linux/arch/powerpc/kvm/tm.S
Simon Guo 7284ca8a5e KVM: PPC: Book3S PR: Support TAR handling for PR KVM HTM
Currently guest kernel doesn't handle TAR facility unavailable and it
always runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not
a frequent-use register and it is not included in SVCPU struct.

Due to the above, the checkpointed TAR val might be a bogus TAR val.
To solve this issue, we will make vcpu->arch.fscr tar bit consistent
with shadow_fscr when TM is enabled.

At the end of emulating treclaim., the correct TAR val need to be loaded
into the register if FSCR_TAR bit is on.

At the beginning of emulating trechkpt., TAR needs to be flushed so that
the right tar val can be copied into tar_tm.

Tested with:
tools/testing/selftests/powerpc/tm/tm-tar
tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar (remove DSCR/PPR
related testing).

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-06-01 10:30:43 +10:00

385 lines
8.4 KiB
ArmAsm

/*
* 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.
*
* Derived from book3s_hv_rmhandlers.S, which is:
*
* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*
*/
#include <asm/reg.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/export.h>
#include <asm/tm.h>
#include <asm/cputable.h>
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
#define VCPU_GPRS_TM(reg) (((reg) * ULONG_SIZE) + VCPU_GPR_TM)
/*
* Save transactional state and TM-related registers.
* Called with:
* - r3 pointing to the vcpu struct
* - r4 points to the MSR with current TS bits:
* (For HV KVM, it is VCPU_MSR ; For PR KVM, it is host MSR).
* This can modify all checkpointed registers, but
* restores r1, r2 before exit.
*/
_GLOBAL(__kvmppc_save_tm)
mflr r0
std r0, PPC_LR_STKOFF(r1)
/* Turn on TM. */
mfmsr r8
li r0, 1
rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG
ori r8, r8, MSR_FP
oris r8, r8, (MSR_VEC | MSR_VSX)@h
mtmsrd r8
rldicl. r4, r4, 64 - MSR_TS_S_LG, 62
beq 1f /* TM not active in guest. */
std r1, HSTATE_SCRATCH2(r13)
std r3, HSTATE_SCRATCH1(r13)
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
BEGIN_FTR_SECTION
/* Emulation of the treclaim instruction needs TEXASR before treclaim */
mfspr r6, SPRN_TEXASR
std r6, VCPU_ORIG_TEXASR(r3)
END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
#endif
/* Clear the MSR RI since r1, r13 are all going to be foobar. */
li r5, 0
mtmsrd r5, 1
li r3, TM_CAUSE_KVM_RESCHED
/* All GPRs are volatile at this point. */
TRECLAIM(R3)
/* Temporarily store r13 and r9 so we have some regs to play with */
SET_SCRATCH0(r13)
GET_PACA(r13)
std r9, PACATMSCRATCH(r13)
ld r9, HSTATE_SCRATCH1(r13)
/* Get a few more GPRs free. */
std r29, VCPU_GPRS_TM(29)(r9)
std r30, VCPU_GPRS_TM(30)(r9)
std r31, VCPU_GPRS_TM(31)(r9)
/* Save away PPR and DSCR soon so don't run with user values. */
mfspr r31, SPRN_PPR
HMT_MEDIUM
mfspr r30, SPRN_DSCR
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
ld r29, HSTATE_DSCR(r13)
mtspr SPRN_DSCR, r29
#endif
