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[Xen-changelog] [xen master] x86emul: check for SYSENTER/SYSEXIT availability



commit d95533f554cde498b9afe731b94a4d9198b47cbe
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Dec 14 10:09:40 2016 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Dec 14 10:09:40 2016 +0100

    x86emul: check for SYSENTER/SYSEXIT availability
    
    We can't exclude someone wanting to hide the instructions from guests.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c 
b/xen/arch/x86/x86_emulate/x86_emulate.c
index e78593d..49ae96a 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1288,6 +1288,7 @@ static bool vcpu_has(
 }
 
 #define vcpu_has_fpu()         vcpu_has(         1, EDX,  0, ctxt, ops)
+#define vcpu_has_sep()         vcpu_has(         1, EDX, 11, ctxt, ops)
 #define vcpu_has_cmov()        vcpu_has(         1, EDX, 15, ctxt, ops)
 #define vcpu_has_clflush()     vcpu_has(         1, EDX, 19, ctxt, ops)
 #define vcpu_has_mmx()         vcpu_has(         1, EDX, 23, ctxt, ops)
@@ -4900,6 +4901,7 @@ x86_emulate(
         uint64_t msr_content;
         int lm;
 
+        vcpu_must_have(sep);
         generate_exception_if(mode_ring0(), EXC_GP, 0);
         generate_exception_if(!in_protmode(ctxt, ops), EXC_GP, 0);
 
@@ -4946,6 +4948,7 @@ x86_emulate(
         uint64_t msr_content;
         bool user64 = rex_prefix & REX_W;
 
+        vcpu_must_have(sep);
         generate_exception_if(!mode_ring0(), EXC_GP, 0);
         generate_exception_if(!in_protmode(ctxt, ops), EXC_GP, 0);
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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