From: Feng Wu <feng.wu@intel.com>
Date: Tue, 1 Apr 2014 09:46:35 +0000 (+0800)
Subject: KVM: Disable SMAP for guests in EPT realmode and EPT unpaging mode
X-Git-Tag: v3.15-rc2~40^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e1e746b3c55d1d1e0841a2e600a154d8f6747232;p=platform%2Fkernel%2Flinux-exynos.git

KVM: Disable SMAP for guests in EPT realmode and EPT unpaging mode

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>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1320e0f..1f68c58 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3484,13 +3484,14 @@ 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;
 		}