Commit 4005996e authored by Avi Kivity's avatar Avi Kivity Committed by Marcelo Tosatti
Browse files

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: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent d867162c

arch/x86/kvm/x86.c

+5 −28
Original line number Diff line number Diff line
@@ -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)