu, Feng April 1, 2014, 9:46 a.m. UTC 
SMAP is disabled if CPU is in non-paging mode in hardware.
However KVM always uses paging mode to emulate guest non-paging
mode with TDP. To emulate this behavior, SMAP needs to be
manually disabled when guest switches to non-paging mode.

Signed-off-by: Feng Wu <feng.wu@intel.com>
---
 arch/x86/kvm/vmx.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
diff mbox

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3927528..e58cb5f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3452,13 +3452,14 @@  static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 			hw_cr4 &= ~X86_CR4_PAE;
 			hw_cr4 |= X86_CR4_PSE;
 			/*
-			 * SMEP is disabled if CPU is in non-paging mode in
-			 * hardware. However KVM always uses paging mode to
+			 * SMEP/SMAP is disabled if CPU is in non-paging mode
+			 * in hardware. However KVM always uses paging mode to
 			 * emulate guest non-paging mode with TDP.
-			 * To emulate this behavior, SMEP needs to be manually
-			 * disabled when guest switches to non-paging mode.
+			 * To emulate this behavior, SMEP/SMAP needs to be
+			 * manually disabled when guest switches to non-paging
+			 * mode.
 			 */
-			hw_cr4 &= ~X86_CR4_SMEP;
+			hw_cr4 &= ~(X86_CR4_SMEP | X86_CR4_SMAP);
 		} else if (!(cr4 & X86_CR4_PAE)) {
 			hw_cr4 &= ~X86_CR4_PAE;
 		}