Linux-2.6.33.2/arch/powerpc/kvm/book3s_64_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 SUSE Linux Products GmbH 2009
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#include <asm/ppc_asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>
#include <asm/exception-64s.h>
#define KVMPPC_HANDLE_EXIT .kvmppc_handle_exit
#define ULONG_SIZE 8
#define VCPU_GPR(n) (VCPU_GPRS + (n * ULONG_SIZE))
.macro mfpaca tmp_reg, src_reg, offset, vcpu_reg
ld \tmp_reg, (PACA_EXMC+\offset)(r13)
std \tmp_reg, VCPU_GPR(\src_reg)(\vcpu_reg)
.endm
.macro DISABLE_INTERRUPTS
mfmsr r0
rldicl r0,r0,48,1
rotldi r0,r0,16
mtmsrd r0,1
.endm
/*****************************************************************************
* *
* Guest entry / exit code that is in kernel module memory (highmem) *
* *
****************************************************************************/
/* Registers:
* r3: kvm_run pointer
* r4: vcpu pointer
*/
_GLOBAL(__kvmppc_vcpu_entry)
kvm_start_entry:
/* Write correct stack frame */
mflr r0
std r0,16(r1)
/* Save host state to the stack */
stdu r1, -SWITCH_FRAME_SIZE(r1)
/* Save r3 (kvm_run) and r4 (vcpu) */
SAVE_2GPRS(3, r1)
/* Save non-volatile registers (r14 - r31) */
SAVE_NVGPRS(r1)
/* Save LR */
mflr r14
std r14, _LINK(r1)
/* XXX optimize non-volatile loading away */
kvm_start_lightweight:
DISABLE_INTERRUPTS
/* Save R1/R2 in the PACA */
std r1, PACAR1(r13)
std r2, (PACA_EXMC+EX_SRR0)(r13)
ld r3, VCPU_HIGHMEM_HANDLER(r4)
std r3, PACASAVEDMSR(r13)
/* Load non-volatile guest state from the vcpu */
ld r14, VCPU_GPR(r14)(r4)
ld r15, VCPU_GPR(r15)(r4)
ld r16, VCPU_GPR(r16)(r4)
ld r17, VCPU_GPR(r17)(r4)
ld r18, VCPU_GPR(r18)(r4)
ld r19, VCPU_GPR(r19)(r4)
ld r20, VCPU_GPR(r20)(r4)
ld r21, VCPU_GPR(r21)(r4)
ld r22, VCPU_GPR(r22)(r4)
ld r23, VCPU_GPR(r23)(r4)
ld r24, VCPU_GPR(r24)(r4)
ld r25, VCPU_GPR(r25)(r4)
ld r26, VCPU_GPR(r26)(r4)
ld r27, VCPU_GPR(r27)(r4)
ld r28, VCPU_GPR(r28)(r4)
ld r29, VCPU_GPR(r29)(r4)
ld r30, VCPU_GPR(r30)(r4)
ld r31, VCPU_GPR(r31)(r4)
ld r9, VCPU_PC(r4) /* r9 = vcpu->arch.pc */
ld r10, VCPU_SHADOW_MSR(r4) /* r10 = vcpu->arch.shadow_msr */
ld r3, VCPU_TRAMPOLINE_ENTER(r4)
mtsrr0 r3
LOAD_REG_IMMEDIATE(r3, MSR_KERNEL & ~(MSR_IR | MSR_DR))
mtsrr1 r3
/* Load guest state in the respective registers */
lwz r3, VCPU_CR(r4) /* r3 = vcpu->arch.cr */
stw r3, (PACA_EXMC + EX_CCR)(r13)
ld r3, VCPU_CTR(r4) /* r3 = vcpu->arch.ctr */
mtctr r3 /* CTR = r3 */
ld r3, VCPU_LR(r4) /* r3 = vcpu->arch.lr */
mtlr r3 /* LR = r3 */
ld r3, VCPU_XER(r4) /* r3 = vcpu->arch.xer */
std r3, (PACA_EXMC + EX_R3)(r13)
/* Some guests may need to have dcbz set to 32 byte length.
*
* Usually we ensure that by patching the guest's instructions
* to trap on dcbz and emulate it in the hypervisor.
*
* If we can, we should tell the CPU to use 32 byte dcbz though,
* because that's a lot faster.
