This is a note to let you know that I've just added the patch titled
KVM: x86/pmu: Move PMU reset logic to common x86 code
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-pmu-move-pmu-reset-logic-to-common-x86-code.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cbb359d81a2695bb5e63ec9de06fcbef28518891 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Fri, 3 Nov 2023 16:05:36 -0700
Subject: KVM: x86/pmu: Move PMU reset logic to common x86 code
From: Sean Christopherson <seanjc@xxxxxxxxxx>
commit cbb359d81a2695bb5e63ec9de06fcbef28518891 upstream.
Move the common (or at least "ignored") aspects of resetting the vPMU to
common x86 code, along with the stop/release helpers that are no used only
by the common pmu.c.
There is no need to manually handle fixed counters as all_valid_pmc_idx
tracks both fixed and general purpose counters, and resetting the vPMU is
far from a hot path, i.e. the extra bit of overhead to the PMC from the
index is a non-issue.
Zero fixed_ctr_ctrl in common code even though it's Intel specific.
Ensuring it's zero doesn't harm AMD/SVM in any way, and stopping the fixed
counters via all_valid_pmc_idx, but not clearing the associated control
bits, would be odd/confusing.
Make the .reset() hook optional as SVM no longer needs vendor specific
handling.
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231103230541.352265-2-seanjc@xxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm-x86-pmu-ops.h | 2 -
arch/x86/kvm/pmu.c | 40 ++++++++++++++++++++++++++++++++-
arch/x86/kvm/pmu.h | 18 --------------
arch/x86/kvm/svm/pmu.c | 16 -------------
arch/x86/kvm/vmx/pmu_intel.c | 20 ----------------
5 files changed, 40 insertions(+), 56 deletions(-)
--- a/arch/x86/include/asm/kvm-x86-pmu-ops.h
+++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h
@@ -22,7 +22,7 @@ KVM_X86_PMU_OP(get_msr)
KVM_X86_PMU_OP(set_msr)
KVM_X86_PMU_OP(refresh)
KVM_X86_PMU_OP(init)
-KVM_X86_PMU_OP(reset)
+KVM_X86_PMU_OP_OPTIONAL(reset)
KVM_X86_PMU_OP_OPTIONAL(deliver_pmi)
KVM_X86_PMU_OP_OPTIONAL(cleanup)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -250,6 +250,24 @@ static bool pmc_resume_counter(struct kv
return true;
}
+static void pmc_release_perf_event(struct kvm_pmc *pmc)
+{
+ if (pmc->perf_event) {
+ perf_event_release_kernel(pmc->perf_event);
+ pmc->perf_event = NULL;
+ pmc->current_config = 0;
+ pmc_to_pmu(pmc)->event_count--;
+ }
+}
+
+static void pmc_stop_counter(struct kvm_pmc *pmc)
+{
+ if (pmc->perf_event) {
+ pmc->counter = pmc_read_counter(pmc);
+ pmc_release_perf_event(pmc);
+ }
+}
+
static int filter_cmp(const void *pa, const void *pb, u64 mask)
{
u64 a = *(u64 *)pa & mask;
@@ -654,7 +672,27 @@ void kvm_pmu_refresh(struct kvm_vcpu *vc
void kvm_pmu_reset(struct kvm_vcpu *vcpu)
{
- static_call(kvm_x86_pmu_reset)(vcpu);
+ struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+ struct kvm_pmc *pmc;
+ int i;
+
+ bitmap_zero(pmu->reprogram_pmi, X86_PMC_IDX_MAX);
+
+ for_each_set_bit(i, pmu->all_valid_pmc_idx, X86_PMC_IDX_MAX) {
+ pmc = static_call(kvm_x86_pmu_pmc_idx_to_pmc)(pmu, i);
+ if (!pmc)
+ continue;
+
+ pmc_stop_counter(pmc);
+ pmc->counter = 0;
+
+ if (pmc_is_gp(pmc))
+ pmc->eventsel = 0;
+ }
+
+ pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = 0;
+
+ static_call_cond(kvm_x86_pmu_reset)(vcpu);
}
void kvm_pmu_init(struct kvm_vcpu *vcpu)
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -80,24 +80,6 @@ static inline void pmc_write_counter(str
pmc->counter &= pmc_bitmask(pmc);
}
-static inline void pmc_release_perf_event(struct kvm_pmc *pmc)
-{
- if (pmc->perf_event) {
- perf_event_release_kernel(pmc->perf_event);
- pmc->perf_event = NULL;
- pmc->current_config = 0;
- pmc_to_pmu(pmc)->event_count--;
- }
-}
-
-static inline void pmc_stop_counter(struct kvm_pmc *pmc)
-{
- if (pmc->perf_event) {
- pmc->counter = pmc_read_counter(pmc);
- pmc_release_perf_event(pmc);
- }
-}
-
static inline bool pmc_is_gp(struct kvm_pmc *pmc)
{
return pmc->type == KVM_PMC_GP;
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -233,21 +233,6 @@ static void amd_pmu_init(struct kvm_vcpu
}
}
-static void amd_pmu_reset(struct kvm_vcpu *vcpu)
-{
- struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
- int i;
-
- for (i = 0; i < KVM_AMD_PMC_MAX_GENERIC; i++) {
- struct kvm_pmc *pmc = &pmu->gp_counters[i];
-
- pmc_stop_counter(pmc);
- pmc->counter = pmc->prev_counter = pmc->eventsel = 0;
- }
-
- pmu->global_ctrl = pmu->global_status = 0;
-}
-
struct kvm_pmu_ops amd_pmu_ops __initdata = {
.hw_event_available = amd_hw_event_available,
.pmc_idx_to_pmc = amd_pmc_idx_to_pmc,
@@ -259,7 +244,6 @@ struct kvm_pmu_ops amd_pmu_ops __initdat
.set_msr = amd_pmu_set_msr,
.refresh = amd_pmu_refresh,
.init = amd_pmu_init,
- .reset = amd_pmu_reset,
.EVENTSEL_EVENT = AMD64_EVENTSEL_EVENT,
.MAX_NR_GP_COUNTERS = KVM_AMD_PMC_MAX_GENERIC,
.MIN_NR_GP_COUNTERS = AMD64_NUM_COUNTERS,
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -632,26 +632,6 @@ static void intel_pmu_init(struct kvm_vc
static void intel_pmu_reset(struct kvm_vcpu *vcpu)
{
- struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
- struct kvm_pmc *pmc = NULL;
- int i;
-
- for (i = 0; i < KVM_INTEL_PMC_MAX_GENERIC; i++) {
- pmc = &pmu->gp_counters[i];
-
- pmc_stop_counter(pmc);
- pmc->counter = pmc->prev_counter = pmc->eventsel = 0;
- }
-
- for (i = 0; i < KVM_PMC_MAX_FIXED; i++) {
- pmc = &pmu->fixed_counters[i];
-
- pmc_stop_counter(pmc);
- pmc->counter = pmc->prev_counter = 0;
- }
-
- pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = 0;
-
intel_pmu_release_guest_lbr_event(vcpu);
}
Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are
queue-6.6/kvm-x86-pmu-reset-the-pmu-i.e.-stop-counters-before-refreshing.patch
queue-6.6/kvm-x86-pmu-move-pmu-reset-logic-to-common-x86-code.patch
queue-6.6/x86-kvm-do-not-try-to-disable-kvmclock-if-it-was-not-enabled.patch
queue-6.6/revert-nsvm-check-for-reserved-encodings-of-tlb_control-in-nested-vmcb.patch
