path: root/arch/powerpc/kvm/bookehv_interrupts.S

/*
 * 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 (C) 2010-2011 Freescale Semiconductor, Inc.
 *
 * Author: Varun Sethi <varun.sethi@freescale.com>
 * Author: Scott Wood <scotwood@freescale.com>
 * Author: Mihai Caraman <mihai.caraman@freescale.com>
 *
 * This file is derived from arch/powerpc/kvm/booke_interrupts.S
 */

#include <asm/ppc_asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/asm-compat.h>
#include <asm/asm-offsets.h>
#include <asm/bitsperlong.h>

#ifdef CONFIG_64BIT
#include <asm/exception-64e.h>
#include <asm/hw_irq.h>
#include <asm/irqflags.h>
#else
#include "../kernel/head_booke.h" /* for THREAD_NORMSAVE() */
#endif

#define LONGBYTES		(BITS_PER_LONG / 8)

#define VCPU_GUEST_SPRG(n)	(VCPU_GUEST_SPRGS + (n * LONGBYTES))

/* The host stack layout: */
#define HOST_R1         0 /* Implied by stwu. */
#define HOST_CALLEE_LR  PPC_LR_STKOFF
#define HOST_RUN        (HOST_CALLEE_LR + LONGBYTES)
/*
 * r2 is special: it holds 'current', and it made nonvolatile in the
 * kernel with the -ffixed-r2 gcc option.
 */
#define HOST_R2         (HOST_RUN + LONGBYTES)
#define HOST_CR         (HOST_R2 + LONGBYTES)
#define HOST_NV_GPRS    (HOST_CR + LONGBYTES)
#define __HOST_NV_GPR(n)  (HOST_NV_GPRS + ((n - 14) * LONGBYTES))
#define HOST_NV_GPR(n)  __HOST_NV_GPR(__REG_##n)
#define HOST_MIN_STACK_SIZE (HOST_NV_GPR(R31) + LONGBYTES)
#define HOST_STACK_SIZE ((HOST_MIN_STACK_SIZE + 15) & ~15) /* Align. */
/* LR in caller stack frame. */
#define HOST_STACK_LR	(HOST_STACK_SIZE + PPC_LR_STKOFF)

#define NEED_EMU		0x00000001 /* emulation -- save nv regs */
#define NEED_DEAR		0x00000002 /* save faulting DEAR */
#define NEED_ESR		0x00000004 /* save faulting ESR */

/*
 * On entry:
 * r4 = vcpu, r5 = srr0, r6 = srr1
 * saved in vcpu: cr, ctr, r3-r13
 */
.macro kvm_handler_common intno, srr0, flags
	/* Restore host stack pointer */
	PPC_STL	r1, VCPU_GPR(R1)(r4)
	PPC_STL	r2, VCPU_GPR(R2)(r4)
	PPC_LL	r1, VCPU_HOST_STACK(r4)
	PPC_LL	r2, HOST_R2(r1)

	mfspr	r10, SPRN_PID
	lwz	r8, VCPU_HOST_PID(r4)
	PPC_LL	r11, VCPU_SHARED(r4)
	PPC_STL	r14, VCPU_GPR(R14)(r4) /* We need a non-volatile GPR. */
	li	r14, \intno

	stw	r10, VCPU_GUEST_PID(r4)
	mtspr	SPRN_PID, r8

#ifdef CONFIG_KVM_EXIT_TIMING
	/* save exit time */
1:	mfspr	r7, SPRN_TBRU
	mfspr	r8, SPRN_TBRL
	mfspr	r9, SPRN_TBRU
	cmpw	r9, r7
	stw	r8, VCPU_TIMING_EXIT_TBL(r4)
	bne-	1b
	stw	r9, VCPU_TIMING_EXIT_TBU(r4)
#endif

	oris	r8, r6, MSR_CE@h
	PPC_STD(r6, VCPU_SHARED_MSR, r11)
	ori	r8, r8, MSR_ME | MSR_RI
	PPC_STL	r5, VCPU_PC(r4)

	/*
	 * Make sure CE/ME/RI are set (if appropriate for exception type)
	 * whether or not the guest had it set.  Since mfmsr/mtmsr are
	 * somewhat expensive, skip in the common case where the guest
	 * had all these bits set (and thus they're still set if
	 * appropriate for the exception type).
	 */
	cmpw	r6, r8
	beq	1f
	mfmsr	r7
	.if	\srr0 != SPRN_MCSRR0 && \srr0 != SPRN_CSRR0
	oris	r7, r7, MSR_CE@h
	.endif
	.if	\srr0 != SPRN_MCSRR0
	ori	r7, r7, MSR_ME | MSR_RI
	.endif
	mtmsr	r7
1:

