[PATCH v1 15/55] powerpc/64s: Always set PMU control registers to frozen/disabled when not in use
Nicholas Piggin
npiggin at gmail.com
Mon Jul 26 13:49:56 AEST 2021
KVM PMU management code looks for particular frozen/disabled bits in
the PMU registers so it knows whether it must clear them when coming
out of a guest or not. Setting this up helps KVM make these optimisations
without getting confused. Longer term the better approach might be to
move guest/host PMU switching to the perf subsystem.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/kernel/cpu_setup_power.c | 4 ++--
arch/powerpc/kernel/dt_cpu_ftrs.c | 6 +++---
arch/powerpc/kvm/book3s_hv.c | 5 +++++
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/cpu_setup_power.c b/arch/powerpc/kernel/cpu_setup_power.c
index a29dc8326622..3dc61e203f37 100644
--- a/arch/powerpc/kernel/cpu_setup_power.c
+++ b/arch/powerpc/kernel/cpu_setup_power.c
@@ -109,7 +109,7 @@ static void init_PMU_HV_ISA207(void)
static void init_PMU(void)
{
mtspr(SPRN_MMCRA, 0);
- mtspr(SPRN_MMCR0, 0);
+ mtspr(SPRN_MMCR0, MMCR0_FC);
mtspr(SPRN_MMCR1, 0);
mtspr(SPRN_MMCR2, 0);
}
@@ -123,7 +123,7 @@ static void init_PMU_ISA31(void)
{
mtspr(SPRN_MMCR3, 0);
mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);
- mtspr(SPRN_MMCR0, MMCR0_PMCCEXT);
+ mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);
}
/*
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 38ea20fadc4a..a6bb0ee179cd 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -353,7 +353,7 @@ static void init_pmu_power8(void)
}
mtspr(SPRN_MMCRA, 0);
- mtspr(SPRN_MMCR0, 0);
+ mtspr(SPRN_MMCR0, MMCR0_FC);
mtspr(SPRN_MMCR1, 0);
mtspr(SPRN_MMCR2, 0);
mtspr(SPRN_MMCRS, 0);
@@ -392,7 +392,7 @@ static void init_pmu_power9(void)
mtspr(SPRN_MMCRC, 0);
mtspr(SPRN_MMCRA, 0);
- mtspr(SPRN_MMCR0, 0);
+ mtspr(SPRN_MMCR0, MMCR0_FC);
mtspr(SPRN_MMCR1, 0);
mtspr(SPRN_MMCR2, 0);
}
@@ -428,7 +428,7 @@ static void init_pmu_power10(void)
mtspr(SPRN_MMCR3, 0);
mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);
- mtspr(SPRN_MMCR0, MMCR0_PMCCEXT);
+ mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);
}
static int __init feat_enable_pmu_power10(struct dt_cpu_feature *f)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ab89db561c85..2eef708c4354 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2691,6 +2691,11 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
#endif
#endif
vcpu->arch.mmcr[0] = MMCR0_FC;
+ if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+ vcpu->arch.mmcr[0] |= MMCR0_PMCCEXT;
+ vcpu->arch.mmcra = MMCRA_BHRB_DISABLE;
+ }
+
vcpu->arch.ctrl = CTRL_RUNLATCH;
/* default to host PVR, since we can't spoof it */
kvmppc_set_pvr_hv(vcpu, mfspr(SPRN_PVR));
--
2.23.0
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