*/
ld r3, VCPU_HFLAGS(r4)
rldicl. r3, r3, 0, 63 /* CR = ((r3 & 1) == 0) */
beq no_dcbz32_on
mfspr r3,SPRN_HID5
ori r3, r3, 0x80 /* XXX HID5_dcbz32 = 0x80 */
mtspr SPRN_HID5,r3
no_dcbz32_on:
/* Load guest GPRs */
ld r3, VCPU_GPR(r9)(r4)
std r3, (PACA_EXMC + EX_R9)(r13)
ld r3, VCPU_GPR(r10)(r4)
std r3, (PACA_EXMC + EX_R10)(r13)
ld r3, VCPU_GPR(r11)(r4)
std r3, (PACA_EXMC + EX_R11)(r13)
ld r3, VCPU_GPR(r12)(r4)
std r3, (PACA_EXMC + EX_R12)(r13)
ld r3, VCPU_GPR(r13)(r4)
std r3, (PACA_EXMC + EX_R13)(r13)
ld r0, VCPU_GPR(r0)(r4)
ld r1, VCPU_GPR(r1)(r4)
ld r2, VCPU_GPR(r2)(r4)
ld r3, VCPU_GPR(r3)(r4)
ld r5, VCPU_GPR(r5)(r4)
ld r6, VCPU_GPR(r6)(r4)
ld r7, VCPU_GPR(r7)(r4)
ld r8, VCPU_GPR(r8)(r4)
ld r4, VCPU_GPR(r4)(r4)
/* This sets the Magic value for the trampoline */
li r11, 1
stb r11, PACA_KVM_IN_GUEST(r13)
/* Jump to SLB patching handlder and into our guest */
RFI
/*
* This is the handler in module memory. It gets jumped at from the
* lowmem trampoline code, so it's basically the guest exit code.
*
*/
.global kvmppc_handler_highmem
kvmppc_handler_highmem:
/*
* Register usage at this point:
*
* R00 = guest R13
* R01 = host R1
* R02 = host R2
* R10 = guest PC
* R11 = guest MSR
* R12 = exit handler id
* R13 = PACA
* PACA.exmc.R9 = guest R1
* PACA.exmc.R10 = guest R10
* PACA.exmc.R11 = guest R11
* PACA.exmc.R12 = guest R12
* PACA.exmc.R13 = guest R2
* PACA.exmc.DAR = guest DAR
* PACA.exmc.DSISR = guest DSISR
* PACA.exmc.LR = guest instruction
* PACA.exmc.CCR = guest CR
* PACA.exmc.SRR0 = guest R0
*
*/
std r3, (PACA_EXMC+EX_R3)(r13)
/* save the exit id in R3 */
mr r3, r12
/* R12 = vcpu */
ld r12, GPR4(r1)
/* Now save the guest state */
std r0, VCPU_GPR(r13)(r12)
std r4, VCPU_GPR(r4)(r12)
std r5, VCPU_GPR(r5)(r12)
std r6, VCPU_GPR(r6)(r12)
std r7, VCPU_GPR(r7)(r12)
std r8, VCPU_GPR(r8)(r12)
std r9, VCPU_GPR(r9)(r12)
/* get registers from PACA */
mfpaca r5, r0, EX_SRR0, r12
mfpaca r5, r3, EX_R3, r12
mfpaca r5, r1, EX_R9, r12
mfpaca r5, r10, EX_R10, r12
mfpaca r5, r11, EX_R11, r12
mfpaca r5, r12, EX_R12, r12
mfpaca r5, r2, EX_R13, r12
lwz r5, (PACA_EXMC+EX_LR)(r13)
stw r5, VCPU_LAST_INST(r12)
lwz r5, (PACA_EXMC+EX_CCR)(r13)
stw r5, VCPU_CR(r12)
ld r5, VCPU_HFLAGS(r12)
rldicl. r5, r5, 0, 63 /* CR = ((r5 & 1) == 0) */
beq no_dcbz32_off
mfspr r5,SPRN_HID5
rldimi r5,r5,6,56
mtspr SPRN_HID5,r5
no_dcbz32_off:
/* XXX maybe skip on lightweight? */
std r14, VCPU_GPR(r14)(r12)
std r15, VCPU_GPR(r15)(r12)
std r16, VCPU_GPR(r16)(r12)
std r17, VCPU_GPR(r17)(r12)
std r18, VCPU_GPR(r18)(r12)
std r19, VCPU_GPR(r19)(r12)
std r20, VCPU_GPR(r20)(r12)
std r21, VCPU_GPR(r21)(r12)
std r22, VCPU_GPR(r22)(r12)