	.if	\flags & NEED_EMU
	PPC_STL	r15, VCPU_GPR(R15)(r4)
	PPC_STL	r16, VCPU_GPR(R16)(r4)
	PPC_STL	r17, VCPU_GPR(R17)(r4)
	PPC_STL	r18, VCPU_GPR(R18)(r4)
	PPC_STL	r19, VCPU_GPR(R19)(r4)
	PPC_STL	r20, VCPU_GPR(R20)(r4)
	PPC_STL	r21, VCPU_GPR(R21)(r4)
	PPC_STL	r22, VCPU_GPR(R22)(r4)
	PPC_STL	r23, VCPU_GPR(R23)(r4)
	PPC_STL	r24, VCPU_GPR(R24)(r4)
	PPC_STL	r25, VCPU_GPR(R25)(r4)
	PPC_STL	r26, VCPU_GPR(R26)(r4)
	PPC_STL	r27, VCPU_GPR(R27)(r4)
	PPC_STL	r28, VCPU_GPR(R28)(r4)
	PPC_STL	r29, VCPU_GPR(R29)(r4)
	PPC_STL	r30, VCPU_GPR(R30)(r4)
	PPC_STL	r31, VCPU_GPR(R31)(r4)

	/*
	 * We don't use external PID support. lwepx faults would need to be
	 * handled by KVM and this implies aditional code in DO_KVM (for
	 * DTB_MISS, DSI and LRAT) to check ESR[EPID] and EPLC[EGS] which
	 * is too intrusive for the host. Get last instuction in
	 * kvmppc_get_last_inst().
	 */
	li	r9, KVM_INST_FETCH_FAILED
	stw	r9, VCPU_LAST_INST(r4)
	.endif

	.if	\flags & NEED_ESR
	mfspr	r8, SPRN_ESR
	PPC_STL	r8, VCPU_FAULT_ESR(r4)
	.endif

	.if	\flags & NEED_DEAR
	mfspr	r9, SPRN_DEAR
	PPC_STL	r9, VCPU_FAULT_DEAR(r4)
	.endif

	b	kvmppc_resume_host
.endm

#ifdef CONFIG_64BIT
/* Exception types */
#define EX_GEN			1
#define EX_GDBELL		2
#define EX_DBG			3
#define EX_MC			4
#define EX_CRIT			5
#define EX_TLB			6

/*
 * For input register values, see arch/powerpc/include/asm/kvm_booke_hv_asm.h
 */
.macro kvm_handler intno type scratch, paca_ex, ex_r10, ex_r11, srr0, srr1, flags
 _GLOBAL(kvmppc_handler_\intno\()_\srr1)
	mr	r11, r4
	/*
	 * Get vcpu from Paca: paca->__current.thread->kvm_vcpu
	 */
	PPC_LL	r4, PACACURRENT(r13)
	PPC_LL	r4, (THREAD + THREAD_KVM_VCPU)(r4)
	PPC_STL	r10, VCPU_CR(r4)
	PPC_STL r11, VCPU_GPR(R4)(r4)
	PPC_STL	r5, VCPU_GPR(R5)(r4)
	PPC_STL	r6, VCPU_GPR(R6)(r4)
	PPC_STL	r8, VCPU_GPR(R8)(r4)
	PPC_STL	r9, VCPU_GPR(R9)(r4)
	.if \type == EX_TLB
	PPC_LL	r5, EX_TLB_R13(r12)
	PPC_LL	r6, EX_TLB_R10(r12)
	PPC_LL	r8, EX_TLB_R11(r12)
	mfspr	r12, \scratch
	.else
	mfspr	r5, \scratch
	PPC_LL	r6, (\paca_ex + \ex_r10)(r13)
	PPC_LL	r8, (\paca_ex + \ex_r11)(r13)
	.endif
	PPC_STL r5, VCPU_GPR(R13)(r4)
	PPC_STL r3, VCPU_GPR(R3)(r4)
	PPC_STL r7, VCPU_GPR(R7)(r4)
	PPC_STL r12, VCPU_GPR(R12)(r4)
	PPC_STL r6, VCPU_GPR(R10)(r4)
	PPC_STL r8, VCPU_GPR(R11)(r4)
	mfctr	r5
	PPC_STL	r5, VCPU_CTR(r4)
	mfspr	r5, \srr0
	mfspr	r6, \srr1
	kvm_handler_common \intno, \srr0, \flags
.endm

