KVM, pkeys: disable pkeys for guests in non-paging mode
Pkeys 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, pkeys needs to be manually disabled when guest
switches to non-paging mode.
Signed-off-by: Huaitong Han <huaitong.han@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1612300..1b8a41f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3893,13 +3893,17 @@
if (!enable_unrestricted_guest && !is_paging(vcpu))
/*
- * SMEP/SMAP is disabled if CPU is in non-paging mode in
- * hardware. However KVM always uses paging mode without
- * unrestricted guest.
- * To emulate this behavior, SMEP/SMAP needs to be manually
- * disabled when guest switches to non-paging mode.
+ * SMEP/SMAP/PKU is disabled if CPU is in non-paging mode in
+ * hardware. To emulate this behavior, SMEP/SMAP/PKU needs
+ * to be manually disabled when guest switches to non-paging
+ * mode.
+ *
+ * If !enable_unrestricted_guest, the CPU is always running
+ * with CR0.PG=1 and CR4 needs to be modified.
+ * If enable_unrestricted_guest, the CPU automatically
+ * disables SMEP/SMAP/PKU when the guest sets CR0.PG=0.
*/
- hw_cr4 &= ~(X86_CR4_SMEP | X86_CR4_SMAP);
+ hw_cr4 &= ~(X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE);
vmcs_writel(CR4_READ_SHADOW, cr4);
vmcs_writel(GUEST_CR4, hw_cr4);