Commit 6e154e56 authored by Mohammed Gamal's avatar Mohammed Gamal Committed by Avi Kivity
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KVM: x86 emulator: Add into, int, and int3 instructions (opcodes 0xcc-0xce) 



This adds support for int instructions to the emulator.

Signed-off-by: default avatarMohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 160ce1f1

arch/x86/kvm/emulate.c

+78 −0
Original line number Diff line number Diff line
@@ -1180,6 +1180,67 @@ static int emulate_popa(struct x86_emulate_ctxt *ctxt, 
	return rc;

}



int emulate_int_real(struct x86_emulate_ctxt *ctxt,

			       struct x86_emulate_ops *ops, int irq)

{

	struct decode_cache *c = &ctxt->decode;

	int rc = X86EMUL_CONTINUE;

	struct desc_ptr dt;

	gva_t cs_addr;

	gva_t eip_addr;

	u16 cs, eip;

	u32 err;



	/* TODO: Add limit checks */

	c->src.val = ctxt->eflags;

	emulate_push(ctxt, ops);



	ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC);



	c->src.val = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);

	emulate_push(ctxt, ops);



	c->src.val = c->eip;

	emulate_push(ctxt, ops);



	ops->get_idt(&dt, ctxt->vcpu);



	eip_addr = dt.address + (irq << 2);

	cs_addr = dt.address + (irq << 2) + 2;



	rc = ops->read_std(cs_addr, &cs, 2, ctxt->vcpu, &err);

	if (rc != X86EMUL_CONTINUE)

		return rc;



	rc = ops->read_std(eip_addr, &eip, 2, ctxt->vcpu, &err);

	if (rc != X86EMUL_CONTINUE)

		return rc;



	rc = load_segment_descriptor(ctxt, ops, cs, VCPU_SREG_CS);

	if (rc != X86EMUL_CONTINUE)

		return rc;



	c->eip = eip;



	return rc;

}



static int emulate_int(struct x86_emulate_ctxt *ctxt,

		       struct x86_emulate_ops *ops, int irq)

{

	switch(ctxt->mode) {

	case X86EMUL_MODE_REAL:

		return emulate_int_real(ctxt, ops, irq);

	case X86EMUL_MODE_VM86:

	case X86EMUL_MODE_PROT16:

	case X86EMUL_MODE_PROT32:

	case X86EMUL_MODE_PROT64:

	default:

		/* Protected mode interrupts unimplemented yet */

		return X86EMUL_UNHANDLEABLE;

	}

}



static int emulate_iret_real(struct x86_emulate_ctxt *ctxt,

			     struct x86_emulate_ops *ops)

{
@@ -2616,6 +2677,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	struct decode_cache *c = &ctxt->decode;

	int rc = X86EMUL_CONTINUE;

	int saved_dst_type = c->dst.type;

	int irq; /* Used for int 3, int, and into */



	ctxt->decode.mem_read.pos = 0;
@@ -2960,6 +3022,22 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		if (rc != X86EMUL_CONTINUE)

			goto done;

		break;

	case 0xcc:		/* int3 */

		irq = 3;

		goto do_interrupt;

	case 0xcd:		/* int n */

		irq = c->src.val;

	do_interrupt:

		rc = emulate_int(ctxt, ops, irq);

		if (rc != X86EMUL_CONTINUE)

			goto done;

		break;

	case 0xce:		/* into */

		if (ctxt->eflags & EFLG_OF) {

			irq = 4;

			goto do_interrupt;

		}

		break;

	case 0xcf:		/* iret */

		rc = emulate_iret(ctxt, ops);