diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_rmhandlers.S')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 60 |
1 files changed, 58 insertions, 2 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 07c8b5b0f9d2..974793435a2e 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -86,6 +86,12 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) lbz r4, LPPACA_PMCINUSE(r3) cmpwi r4, 0 beq 23f /* skip if not */ +BEGIN_FTR_SECTION + ld r3, HSTATE_MMCR(r13) + andi. r4, r3, MMCR0_PMAO_SYNC | MMCR0_PMAO + cmpwi r4, MMCR0_PMAO + beql kvmppc_fix_pmao +END_FTR_SECTION_IFSET(CPU_FTR_PMAO_BUG) lwz r3, HSTATE_PMC(r13) lwz r4, HSTATE_PMC + 4(r13) lwz r5, HSTATE_PMC + 8(r13) @@ -737,6 +743,12 @@ skip_tm: sldi r3, r3, 31 /* MMCR0_FC (freeze counters) bit */ mtspr SPRN_MMCR0, r3 /* freeze all counters, disable ints */ isync +BEGIN_FTR_SECTION + ld r3, VCPU_MMCR(r4) + andi. r5, r3, MMCR0_PMAO_SYNC | MMCR0_PMAO + cmpwi r5, MMCR0_PMAO + beql kvmppc_fix_pmao +END_FTR_SECTION_IFSET(CPU_FTR_PMAO_BUG) lwz r3, VCPU_PMC(r4) /* always load up guest PMU registers */ lwz r5, VCPU_PMC + 4(r4) /* to prevent information leak */ lwz r6, VCPU_PMC + 8(r4) @@ -1439,6 +1451,30 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM) 25: /* Save PMU registers if requested */ /* r8 and cr0.eq are live here */ +BEGIN_FTR_SECTION + /* + * POWER8 seems to have a hardware bug where setting + * MMCR0[PMAE] along with MMCR0[PMC1CE] and/or MMCR0[PMCjCE] + * when some counters are already negative doesn't seem + * to cause a performance monitor alert (and hence interrupt). + * The effect of this is that when saving the PMU state, + * if there is no PMU alert pending when we read MMCR0 + * before freezing the counters, but one becomes pending + * before we read the counters, we lose it. + * To work around this, we need a way to freeze the counters + * before reading MMCR0. Normally, freezing the counters + * is done by writing MMCR0 (to set MMCR0[FC]) which + * unavoidably writes MMCR0[PMA0] as well. On POWER8, + * we can also freeze the counters using MMCR2, by writing + * 1s to all the counter freeze condition bits (there are + * 9 bits each for 6 counters). + */ + li r3, -1 /* set all freeze bits */ + clrrdi r3, r3, 10 + mfspr r10, SPRN_MMCR2 + mtspr SPRN_MMCR2, r3 + isync +END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) li r3, 1 sldi r3, r3, 31 /* MMCR0_FC (freeze counters) bit */ mfspr r4, SPRN_MMCR0 /* save MMCR0 */ @@ -1462,6 +1498,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206) std r4, VCPU_MMCR(r9) std r5, VCPU_MMCR + 8(r9) std r6, VCPU_MMCR + 16(r9) +BEGIN_FTR_SECTION + std r10, VCPU_MMCR + 24(r9) +END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) std r7, VCPU_SIAR(r9) std r8, VCPU_SDAR(r9) mfspr r3, SPRN_PMC1 @@ -1485,12 +1524,10 @@ BEGIN_FTR_SECTION stw r11, VCPU_PMC + 28(r9) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201) BEGIN_FTR_SECTION - mfspr r4, SPRN_MMCR2 mfspr r5, SPRN_SIER mfspr r6, SPRN_SPMC1 mfspr r7, SPRN_SPMC2 mfspr r8, SPRN_MMCRS - std r4, VCPU_MMCR + 24(r9) std r5, VCPU_SIER(r9) stw r6, VCPU_PMC + 24(r9) stw r7, VCPU_PMC + 28(r9) @@ -2227,6 +2264,7 @@ machine_check_realmode: beq mc_cont /* If not, deliver a machine check. SRR0/1 are already set */ li r10, BOOK3S_INTERRUPT_MACHINE_CHECK + ld r11, VCPU_MSR(r9) bl kvmppc_msr_interrupt b fast_interrupt_c_return @@ -2431,3 +2469,21 @@ kvmppc_msr_interrupt: li r0, 1 1: rldimi r11, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG blr + +/* + * This works around a hardware bug on POWER8E processors, where + * writing a 1 to the MMCR0[PMAO] bit doesn't generate a + * performance monitor interrupt. Instead, when we need to have + * an interrupt pending, we have to arrange for a counter to overflow. + */ +kvmppc_fix_pmao: + li r3, 0 + mtspr SPRN_MMCR2, r3 + lis r3, (MMCR0_PMXE | MMCR0_FCECE)@h + ori r3, r3, MMCR0_PMCjCE | MMCR0_C56RUN + mtspr SPRN_MMCR0, r3 + lis r3, 0x7fff + ori r3, r3, 0xffff + mtspr SPRN_PMC6, r3 + isync + blr |