[Xen-changelog] [xen stable-4.9] x86/emul: Fix the emulation of invlpga

[patchbot@xxxxxxx]

commit be5de7ad4261e5ad99ef9959e23c86c750da5b77
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Mar 6 15:59:13 2018 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Mar 6 15:59:13 2018 +0100

    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>
    master commit: a91b2ec337a45d5d98e5a4387aa6563bc5cdc4c9
    master date: 2018-02-05 18:17:22 +0000
---
 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 feee054047..5ab16b46b6 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -5041,8 +5041,15 @@ 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#stable-4.9

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