KVM: x86/vPMU: whitespace and stylistic adjustments in PMU code

Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 38819bc..24d213b 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -103,25 +103,31 @@ static void kvm_perf_overflow(struct perf_event *perf_event,
 {
        struct kvm_pmc *pmc = perf_event->overflow_handler_context;
        struct kvm_pmu *pmu = pmc_to_pmu(pmc);
-       if (!test_and_set_bit(pmc->idx, (unsigned long *)&pmu->reprogram_pmi)) {
+
+       if (!test_and_set_bit(pmc->idx,
+                             (unsigned long *)&pmu->reprogram_pmi)) {
                __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
                kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
        }
 }
 
 static void kvm_perf_overflow_intr(struct perf_event *perf_event,
-               struct perf_sample_data *data, struct pt_regs *regs)
+                                  struct perf_sample_data *data,
+                                  struct pt_regs *regs)
 {
        struct kvm_pmc *pmc = perf_event->overflow_handler_context;
        struct kvm_pmu *pmu = pmc_to_pmu(pmc);
-       if (!test_and_set_bit(pmc->idx, (unsigned long *)&pmu->reprogram_pmi)) {
+
+       if (!test_and_set_bit(pmc->idx,
+                             (unsigned long *)&pmu->reprogram_pmi)) {
                __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
                kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
+
                /*
                 * Inject PMI. If vcpu was in a guest mode during NMI PMI
                 * can be ejected on a guest mode re-entry. Otherwise we can't
                 * be sure that vcpu wasn't executing hlt instruction at the
-                * time of vmexit and is not going to re-enter guest mode until,
+                * time of vmexit and is not going to re-enter guest mode until
                 * woken up. So we should wake it, but this is impossible from
                 * NMI context. Do it from irq work instead.
                 */
@@ -157,8 +163,9 @@ static void pmc_stop_counter(struct kvm_pmc *pmc)
 }
 
 static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
-               unsigned config, bool exclude_user, bool exclude_kernel,
-               bool intr, bool in_tx, bool in_tx_cp)
+                                 unsigned config, bool exclude_user,
+                                 bool exclude_kernel, bool intr,
+                                 bool in_tx, bool in_tx_cp)
 {
        struct perf_event *event;
        struct perf_event_attr attr = {
@@ -171,6 +178,7 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
                .exclude_kernel = exclude_kernel,
                .config = config,
        };
+
        if (in_tx)
                attr.config |= HSW_IN_TX;
        if (in_tx_cp)
@@ -182,8 +190,8 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
                                                 intr ? kvm_perf_overflow_intr :
                                                 kvm_perf_overflow, pmc);
        if (IS_ERR(event)) {
-               printk_once("kvm: pmu event creation failed %ld\n",
-                               PTR_ERR(event));
+               printk_once("kvm_pmu: event creation failed %ld\n",
+                           PTR_ERR(event));
                return;
        }
 
@@ -227,10 +235,10 @@ static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
        unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
 
        if (!(eventsel & (ARCH_PERFMON_EVENTSEL_EDGE |
-                               ARCH_PERFMON_EVENTSEL_INV |
-                               ARCH_PERFMON_EVENTSEL_CMASK |
-                               HSW_IN_TX |
-                               HSW_IN_TX_CHECKPOINTED))) {
+                         ARCH_PERFMON_EVENTSEL_INV |
+                         ARCH_PERFMON_EVENTSEL_CMASK |
+                         HSW_IN_TX |
+                         HSW_IN_TX_CHECKPOINTED))) {
                config = find_arch_event(pmc_to_pmu(pmc), event_select,
                                unit_mask);
                if (config != PERF_COUNT_HW_MAX)
@@ -241,28 +249,28 @@ static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
                config = eventsel & X86_RAW_EVENT_MASK;
 
        pmc_reprogram_counter(pmc, type, config,
-                       !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
-                       !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
-                       eventsel & ARCH_PERFMON_EVENTSEL_INT,
-                       (eventsel & HSW_IN_TX),
-                       (eventsel & HSW_IN_TX_CHECKPOINTED));
+                             !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
+                             !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
+                             eventsel & ARCH_PERFMON_EVENTSEL_INT,
+                             (eventsel & HSW_IN_TX),
+                             (eventsel & HSW_IN_TX_CHECKPOINTED));
 }
 
-static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx)
+static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
 {
-       unsigned en = en_pmi & 0x3;
-       bool pmi = en_pmi & 0x8;
+       unsigned en_field = ctrl & 0x3;
+       bool pmi = ctrl & 0x8;
 
        pmc_stop_counter(pmc);
 
