[Xen-changelog] [xen master] x86/emul: Fix the emulation of invlpga

[patchbot@xxxxxxx]

commit a91b2ec337a45d5d98e5a4387aa6563bc5cdc4c9
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Feb 2 16:10:17 2018 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Feb 5 18:17:22 2018 +0000

    x86/emul: Fix the emulation of invlpga
    
    The instruction requires EFER.SVME set to be usable in the first place.
    
    Furthermore, the emulation doesn't handle ASIDs, so avoid giving the
    impression that they work.  Permit ASID 0 which is reserved for non-root
    mode (in which case the instruction is identical to invlpg), but raise #UD 
for
    any other ASID.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c 
b/xen/arch/x86/x86_emulate/x86_emulate.c
index bc8fa1d..d192280 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -5120,8 +5120,15 @@ x86_emulate(
             break;
 
         case 0xdf: /* invlpga */
-            generate_exception_if(!in_protmode(ctxt, ops), EXC_UD);
+            fail_if(!ops->read_msr);
+            if ( (rc = ops->read_msr(MSR_EFER,
+                                     &msr_val, ctxt)) != X86EMUL_OKAY )
+                goto done;
+            /* Finding SVME set implies vcpu_has_svm(). */
+            generate_exception_if(!(msr_val & EFER_SVME) ||
+                                  !in_protmode(ctxt, ops), EXC_UD);
             generate_exception_if(!mode_ring0(), EXC_GP, 0);
+            generate_exception_if(_regs.ecx, EXC_UD); /* TODO: Support ASIDs. 
*/
             fail_if(ops->invlpg == NULL);
             if ( (rc = ops->invlpg(x86_seg_none, truncate_ea(_regs.r(ax)),
                                    ctxt)) )
--
generated by git-patchbot for /home/xen/git/xen.git#master

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