File 533ad1ee-VMX-fix-PAT-value-seen-by-guest.patch of Package xen

Overview Repositories Revisions Requests Users Attributes Meta

File 533ad1ee-VMX-fix-PAT-value-seen-by-guest.patch of Package xen (Revision 200275861e2840e67d27d7ee4b346f69)

Currently displaying revision 200275861e2840e67d27d7ee4b346f69 , Show latest

# Commit fce79f8ce91dc45f3a4d699ee67c49e6cbeb1197
# Date 2014-04-01 16:49:18 +0200
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
VMX: fix PAT value seen by guest

The XSA-60 fixes introduced a window during which the guest PAT gets
forced to all zeros. This shouldn't be visible to the guest. Therefore
we need to intercept PAT MSR accesses during that time period.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Liu Jinsong <jinsong.liu@intel.com>

--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -984,6 +984,8 @@ static void vmx_handle_cd(struct vcpu *v
 
             vmx_get_guest_pat(v, pat);
             vmx_set_guest_pat(v, uc_pat);
+            vmx_enable_intercept_for_msr(v, MSR_IA32_CR_PAT,
+                                         MSR_TYPE_R | MSR_TYPE_W);
 
             wbinvd();               /* flush possibly polluted cache */
             hvm_asid_flush_vcpu(v); /* invalidate memory type cached in TLB */
@@ -993,6 +995,9 @@ static void vmx_handle_cd(struct vcpu *v
         {
             v->arch.hvm_vcpu.cache_mode = NORMAL_CACHE_MODE;
             vmx_set_guest_pat(v, *pat);
+            if ( !iommu_enabled || iommu_snoop )
+                vmx_disable_intercept_for_msr(v, MSR_IA32_CR_PAT,
+                                              MSR_TYPE_R | MSR_TYPE_W);
             hvm_asid_flush_vcpu(v); /* no need to flush cache */
         }
     }

Places

File 533ad1ee-VMX-fix-PAT-value-seen-by-guest.patch of Package xen (Revision 200275861e2840e67d27d7ee4b346f69)

Places