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>
This commit is contained in:
Huaitong Han 2016-03-22 16:51:15 +08:00 committed by Paolo Bonzini
parent e0b18ef718
commit ddba262891

View File

@ -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);