Update 'book3s_hv_pmu.c' to add five new perf-events mapped to the five
Hostwide counters. Since these newly introduced perf events are at system
wide scope and can be read from any L1-Lpar CPU, 'kvmppv_pmu's scope and
capabilities are updated appropriately.
Also introduce two new helpers. First is kvmppc_update_l0_stats() that uses
the infrastructure introduced in previous patches to issues the
H_GUEST_GET_STATE hcall L0-PowerVM to fetch guest-state-buffer holding the
latest values of these counters which is then parsed and 'l0_stats'
variable updated.
Second helper is kvmppc_pmu_event_update() which is called from
'kvmppv_pmu' callbacks and uses kvmppc_update_l0_stats() to update
'l0_stats' and the update the 'struct perf_event's event-counter.
Some minor updates to kvmppc_pmu_{add, del, read}() to remove some debug
scaffolding code.
Signed-off-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv_pmu.c | 92 +++++++++++++++++++++++++++++++-
1 file changed, 91 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv_pmu.c b/arch/powerpc/kvm/book3s_hv_pmu.c
index f7fd5190ecf7..99bd1ae2dddf 100644
--- a/arch/powerpc/kvm/book3s_hv_pmu.c
+++ b/arch/powerpc/kvm/book3s_hv_pmu.c
@@ -30,6 +30,11 @@
#include "asm/guest-state-buffer.h"
enum kvmppc_pmu_eventid {
+ KVMPPC_EVENT_HOST_HEAP,
+ KVMPPC_EVENT_HOST_HEAP_MAX,
+ KVMPPC_EVENT_HOST_PGTABLE,
+ KVMPPC_EVENT_HOST_PGTABLE_MAX,
+ KVMPPC_EVENT_HOST_PGTABLE_RECLAIM,
KVMPPC_EVENT_MAX,
};
@@ -51,8 +56,14 @@ static DEFINE_SPINLOCK(lock_l0_stats);
/* GSB related structs needed to talk to L0 */
static struct kvmppc_gs_msg *gsm_l0_stats;
static struct kvmppc_gs_buff *gsb_l0_stats;
+static struct kvmppc_gs_parser gsp_l0_stats;
static struct attribute *kvmppc_pmu_events_attr[] = {
+ KVMPPC_PMU_EVENT_ATTR(host_heap, KVMPPC_EVENT_HOST_HEAP),
+ KVMPPC_PMU_EVENT_ATTR(host_heap_max, KVMPPC_EVENT_HOST_HEAP_MAX),
+ KVMPPC_PMU_EVENT_ATTR(host_pagetable, KVMPPC_EVENT_HOST_PGTABLE),
+ KVMPPC_PMU_EVENT_ATTR(host_pagetable_max, KVMPPC_EVENT_HOST_PGTABLE_MAX),
+ KVMPPC_PMU_EVENT_ATTR(host_pagetable_reclaim, KVMPPC_EVENT_HOST_PGTABLE_RECLAIM),
NULL,
};
@@ -61,7 +72,7 @@ static const struct attribute_group kvmppc_pmu_events_group = {
.attrs = kvmppc_pmu_events_attr,
};
-PMU_FORMAT_ATTR(event, "config:0");
+PMU_FORMAT_ATTR(event, "config:0-5");
static struct attribute *kvmppc_pmu_format_attr[] = {
&format_attr_event.attr,
NULL,
@@ -78,6 +89,79 @@ static const struct attribute_group *kvmppc_pmu_attr_groups[] = {
NULL,
};
+/*
+ * Issue the hcall to get the L0-host stats.
+ * Should be called with l0-stat lock held
+ */
+static int kvmppc_update_l0_stats(void)
+{
+ int rc;
+
+ /* With HOST_WIDE flags guestid and vcpuid will be ignored */
+ rc = kvmppc_gsb_recv(gsb_l0_stats, KVMPPC_GS_FLAGS_HOST_WIDE);
+ if (rc)
+ goto out;
+
+ /* Parse the guest state buffer is successful */
+ rc = kvmppc_gse_parse(&gsp_l0_stats, gsb_l0_stats);
+ if (rc)
+ goto out;
+
+ /* Update the l0 returned stats*/
+ memset(&l0_stats, 0, sizeof(l0_stats));
+ rc = kvmppc_gsm_refresh_info(gsm_l0_stats, gsb_l0_stats);
+
+out:
+ return rc;
+}
+
+/* Update the value of the given perf_event */
+static int kvmppc_pmu_event_update(struct perf_event *event)
+{
+ int rc;
+ u64 curr_val, prev_val;
+ unsigned long flags;
+ unsigned int config = event->attr.config;
+
+ /* Ensure no one else is modifying the l0_stats */
+ spin_lock_irqsave(&lock_l0_stats, flags);
+
+ rc = kvmppc_update_l0_stats();
+ if (!rc) {
+ switch (config) {
+ case KVMPPC_EVENT_HOST_HEAP:
+ curr_val = l0_stats.guest_heap;
+ break;
+ case KVMPPC_EVENT_HOST_HEAP_MAX:
+ curr_val = l0_stats.guest_heap_max;
+ break;
+ case KVMPPC_EVENT_HOST_PGTABLE:
+ curr_val = l0_stats.guest_pgtable_size;
+ break;
+ case KVMPPC_EVENT_HOST_PGTABLE_MAX:
+ curr_val = l0_stats.guest_pgtable_size_max;
+ break;
+ case KVMPPC_EVENT_HOST_PGTABLE_RECLAIM:
+ curr_val = l0_stats.guest_pgtable_reclaim;
+ break;
+ default:
+ rc = -ENOENT;
+ break;
+ }
+ }
+
+ spin_unlock_irqrestore(&lock_l0_stats, flags);
+
+ /* If no error than update the perf event */
+ if (!rc) {
+ prev_val = local64_xchg(&event->hw.prev_count, curr_val);
+ if (curr_val > prev_val)
+ local64_add(curr_val - prev_val, &event->count);
+ }
+
+ return rc;
+}
+
static int kvmppc_pmu_event_init(struct perf_event *event)
{
unsigned int config = event->attr.config;
@@ -100,15 +184,19 @@ static int kvmppc_pmu_event_init(struct perf_event *event)
static void kvmppc_pmu_del(struct perf_event *event, int flags)
{
+ /* Do nothing */
}
static int kvmppc_pmu_add(struct perf_event *event, int flags)
{
+ if (flags & PERF_EF_START)
+ return kvmppc_pmu_event_update(event);
return 0;
}
static void kvmppc_pmu_read(struct perf_event *event)
{
+ kvmppc_pmu_event_update(event);
}
/* Return the size of the needed guest state buffer */
@@ -282,6 +370,8 @@ static struct pmu kvmppc_pmu = {
.read = kvmppc_pmu_read,
.attr_groups = kvmppc_pmu_attr_groups,
.type = -1,
+ .scope = PERF_PMU_SCOPE_SYS_WIDE,
+ .capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
};
int kvmppc_register_pmu(void)
--
2.47.1