#define EX_PARAMS(type) \
	EX_##type, \
	SPRN_SPRG_##type##_SCRATCH, \
	PACA_EX##type, \
	EX_R10, \
	EX_R11

#define EX_PARAMS_TLB \
	EX_TLB, \
	SPRN_SPRG_GEN_SCRATCH, \
	PACA_EXTLB, \
	EX_TLB_R10, \
	EX_TLB_R11

kvm_handler BOOKE_INTERRUPT_CRITICAL, EX_PARAMS(CRIT), \
	SPRN_CSRR0, SPRN_CSRR1, 0
kvm_handler BOOKE_INTERRUPT_MACHINE_CHECK, EX_PARAMS(MC), \
	SPRN_MCSRR0, SPRN_MCSRR1, 0
kvm_handler BOOKE_INTERRUPT_DATA_STORAGE, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1,(NEED_EMU | NEED_DEAR | NEED_ESR)
kvm_handler BOOKE_INTERRUPT_INST_STORAGE, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, NEED_ESR
kvm_handler BOOKE_INTERRUPT_EXTERNAL, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_ALIGNMENT, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1,(NEED_DEAR | NEED_ESR)
kvm_handler BOOKE_INTERRUPT_PROGRAM, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, (NEED_ESR | NEED_EMU)
kvm_handler BOOKE_INTERRUPT_FP_UNAVAIL, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_AP_UNAVAIL, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_DECREMENTER, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_FIT, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_WATCHDOG, EX_PARAMS(CRIT),\
	SPRN_CSRR0, SPRN_CSRR1, 0
/*
 * Only bolted TLB miss exception handlers are supported for now
 */
kvm_handler BOOKE_INTERRUPT_DTLB_MISS, EX_PARAMS_TLB, \
	SPRN_SRR0, SPRN_SRR1, (NEED_EMU | NEED_DEAR | NEED_ESR)
kvm_handler BOOKE_INTERRUPT_ITLB_MISS, EX_PARAMS_TLB, \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_ALTIVEC_UNAVAIL, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_ALTIVEC_ASSIST, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_PERFORMANCE_MONITOR, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_DOORBELL, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_DOORBELL_CRITICAL, EX_PARAMS(CRIT), \
	SPRN_CSRR0, SPRN_CSRR1, 0
kvm_handler BOOKE_INTERRUPT_HV_PRIV, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, NEED_EMU
kvm_handler BOOKE_INTERRUPT_HV_SYSCALL, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_GUEST_DBELL, EX_PARAMS(GDBELL), \
	SPRN_GSRR0, SPRN_GSRR1, 0
kvm_handler BOOKE_INTERRUPT_GUEST_DBELL_CRIT, EX_PARAMS(CRIT), \
	SPRN_CSRR0, SPRN_CSRR1, 0
kvm_handler BOOKE_INTERRUPT_DEBUG, EX_PARAMS(DBG), \
	SPRN_DSRR0, SPRN_DSRR1, 0
kvm_handler BOOKE_INTERRUPT_DEBUG, EX_PARAMS(CRIT), \
	SPRN_CSRR0, SPRN_CSRR1, 0
kvm_handler BOOKE_INTERRUPT_LRAT_ERROR, EX_PARAMS(GEN), \
	SPRN_SRR0, SPRN_SRR1, (NEED_EMU | NEED_DEAR | NEED_ESR)
#else
/*
 * For input register values, see arch/powerpc/include/asm/kvm_booke_hv_asm.h
 */
.macro kvm_handler intno srr0, srr1, flags
_GLOBAL(kvmppc_handler_\intno\()_\srr1)
	PPC_LL	r11, THREAD_KVM_VCPU(r10)
	PPC_STL r3, VCPU_GPR(R3)(r11)
	mfspr	r3, SPRN_SPRG_RSCRATCH0
	PPC_STL	r4, VCPU_GPR(R4)(r11)
	PPC_LL	r4, THREAD_NORMSAVE(0)(r10)
	PPC_STL	r5, VCPU_GPR(R5)(r11)
	PPC_STL	r13, VCPU_CR(r11)
	mfspr	r5, \srr0
	PPC_STL	r3, VCPU_GPR(R10)(r11)
	PPC_LL	r3, THREAD_NORMSAVE(2)(r10)
	PPC_STL	r6, VCPU_GPR(R6)(r11)
	PPC_STL	r4, VCPU_GPR(R11)(r11)
	mfspr	r6, \srr1
	PPC_STL	r7, VCPU_GPR(R7)(r11)
	PPC_STL	r8, VCPU_GPR(R8)(r11)
	PPC_STL	r9, VCPU_GPR(R9)(r11)
	PPC_STL r3, VCPU_GPR(R13)(r11)
	mfctr	r7
	PPC_STL	r12, VCPU_GPR(R12)(r11)
	PPC_STL	r7, VCPU_CTR(r11)
	mr	r4, r11
	kvm_handler_common \intno, \srr0, \flags
.endm

