Il 29/08/2014 10:52, Nadav Amit ha scritto:
> > Patch looks good, but where is the check that MOD == 3 in the "case
> > RMExt"? Am I just not seeing it?
>
> This seems to be part of the “case GroupDual”.
GroupDual handles it, but the EXT() macro you're using is exactly what
you want:
#define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */
I guess what's missing is
------------------ 8< ------------------
Subject: [PATCH] Check ModRM for RMExt
Some group7 extensions are only defined for mod==3. Check this and
reject emulation if mod!=3.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 56657b0bb3bb..d472e4d50e3c 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4360,6 +4360,8 @@ done_prefixes:
opcode = opcode.u.gdual->mod012[goffset];
break;
case RMExt:
+ if ((ctxt->modrm >> 6) == 3)
+ return EMULATION_FAILED;
goffset = ctxt->modrm & 7;
opcode = opcode.u.group[goffset];
break;
What do you think?
Paolo
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