linux/arch/powerpc/kvm/bookehv_interrupts.S

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/* SPDX-License-Identifier: GPL-2.0-only */
/*
*
* 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)
START_BTB_FLUSH_SECTION
BTB_FLUSH(r10)
END_BTB_FLUSH_SECTION
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)
KVM: PPC: Bookehv: Get vcpu's last instruction for emulation On book3e, KVM uses load external pid (lwepx) dedicated instruction to read guest last instruction on the exit path. lwepx exceptions (DTLB_MISS, DSI and LRAT), generated by loading a guest address, needs to be handled by KVM. These exceptions are generated in a substituted guest translation context (EPLC[EGS] = 1) from host context (MSR[GS] = 0). Currently, KVM hooks only interrupts generated from guest context (MSR[GS] = 1), doing minimal checks on the fast path to avoid host performance degradation. lwepx exceptions originate from host state (MSR[GS] = 0) which implies additional checks in DO_KVM macro (beside the current MSR[GS] = 1) by looking at the Exception Syndrome Register (ESR[EPID]) and the External PID Load Context Register (EPLC[EGS]). Doing this on each Data TLB miss exception is obvious too intrusive for the host. Read guest last instruction from kvmppc_load_last_inst() by searching for the physical address and kmap it. This address the TODO for TLB eviction and execute-but-not-read entries, and allow us to get rid of lwepx until we are able to handle failures. A simple stress benchmark shows a 1% sys performance degradation compared with previous approach (lwepx without failure handling): time for i in `seq 1 10000`; do /bin/echo > /dev/null; done real 0m 8.85s user 0m 4.34s sys 0m 4.48s vs real 0m 8.84s user 0m 4.36s sys 0m 4.44s A solution to use lwepx and to handle its exceptions in KVM would be to temporary highjack the interrupt vector from host. This imposes additional synchronizations for cores like FSL e6500 that shares host IVOR registers between hardware threads. This optimized solution can be later developed on top of this patch. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-24 00:06:22 +08:00
/*
* 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)
powerpc/booke64: Use SPRG7 for VDSO Previously SPRG3 was marked for use by both VDSO and critical interrupts (though critical interrupts were not fully implemented). In commit 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad ("powerpc/booke64: Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman made an attempt to resolve this conflict by restoring the VDSO value early in the critical interrupt, but this has some issues: - It's incompatible with EXCEPTION_COMMON which restores r13 from the by-then-overwritten scratch (this cost me some debugging time). - It forces critical exceptions to be a special case handled differently from even machine check and debug level exceptions. - It didn't occur to me that it was possible to make this work at all (by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after I made (most of) this patch. :-) It might be worth investigating using a load rather than SPRG on return from all exceptions (except TLB misses where the scratch never leaves the SPRG) -- it could save a few cycles. Until then, let's stick with SPRG for all exceptions. Since we cannot use SPRG4-7 for scratch without corrupting the state of a KVM guest, move VDSO to SPRG7 on book3e. Since neither SPRG4-7 nor critical interrupts exist on book3s, SPRG3 is still used for VDSO there. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Mihai Caraman <mihai.caraman@freescale.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: kvm-ppc@vger.kernel.org
2014-03-11 06:29:38 +08:00
#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
powerpc/booke64: Use SPRG7 for VDSO Previously SPRG3 was marked for use by both VDSO and critical interrupts (though critical interrupts were not fully implemented). In commit 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad ("powerpc/booke64: Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman made an attempt to resolve this conflict by restoring the VDSO value early in the critical interrupt, but this has some issues: - It's incompatible with EXCEPTION_COMMON which restores r13 from the by-then-overwritten scratch (this cost me some debugging time). - It forces critical exceptions to be a special case handled differently from even machine check and debug level exceptions. - It didn't occur to me that it was possible to make this work at all (by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after I made (most of) this patch. :-) It might be worth investigating using a load rather than SPRG on return from all exceptions (except TLB misses where the scratch never leaves the SPRG) -- it could save a few cycles. Until then, let's stick with SPRG for all exceptions. Since we cannot use SPRG4-7 for scratch without corrupting the state of a KVM guest, move VDSO to SPRG7 on book3e. Since neither SPRG4-7 nor critical interrupts exist on book3s, SPRG3 is still used for VDSO there. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Mihai Caraman <mihai.caraman@freescale.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: kvm-ppc@vger.kernel.org
2014-03-11 06:29:38 +08:00
#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