.macro kvm_lvl_handler intno scratch srr0, srr1, flags
_GLOBAL(kvmppc_handler_\intno\()_\srr1)
	mfspr	r10, SPRN_SPRG_THREAD
	PPC_LL	r11, THREAD_KVM_VCPU(r10)
	PPC_STL r3, VCPU_GPR(R3)(r11)
	mfspr	r3, \scratch
	PPC_STL	r4, VCPU_GPR(R4)(r11)
	PPC_LL	r4, GPR9(r8)
	PPC_STL	r5, VCPU_GPR(R5)(r11)
	PPC_STL	r9, VCPU_CR(r11)
	mfspr	r5, \srr0
	PPC_STL	r3, VCPU_GPR(R8)(r11)
	PPC_LL	r3, GPR10(r8)
	PPC_STL	r6, VCPU_GPR(R6)(r11)
	PPC_STL	r4, VCPU_GPR(R9)(r11)
	mfspr	r6, \srr1
	PPC_LL	r4, GPR11(r8)
	PPC_STL	r7, VCPU_GPR(R7)(r11)
	PPC_STL r3, VCPU_GPR(R10)(r11)
	mfctr	r7
	PPC_STL	r12, VCPU_GPR(R12)(r11)
	PPC_STL r13, VCPU_GPR(R13)(r11)
	PPC_STL	r4, VCPU_GPR(R11)(r11)
	PPC_STL	r7, VCPU_CTR(r11)
	mr	r4, r11
	kvm_handler_common \intno, \srr0, \flags
.endm

kvm_lvl_handler BOOKE_INTERRUPT_CRITICAL, \
	SPRN_SPRG_RSCRATCH_CRIT, SPRN_CSRR0, SPRN_CSRR1, 0
kvm_lvl_handler BOOKE_INTERRUPT_MACHINE_CHECK, \
	SPRN_SPRG_RSCRATCH_MC, SPRN_MCSRR0, SPRN_MCSRR1, 0
kvm_handler BOOKE_INTERRUPT_DATA_STORAGE, \
	SPRN_SRR0, SPRN_SRR1, (NEED_EMU | NEED_DEAR | NEED_ESR)
kvm_handler BOOKE_INTERRUPT_INST_STORAGE, SPRN_SRR0, SPRN_SRR1, NEED_ESR
kvm_handler BOOKE_INTERRUPT_EXTERNAL, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_ALIGNMENT, \
	SPRN_SRR0, SPRN_SRR1, (NEED_DEAR | NEED_ESR)
kvm_handler BOOKE_INTERRUPT_PROGRAM, SPRN_SRR0, SPRN_SRR1, (NEED_ESR | NEED_EMU)
kvm_handler BOOKE_INTERRUPT_FP_UNAVAIL, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_SYSCALL, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_AP_UNAVAIL, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_DECREMENTER, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_FIT, SPRN_SRR0, SPRN_SRR1, 0
kvm_lvl_handler BOOKE_INTERRUPT_WATCHDOG, \
	SPRN_SPRG_RSCRATCH_CRIT, SPRN_CSRR0, SPRN_CSRR1, 0
kvm_handler BOOKE_INTERRUPT_DTLB_MISS, \
	SPRN_SRR0, SPRN_SRR1, (NEED_EMU | NEED_DEAR | NEED_ESR)
kvm_handler BOOKE_INTERRUPT_ITLB_MISS, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_PERFORMANCE_MONITOR, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_DOORBELL, SPRN_SRR0, SPRN_SRR1, 0
kvm_lvl_handler BOOKE_INTERRUPT_DOORBELL_CRITICAL, \
	SPRN_SPRG_RSCRATCH_CRIT, SPRN_CSRR0, SPRN_CSRR1, 0
kvm_handler BOOKE_INTERRUPT_HV_PRIV, SPRN_SRR0, SPRN_SRR1, NEED_EMU
kvm_handler BOOKE_INTERRUPT_HV_SYSCALL, SPRN_SRR0, SPRN_SRR1, 0
kvm_handler BOOKE_INTERRUPT_GUEST_DBELL, SPRN_GSRR0, SPRN_GSRR1, 0
kvm_lvl_handler BOOKE_INTERRUPT_GUEST_DBELL_CRIT, \
	SPRN_SPRG_RSCRATCH_CRIT, SPRN_CSRR0, SPRN_CSRR1, 0
kvm_lvl_handler BOOKE_INTERRUPT_DEBUG, \
	SPRN_SPRG_RSCRATCH_CRIT, SPRN_CSRR0, SPRN_CSRR1, 0
kvm_lvl_handler BOOKE_INTERRUPT_DEBUG, \
	SPRN_SPRG_RSCRATCH_DBG, SPRN_DSRR0, SPRN_DSRR1, 0
#endif

