KVM: x86/pmu: Move PMU reset logic to common x86 code

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@vger.kernel.org
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20231103230541.352265-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h
index 6c98f4b..058bc63 100644 (file)
--- 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)
 

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 9ae07db..027e9c3 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -250,6 +250,24 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc)
        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 *vcpu)
 
 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)

diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 1d64113..a46aa9b 100644 (file)
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -80,24 +80,6 @@ static inline void pmc_write_counter(struct kvm_pmc *pmc, u64 val)
        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;

diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 373ff6a..3fd47de 100644 (file)
--- 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 *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 __initdata = {
        .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,

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 820d3e1..90c1f7f 100644 (file)
--- 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_vcpu *vcpu)
 
 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);
 }