linux/arch/powerpc/kvm/book3s_segment.S

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/*
* 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 SUSE Linux Products GmbH 2010
*
* Authors: Alexander Graf <agraf@suse.de>
*/
/* Real mode helpers */
#if defined(CONFIG_PPC_BOOK3S_64)
#define GET_SHADOW_VCPU(reg) \
addi reg, r13, PACA_KVM_SVCPU
#elif defined(CONFIG_PPC_BOOK3S_32)
#define GET_SHADOW_VCPU(reg) \
tophys(reg, r2); \
lwz reg, (THREAD + THREAD_KVM_SVCPU)(reg); \
tophys(reg, reg)
#endif
/* Disable for nested KVM */
#define USE_QUICK_LAST_INST
/* Get helper functions for subarch specific functionality */
#if defined(CONFIG_PPC_BOOK3S_64)
#include "book3s_64_slb.S"
#elif defined(CONFIG_PPC_BOOK3S_32)
#include "book3s_32_sr.S"
#endif
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
.global kvmppc_handler_trampoline_enter
kvmppc_handler_trampoline_enter:
/* Required state:
*
* MSR = ~IR|DR
* R13 = PACA
* R1 = host R1
* R2 = host R2
* R10 = guest MSR
* all other volatile GPRS = free
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
*/
/* r3 = shadow vcpu */
GET_SHADOW_VCPU(r3)
/* Move SRR0 and SRR1 into the respective regs */
PPC_LL r9, SVCPU_PC(r3)
mtsrr0 r9
mtsrr1 r10
/* Activate guest mode, so faults get handled by KVM */
li r11, KVM_GUEST_MODE_GUEST
stb r11, SVCPU_IN_GUEST(r3)
/* Switch to guest segment. This is subarch specific. */
LOAD_GUEST_SEGMENTS
/* Enter guest */
PPC_LL r4, (SVCPU_CTR)(r3)
PPC_LL r5, (SVCPU_LR)(r3)
lwz r6, (SVCPU_CR)(r3)
lwz r7, (SVCPU_XER)(r3)
mtctr r4
mtlr r5
mtcr r6
mtxer r7
PPC_LL r0, (SVCPU_R0)(r3)
PPC_LL r1, (SVCPU_R1)(r3)
PPC_LL r2, (SVCPU_R2)(r3)
PPC_LL r4, (SVCPU_R4)(r3)
PPC_LL r5, (SVCPU_R5)(r3)
PPC_LL r6, (SVCPU_R6)(r3)
PPC_LL r7, (SVCPU_R7)(r3)
PPC_LL r8, (SVCPU_R8)(r3)
PPC_LL r9, (SVCPU_R9)(r3)
PPC_LL r10, (SVCPU_R10)(r3)
PPC_LL r11, (SVCPU_R11)(r3)
PPC_LL r12, (SVCPU_R12)(r3)
PPC_LL r13, (SVCPU_R13)(r3)
PPC_LL r3, (SVCPU_R3)(r3)
RFI
kvmppc_handler_trampoline_enter_end:
/******************************************************************************
* *
* Exit code *
* *
*****************************************************************************/
.global kvmppc_handler_trampoline_exit
kvmppc_handler_trampoline_exit:
/* Register usage at this point:
*
* SPRG_SCRATCH0 = guest R13
* R12 = exit handler id
* R13 = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
* SVCPU.SCRATCH0 = guest R12
* SVCPU.SCRATCH1 = guest CR
*
*/
/* Save registers */
PPC_STL r0, (SHADOW_VCPU_OFF + SVCPU_R0)(r13)
PPC_STL r1, (SHADOW_VCPU_OFF + SVCPU_R1)(r13)
PPC_STL r2, (SHADOW_VCPU_OFF + SVCPU_R2)(r13)
PPC_STL r3, (SHADOW_VCPU_OFF + SVCPU_R3)(r13)
PPC_STL r4, (SHADOW_VCPU_OFF + SVCPU_R4)(r13)
PPC_STL r5, (SHADOW_VCPU_OFF + SVCPU_R5)(r13)
PPC_STL r6, (SHADOW_VCPU_OFF + SVCPU_R6)(r13)
PPC_STL r7, (SHADOW_VCPU_OFF + SVCPU_R7)(r13)
PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_R8)(r13)
PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_R9)(r13)
PPC_STL r10, (SHADOW_VCPU_OFF + SVCPU_R10)(r13)
PPC_STL r11, (SHADOW_VCPU_OFF + SVCPU_R11)(r13)
/* Restore R1/R2 so we can handle faults */
PPC_LL r1, (SHADOW_VCPU_OFF + SVCPU_HOST_R1)(r13)
PPC_LL r2, (SHADOW_VCPU_OFF + SVCPU_HOST_R2)(r13)
/* Save guest PC and MSR */
mfsrr0 r3
mfsrr1 r4
PPC_STL r3, (SHADOW_VCPU_OFF + SVCPU_PC)(r13)
PPC_STL r4, (SHADOW_VCPU_OFF + SVCPU_SHADOW_SRR1)(r13)
/* Get scratch'ed off registers */
mfspr r9, SPRN_SPRG_SCRATCH0
PPC_LL r8, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
lwz r7, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_R13)(r13)
PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_R12)(r13)
stw r7, (SHADOW_VCPU_OFF + SVCPU_CR)(r13)
/* Save more register state */
mfxer r5
mfdar r6
mfdsisr r7
mfctr r8
mflr r9
stw r5, (SHADOW_VCPU_OFF + SVCPU_XER)(r13)
PPC_STL r6, (SHADOW_VCPU_OFF + SVCPU_FAULT_DAR)(r13)
stw r7, (SHADOW_VCPU_OFF + SVCPU_FAULT_DSISR)(r13)
PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_CTR)(r13)
PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_LR)(r13)
/*
* In order for us to easily get the last instruction,
* we got the #vmexit at, we exploit the fact that the
* virtual layout is still the same here, so we can just
* ld from the guest's PC address
*/
/* We only load the last instruction when it's safe */
cmpwi r12, BOOK3S_INTERRUPT_DATA_STORAGE
beq ld_last_inst
cmpwi r12, BOOK3S_INTERRUPT_PROGRAM
beq ld_last_inst
cmpwi r12, BOOK3S_INTERRUPT_ALIGNMENT
beq- ld_last_inst
b no_ld_last_inst
ld_last_inst:
/* Save off the guest instruction we're at */
/* In case lwz faults */
li r0, KVM_INST_FETCH_FAILED
#ifdef USE_QUICK_LAST_INST
/* Set guest mode to 'jump over instruction' so if lwz faults
* we'll just continue at the next IP. */
li r9, KVM_GUEST_MODE_SKIP
stb r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)
/* 1) enable paging for data */
mfmsr r9
ori r11, r9, MSR_DR /* Enable paging for data */
mtmsr r11
sync
/* 2) fetch the instruction */
lwz r0, 0(r3)
/* 3) disable paging again */
mtmsr r9
sync
#endif
stw r0, (SHADOW_VCPU_OFF + SVCPU_LAST_INST)(r13)
no_ld_last_inst:
/* Unset guest mode */
li r9, KVM_GUEST_MODE_NONE
stb r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)
/* Switch back to host MMU */
LOAD_HOST_SEGMENTS
/* Register usage at this point:
*
* R1 = host R1
* R2 = host R2
* R12 = exit handler id
* R13 = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
* SVCPU.* = guest *
*
*/
/* RFI into the highmem handler */
mfmsr r7
ori r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME /* Enable paging */
mtsrr1 r7
/* Load highmem handler address */
PPC_LL r8, (SHADOW_VCPU_OFF + SVCPU_VMHANDLER)(r13)
mtsrr0 r8
RFI
kvmppc_handler_trampoline_exit_end: