arch/powerpc/kvm/emulate.c - kernel/windcharger - Git at Google

 /*
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License, version 2, as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  * Copyright IBM Corp. 2007
  *
  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  */

 #include <linux/jiffies.h>
 #include <linux/timer.h>
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/kvm_host.h>

 #include <asm/reg.h>
 #include <asm/time.h>
 #include <asm/byteorder.h>
 #include <asm/kvm_ppc.h>
 #include <asm/disassemble.h>
 #include "timing.h"

 #define OP_TRAP 3

 #define OP_31_XOP_LWZX      23
 #define OP_31_XOP_LBZX      87
 #define OP_31_XOP_STWX      151
 #define OP_31_XOP_STBX      215
 #define OP_31_XOP_STBUX     247
 #define OP_31_XOP_LHZX      279
 #define OP_31_XOP_LHZUX     311
 #define OP_31_XOP_MFSPR     339
 #define OP_31_XOP_STHX      407
 #define OP_31_XOP_STHUX     439
 #define OP_31_XOP_MTSPR     467
 #define OP_31_XOP_DCBI      470
 #define OP_31_XOP_LWBRX     534
 #define OP_31_XOP_TLBSYNC   566
 #define OP_31_XOP_STWBRX    662
 #define OP_31_XOP_LHBRX     790
 #define OP_31_XOP_STHBRX    918

 #define OP_LWZ  32
 #define OP_LWZU 33
 #define OP_LBZ  34
 #define OP_LBZU 35
 #define OP_STW  36
 #define OP_STWU 37
 #define OP_STB  38
 #define OP_STBU 39
 #define OP_LHZ  40
 #define OP_LHZU 41
 #define OP_STH  44
 #define OP_STHU 45

 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.tcr & TCR_DIE) {
 		/* The decrementer ticks at the same rate as the timebase, so
 		 * that's how we convert the guest DEC value to the number of
 		 * host ticks. */
 		unsigned long nr_jiffies;

 		nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
 		mod_timer(&vcpu->arch.dec_timer,
 		          get_jiffies_64() + nr_jiffies);
 	} else {
 		del_timer(&vcpu->arch.dec_timer);
 	}
 }

 /* XXX to do:
  * lhax
  * lhaux
  * lswx
  * lswi
  * stswx
  * stswi
  * lha
  * lhau
  * lmw
  * stmw
  *
  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
  */
 /* XXX Should probably auto-generate instruction decoding for a particular core
  * from opcode tables in the future. */
 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	u32 inst = vcpu->arch.last_inst;
 	u32 ea;
 	int ra;
 	int rb;
 	int rs;
 	int rt;
 	int sprn;
 	enum emulation_result emulated = EMULATE_DONE;
 	int advance = 1;

 	/* this default type might be overwritten by subcategories */
 	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);

 	switch (get_op(inst)) {
 	case OP_TRAP:
 		vcpu->arch.esr |= ESR_PTR;
 		kvmppc_core_queue_program(vcpu);
 		advance = 0;
 		break;

 	case 31:
 		switch (get_xop(inst)) {

 		case OP_31_XOP_LWZX:
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 			break;

 		case OP_31_XOP_LBZX:
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 			break;

 		case OP_31_XOP_STWX:
 			rs = get_rs(inst);
 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               4, 1);
 			break;

 		case OP_31_XOP_STBX:
 			rs = get_rs(inst);
 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               1, 1);
 			break;

 		case OP_31_XOP_STBUX:
 			rs = get_rs(inst);
 			ra = get_ra(inst);
 			rb = get_rb(inst);

 			ea = vcpu->arch.gpr[rb];
 			if (ra)
 				ea += vcpu->arch.gpr[ra];

 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               1, 1);
 			vcpu->arch.gpr[rs] = ea;
 			break;

 		case OP_31_XOP_LHZX:
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 			break;

 		case OP_31_XOP_LHZUX:
 			rt = get_rt(inst);
 			ra = get_ra(inst);
 			rb = get_rb(inst);

 			ea = vcpu->arch.gpr[rb];
 			if (ra)
 				ea += vcpu->arch.gpr[ra];

 			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 			vcpu->arch.gpr[ra] = ea;
 			break;

 		case OP_31_XOP_MFSPR:
 			sprn = get_sprn(inst);
 			rt = get_rt(inst);

 			switch (sprn) {
 			case SPRN_SRR0:
 				vcpu->arch.gpr[rt] = vcpu->arch.srr0; break;
 			case SPRN_SRR1:
 				vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
 			case SPRN_PVR:
 				vcpu->arch.gpr[rt] = vcpu->arch.pvr; break;

 			/* Note: mftb and TBRL/TBWL are user-accessible, so
 			 * the guest can always access the real TB anyways.
 			 * In fact, we probably will never see these traps. */
 			case SPRN_TBWL:
 				vcpu->arch.gpr[rt] = mftbl(); break;
 			case SPRN_TBWU:
 				vcpu->arch.gpr[rt] = mftbu(); break;

 			case SPRN_SPRG0:
 				vcpu->arch.gpr[rt] = vcpu->arch.sprg0; break;
 			case SPRN_SPRG1:
 				vcpu->arch.gpr[rt] = vcpu->arch.sprg1; break;
 			case SPRN_SPRG2:
 				vcpu->arch.gpr[rt] = vcpu->arch.sprg2; break;
 			case SPRN_SPRG3:
 				vcpu->arch.gpr[rt] = vcpu->arch.sprg3; break;
 			/* Note: SPRG4-7 are user-readable, so we don't get
 			 * a trap. */

 			default:
 				emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 				if (emulated == EMULATE_FAIL) {
 					printk("mfspr: unknown spr %x\n", sprn);
 					vcpu->arch.gpr[rt] = 0;
 				}
 				break;
 			}
 			break;

 		case OP_31_XOP_STHX:
 			rs = get_rs(inst);
 			ra = get_ra(inst);
 			rb = get_rb(inst);

 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               2, 1);
 			break;

 		case OP_31_XOP_STHUX:
 			rs = get_rs(inst);
 			ra = get_ra(inst);
 			rb = get_rb(inst);

 			ea = vcpu->arch.gpr[rb];
 			if (ra)
 				ea += vcpu->arch.gpr[ra];

 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               2, 1);
 			vcpu->arch.gpr[ra] = ea;
 			break;

 		case OP_31_XOP_MTSPR:
 			sprn = get_sprn(inst);
 			rs = get_rs(inst);
 			switch (sprn) {
 			case SPRN_SRR0:
 				vcpu->arch.srr0 = vcpu->arch.gpr[rs]; break;
 			case SPRN_SRR1:
 				vcpu->arch.srr1 = vcpu->arch.gpr[rs]; break;

 			/* XXX We need to context-switch the timebase for
 			 * watchdog and FIT. */
 			case SPRN_TBWL: break;
 			case SPRN_TBWU: break;

 			case SPRN_DEC:
 				vcpu->arch.dec = vcpu->arch.gpr[rs];
 				kvmppc_emulate_dec(vcpu);
 				break;

 			case SPRN_SPRG0:
 				vcpu->arch.sprg0 = vcpu->arch.gpr[rs]; break;
 			case SPRN_SPRG1:
 				vcpu->arch.sprg1 = vcpu->arch.gpr[rs]; break;
 			case SPRN_SPRG2:
 				vcpu->arch.sprg2 = vcpu->arch.gpr[rs]; break;
 			case SPRN_SPRG3:
 				vcpu->arch.sprg3 = vcpu->arch.gpr[rs]; break;

 			default:
 				emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 				if (emulated == EMULATE_FAIL)
 					printk("mtspr: unknown spr %x\n", sprn);
 				break;
 			}
 			break;

 		case OP_31_XOP_DCBI:
 			/* Do nothing. The guest is performing dcbi because
 			 * hardware DMA is not snooped by the dcache, but
 			 * emulated DMA either goes through the dcache as
 			 * normal writes, or the host kernel has handled dcache
 			 * coherence. */
 			break;

 		case OP_31_XOP_LWBRX:
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 			break;

 		case OP_31_XOP_TLBSYNC:
 			break;

 		case OP_31_XOP_STWBRX:
 			rs = get_rs(inst);
 			ra = get_ra(inst);
 			rb = get_rb(inst);

