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Commit da9cb575 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: introduce struct x86_exception to communicate faults 



Introduce a structure that can contain an exception to be passed back
to main kvm code.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent a4ee1ca4

arch/x86/include/asm/kvm_emulate.h

+8 −3
Original line number Diff line number Diff line
@@ -15,6 +15,12 @@ 


struct x86_emulate_ctxt;



struct x86_exception {

	u8 vector;

	bool error_code_valid;

	u16 error_code;

};



/*

 * x86_emulate_ops:

 *
@@ -229,9 +235,8 @@ struct x86_emulate_ctxt { 


	bool perm_ok; /* do not check permissions if true */



	int exception; /* exception that happens during emulation or -1 */

	u32 error_code; /* error code for exception */

	bool error_code_valid;

	bool have_exception;

	struct x86_exception exception;



	/* decode cache */

	struct decode_cache decode;

arch/x86/kvm/emulate.c

+23 −3
Original line number Diff line number Diff line
@@ -469,9 +469,9 @@ static ulong linear(struct x86_emulate_ctxt *ctxt, 
static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,

				      u32 error, bool valid)

{

	ctxt->exception = vec;

	ctxt->error_code = error;

	ctxt->error_code_valid = valid;

	ctxt->exception.vector = vec;

	ctxt->exception.error_code = error;

	ctxt->exception.error_code_valid = valid;

}



static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
@@ -3015,23 +3015,27 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 


	if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {

		emulate_ud(ctxt);

		rc = X86EMUL_PROPAGATE_FAULT;

		goto done;

	}



	/* LOCK prefix is allowed only with some instructions */

	if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {

		emulate_ud(ctxt);

		rc = X86EMUL_PROPAGATE_FAULT;

		goto done;

	}



	if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) {

		emulate_ud(ctxt);

		rc = X86EMUL_PROPAGATE_FAULT;

		goto done;

	}



	/* Privileged instruction can be executed only in CPL=0 */

	if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) {

		emulate_gp(ctxt, 0);

		rc = X86EMUL_PROPAGATE_FAULT;

		goto done;

	}
@@ -3210,6 +3214,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	case 0x8c:  /* mov r/m, sreg */

		if (c->modrm_reg > VCPU_SREG_GS) {

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		c->dst.val = ops->get_segment_selector(c->modrm_reg, ctxt->vcpu);
@@ -3225,6 +3230,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		if (c->modrm_reg == VCPU_SREG_CS ||

		    c->modrm_reg > VCPU_SREG_GS) {

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}
@@ -3357,6 +3363,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		c->dst.bytes = min(c->dst.bytes, 4u);

		if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val,
@@ -3371,6 +3378,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		if (!emulator_io_permited(ctxt, ops, c->dst.val,

					  c->src.bytes)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		ops->pio_out_emulated(c->src.bytes, c->dst.val,
@@ -3396,6 +3404,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	case 0xfa: /* cli */

		if (emulator_bad_iopl(ctxt, ops)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		} else

			ctxt->eflags &= ~X86_EFLAGS_IF;
@@ -3403,6 +3412,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	case 0xfb: /* sti */

		if (emulator_bad_iopl(ctxt, ops)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		} else {

			ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
@@ -3475,6 +3485,8 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	ctxt->eip = c->eip;



done:

	if (rc == X86EMUL_PROPAGATE_FAULT)

		ctxt->have_exception = true;

	return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;



twobyte_insn:
@@ -3537,6 +3549,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
			break;

		case 5: /* not defined */

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		case 7: /* invlpg*/

			emulate_invlpg(ctxt->vcpu,
@@ -3567,6 +3580,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		case 5 ... 7:

		case 9 ... 15:

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		c->dst.val = ops->get_cr(c->modrm_reg, ctxt->vcpu);
@@ -3575,6 +3589,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&

		    (c->modrm_reg == 4 || c->modrm_reg == 5)) {

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		ops->get_dr(c->modrm_reg, &c->dst.val, ctxt->vcpu);
@@ -3582,6 +3597,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	case 0x22: /* mov reg, cr */

		if (ops->set_cr(c->modrm_reg, c->src.val, ctxt->vcpu)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		c->dst.type = OP_NONE;
@@ -3590,6 +3606,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&

		    (c->modrm_reg == 4 || c->modrm_reg == 5)) {

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}
@@ -3598,6 +3615,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
				 ~0ULL : ~0U), ctxt->vcpu) < 0) {

			/* #UD condition is already handled by the code above */

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}
@@ -3609,6 +3627,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
			| ((u64)c->regs[VCPU_REGS_RDX] << 32);

		if (ops->set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		}

		rc = X86EMUL_CONTINUE;
@@ -3617,6 +3636,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		/* rdmsr */

		if (ops->get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			goto done;

		} else {

			c->regs[VCPU_REGS_RAX] = (u32)msr_data;

arch/x86/kvm/x86.c

+7 −6
Original line number Diff line number Diff line
@@ -4254,12 +4254,13 @@ static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask) 
static void inject_emulated_exception(struct kvm_vcpu *vcpu)

{

	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;

	if (ctxt->exception == PF_VECTOR)

	if (ctxt->exception.vector == PF_VECTOR)

		kvm_propagate_fault(vcpu);

	else if (ctxt->error_code_valid)

		kvm_queue_exception_e(vcpu, ctxt->exception, ctxt->error_code);

	else if (ctxt->exception.error_code_valid)

		kvm_queue_exception_e(vcpu, ctxt->exception.vector,

				      ctxt->exception.error_code);

	else

		kvm_queue_exception(vcpu, ctxt->exception);

		kvm_queue_exception(vcpu, ctxt->exception.vector);

}



static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
@@ -4371,7 +4372,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, 
	if (!(emulation_type & EMULTYPE_NO_DECODE)) {

		init_emulate_ctxt(vcpu);

		vcpu->arch.emulate_ctxt.interruptibility = 0;

		vcpu->arch.emulate_ctxt.exception = -1;

		vcpu->arch.emulate_ctxt.have_exception = false;

		vcpu->arch.emulate_ctxt.perm_ok = false;



		r = x86_decode_insn(&vcpu->arch.emulate_ctxt);
@@ -4437,7 +4438,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, 
	}



done:

	if (vcpu->arch.emulate_ctxt.exception >= 0) {

	if (vcpu->arch.emulate_ctxt.have_exception) {

		inject_emulated_exception(vcpu);

		r = EMULATE_DONE;

	} else if (vcpu->arch.pio.count) {