Messages in this thread Patch in this message | | | From | Nadav Amit <> | Subject | [PATCH 2/3] KVM: x86: Emulator support for #UD on CPL>0 | Date | Wed, 18 Jun 2014 17:19:35 +0300 |
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Certain instructions (e.g., mwait and monitor) cause a #UD exception when they are executed in privilaged mode. This is in contrast to the regular privilaged instructions which cause #GP. In order not to mess with SVM interception of mwait and monitor which assumes privilage level assertions take place before interception, a flag has been added.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> --- arch/x86/kvm/emulate.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index f90194d..ef7a5a0 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -163,6 +163,7 @@ #define SrcWrite ((u64)1 << 46) /* Write back src operand */ #define NoMod ((u64)1 << 47) /* Mod field is ignored */ #define NoBigReal ((u64)1 << 48) /* No big real mode */ +#define UDOnPriv ((u64)1 << 49) /* #UD instead of #GP on CPL > 0 */ #define DstXacc (DstAccLo | SrcAccHi | SrcWrite) @@ -4560,7 +4561,10 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) /* Privileged instruction can be executed only in CPL=0 */ if ((ctxt->d & Priv) && ops->cpl(ctxt)) { - rc = emulate_gp(ctxt, 0); + if (ctxt->d & UDOnPriv) + rc = emulate_ud(ctxt); + else + rc = emulate_gp(ctxt, 0); goto done; } -- 1.9.1
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