 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               4, 0);
 			break;

 		case OP_31_XOP_LHBRX:
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 			break;

 		case OP_31_XOP_STHBRX:
 			rs = get_rs(inst);
 			ra = get_ra(inst);
 			rb = get_rb(inst);

 			emulated = kvmppc_handle_store(run, vcpu,
 			                               vcpu->arch.gpr[rs],
 			                               2, 0);
 			break;

 		default:
 			/* Attempt core-specific emulation below. */
 			emulated = EMULATE_FAIL;
 		}
 		break;

 	case OP_LWZ:
 		rt = get_rt(inst);
 		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 		break;

 	case OP_LWZU:
 		ra = get_ra(inst);
 		rt = get_rt(inst);
 		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 		vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 		break;

 	case OP_LBZ:
 		rt = get_rt(inst);
 		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 		break;

 	case OP_LBZU:
 		ra = get_ra(inst);
 		rt = get_rt(inst);
 		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 		vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 		break;

 	case OP_STW:
 		rs = get_rs(inst);
 		emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 		                               4, 1);
 		break;

 	case OP_STWU:
 		ra = get_ra(inst);
 		rs = get_rs(inst);
 		emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 		                               4, 1);
 		vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 		break;

 	case OP_STB:
 		rs = get_rs(inst);
 		emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 		                               1, 1);
 		break;

 	case OP_STBU:
 		ra = get_ra(inst);
 		rs = get_rs(inst);
 		emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 		                               1, 1);
 		vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 		break;

 	case OP_LHZ:
 		rt = get_rt(inst);
 		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 		break;

 	case OP_LHZU:
 		ra = get_ra(inst);
 		rt = get_rt(inst);
 		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 		vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 		break;

 	case OP_STH:
 		rs = get_rs(inst);
 		emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 		                               2, 1);
 		break;

 	case OP_STHU:
 		ra = get_ra(inst);
 		rs = get_rs(inst);
 		emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 		                               2, 1);
 		vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 		break;

 	default:
 		emulated = EMULATE_FAIL;
 	}

 	if (emulated == EMULATE_FAIL) {
 		emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 		if (emulated == EMULATE_FAIL) {
 			advance = 0;
 			printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 			       "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 		}
 	}

 	KVMTRACE_3D(PPC_INSTR, vcpu, inst, (int)vcpu->arch.pc, emulated, entryexit);

 	if (advance)
 		vcpu->arch.pc += 4; /* Advance past emulated instruction. */

 	return emulated;
 }
	/*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License, version 2, as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	*
	* Copyright IBM Corp. 2007
	*
	* Authors: Hollis Blanchard <hollisb@us.ibm.com>
	*/

	#include <linux/jiffies.h>
	#include <linux/timer.h>
	#include <linux/types.h>
	#include <linux/string.h>
	#include <linux/kvm_host.h>

	#include <asm/reg.h>
	#include <asm/time.h>
	#include <asm/byteorder.h>
	#include <asm/kvm_ppc.h>
	#include <asm/disassemble.h>
	#include "timing.h"

	#define OP_TRAP 3

	#define OP_31_XOP_LWZX 23
	#define OP_31_XOP_LBZX 87
	#define OP_31_XOP_STWX 151
	#define OP_31_XOP_STBX 215
	#define OP_31_XOP_STBUX 247
	#define OP_31_XOP_LHZX 279
	#define OP_31_XOP_LHZUX 311
	#define OP_31_XOP_MFSPR 339
	#define OP_31_XOP_STHX 407
	#define OP_31_XOP_STHUX 439
	#define OP_31_XOP_MTSPR 467
	#define OP_31_XOP_DCBI 470
	#define OP_31_XOP_LWBRX 534
	#define OP_31_XOP_TLBSYNC 566
	#define OP_31_XOP_STWBRX 662
	#define OP_31_XOP_LHBRX 790
	#define OP_31_XOP_STHBRX 918

