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8943633cf9
It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
176 lines
4.5 KiB
ArmAsm
176 lines
4.5 KiB
ArmAsm
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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*
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* Derived from book3s_interrupts.S, which is:
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* Copyright SUSE Linux Products GmbH 2009
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*
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* Authors: Alexander Graf <agraf@suse.de>
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*/
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#include <asm/ppc_asm.h>
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#include <asm/kvm_asm.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/asm-offsets.h>
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#include <asm/exception-64s.h>
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#include <asm/ppc-opcode.h>
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/*****************************************************************************
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* *
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* Guest entry / exit code that is in kernel module memory (vmalloc) *
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* *
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****************************************************************************/
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/* Registers:
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* r4: vcpu pointer
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*/
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_GLOBAL(__kvmppc_vcore_entry)
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/* Write correct stack frame */
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mflr r0
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std r0,PPC_LR_STKOFF(r1)
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/* Save host state to the stack */
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stdu r1, -SWITCH_FRAME_SIZE(r1)
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/* Save non-volatile registers (r14 - r31) and CR */
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SAVE_NVGPRS(r1)
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mfcr r3
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std r3, _CCR(r1)
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/* Save host DSCR */
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BEGIN_FTR_SECTION
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mfspr r3, SPRN_DSCR
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std r3, HSTATE_DSCR(r13)
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END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
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/* Save host DABR */
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mfspr r3, SPRN_DABR
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std r3, HSTATE_DABR(r13)
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/* Hard-disable interrupts */
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mfmsr r10
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std r10, HSTATE_HOST_MSR(r13)
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rldicl r10,r10,48,1
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rotldi r10,r10,16
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mtmsrd r10,1
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/* Save host PMU registers */
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/* R4 is live here (vcpu pointer) but not r3 or r5 */
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li r3, 1
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sldi r3, r3, 31 /* MMCR0_FC (freeze counters) bit */
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mfspr r7, SPRN_MMCR0 /* save MMCR0 */
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mtspr SPRN_MMCR0, r3 /* freeze all counters, disable interrupts */
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mfspr r6, SPRN_MMCRA
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BEGIN_FTR_SECTION
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/* On P7, clear MMCRA in order to disable SDAR updates */
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li r5, 0
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mtspr SPRN_MMCRA, r5
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END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
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isync
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ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */
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lbz r5, LPPACA_PMCINUSE(r3)
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cmpwi r5, 0
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beq 31f /* skip if not */
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mfspr r5, SPRN_MMCR1
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std r7, HSTATE_MMCR(r13)
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std r5, HSTATE_MMCR + 8(r13)
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std r6, HSTATE_MMCR + 16(r13)
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mfspr r3, SPRN_PMC1
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mfspr r5, SPRN_PMC2
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mfspr r6, SPRN_PMC3
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mfspr r7, SPRN_PMC4
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mfspr r8, SPRN_PMC5
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mfspr r9, SPRN_PMC6
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BEGIN_FTR_SECTION
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mfspr r10, SPRN_PMC7
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mfspr r11, SPRN_PMC8
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END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
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stw r3, HSTATE_PMC(r13)
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stw r5, HSTATE_PMC + 4(r13)
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stw r6, HSTATE_PMC + 8(r13)
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stw r7, HSTATE_PMC + 12(r13)
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stw r8, HSTATE_PMC + 16(r13)
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stw r9, HSTATE_PMC + 20(r13)
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BEGIN_FTR_SECTION
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stw r10, HSTATE_PMC + 24(r13)
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stw r11, HSTATE_PMC + 28(r13)
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END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
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31:
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/*
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* Put whatever is in the decrementer into the
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* hypervisor decrementer.
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*/
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mfspr r8,SPRN_DEC
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mftb r7
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mtspr SPRN_HDEC,r8
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extsw r8,r8
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add r8,r8,r7
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std r8,HSTATE_DECEXP(r13)
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/*
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* On PPC970, if the guest vcpu has an external interrupt pending,
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* send ourselves an IPI so as to interrupt the guest once it
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* enables interrupts. (It must have interrupts disabled,
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* otherwise we would already have delivered the interrupt.)
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*/
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BEGIN_FTR_SECTION
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ld r0, VCPU_PENDING_EXC(r4)
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li r7, (1 << BOOK3S_IRQPRIO_EXTERNAL)
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oris r7, r7, (1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
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and. r0, r0, r7
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beq 32f
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mr r31, r4
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lhz r3, PACAPACAINDEX(r13)
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bl smp_send_reschedule
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nop
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mr r4, r31
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32:
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END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
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/* Jump to partition switch code */
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bl .kvmppc_hv_entry_trampoline
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nop
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/*
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* We return here in virtual mode after the guest exits
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* with something that we can't handle in real mode.
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* Interrupts are enabled again at this point.
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*/
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.global kvmppc_handler_highmem
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kvmppc_handler_highmem:
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/*
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* Register usage at this point:
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*
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* R1 = host R1
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* R2 = host R2
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* R12 = exit handler id
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* R13 = PACA
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*/
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/* Restore non-volatile host registers (r14 - r31) and CR */
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REST_NVGPRS(r1)
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ld r4, _CCR(r1)
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mtcr r4
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addi r1, r1, SWITCH_FRAME_SIZE
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ld r0, PPC_LR_STKOFF(r1)
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mtlr r0
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blr
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