KVM: Drop ad-hoc vendor specific instruction restriction

Use the new support in the emulator, and drop the ad-hoc code in x86.c.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 5 insertions, 28 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dd8016d2efa9..8575d85202d7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4411,39 +4411,16 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
                 vcpu->arch.emulate_ctxt.have_exception = false;
                 vcpu->arch.emulate_ctxt.perm_ok = false;
 
+                vcpu->arch.emulate_ctxt.only_vendor_specific_insn
+                        = emulation_type & EMULTYPE_TRAP_UD;
+
                 r = x86_decode_insn(&vcpu->arch.emulate_ctxt, insn, insn_len);
 
                 trace_kvm_emulate_insn_start(vcpu);
-
-                /* Only allow emulation of specific instructions on #UD
-                 * (namely VMMCALL, sysenter, sysexit, syscall)*/
-                if (emulation_type & EMULTYPE_TRAP_UD) {
-                        if (!c->twobyte)
-                                return EMULATE_FAIL;
-                        switch (c->b) {
-                        case 0x01: /* VMMCALL */
-                                if (c->modrm_mod != 3 || c->modrm_rm != 1)
-                                        return EMULATE_FAIL;
-                                break;
-                        case 0x34: /* sysenter */
-                        case 0x35: /* sysexit */
-                                if (c->modrm_mod != 0 || c->modrm_rm != 0)
-                                        return EMULATE_FAIL;
-                                break;
-                        case 0x05: /* syscall */
-                                if (c->modrm_mod != 0 || c->modrm_rm != 0)
-                                        return EMULATE_FAIL;
-                                break;
-                        default:
-                                return EMULATE_FAIL;
-                        }
-
-                        if (!(c->modrm_reg == 0 || c->modrm_reg == 3))
-                                return EMULATE_FAIL;
-                }
-
                 ++vcpu->stat.insn_emulation;
                 if (r)  {
+                        if (emulation_type & EMULTYPE_TRAP_UD)
+                                return EMULATE_FAIL;
                         if (reexecute_instruction(vcpu, cr2))
                                 return EMULATE_DONE;
                         if (emulation_type & EMULTYPE_SKIP)