diff options
| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-08-29 11:26:55 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-08-29 14:02:49 +0200 |
| commit | 0f54a321302dfbdbd707ba989b2f468e58b9a363 (patch) | |
| tree | dd6ae5b4184d341db6cbdaf317c1a1f3837a5c0c | |
| parent | 48d89b92609a66bc41f479c560640bc413add3b4 (diff) | |
KVM: vmx: VMXOFF emulation in vm86 should cause #UD
Unlike VMCALL, the instructions VMXOFF, VMLAUNCH and VMRESUME should cause a UD
exception in real-mode or vm86. However, the emulator considers all these
instructions the same for the matter of mode checks, and emulation upon exit
due to #UD exception.
As a result, the hypervisor behaves incorrectly on vm86 mode. VMXOFF, VMLAUNCH
or VMRESUME cause on vm86 exit due to #UD. The hypervisor then emulates these
instruction and inject #GP to the guest instead of #UD.
This patch creates a new group for these instructions and mark only VMCALL as
an instruction which can be emulated.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index e5bf13003cd2..a240fac29e76 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3139,12 +3139,8 @@ static int em_clts(struct x86_emulate_ctxt *ctxt) static int em_vmcall(struct x86_emulate_ctxt *ctxt) { - int rc; - - if (ctxt->modrm_mod != 3 || ctxt->modrm_rm != 1) - return X86EMUL_UNHANDLEABLE; + int rc = ctxt->ops->fix_hypercall(ctxt); - rc = ctxt->ops->fix_hypercall(ctxt); if (rc != X86EMUL_CONTINUE) return rc; @@ -3562,6 +3558,12 @@ static int check_perm_out(struct x86_emulate_ctxt *ctxt) F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \ F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e) +static const struct opcode group7_rm0[] = { + N, + I(SrcNone | Priv | EmulateOnUD, em_vmcall), + N, N, N, N, N, N, +}; + static const struct opcode group7_rm1[] = { DI(SrcNone | Priv, monitor), DI(SrcNone | Priv, mwait), @@ -3655,7 +3657,7 @@ static const struct group_dual group7 = { { II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg), }, { - I(SrcNone | Priv | EmulateOnUD, em_vmcall), + EXT(0, group7_rm0), EXT(0, group7_rm1), N, EXT(0, group7_rm3), II(SrcNone | DstMem | Mov, em_smsw, smsw), N, |