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Commit abcf14b5 authored by Mohammed Gamal's avatar Mohammed Gamal Committed by Avi Kivity
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KVM: x86 emulator: Add pusha and popa instructions 



This adds pusha and popa instructions (opcodes 0x60-0x61), this enables booting
MINIX with invalid guest state emulation on.

[marcelo: remove unused variable]

Signed-off-by: default avatarMohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 94677e61

arch/x86/kvm/emulate.c

+47 −1
Original line number Diff line number Diff line
@@ -139,7 +139,8 @@ static u32 opcode_table[256] = { 
	DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack,

	DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack,

	/* 0x60 - 0x67 */

	0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ ,

	ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,

	0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ ,

	0, 0, 0, 0,

	/* 0x68 - 0x6F */

	SrcImm | Mov | Stack, 0, SrcImmByte | Mov | Stack, 0,
@@ -1225,6 +1226,43 @@ static int emulate_pop_sreg(struct x86_emulate_ctxt *ctxt, 
	return rc;

}



static void emulate_pusha(struct x86_emulate_ctxt *ctxt)

{

	struct decode_cache *c = &ctxt->decode;

	unsigned long old_esp = c->regs[VCPU_REGS_RSP];

	int reg = VCPU_REGS_RAX;



	while (reg <= VCPU_REGS_RDI) {

		(reg == VCPU_REGS_RSP) ?

		(c->src.val = old_esp) : (c->src.val = c->regs[reg]);



		emulate_push(ctxt);

		++reg;

	}

}



static int emulate_popa(struct x86_emulate_ctxt *ctxt,

			struct x86_emulate_ops *ops)

{

	struct decode_cache *c = &ctxt->decode;

	int rc = 0;

	int reg = VCPU_REGS_RDI;



	while (reg >= VCPU_REGS_RAX) {

		if (reg == VCPU_REGS_RSP) {

			register_address_increment(c, &c->regs[VCPU_REGS_RSP],

							c->op_bytes);

			--reg;

		}



		rc = emulate_pop(ctxt, ops, &c->regs[reg], c->op_bytes);

		if (rc != 0)

			break;

		--reg;

	}

	return rc;

}



static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt,

				struct x86_emulate_ops *ops)

{
@@ -1816,6 +1854,14 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		if (rc != 0)

			goto done;

		break;

	case 0x60:	/* pusha */

		emulate_pusha(ctxt);

		break;

	case 0x61:	/* popa */

		rc = emulate_popa(ctxt, ops);

		if (rc != 0)

			goto done;

		break;

	case 0x63:		/* movsxd */

		if (ctxt->mode != X86EMUL_MODE_PROT64)

			goto cannot_emulate;