-       if (!en || !pmc_is_enabled(pmc))
+       if (!en_field || !pmc_is_enabled(pmc))
                return;
 
        pmc_reprogram_counter(pmc, PERF_TYPE_HARDWARE,
-                       arch_events[fixed_pmc_events[idx]].event_type,
-                       !(en & 0x2), /* exclude user */
-                       !(en & 0x1), /* exclude kernel */
-                       pmi, false, false);
+                             arch_events[fixed_pmc_events[idx]].event_type,
+                             !(en_field & 0x2), /* exclude user */
+                             !(en_field & 0x1), /* exclude kernel */
+                             pmi, false, false);
 }
 
 static inline u8 fixed_ctrl_field(u64 ctrl, int idx)
@@ -275,21 +283,22 @@ static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
        int i;
 
        for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
-               u8 en_pmi = fixed_ctrl_field(data, i);
+               u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
+               u8 new_ctrl = fixed_ctrl_field(data, i);
                struct kvm_pmc *pmc = get_fixed_pmc_idx(pmu, i);
 
-               if (fixed_ctrl_field(pmu->fixed_ctr_ctrl, i) == en_pmi)
+               if (old_ctrl == new_ctrl)
                        continue;
 
-               reprogram_fixed_counter(pmc, en_pmi, i);
+               reprogram_fixed_counter(pmc, new_ctrl, i);
        }
 
        pmu->fixed_ctr_ctrl = data;
 }
 
-static void reprogram_counter(struct kvm_pmu *pmu, int idx)
+static void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx)
 {
-       struct kvm_pmc *pmc = global_idx_to_pmc(pmu, idx);
+       struct kvm_pmc *pmc = global_idx_to_pmc(pmu, pmc_idx);
 
        if (!pmc)
                return;
@@ -297,9 +306,10 @@ static void reprogram_counter(struct kvm_pmu *pmu, int idx)
        if (pmc_is_gp(pmc))
                reprogram_gp_counter(pmc, pmc->eventsel);
        else {
-               int fidx = idx - INTEL_PMC_IDX_FIXED;
-               reprogram_fixed_counter(pmc,
-                               fixed_ctrl_field(pmu->fixed_ctr_ctrl, fidx), fidx);
+               int idx = pmc_idx - INTEL_PMC_IDX_FIXED;
+               u8 ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, idx);
+
+               reprogram_fixed_counter(pmc, ctrl, idx);
        }
 }
 
@@ -423,37 +433,43 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
        return 1;
 }
 
-int kvm_pmu_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned pmc)
+/* check if idx is a valid index to access PMU */
+int kvm_pmu_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
 {
        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
-       bool fixed = pmc & (1u << 30);
-       pmc &= ~(3u << 30);
-       return (!fixed && pmc >= pmu->nr_arch_gp_counters) ||
-               (fixed && pmc >= pmu->nr_arch_fixed_counters);
+       bool fixed = idx & (1u << 30);
+       idx &= ~(3u << 30);
+       return (!fixed && idx >= pmu->nr_arch_gp_counters) ||
+               (fixed && idx >= pmu->nr_arch_fixed_counters);
 }
 
-int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data)
+int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
 {
        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
-       bool fast_mode = pmc & (1u << 31);
-       bool fixed = pmc & (1u << 30);
+       bool fast_mode = idx & (1u << 31);
+       bool fixed = idx & (1u << 30);
        struct kvm_pmc *counters;
-       u64 ctr;
+       u64 ctr_val;
 
-       pmc &= ~(3u << 30);
-       if (!fixed && pmc >= pmu->nr_arch_gp_counters)
+       idx &= ~(3u << 30);
+       if (!fixed && idx >= pmu->nr_arch_gp_counters)
                return 1;
-       if (fixed && pmc >= pmu->nr_arch_fixed_counters)
+       if (fixed && idx >= pmu->nr_arch_fixed_counters)
                return 1;
        counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
-       ctr = pmc_read_counter(&counters[pmc]);
+
+       ctr_val = pmc_read_counter(&counters[idx]);
        if (fast_mode)
-               ctr = (u32)ctr;
-       *data = ctr;
+               ctr_val = (u32)ctr_val;
 
+       *data = ctr_val;
        return 0;
 }
 
+/* refresh PMU settings. This function generally is called when underlying
+ * settings are changed (such as changes of PMU CPUID by guest VMs), which
+ * should rarely happen.
+ */
 void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
 {
        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);