/* Registers:
 *  SPRG_SCRATCH0: guest r10
 *  r4: vcpu pointer
 *  r11: vcpu->arch.shared
 *  r14: KVM exit number
 */
_GLOBAL(kvmppc_resume_host)
	/* Save remaining volatile guest register state to vcpu. */
	mfspr	r3, SPRN_VRSAVE
	PPC_STL	r0, VCPU_GPR(R0)(r4)
	mflr	r5
	mfspr	r6, SPRN_SPRG4
	PPC_STL	r5, VCPU_LR(r4)
	mfspr	r7, SPRN_SPRG5
	stw	r3, VCPU_VRSAVE(r4)
#ifdef CONFIG_64BIT
	PPC_LL	r3, PACA_SPRG_VDSO(r13)
#endif
	mfspr	r5, SPRN_SPRG9
	PPC_STD(r6, VCPU_SHARED_SPRG4, r11)
	mfspr	r8, SPRN_SPRG6
	PPC_STD(r7, VCPU_SHARED_SPRG5, r11)
	mfspr	r9, SPRN_SPRG7
#ifdef CONFIG_64BIT
	mtspr	SPRN_SPRG_VDSO_WRITE, r3
#endif
	PPC_STD(r5, VCPU_SPRG9, r4)
	PPC_STD(r8, VCPU_SHARED_SPRG6, r11)
	mfxer	r3
	PPC_STD(r9, VCPU_SHARED_SPRG7, r11)

	/* save guest MAS registers and restore host mas4 & mas6 */
	mfspr	r5, SPRN_MAS0
	PPC_STL	r3, VCPU_XER(r4)
	mfspr	r6, SPRN_MAS1
	stw	r5, VCPU_SHARED_MAS0(r11)
	mfspr	r7, SPRN_MAS2
	stw	r6, VCPU_SHARED_MAS1(r11)
	PPC_STD(r7, VCPU_SHARED_MAS2, r11)
	mfspr	r5, SPRN_MAS3
	mfspr	r6, SPRN_MAS4
	stw	r5, VCPU_SHARED_MAS7_3+4(r11)
	mfspr	r7, SPRN_MAS6
	stw	r6, VCPU_SHARED_MAS4(r11)
	mfspr	r5, SPRN_MAS7
	lwz	r6, VCPU_HOST_MAS4(r4)
	stw	r7, VCPU_SHARED_MAS6(r11)
	lwz	r8, VCPU_HOST_MAS6(r4)
	mtspr	SPRN_MAS4, r6
	stw	r5, VCPU_SHARED_MAS7_3+0(r11)
	mtspr	SPRN_MAS6, r8
	/* Enable MAS register updates via exception */
	mfspr	r3, SPRN_EPCR
	rlwinm	r3, r3, 0, ~SPRN_EPCR_DMIUH
	mtspr	SPRN_EPCR, r3
	isync

#ifdef CONFIG_64BIT
	/*
	 * We enter with interrupts disabled in hardware, but
	 * we need to call RECONCILE_IRQ_STATE to ensure
	 * that the software state is kept in sync.
	 */
	RECONCILE_IRQ_STATE(r3,r5)
#endif