/* Save all but r9, r13 & r29-r31 */
reg = 0
.rept 29
.if (reg != 9) && (reg != 13)
std reg, VCPU_GPRS_TM(reg)(r9)
.endif
reg = reg + 1
.endr
/* ... now save r13 */
GET_SCRATCH0(r4)
std r4, VCPU_GPRS_TM(13)(r9)
/* ... and save r9 */
ld r4, PACATMSCRATCH(r13)
std r4, VCPU_GPRS_TM(9)(r9)
/* Reload stack pointer and TOC. */
ld r1, HSTATE_SCRATCH2(r13)
ld r2, PACATOC(r13)
/* Set MSR RI now we have r1 and r13 back. */
li r5, MSR_RI
mtmsrd r5, 1
/* Save away checkpinted SPRs. */
std r31, VCPU_PPR_TM(r9)
std r30, VCPU_DSCR_TM(r9)
mflr r5
mfcr r6
mfctr r7
mfspr r8, SPRN_AMR
mfspr r10, SPRN_TAR
mfxer r11
std r5, VCPU_LR_TM(r9)
stw r6, VCPU_CR_TM(r9)
std r7, VCPU_CTR_TM(r9)
std r8, VCPU_AMR_TM(r9)
std r10, VCPU_TAR_TM(r9)
std r11, VCPU_XER_TM(r9)
/* Restore r12 as trap number. */
lwz r12, VCPU_TRAP(r9)
/* Save FP/VSX. */
addi r3, r9, VCPU_FPRS_TM
bl store_fp_state
addi r3, r9, VCPU_VRS_TM
bl store_vr_state
mfspr r6, SPRN_VRSAVE
stw r6, VCPU_VRSAVE_TM(r9)
1:
/*
* We need to save these SPRs after the treclaim so that the software
* error code is recorded correctly in the TEXASR. Also the user may
* change these outside of a transaction, so they must always be
* context switched.
*/
mfspr r7, SPRN_TEXASR
std r7, VCPU_TEXASR(r9)
11:
mfspr r5, SPRN_TFHAR
mfspr r6, SPRN_TFIAR
std r5, VCPU_TFHAR(r9)
std r6, VCPU_TFIAR(r9)
ld r0, PPC_LR_STKOFF(r1)
mtlr r0
blr
/*
* _kvmppc_save_tm_pr() is a wrapper around __kvmppc_save_tm(), so that it can
* be invoked from C function by PR KVM only.
*/
_GLOBAL(_kvmppc_save_tm_pr)
mflr r5
std r5, PPC_LR_STKOFF(r1)
stdu r1, -SWITCH_FRAME_SIZE(r1)
SAVE_NVGPRS(r1)
/* save MSR since TM/math bits might be impacted
* by __kvmppc_save_tm().
*/
mfmsr r5
SAVE_GPR(5, r1)
/* also save DSCR/CR/TAR so that it can be recovered later */
mfspr r6, SPRN_DSCR
SAVE_GPR(6, r1)
mfcr r7
stw r7, _CCR(r1)
mfspr r8, SPRN_TAR
SAVE_GPR(8, r1)
bl __kvmppc_save_tm
REST_GPR(8, r1)
mtspr SPRN_TAR, r8
ld r7, _CCR(r1)
mtcr r7
REST_GPR(6, r1)
mtspr SPRN_DSCR, r6
/* need preserve current MSR's MSR_TS bits */
REST_GPR(5, r1)
mfmsr r6
rldicl r6, r6, 64 - MSR_TS_S_LG, 62
rldimi r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG
mtmsrd r5
REST_NVGPRS(r1)
addi r1, r1, SWITCH_FRAME_SIZE
ld r5, PPC_LR_STKOFF(r1)
mtlr r5
blr
EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr);
/*
* Restore transactional state and TM-related registers.
* Called with:
* - r3 pointing to the vcpu struct.
* - r4 is the guest MSR with desired TS bits:
* For HV KVM, it is VCPU_MSR
* For PR KVM, it is provided by caller
* This potentially modifies all checkpointed registers.
* It restores r1, r2 from the PACA.
*/
_GLOBAL(__kvmppc_restore_tm)
mflr r0
std r0, PPC_LR_STKOFF(r1)
/* Turn on TM/FP/VSX/VMX so we can restore them. */
mfmsr r5
li r6, MSR_TM >> 32
sldi r6, r6, 32
or r5, r5, r6
ori r5, r5, MSR_FP
oris r5, r5, (MSR_VEC | MSR_VSX)@h
mtmsrd r5
/*
* The user may change these outside of a transaction, so they must
* always be context switched.
*/
ld r5, VCPU_TFHAR(r3)