std r23, VCPU_GPR(r23)(r12)
std r24, VCPU_GPR(r24)(r12)
std r25, VCPU_GPR(r25)(r12)
std r26, VCPU_GPR(r26)(r12)
std r27, VCPU_GPR(r27)(r12)
std r28, VCPU_GPR(r28)(r12)
std r29, VCPU_GPR(r29)(r12)
std r30, VCPU_GPR(r30)(r12)
std r31, VCPU_GPR(r31)(r12)
/* Restore non-volatile host registers (r14 - r31) */
REST_NVGPRS(r1)
/* Save guest PC (R10) */
std r10, VCPU_PC(r12)
/* Save guest msr (R11) */
std r11, VCPU_SHADOW_MSR(r12)
/* Save guest CTR (in R12) */
mfctr r5
std r5, VCPU_CTR(r12)
/* Save guest LR */
mflr r5
std r5, VCPU_LR(r12)
/* Save guest XER */
mfxer r5
std r5, VCPU_XER(r12)
/* Save guest DAR */
ld r5, (PACA_EXMC+EX_DAR)(r13)
std r5, VCPU_FAULT_DEAR(r12)
/* Save guest DSISR */
lwz r5, (PACA_EXMC+EX_DSISR)(r13)
std r5, VCPU_FAULT_DSISR(r12)
/* Restore host msr -> SRR1 */
ld r7, VCPU_HOST_MSR(r12)
mtsrr1 r7
/* Restore host IP -> SRR0 */
ld r6, VCPU_HOST_RETIP(r12)
mtsrr0 r6
/*
* For some interrupts, we need to call the real Linux
* handler, so it can do work for us. This has to happen
* as if the interrupt arrived from the kernel though,
* so let's fake it here where most state is restored.
*
* Call Linux for hardware interrupts/decrementer
* r3 = address of interrupt handler (exit reason)
*/
cmpwi r3, BOOK3S_INTERRUPT_EXTERNAL
beq call_linux_handler
cmpwi r3, BOOK3S_INTERRUPT_DECREMENTER
beq call_linux_handler
/* Back to Interruptable Mode! (goto kvm_return_point) */
RFI
call_linux_handler:
/*
* If we land here we need to jump back to the handler we
* came from.
*
* We have a page that we can access from real mode, so let's
* jump back to that and use it as a trampoline to get back into the
* interrupt handler!
*
* R3 still contains the exit code,
* R6 VCPU_HOST_RETIP and
* R7 VCPU_HOST_MSR
*/
mtlr r3
ld r5, VCPU_TRAMPOLINE_LOWMEM(r12)
mtsrr0 r5
LOAD_REG_IMMEDIATE(r5, MSR_KERNEL & ~(MSR_IR | MSR_DR))
mtsrr1 r5
RFI
.global kvm_return_point
kvm_return_point:
/* Jump back to lightweight entry if we're supposed to */
/* go back into the guest */
mr r5, r3
/* Restore r3 (kvm_run) and r4 (vcpu) */
REST_2GPRS(3, r1)
bl KVMPPC_HANDLE_EXIT
#if 0 /* XXX get lightweight exits back */
cmpwi r3, RESUME_GUEST
bne kvm_exit_heavyweight
/* put VCPU and KVM_RUN back into place and roll again! */
REST_2GPRS(3, r1)
b kvm_start_lightweight
kvm_exit_heavyweight:
/* Restore non-volatile host registers */
ld r14, _LINK(r1)
mtlr r14
REST_NVGPRS(r1)
addi r1, r1, SWITCH_FRAME_SIZE
#else
ld r4, _LINK(r1)
mtlr r4
cmpwi r3, RESUME_GUEST
bne kvm_exit_heavyweight
REST_2GPRS(3, r1)
addi r1, r1, SWITCH_FRAME_SIZE
b kvm_start_entry
kvm_exit_heavyweight:
addi r1, r1, SWITCH_FRAME_SIZE
#endif
blr