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Diffstat (limited to 'arch/x86/kvm/pmu.c')
-rw-r--r--arch/x86/kvm/pmu.c286
1 files changed, 236 insertions, 50 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 58e5a456273a..612e6c70ce2e 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -29,9 +29,18 @@
struct x86_pmu_capability __read_mostly kvm_pmu_cap;
EXPORT_SYMBOL_GPL(kvm_pmu_cap);
-static const struct x86_cpu_id vmx_icl_pebs_cpu[] = {
+/* Precise Distribution of Instructions Retired (PDIR) */
+static const struct x86_cpu_id vmx_pebs_pdir_cpu[] = {
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, NULL),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, NULL),
+ /* Instruction-Accurate PDIR (PDIR++) */
+ X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, NULL),
+ {}
+};
+
+/* Precise Distribution (PDist) */
+static const struct x86_cpu_id vmx_pebs_pdist_cpu[] = {
+ X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, NULL),
{}
};
@@ -156,6 +165,28 @@ static void kvm_perf_overflow(struct perf_event *perf_event,
kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
}
+static u64 pmc_get_pebs_precise_level(struct kvm_pmc *pmc)
+{
+ /*
+ * For some model specific pebs counters with special capabilities
+ * (PDIR, PDIR++, PDIST), KVM needs to raise the event precise
+ * level to the maximum value (currently 3, backwards compatible)
+ * so that the perf subsystem would assign specific hardware counter
+ * with that capability for vPMC.
+ */
+ if ((pmc->idx == 0 && x86_match_cpu(vmx_pebs_pdist_cpu)) ||
+ (pmc->idx == 32 && x86_match_cpu(vmx_pebs_pdir_cpu)))
+ return 3;
+
+ /*
+ * The non-zero precision level of guest event makes the ordinary
+ * guest event becomes a guest PEBS event and triggers the host
+ * PEBS PMI handler to determine whether the PEBS overflow PMI
+ * comes from the host counters or the guest.
+ */
+ return 1;
+}
+
static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
bool exclude_user, bool exclude_kernel,
bool intr)
@@ -187,22 +218,12 @@ static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
}
if (pebs) {
/*
- * The non-zero precision level of guest event makes the ordinary
- * guest event becomes a guest PEBS event and triggers the host
- * PEBS PMI handler to determine whether the PEBS overflow PMI
- * comes from the host counters or the guest.
- *
* For most PEBS hardware events, the difference in the software
* precision levels of guest and host PEBS events will not affect
* the accuracy of the PEBS profiling result, because the "event IP"
* in the PEBS record is calibrated on the guest side.
- *
- * On Icelake everything is fine. Other hardware (GLC+, TNT+) that
- * could possibly care here is unsupported and needs changes.
*/
- attr.precise_ip = 1;
- if (x86_match_cpu(vmx_icl_pebs_cpu) && pmc->idx == 32)
- attr.precise_ip = 3;
+ attr.precise_ip = pmc_get_pebs_precise_level(pmc);
}
event = perf_event_create_kernel_counter(&attr, -1, current,
@@ -255,48 +276,128 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc)
return true;
}
-static int cmp_u64(const void *pa, const void *pb)
+static int filter_cmp(const void *pa, const void *pb, u64 mask)
{
- u64 a = *(u64 *)pa;
- u64 b = *(u64 *)pb;
+ u64 a = *(u64 *)pa & mask;
+ u64 b = *(u64 *)pb & mask;
return (a > b) - (a < b);
}
+
+static int filter_sort_cmp(const void *pa, const void *pb)
+{
+ return filter_cmp(pa, pb, (KVM_PMU_MASKED_ENTRY_EVENT_SELECT |
+ KVM_PMU_MASKED_ENTRY_EXCLUDE));
+}
+
+/*
+ * For the event filter, searching is done on the 'includes' list and
+ * 'excludes' list separately rather than on the 'events' list (which
+ * has both). As a result the exclude bit can be ignored.
