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authorFeng Wu <feng.wu@intel.com>2014-04-01 17:46:35 +0800
committerMarcelo Tosatti <mtosatti@redhat.com>2014-04-14 17:50:35 -0300
commite1e746b3c55d1d1e0841a2e600a154d8f6747232 (patch)
tree8f0bc502eddc2329e0e6852b90c0887bac81cf6f /arch
parent97ec8c067d322d32effdc1701760d3babbc5595f (diff)
downloadlinux-e1e746b3c55d1d1e0841a2e600a154d8f6747232.tar.bz2
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/vmx.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1320e0f8e611..1f68c5831924 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;
}