	/* Switch to kernel stack and jump to handler. */
	PPC_LL	r3, HOST_RUN(r1)
	mr	r5, r14 /* intno */
	mr	r14, r4 /* Save vcpu pointer. */
	bl	kvmppc_handle_exit

	/* Restore vcpu pointer and the nonvolatiles we used. */
	mr	r4, r14
	PPC_LL	r14, VCPU_GPR(R14)(r4)

	andi.	r5, r3, RESUME_FLAG_NV
	beq	skip_nv_load
	PPC_LL	r15, VCPU_GPR(R15)(r4)
	PPC_LL	r16, VCPU_GPR(R16)(r4)
	PPC_LL	r17, VCPU_GPR(R17)(r4)
	PPC_LL	r18, VCPU_GPR(R18)(r4)
	PPC_LL	r19, VCPU_GPR(R19)(r4)
	PPC_LL	r20, VCPU_GPR(R20)(r4)
	PPC_LL	r21, VCPU_GPR(R21)(r4)
	PPC_LL	r22, VCPU_GPR(R22)(r4)
	PPC_LL	r23, VCPU_GPR(R23)(r4)
	PPC_LL	r24, VCPU_GPR(R24)(r4)
	PPC_LL	r25, VCPU_GPR(R25)(r4)
	PPC_LL	r26, VCPU_GPR(R26)(r4)
	PPC_LL	r27, VCPU_GPR(R27)(r4)
	PPC_LL	r28, VCPU_GPR(R28)(r4)
	PPC_LL	r29, VCPU_GPR(R29)(r4)
	PPC_LL	r30, VCPU_GPR(R30)(r4)
	PPC_LL	r31, VCPU_GPR(R31)(r4)
skip_nv_load:
	/* Should we return to the guest? */
	andi.	r5, r3, RESUME_FLAG_HOST
	beq	lightweight_exit

	srawi	r3, r3, 2 /* Shift -ERR back down. */

heavyweight_exit:
	/* Not returning to guest. */
	PPC_LL	r5, HOST_STACK_LR(r1)
	lwz	r6, HOST_CR(r1)

	/*
	 * We already saved guest volatile register state; now save the
	 * non-volatiles.
	 */

	PPC_STL	r15, VCPU_GPR(R15)(r4)
	PPC_STL	r16, VCPU_GPR(R16)(r4)
	PPC_STL	r17, VCPU_GPR(R17)(r4)
	PPC_STL	r18, VCPU_GPR(R18)(r4)
	PPC_STL	r19, VCPU_GPR(R19)(r4)
	PPC_STL	r20, VCPU_GPR(R20)(r4)
	PPC_STL	r21, VCPU_GPR(R21)(r4)
	PPC_STL	r22, VCPU_GPR(R22)(r4)
	PPC_STL	r23, VCPU_GPR(R23)(r4)
	PPC_STL	r24, VCPU_GPR(R24)(r4)
	PPC_STL	r25, VCPU_GPR(R25)(r4)
	PPC_STL	r26, VCPU_GPR(R26)(r4)
	PPC_STL	r27, VCPU_GPR(R27)(r4)
	PPC_STL	r28, VCPU_GPR(R28)(r4)
	PPC_STL	r29, VCPU_GPR(R29)(r4)
	PPC_STL	r30, VCPU_GPR(R30)(r4)
	PPC_STL	r31, VCPU_GPR(R31)(r4)

	/* Load host non-volatile register state from host stack. */
	PPC_LL	r14, HOST_NV_GPR(R14)(r1)
	PPC_LL	r15, HOST_NV_GPR(R15)(r1)
	PPC_LL	r16, HOST_NV_GPR(R16)(r1)
	PPC_LL	r17, HOST_NV_GPR(R17)(r1)
	PPC_LL	r18, HOST_NV_GPR(R18)(r1)
	PPC_LL	r19, HOST_NV_GPR(R19)(r1)
	PPC_LL	r20, HOST_NV_GPR(R20)(r1)
	PPC_LL	r21, HOST_NV_GPR(R21)(r1)
	PPC_LL	r22, HOST_NV_GPR(R22)(r1)
	PPC_LL	r23, HOST_NV_GPR(R23)(r1)
	PPC_LL	r24, HOST_NV_GPR(R24)(r1)
	PPC_LL	r25, HOST_NV_GPR(R25)(r1)
	PPC_LL	r26, HOST_NV_GPR(R26)(r1)
	PPC_LL	r27, HOST_NV_GPR(R27)(r1)
	PPC_LL	r28, HOST_NV_GPR(R28)(r1)
	PPC_LL	r29, HOST_NV_GPR(R29)(r1)
	PPC_LL	r30, HOST_NV_GPR(R30)(r1)
	PPC_LL	r31, HOST_NV_GPR(R31)(r1)