+ */
+static int filter_event_cmp(const void *pa, const void *pb)
+{
+ return filter_cmp(pa, pb, (KVM_PMU_MASKED_ENTRY_EVENT_SELECT));
+}
+
+static int find_filter_index(u64 *events, u64 nevents, u64 key)
+{
+ u64 *fe = bsearch(&key, events, nevents, sizeof(events[0]),
+ filter_event_cmp);
+
+ if (!fe)
+ return -1;
+
+ return fe - events;
+}
+
+static bool is_filter_entry_match(u64 filter_event, u64 umask)
+{
+ u64 mask = filter_event >> (KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT - 8);
+ u64 match = filter_event & KVM_PMU_MASKED_ENTRY_UMASK_MATCH;
+
+ BUILD_BUG_ON((KVM_PMU_ENCODE_MASKED_ENTRY(0, 0xff, 0, false) >>
+ (KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT - 8)) !=
+ ARCH_PERFMON_EVENTSEL_UMASK);
+
+ return (umask & mask) == match;
+}
+
+static bool filter_contains_match(u64 *events, u64 nevents, u64 eventsel)
+{
+ u64 event_select = eventsel & kvm_pmu_ops.EVENTSEL_EVENT;
+ u64 umask = eventsel & ARCH_PERFMON_EVENTSEL_UMASK;
+ int i, index;
+
+ index = find_filter_index(events, nevents, event_select);
+ if (index < 0)
+ return false;
+
+ /*
+ * Entries are sorted by the event select. Walk the list in both
+ * directions to process all entries with the targeted event select.
+ */
+ for (i = index; i < nevents; i++) {
+ if (filter_event_cmp(&events[i], &event_select))
+ break;
+
+ if (is_filter_entry_match(events[i], umask))
+ return true;
+ }
+
+ for (i = index - 1; i >= 0; i--) {
+ if (filter_event_cmp(&events[i], &event_select))
+ break;
+
+ if (is_filter_entry_match(events[i], umask))
+ return true;
+ }
+
+ return false;
+}
+
+static bool is_gp_event_allowed(struct kvm_x86_pmu_event_filter *f,
+ u64 eventsel)
+{
+ if (filter_contains_match(f->includes, f->nr_includes, eventsel) &&
+ !filter_contains_match(f->excludes, f->nr_excludes, eventsel))
+ return f->action == KVM_PMU_EVENT_ALLOW;
+
+ return f->action == KVM_PMU_EVENT_DENY;
+}
+
+static bool is_fixed_event_allowed(struct kvm_x86_pmu_event_filter *filter,
+ int idx)
+{
+ int fixed_idx = idx - INTEL_PMC_IDX_FIXED;
+
+ if (filter->action == KVM_PMU_EVENT_DENY &&
+ test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
+ return false;
+ if (filter->action == KVM_PMU_EVENT_ALLOW &&
+ !test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
+ return false;
+
+ return true;
+}
+
static bool check_pmu_event_filter(struct kvm_pmc *pmc)
{
- struct kvm_pmu_event_filter *filter;
+ struct kvm_x86_pmu_event_filter *filter;
struct kvm *kvm = pmc->vcpu->kvm;
- bool allow_event = true;
- __u64 key;
- int idx;
if (!static_call(kvm_x86_pmu_hw_event_available)(pmc))
return false;
filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
if (!filter)
- goto out;
+ return true;
- if (pmc_is_gp(pmc)) {
- key = pmc->eventsel & AMD64_RAW_EVENT_MASK_NB;
- if (bsearch(&key, filter->events, filter->nevents,
- sizeof(__u64), cmp_u64))
- allow_event = filter->action == KVM_PMU_EVENT_ALLOW;
- else
- allow_event = filter->action == KVM_PMU_EVENT_DENY;
- } else {
- idx = pmc->idx - INTEL_PMC_IDX_FIXED;
- if (filter->action == KVM_PMU_EVENT_DENY &&
- test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
- allow_event = false;
- if (filter->action == KVM_PMU_EVENT_ALLOW &&
- !test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
- allow_event = false;
- }
+ if (pmc_is_gp(pmc))
+ return is_gp_event_allowed(filter, pmc->eventsel);
-out:
- return allow_event;
+ return is_fixed_event_allowed(filter, pmc->idx);
}
static void reprogram_counter(struct kvm_pmc *pmc)
@@ -593,43 +694,128 @@ void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id)
}
EXPORT_SYMBOL_GPL(kvm_pmu_trigger_event);
+static bool is_masked_filter_valid(const struct kvm_x86_pmu_event_filter *filter)
+{
+ u64 mask = kvm_pmu_ops.EVENTSEL_EVENT |
+ KVM_PMU_MASKED_ENTRY_UMASK_MASK |
+ KVM_PMU_MASKED_ENTRY_UMASK_MATCH |
+ KVM_PMU_MASKED_ENTRY_EXCLUDE;
+ int i;
+
+ for (i = 0; i < filter->nevents; i++) {
+ if (filter->events[i] & ~mask)
+ return false;
+ }
+
+ return true;
+}
+
+static void convert_to_masked_filter(struct kvm_x86_pmu_event_filter *filter)
+{
+ int i, j;
+
+ for (i = 0, j = 0; i < filter->nevents; i++) {
+ /*
+ * Skip events that are impossible to match against a guest
+ * event. When filtering, only the event select + unit mask
+ * of the guest event is used. To maintain backwards
+ * compatibility, impossible filters can't be rejected :-(
+ */
+ if (filter->events[i] & ~(kvm_pmu_ops.EVENTSEL_EVENT |
+ ARCH_PERFMON_EVENTSEL_UMASK))
+ continue;
+ /*
+ * Convert userspace events to a common in-kernel event so
+ * only one code path is needed to support both events. For
+ * the in-kernel events use masked events because they are
+ * flexible enough to handle both cases. To convert to masked
+ * events all that's needed is to add an "all ones" umask_mask,
+ * (unmasked filter events don't support EXCLUDE).