ld r6, VCPU_TFIAR(r3)
ld r7, VCPU_TEXASR(r3)
mtspr SPRN_TFHAR, r5
mtspr SPRN_TFIAR, r6
mtspr SPRN_TEXASR, r7
mr r5, r4
rldicl. r5, r5, 64 - MSR_TS_S_LG, 62
beqlr /* TM not active in guest */
std r1, HSTATE_SCRATCH2(r13)
/* Make sure the failure summary is set, otherwise we'll program check
* when we trechkpt. It's possible that this might have been not set
* on a kvmppc_set_one_reg() call but we shouldn't let this crash the
* host.
*/
oris r7, r7, (TEXASR_FS)@h
mtspr SPRN_TEXASR, r7
/*
* We need to load up the checkpointed state for the guest.
* We need to do this early as it will blow away any GPRs, VSRs and
* some SPRs.
*/
mr r31, r3
addi r3, r31, VCPU_FPRS_TM
bl load_fp_state
addi r3, r31, VCPU_VRS_TM
bl load_vr_state
mr r3, r31
lwz r7, VCPU_VRSAVE_TM(r3)
mtspr SPRN_VRSAVE, r7
ld r5, VCPU_LR_TM(r3)
lwz r6, VCPU_CR_TM(r3)
ld r7, VCPU_CTR_TM(r3)
ld r8, VCPU_AMR_TM(r3)
ld r9, VCPU_TAR_TM(r3)
ld r10, VCPU_XER_TM(r3)
mtlr r5
mtcr r6
mtctr r7
mtspr SPRN_AMR, r8
mtspr SPRN_TAR, r9
mtxer r10
/*
* Load up PPR and DSCR values but don't put them in the actual SPRs
* till the last moment to avoid running with userspace PPR and DSCR for
* too long.
*/
ld r29, VCPU_DSCR_TM(r3)
ld r30, VCPU_PPR_TM(r3)
std r2, PACATMSCRATCH(r13) /* Save TOC */
/* Clear the MSR RI since r1, r13 are all going to be foobar. */
li r5, 0
mtmsrd r5, 1
/* Load GPRs r0-r28 */
reg = 0
.rept 29
ld reg, VCPU_GPRS_TM(reg)(r31)
reg = reg + 1
.endr
mtspr SPRN_DSCR, r29
mtspr SPRN_PPR, r30
/* Load final GPRs */
ld 29, VCPU_GPRS_TM(29)(r31)
ld 30, VCPU_GPRS_TM(30)(r31)
ld 31, VCPU_GPRS_TM(31)(r31)
/* TM checkpointed state is now setup. All GPRs are now volatile. */
TRECHKPT
/* Now let's get back the state we need. */
HMT_MEDIUM
GET_PACA(r13)
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
ld r29, HSTATE_DSCR(r13)
mtspr SPRN_DSCR, r29
#endif
ld r1, HSTATE_SCRATCH2(r13)
ld r2, PACATMSCRATCH(r13)
/* Set the MSR RI since we have our registers back. */
li r5, MSR_RI
mtmsrd r5, 1
ld r0, PPC_LR_STKOFF(r1)
mtlr r0
blr
/*
* _kvmppc_restore_tm_pr() is a wrapper around __kvmppc_restore_tm(), so that it
* can be invoked from C function by PR KVM only.
*/
_GLOBAL(_kvmppc_restore_tm_pr)
mflr r5
std r5, PPC_LR_STKOFF(r1)
stdu r1, -SWITCH_FRAME_SIZE(r1)
SAVE_NVGPRS(r1)
/* save MSR to avoid TM/math bits change */
mfmsr r5
SAVE_GPR(5, r1)
/* also save DSCR/CR/TAR so that it can be recovered later */
mfspr r6, SPRN_DSCR
SAVE_GPR(6, r1)
mfcr r7
stw r7, _CCR(r1)
mfspr r8, SPRN_TAR
SAVE_GPR(8, r1)
bl __kvmppc_restore_tm
REST_GPR(8, r1)
mtspr SPRN_TAR, r8
ld r7, _CCR(r1)
mtcr r7
REST_GPR(6, r1)
mtspr SPRN_DSCR, r6
/* need preserve current MSR's MSR_TS bits */
REST_GPR(5, r1)
mfmsr r6
rldicl r6, r6, 64 - MSR_TS_S_LG, 62
rldimi r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG
mtmsrd r5
REST_NVGPRS(r1)
addi r1, r1, SWITCH_FRAME_SIZE
ld r5, PPC_LR_STKOFF(r1)
mtlr r5
blr
EXPORT_SYMBOL_GPL(_kvmppc_restore_tm_pr);
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */