[Xen-changelog] [xen master] x86/hvm: disable pkeys for guests in non-paging mode

[patchbot@xxxxxxx]

commit c41e0266dd59ab50b7a153157e9bd2a3ad114b53
Author:     Huaitong Han <huaitong.han@xxxxxxxxx>
AuthorDate: Thu Feb 4 11:40:08 2016 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Feb 4 11:40:08 2016 +0100

    x86/hvm: disable pkeys for guests in non-paging mode
    
    This patch disables pkeys for guest in non-paging mode, However XEN always 
uses
    paging mode to emulate guest non-paging mode, To emulate this behavior, 
pkeys
    needs to be manually disabled when guest switches to non-paging mode.
    
    Signed-off-by: Huaitong Han <huaitong.han@xxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vmx.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 195def6..b9f340c 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1379,12 +1379,13 @@ static void vmx_update_guest_cr(struct vcpu *v, 
unsigned int cr)
         if ( !hvm_paging_enabled(v) )
         {
             /*
-             * SMEP/SMAP is disabled if CPU is in non-paging mode in hardware.
-             * However Xen always uses paging mode to emulate guest non-paging
-             * mode. To emulate this behavior, SMEP/SMAP needs to be manually
-             * disabled when guest VCPU is in non-paging mode.
+             * SMEP/SMAP/PKU is disabled if CPU is in non-paging mode in
+             * hardware. However Xen always uses paging mode to emulate guest
+             * non-paging mode. To emulate this behavior, SMEP/SMAP/PKU needs
+             * to be manually disabled when guest VCPU is in non-paging mode.
              */
-            v->arch.hvm_vcpu.hw_cr[4] &= ~(X86_CR4_SMEP | X86_CR4_SMAP);
+            v->arch.hvm_vcpu.hw_cr[4] &=
+                ~(X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE);
         }
         __vmwrite(GUEST_CR4, v->arch.hvm_vcpu.hw_cr[4]);
         break;
--
generated by git-patchbot for /home/xen/git/xen.git#master

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