	#define OP_LWZ 32
	#define OP_LWZU 33
	#define OP_LBZ 34
	#define OP_LBZU 35
	#define OP_STW 36
	#define OP_STWU 37
	#define OP_STB 38
	#define OP_STBU 39
	#define OP_LHZ 40
	#define OP_LHZU 41
	#define OP_STH 44
	#define OP_STHU 45

	void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
	{
	if (vcpu->arch.tcr & TCR_DIE) {
	/* The decrementer ticks at the same rate as the timebase, so
	* that's how we convert the guest DEC value to the number of
	* host ticks. */
	unsigned long nr_jiffies;

	nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
	mod_timer(&vcpu->arch.dec_timer,
	get_jiffies_64() + nr_jiffies);
	} else {
	del_timer(&vcpu->arch.dec_timer);
	}
	}

	/* XXX to do:
	* lhax
	* lhaux
	* lswx
	* lswi
	* stswx
	* stswi
	* lha
	* lhau
	* lmw
	* stmw
	*
	* XXX is_bigendian should depend on MMU mapping or MSR[LE]
	*/
	/* XXX Should probably auto-generate instruction decoding for a particular core
	* from opcode tables in the future. */
	int kvmppc_emulate_instruction(struct kvm_run run, struct kvm_vcpu vcpu)
	{
	u32 inst = vcpu->arch.last_inst;
	u32 ea;
	int ra;
	int rb;
	int rs;
	int rt;
	int sprn;
	enum emulation_result emulated = EMULATE_DONE;
	int advance = 1;

	/* this default type might be overwritten by subcategories */
	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);

	switch (get_op(inst)) {
	case OP_TRAP:
	vcpu->arch.esr \|= ESR_PTR;
	kvmppc_core_queue_program(vcpu);
	advance = 0;
	break;

	case 31:
	switch (get_xop(inst)) {

	case OP_31_XOP_LWZX:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
	break;

	case OP_31_XOP_LBZX:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
	break;

	case OP_31_XOP_STWX:
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	4, 1);
	break;

	case OP_31_XOP_STBX:
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	1, 1);
	break;

	case OP_31_XOP_STBUX:
	rs = get_rs(inst);
	ra = get_ra(inst);
	rb = get_rb(inst);

	ea = vcpu->arch.gpr[rb];
	if (ra)
	ea += vcpu->arch.gpr[ra];

	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	1, 1);
	vcpu->arch.gpr[rs] = ea;
	break;

	case OP_31_XOP_LHZX:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
	break;

	case OP_31_XOP_LHZUX:
	rt = get_rt(inst);
	ra = get_ra(inst);
	rb = get_rb(inst);

	ea = vcpu->arch.gpr[rb];
	if (ra)
	ea += vcpu->arch.gpr[ra];

	emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
	vcpu->arch.gpr[ra] = ea;
	break;

	case OP_31_XOP_MFSPR:
	sprn = get_sprn(inst);
	rt = get_rt(inst);

	switch (sprn) {
	case SPRN_SRR0:
	vcpu->arch.gpr[rt] = vcpu->arch.srr0; break;
	case SPRN_SRR1:
	vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
	case SPRN_PVR:
	vcpu->arch.gpr[rt] = vcpu->arch.pvr; break;

	/* Note: mftb and TBRL/TBWL are user-accessible, so
	* the guest can always access the real TB anyways.
	* In fact, we probably will never see these traps. */
	case SPRN_TBWL:
	vcpu->arch.gpr[rt] = mftbl(); break;
	case SPRN_TBWU:
	vcpu->arch.gpr[rt] = mftbu(); break;

	case SPRN_SPRG0:
	vcpu->arch.gpr[rt] = vcpu->arch.sprg0; break;
	case SPRN_SPRG1:
	vcpu->arch.gpr[rt] = vcpu->arch.sprg1; break;
	case SPRN_SPRG2:
	vcpu->arch.gpr[rt] = vcpu->arch.sprg2; break;
	case SPRN_SPRG3:
	vcpu->arch.gpr[rt] = vcpu->arch.sprg3; break;
	/* Note: SPRG4-7 are user-readable, so we don't get
	* a trap. */

	default:
	emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
	if (emulated == EMULATE_FAIL) {
	printk("mfspr: unknown spr %x\n", sprn);
	vcpu->arch.gpr[rt] = 0;
	}
	break;
	}
	break;

	case OP_31_XOP_STHX:
	rs = get_rs(inst);
	ra = get_ra(inst);
	rb = get_rb(inst);

