Subject: [PATCH 1/2] KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures From: Paul Mackerras Date: 2016-07-28 6:11:18 This moves the transactional memory state save and restore sequences out of the guest entry/exit paths into separate procedures. This is so that these sequences can be used in going into and out of nap in a subsequent patch. The only code changes here are (a) saving and restore LR on the stack, since these new procedures get called with a bl instruction, (b) explicitly saving r1 into the PACA instead of assuming that HSTATE_HOST_R1(r13) is already set, and (c) removing an unnecessary and redundant setting of MSR[TM] that should have been removed by commit 9d4d0bdd9e0a ("KVM: PPC: Book3S HV: Add transactional memory support", 2013-09-24) but wasn't. Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 449 +++++++++++++++++--------------- 1 file changed, 237 insertions(+), 212 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 0d246fc..cfa4031 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -689,112 +689,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) #ifdef CONFIG_PPC_TRANSACTIONAL_MEM BEGIN_FTR_SECTION - b skip_tm -END_FTR_SECTION_IFCLR(CPU_FTR_TM) - - /* 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(r4) - ld r6, VCPU_TFIAR(r4) - ld r7, VCPU_TEXASR(r4) - mtspr SPRN_TFHAR, r5 - mtspr SPRN_TFIAR, r6 - mtspr SPRN_TEXASR, r7 - - ld r5, VCPU_MSR(r4) - rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 - beq skip_tm /* TM not active in guest */ - - /* 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, r4 - addi r3, r31, VCPU_FPRS_TM - bl load_fp_state - addi r3, r31, VCPU_VRS_TM - bl load_vr_state - mr r4, r31 - lwz r7, VCPU_VRSAVE_TM(r4) - mtspr SPRN_VRSAVE, r7 - - ld r5, VCPU_LR_TM(r4) - lwz r6, VCPU_CR_TM(r4) - ld r7, VCPU_CTR_TM(r4) - ld r8, VCPU_AMR_TM(r4) - ld r9, VCPU_TAR_TM(r4) - mtlr r5 - mtcr r6 - mtctr r7 - mtspr SPRN_AMR, r8 - mtspr SPRN_TAR, r9 - - /* - * 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(r4) - ld r30, VCPU_PPR_TM(r4) - - 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) - ld r29, HSTATE_DSCR(r13) - mtspr SPRN_DSCR, r29 - ld r4, HSTATE_KVM_VCPU(r13) - ld r1, HSTATE_HOST_R1(r13) - ld r2, PACATMSCRATCH(r13) - - /* Set the MSR RI since we have our registers back. */ - li r5, MSR_RI - mtmsrd r5, 1 -skip_tm: + bl kvmppc_restore_tm +END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif /* Load guest PMU registers */ @@ -875,12 +771,6 @@ BEGIN_FTR_SECTION /* Skip next section on POWER7 */ b 8f END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) - /* Turn on TM so we can access TFHAR/TFIAR/TEXASR */ - mfmsr r8 - li r0, 1 - rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG - mtmsrd r8 - /* Load up POWER8-specific registers */ ld r5, VCPU_IAMR(r4) lwz r6, VCPU_PSPB(r4) @@ -1470,106 +1360,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) #ifdef CONFIG_PPC_TRANSACTIONAL_MEM BEGIN_FTR_SECTION - b 2f -END_FTR_SECTION_IFCLR(CPU_FTR_TM) - /* Turn on TM. */ - mfmsr r8 - li r0, 1 - rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG - mtmsrd r8 - - ld r5, VCPU_MSR(r9) - rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 - beq 1f /* TM not active in guest. */ - - li r3, TM_CAUSE_KVM_RESCHED - - /* Clear the MSR RI since r1, r13 are all going to be foobar. */ - li r5, 0 - mtmsrd r5, 1 - - /* 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_KVM_VCPU(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 - ld r29, HSTATE_DSCR(r13) - mtspr SPRN_DSCR, r29 - - /* 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_HOST_R1(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 - 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) - - /* 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 r5, SPRN_TFHAR - mfspr r6, SPRN_TFIAR - mfspr r7, SPRN_TEXASR - std r5, VCPU_TFHAR(r9) - std r6, VCPU_TFIAR(r9) - std r7, VCPU_TEXASR(r9) -2: + bl kvmppc_save_tm +END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif /* Increment yield count if they have a VPA */ @@ -2694,6 +2486,239 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) mr r4,r31 blr +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +/* + * Save transactional state and TM-related registers. + * Called with r9 pointing to the vcpu struct. + * This can modify all checkpointed registers, but + * restores r1, r2 and r9 (vcpu pointer) before exit. + */ +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 + mtmsrd r8 + + ld r5, VCPU_MSR(r9) + rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 + beq 1f /* TM not active in guest. */ + + std r1, HSTATE_HOST_R1(r13) + li r3, TM_CAUSE_KVM_RESCHED + + /* Clear the MSR RI since r1, r13 are all going to be foobar. */ + li r5, 0 + mtmsrd r5, 1 + + /* 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_KVM_VCPU(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 + ld r29, HSTATE_DSCR(r13) + mtspr SPRN_DSCR, r29 + + /* 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_HOST_R1(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 + 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) + + /* 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 r5, SPRN_TFHAR + mfspr r6, SPRN_TFIAR + mfspr r7, SPRN_TEXASR + std r5, VCPU_TFHAR(r9) + std r6, VCPU_TFIAR(r9) + std r7, VCPU_TEXASR(r9) + + ld r0, PPC_LR_STKOFF(r1) + mtlr r0 + blr + +/* + * Restore transactional state and TM-related registers. + * Called with r4 pointing to the vcpu struct. + * This potentially modifies all checkpointed registers. + * It restores r1, r2, r4 from the PACA. + */ +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(r4) + ld r6, VCPU_TFIAR(r4) + ld r7, VCPU_TEXASR(r4) + mtspr SPRN_TFHAR, r5 + mtspr SPRN_TFIAR, r6 + mtspr SPRN_TEXASR, r7 + + ld r5, VCPU_MSR(r4) + rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 + beqlr /* TM not active in guest */ + std r1, HSTATE_HOST_R1(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, r4 + addi r3, r31, VCPU_FPRS_TM + bl load_fp_state + addi r3, r31, VCPU_VRS_TM + bl load_vr_state + mr r4, r31 + lwz r7, VCPU_VRSAVE_TM(r4) + mtspr SPRN_VRSAVE, r7 + + ld r5, VCPU_LR_TM(r4) + lwz r6, VCPU_CR_TM(r4) + ld r7, VCPU_CTR_TM(r4) + ld r8, VCPU_AMR_TM(r4) + ld r9, VCPU_TAR_TM(r4) + mtlr r5 + mtcr r6 + mtctr r7 + mtspr SPRN_AMR, r8 + mtspr SPRN_TAR, r9 + + /* + * 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(r4) + ld r30, VCPU_PPR_TM(r4) + + 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) + ld r29, HSTATE_DSCR(r13) + mtspr SPRN_DSCR, r29 + ld r4, HSTATE_KVM_VCPU(r13) + ld r1, HSTATE_HOST_R1(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 +#endif + /* * We come here if we get any exception or interrupt while we are * executing host real mode code while in guest MMU context. -- 2.8.0.rc3