From 68efa764f3429f2bd71f431e91c04b0bcb7d34f1 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Wed, 18 Jun 2014 17:19:35 +0300 Subject: [PATCH] KVM: x86: Emulator support for #UD on CPL>0 Certain instructions (e.g., mwait and monitor) cause a #UD exception when they are executed in user mode. This is in contrast to the regular privileged instructions which cause #GP. In order not to mess with SVM interception of mwait and monitor which assumes privilege level assertions take place before interception, a flag has been added. Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini --- 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 b61ffe9d86a7..dd074106d0c9 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -165,6 +165,7 @@ #define Intercept ((u64)1 << 48) /* Has valid intercept field */ #define CheckPerm ((u64)1 << 49) /* Has valid check_perm field */ #define NoBigReal ((u64)1 << 50) /* No big real mode */ +#define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */ #define DstXacc (DstAccLo | SrcAccHi | SrcWrite) @@ -4608,7 +4609,10 @@ 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 & PrivUD) + rc = emulate_ud(ctxt); + else + rc = emulate_gp(ctxt, 0); goto done; } -- GitLab