[Xen-changelog] [xen stable-4.7] xen/hvm: Fix advertisement of available xstates following c/s c52319642

[patchbot@xxxxxxx]

commit 81722e7d443d33f48416c31f03ab4c2a9ba54b23
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Jun 10 19:11:12 2016 +0100
Commit:     Wei Liu <wei.liu2@xxxxxxxxxx>
CommitDate: Mon Jun 13 11:41:30 2016 +0100

    xen/hvm: Fix advertisement of available xstates following c/s c52319642
    
    PKU lives in CPUID.7[0].ECX, not EBX.  This causes hardware with BMI1 to
    accidentally advertise PKU in CPUID.0xD[0].EAX.  Any OS which proceeds to
    blindly write this into %xcr0 takes a #GP fault.  (Experimentally, Windows
    Vista 32bit falls into this category.)
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
    Release-acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
    master commit: 96a745cc270060712f9ea86c5f909ef443be0309
---
 xen/arch/x86/hvm/hvm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index d224bc7..17fb210 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3466,7 +3466,7 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, 
unsigned int *ebx,
                                   xstate_sizes[_XSTATE_BNDCSR]);
             }
 
-            if ( _ebx & cpufeat_mask(X86_FEATURE_PKU) )
+            if ( _ecx & cpufeat_mask(X86_FEATURE_PKU) )
             {
                 xfeature_mask |= XSTATE_PKRU;
                 xstate_size = max(xstate_size,
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.7

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