Commit ddba2628 authored by Huaitong Han's avatar Huaitong Han Committed by Paolo Bonzini
Browse files

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: default avatarHuaitong Han <huaitong.han@intel.com>
Reviewed-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e0b18ef7

arch/x86/kvm/vmx.c

+10 −6
Original line number Diff line number Diff line
@@ -3893,13 +3893,17 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) 


	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);