	/* Return to kvm_vcpu_run(). */
	mtlr	r5
	mtcr	r6
	addi	r1, r1, HOST_STACK_SIZE
	/* r3 still contains the return code from kvmppc_handle_exit(). */
	blr

/* Registers:
 *  r3: kvm_run pointer
 *  r4: vcpu pointer
 */
_GLOBAL(__kvmppc_vcpu_run)
	stwu	r1, -HOST_STACK_SIZE(r1)
	PPC_STL	r1, VCPU_HOST_STACK(r4)	/* Save stack pointer to vcpu. */

	/* Save host state to stack. */
	PPC_STL	r3, HOST_RUN(r1)
	mflr	r3
	mfcr	r5
	PPC_STL	r3, HOST_STACK_LR(r1)

	stw	r5, HOST_CR(r1)

	/* Save host non-volatile register state to stack. */
	PPC_STL	r14, HOST_NV_GPR(R14)(r1)
	PPC_STL	r15, HOST_NV_GPR(R15)(r1)
	PPC_STL	r16, HOST_NV_GPR(R16)(r1)
	PPC_STL	r17, HOST_NV_GPR(R17)(r1)
	PPC_STL	r18, HOST_NV_GPR(R18)(r1)
	PPC_STL	r19, HOST_NV_GPR(R19)(r1)
	PPC_STL	r20, HOST_NV_GPR(R20)(r1)
	PPC_STL	r21, HOST_NV_GPR(R21)(r1)
	PPC_STL	r22, HOST_NV_GPR(R22)(r1)
	PPC_STL	r23, HOST_NV_GPR(R23)(r1)
	PPC_STL	r24, HOST_NV_GPR(R24)(r1)
	PPC_STL	r25, HOST_NV_GPR(R25)(r1)
	PPC_STL	r26, HOST_NV_GPR(R26)(r1)
	PPC_STL	r27, HOST_NV_GPR(R27)(r1)
	PPC_STL	r28, HOST_NV_GPR(R28)(r1)
	PPC_STL	r29, HOST_NV_GPR(R29)(r1)
	PPC_STL	r30, HOST_NV_GPR(R30)(r1)
	PPC_STL	r31, HOST_NV_GPR(R31)(r1)

	/* Load guest non-volatiles. */
	PPC_LL	r14, VCPU_GPR(R14)(r4)
	PPC_LL	r15, VCPU_GPR(R15)(r4)
	PPC_LL	r16, VCPU_GPR(R16)(r4)
	PPC_LL	r17, VCPU_GPR(R17)(r4)
	PPC_LL	r18, VCPU_GPR(R18)(r4)
	PPC_LL	r19, VCPU_GPR(R19)(r4)
	PPC_LL	r20, VCPU_GPR(R20)(r4)
	PPC_LL	r21, VCPU_GPR(R21)(r4)
	PPC_LL	r22, VCPU_GPR(R22)(r4)
	PPC_LL	r23, VCPU_GPR(R23)(r4)
	PPC_LL	r24, VCPU_GPR(R24)(r4)
	PPC_LL	r25, VCPU_GPR(R25)(r4)
	PPC_LL	r26, VCPU_GPR(R26)(r4)
	PPC_LL	r27, VCPU_GPR(R27)(r4)
	PPC_LL	r28, VCPU_GPR(R28)(r4)
	PPC_LL	r29, VCPU_GPR(R29)(r4)
	PPC_LL	r30, VCPU_GPR(R30)(r4)
	PPC_LL	r31, VCPU_GPR(R31)(r4)


lightweight_exit:
	PPC_STL	r2, HOST_R2(r1)

	mfspr	r3, SPRN_PID
	stw	r3, VCPU_HOST_PID(r4)
	lwz	r3, VCPU_GUEST_PID(r4)
	mtspr	SPRN_PID, r3

