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>

1 files changed, 64 insertions, 48 deletions

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 38819bc923cf..24d213bd42d4 100644
--- 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);