[xen stable-4.12] x86/msr: fix handling of MSR_IA32_PERF_{STATUS/CTL} (again)

[patchbot@xxxxxxx]

commit f1f322610718c40680ac09e66f6c82e69c78ba3a
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Feb 4 15:39:45 2021 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Feb 4 15:39:45 2021 +0100

    x86/msr: fix handling of MSR_IA32_PERF_{STATUS/CTL} (again)
    
    X86_VENDOR_* aren't bit masks in the older trees.
    
    Reported-by: James Dingwall <james@xxxxxxxxxxxxxx>
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/msr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/msr.c b/xen/arch/x86/msr.c
index 927ed625df..aefe0cbb4b 100644
--- a/xen/arch/x86/msr.c
+++ b/xen/arch/x86/msr.c
@@ -226,7 +226,8 @@ int guest_rdmsr(const struct vcpu *v, uint32_t msr, 
uint64_t *val)
          */
     case MSR_IA32_PERF_STATUS:
     case MSR_IA32_PERF_CTL:
-        if ( !(cp->x86_vendor & (X86_VENDOR_INTEL | X86_VENDOR_CENTAUR)) )
+        if ( cp->x86_vendor != X86_VENDOR_INTEL &&
+             cp->x86_vendor != X86_VENDOR_CENTAUR )
             goto gp_fault;
 
         *val = 0;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.12