	PPC_LL	r11, VCPU_SHARED(r4)
	/* Disable MAS register updates via exception */
	mfspr	r3, SPRN_EPCR
	oris	r3, r3, SPRN_EPCR_DMIUH@h
	mtspr	SPRN_EPCR, r3
	isync
	/* Save host mas4 and mas6 and load guest MAS registers */
	mfspr	r3, SPRN_MAS4
	stw	r3, VCPU_HOST_MAS4(r4)
	mfspr	r3, SPRN_MAS6
	stw	r3, VCPU_HOST_MAS6(r4)
	lwz	r3, VCPU_SHARED_MAS0(r11)
	lwz	r5, VCPU_SHARED_MAS1(r11)
	PPC_LD(r6, VCPU_SHARED_MAS2, r11)
	lwz	r7, VCPU_SHARED_MAS7_3+4(r11)
	lwz	r8, VCPU_SHARED_MAS4(r11)
	mtspr	SPRN_MAS0, r3
	mtspr	SPRN_MAS1, r5
	mtspr	SPRN_MAS2, r6
	mtspr	SPRN_MAS3, r7
	mtspr	SPRN_MAS4, r8
	lwz	r3, VCPU_SHARED_MAS6(r11)
	lwz	r5, VCPU_SHARED_MAS7_3+0(r11)
	mtspr	SPRN_MAS6, r3
	mtspr	SPRN_MAS7, r5

	/*
	 * Host interrupt handlers may have clobbered these guest-readable
	 * SPRGs, so we need to reload them here with the guest's values.
	 */
	lwz	r3, VCPU_VRSAVE(r4)
	PPC_LD(r5, VCPU_SHARED_SPRG4, r11)
	mtspr	SPRN_VRSAVE, r3
	PPC_LD(r6, VCPU_SHARED_SPRG5, r11)
	mtspr	SPRN_SPRG4W, r5
	PPC_LD(r7, VCPU_SHARED_SPRG6, r11)
	mtspr	SPRN_SPRG5W, r6
	PPC_LD(r8, VCPU_SHARED_SPRG7, r11)
	mtspr	SPRN_SPRG6W, r7
	PPC_LD(r5, VCPU_SPRG9, r4)
	mtspr	SPRN_SPRG7W, r8
	mtspr	SPRN_SPRG9, r5

	/* Load some guest volatiles. */
	PPC_LL	r3, VCPU_LR(r4)
	PPC_LL	r5, VCPU_XER(r4)
	PPC_LL	r6, VCPU_CTR(r4)
	PPC_LL	r7, VCPU_CR(r4)
	PPC_LL	r8, VCPU_PC(r4)
	PPC_LD(r9, VCPU_SHARED_MSR, r11)
	PPC_LL	r0, VCPU_GPR(R0)(r4)
	PPC_LL	r1, VCPU_GPR(R1)(r4)
	PPC_LL	r2, VCPU_GPR(R2)(r4)
	PPC_LL	r10, VCPU_GPR(R10)(r4)
	PPC_LL	r11, VCPU_GPR(R11)(r4)
	PPC_LL	r12, VCPU_GPR(R12)(r4)
	PPC_LL	r13, VCPU_GPR(R13)(r4)
	mtlr	r3
	mtxer	r5
	mtctr	r6
	mtsrr0	r8
	mtsrr1	r9

#ifdef CONFIG_KVM_EXIT_TIMING
	/* save enter time */
1:
	mfspr	r6, SPRN_TBRU
	mfspr	r9, SPRN_TBRL
	mfspr	r8, SPRN_TBRU
	cmpw	r8, r6
	stw	r9, VCPU_TIMING_LAST_ENTER_TBL(r4)
	bne	1b
	stw	r8, VCPU_TIMING_LAST_ENTER_TBU(r4)
#endif

	/*
	 * Don't execute any instruction which can change CR after
	 * below instruction.
	 */
	mtcr	r7

	/* Finish loading guest volatiles and jump to guest. */
	PPC_LL	r5, VCPU_GPR(R5)(r4)
	PPC_LL	r6, VCPU_GPR(R6)(r4)
	PPC_LL	r7, VCPU_GPR(R7)(r4)
	PPC_LL	r8, VCPU_GPR(R8)(r4)
	PPC_LL	r9, VCPU_GPR(R9)(r4)

	PPC_LL	r3, VCPU_GPR(R3)(r4)
	PPC_LL	r4, VCPU_GPR(R4)(r4)
	rfi