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[5/6] x86emul: check for SYSENTER/SYSEXIT availability

Message ID 58500E6602000078001289F8@prv-mh.provo.novell.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jan Beulich Dec. 13, 2016, 2:06 p.m. UTC 
We can't exclude someone wanting to hide the instructions from guests.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
Looks like I can't count - I've mistakenly omitted this patch from
the overview mail, so there'll be a total of 7.
x86emul: check for SYSENTER/SYSEXIT availability

We can't exclude someone wanting to hide the instructions from guests.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1306,6 +1306,7 @@ static bool vcpu_has(
 
 #define vcpu_has_fpu()         vcpu_has(         1, EDX,  0, ctxt, ops)
 #define vcpu_has_cx8()         vcpu_has(         1, EDX,  8, 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)
@@ -5132,6 +5133,7 @@ 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);
 
@@ -5179,6 +5181,7 @@ x86_emulate(
     {
         uint64_t msr_content;
 
+        vcpu_must_have(sep);
         generate_exception_if(!mode_ring0(), EXC_GP, 0);
         generate_exception_if(!in_protmode(ctxt, ops), EXC_GP, 0);

Comments

Andrew Cooper Dec. 13, 2016, 2:28 p.m. UTC | #1 
On 13/12/16 14:06, Jan Beulich wrote:
> We can't exclude someone wanting to hide the instructions from guests.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
diff mbox

Patch

--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1306,6 +1306,7 @@  static bool vcpu_has(
 
 #define vcpu_has_fpu()         vcpu_has(         1, EDX,  0, ctxt, ops)
 #define vcpu_has_cx8()         vcpu_has(         1, EDX,  8, 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)
@@ -5132,6 +5133,7 @@  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);
 
@@ -5179,6 +5181,7 @@  x86_emulate(
     {
         uint64_t msr_content;
 
+        vcpu_must_have(sep);
         generate_exception_if(!mode_ring0(), EXC_GP, 0);
         generate_exception_if(!in_protmode(ctxt, ops), EXC_GP, 0);