+ */
+ filter->events[j++] = filter->events[i] |
+ (0xFFULL << KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT);
+ }
+
+ filter->nevents = j;
+}
+
+static int prepare_filter_lists(struct kvm_x86_pmu_event_filter *filter)
+{
+ int i;
+
+ if (!(filter->flags & KVM_PMU_EVENT_FLAG_MASKED_EVENTS))
+ convert_to_masked_filter(filter);
+ else if (!is_masked_filter_valid(filter))
+ return -EINVAL;
+
+ /*
+ * Sort entries by event select and includes vs. excludes so that all
+ * entries for a given event select can be processed efficiently during
+ * filtering. The EXCLUDE flag uses a more significant bit than the
+ * event select, and so the sorted list is also effectively split into
+ * includes and excludes sub-lists.
+ */
+ sort(&filter->events, filter->nevents, sizeof(filter->events[0]),
+ filter_sort_cmp, NULL);
+
+ i = filter->nevents;
+ /* Find the first EXCLUDE event (only supported for masked events). */
+ if (filter->flags & KVM_PMU_EVENT_FLAG_MASKED_EVENTS) {
+ for (i = 0; i < filter->nevents; i++) {
+ if (filter->events[i] & KVM_PMU_MASKED_ENTRY_EXCLUDE)
+ break;
+ }
+ }
+
+ filter->nr_includes = i;
+ filter->nr_excludes = filter->nevents - filter->nr_includes;
+ filter->includes = filter->events;
+ filter->excludes = filter->events + filter->nr_includes;
+
+ return 0;
+}
+
int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp)
{
- struct kvm_pmu_event_filter tmp, *filter;
+ struct kvm_pmu_event_filter __user *user_filter = argp;
+ struct kvm_x86_pmu_event_filter *filter;
+ struct kvm_pmu_event_filter tmp;
struct kvm_vcpu *vcpu;
unsigned long i;
size_t size;
int r;
- if (copy_from_user(&tmp, argp, sizeof(tmp)))
+ if (copy_from_user(&tmp, user_filter, sizeof(tmp)))
return -EFAULT;
if (tmp.action != KVM_PMU_EVENT_ALLOW &&
tmp.action != KVM_PMU_EVENT_DENY)
return -EINVAL;
- if (tmp.flags != 0)
+ if (tmp.flags & ~KVM_PMU_EVENT_FLAGS_VALID_MASK)
return -EINVAL;
if (tmp.nevents > KVM_PMU_EVENT_FILTER_MAX_EVENTS)
return -E2BIG;
size = struct_size(filter, events, tmp.nevents);
- filter = kmalloc(size, GFP_KERNEL_ACCOUNT);
+ filter = kzalloc(size, GFP_KERNEL_ACCOUNT);
if (!filter)
return -ENOMEM;
+ filter->action = tmp.action;
+ filter->nevents = tmp.nevents;
+ filter->fixed_counter_bitmap = tmp.fixed_counter_bitmap;
+ filter->flags = tmp.flags;
+
r = -EFAULT;
- if (copy_from_user(filter, argp, size))
+ if (copy_from_user(filter->events, user_filter->events,
+ sizeof(filter->events[0]) * filter->nevents))
goto cleanup;
- /* Ensure nevents can't be changed between the user copies. */
- *filter = tmp;
-
- /*
- * Sort the in-kernel list so that we can search it with bsearch.
- */
- sort(&filter->events, filter->nevents, sizeof(__u64), cmp_u64, NULL);
+ r = prepare_filter_lists(filter);
+ if (r)
+ goto cleanup;
mutex_lock(&kvm->lock);
filter = rcu_replace_pointer(kvm->arch.pmu_event_filter, filter,