	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	2, 1);
	break;

	case OP_31_XOP_STHUX:
	rs = get_rs(inst);
	ra = get_ra(inst);
	rb = get_rb(inst);

	ea = vcpu->arch.gpr[rb];
	if (ra)
	ea += vcpu->arch.gpr[ra];

	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	2, 1);
	vcpu->arch.gpr[ra] = ea;
	break;

	case OP_31_XOP_MTSPR:
	sprn = get_sprn(inst);
	rs = get_rs(inst);
	switch (sprn) {
	case SPRN_SRR0:
	vcpu->arch.srr0 = vcpu->arch.gpr[rs]; break;
	case SPRN_SRR1:
	vcpu->arch.srr1 = vcpu->arch.gpr[rs]; break;

	/* XXX We need to context-switch the timebase for
	* watchdog and FIT. */
	case SPRN_TBWL: break;
	case SPRN_TBWU: break;

	case SPRN_DEC:
	vcpu->arch.dec = vcpu->arch.gpr[rs];
	kvmppc_emulate_dec(vcpu);
	break;

	case SPRN_SPRG0:
	vcpu->arch.sprg0 = vcpu->arch.gpr[rs]; break;
	case SPRN_SPRG1:
	vcpu->arch.sprg1 = vcpu->arch.gpr[rs]; break;
	case SPRN_SPRG2:
	vcpu->arch.sprg2 = vcpu->arch.gpr[rs]; break;
	case SPRN_SPRG3:
	vcpu->arch.sprg3 = vcpu->arch.gpr[rs]; break;

	default:
	emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
	if (emulated == EMULATE_FAIL)
	printk("mtspr: unknown spr %x\n", sprn);
	break;
	}
	break;

	case OP_31_XOP_DCBI:
	/* Do nothing. The guest is performing dcbi because
	* hardware DMA is not snooped by the dcache, but
	* emulated DMA either goes through the dcache as
	* normal writes, or the host kernel has handled dcache
	* coherence. */
	break;

	case OP_31_XOP_LWBRX:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
	break;

	case OP_31_XOP_TLBSYNC:
	break;

	case OP_31_XOP_STWBRX:
	rs = get_rs(inst);
	ra = get_ra(inst);
	rb = get_rb(inst);

	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	4, 0);
	break;

	case OP_31_XOP_LHBRX:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
	break;

	case OP_31_XOP_STHBRX:
	rs = get_rs(inst);
	ra = get_ra(inst);
	rb = get_rb(inst);

	emulated = kvmppc_handle_store(run, vcpu,
	vcpu->arch.gpr[rs],
	2, 0);
	break;

	default:
	/* Attempt core-specific emulation below. */
	emulated = EMULATE_FAIL;
	}
	break;

	case OP_LWZ:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
	break;

	case OP_LWZU:
	ra = get_ra(inst);
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
	vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
	break;

	case OP_LBZ:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
	break;

	case OP_LBZU:
	ra = get_ra(inst);
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
	vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
	break;

	case OP_STW:
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
	4, 1);
	break;

	case OP_STWU:
	ra = get_ra(inst);
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
	4, 1);
	vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
	break;

	case OP_STB:
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
	1, 1);
	break;

	case OP_STBU:
	ra = get_ra(inst);
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
	1, 1);
	vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
	break;

	case OP_LHZ:
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
	break;

	case OP_LHZU:
	ra = get_ra(inst);
	rt = get_rt(inst);
	emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
	vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
	break;

	case OP_STH:
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
	2, 1);
	break;

	case OP_STHU:
	ra = get_ra(inst);
	rs = get_rs(inst);
	emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
	2, 1);
	vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
	break;

	default:
	emulated = EMULATE_FAIL;
	}

	if (emulated == EMULATE_FAIL) {
	emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
	if (emulated == EMULATE_FAIL) {
	advance = 0;
	printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
	"(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
	}
	}

	KVMTRACE_3D(PPC_INSTR, vcpu, inst, (int)vcpu->arch.pc, emulated, entryexit);

	if (advance)
	vcpu->arch.pc += 4; /* Advance past emulated instruction. */

	return emulated;
	}