Introduce a QMP command 'query-kvmstats' to query KVM for vm and vcpu
fd-based statistics. The kernel support is provided by commit:
cb082bfab59a ("KVM: stats: Add fd-based API to read binary stats data")
The interface supports an optional 'filter' argument to specify a
particular stat to query.
Examples:
{ "execute": "query-kvmstats" }
{ "return": [
{ "name": "vm",
"stats": [
{ "name": "max_mmu_page_hash_collisions",
"unit": "none",
"base": 10,
"val": [ 0 ],
"exponent": 0,
"type": "peak" },
{ "name": "nx_lpage_splits",
"unit": "none",
"base": 10,
"val": [ 120 ],
"exponent": 0,
"type": "instant" },
...
} ] },
{ "name": "vcpu_0",
"stats": [
{ "name": "req_event",
"unit": "none",
"base": 10,
"val": [ 500 ],
"exponent": 0,
"type": "cumulative" },
...
{ "execute": "query-kvmstats", "arguments" : { "filter" : "req_event" } }
{ "return": [
{ "name": "vm",
"stats": [] },
{ "name": "vcpu_0",
"stats": [
{ "name": "req_event",
"unit": "none",
"base": 10,
"val": [ 500 ],
"exponent": 0,
"type": "cumulative" }
] },
{ "name": "vcpu_1",
"stats": [
{ "name": "req_event",
"unit": "none",
"base": 10,
"val": [ 61 ],
"exponent": 0,
"type": "cumulative" }
] } ] }
Signed-off-by: Mark Kanda <mark.ka...@oracle.com>
---
accel/kvm/kvm-all.c | 246 ++++++++++++++++++++++++++++++++++++++++++++
qapi/misc.json | 73 +++++++++++++
2 files changed, 319 insertions(+)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index db8d83b137..597d0c7a09 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -47,6 +47,7 @@
#include "kvm-cpus.h"
#include "hw/boards.h"
+#include "qapi/qapi-commands-misc.h"
/* This check must be after config-host.h is included */
#ifdef CONFIG_EVENTFD
@@ -3406,6 +3407,251 @@ int kvm_on_sigbus(int code, void *addr)
#endif
}
+typedef struct KvmStatsArgs {
+ KvmStats *kvm_stat; /* QAPI auto-generated struct */
+ char *filter;
+ Error **errp;
+} KvmStatsArgs;
+
+static KvmStatDataList *add_kvmstat_entry(struct kvm_stats_desc *pdesc,
+ uint64_t *stats_data,
+ KvmStatDataList *data_list,
+ Error **errp)
+{
+ KvmStatDataList *data_entry;
+ uint64List *val_list = NULL;
+ Error *local_err = NULL;
+ int i;
+
+ data_entry = g_malloc0(sizeof(*data_entry));
+ data_entry->value = g_malloc0(sizeof(*data_entry->value));
+ data_entry->value->name = g_strdup(pdesc->name);
+
+ /* Convert flags to type, unit and base (QAPI auto-generated enums) */
+ switch (pdesc->flags & KVM_STATS_TYPE_MASK) {
+ case KVM_STATS_TYPE_CUMULATIVE:
+ data_entry->value->type = KVM_STAT_TYPE_CUMULATIVE;
+ break;
+ case KVM_STATS_TYPE_INSTANT:
+ data_entry->value->type = KVM_STAT_TYPE_INSTANT;
+ break;
+ case KVM_STATS_TYPE_PEAK:
+ data_entry->value->type = KVM_STAT_TYPE_PEAK;
+ break;
+ default:
+ error_setg(&local_err, "KVM stats: invalid type %u",
+ (pdesc->flags & KVM_STATS_TYPE_MASK)
+ >> KVM_STATS_TYPE_SHIFT);
+ goto exit;
+ }
+
+ switch (pdesc->flags & KVM_STATS_UNIT_MASK) {
+ case KVM_STATS_UNIT_NONE:
+ data_entry->value->unit = KVM_STAT_UNIT_NONE;
+ break;
+ case KVM_STATS_UNIT_BYTES:
+ data_entry->value->unit = KVM_STAT_UNIT_BYTES;
+ break;
+ case KVM_STATS_UNIT_CYCLES:
+ data_entry->value->unit = KVM_STAT_UNIT_CYCLES;
+ break;
+ case KVM_STATS_UNIT_SECONDS:
+ data_entry->value->unit = KVM_STAT_UNIT_SECONDS;
+ break;
+ default:
+ error_setg(&local_err, "KVM stats: invalid unit %u",
+ (pdesc->flags & KVM_STATS_UNIT_MASK)
+ >> KVM_STATS_UNIT_SHIFT);
+ goto exit;
+ }
+
+ switch (pdesc->flags & KVM_STATS_BASE_MASK) {
+ case KVM_STATS_BASE_POW10:
+ data_entry->value->base = 10;
+ break;
+ case KVM_STATS_BASE_POW2:
+ data_entry->value->base = 2;
+ break;
+ default:
+ error_setg(&local_err, "KVM stats: invalid base %u",
+ (pdesc->flags & KVM_STATS_BASE_MASK)
+ >> KVM_STATS_BASE_SHIFT);
+ goto exit;
+ }
+
+ data_entry->value->exponent = pdesc->exponent;
+
+ /* Alloc and populate data list */
+ for (i = 0; i < pdesc->size; i++) {
+ uint64List *val_entry = g_malloc0(sizeof(*val_entry));
+ val_entry->value = stats_data[i];
+ val_entry->next = val_list;
+ val_list = val_entry;
+ }
+ data_entry->value->val = val_list;
+ data_entry->next = data_list;
+ data_list = data_entry;
+
+ return data_list;
+
+exit:
+ error_propagate(errp, local_err);
+ g_free(data_entry->value->name);
+ g_free(data_entry->value);
+ g_free(data_entry);
+
+ return data_list;
+}
+
+static void query_kvmstats(KvmStatsArgs *kvm_stat_args, int stats_fd)
+{
+ size_t size_desc, size_data;
+ struct kvm_stats_header *header;
+ char *id = NULL;
+ struct kvm_stats_desc *stats_desc = NULL;
+ Error *local_err = NULL;
+ ssize_t ret;
+ int i;
+ KvmStatDataList *data_list = NULL; /* QAPI auto-generated struct */
+
+ /* Read kvm stats header */
+ header = g_malloc(sizeof(*header));
+ ret = read(stats_fd, header, sizeof(*header));
+ if (ret != sizeof(*header)) {
+ error_setg(&local_err, "KVM stats: failed to read stats header: "
+ "expected %zu actual %zu", sizeof(*header), ret);
+ goto exit;
+ }
+ size_desc = sizeof(*stats_desc) + header->name_size;
+
+ /* Read kvm stats id string */
+ id = g_malloc(header->name_size);
+ ret = read(stats_fd, id, header->name_size);
+ if (ret != header->name_size) {
+ error_setg(&local_err, "KVM stats: failed to read id string: "
+ "expected %zu actual %zu", (size_t) header->name_size, ret);
+ goto exit;
+ }
+
+ /* Read kvm stats descriptors */
+ stats_desc = g_malloc0(header->num_desc * size_desc);
+ ret = pread(stats_fd, stats_desc,
+ size_desc * header->num_desc, header->desc_offset);
+
+ if (ret != size_desc * header->num_desc) {
+ error_setg(&local_err, "KVM stats: failed to read stats descriptors: "
+ "expected %zu actual %zu",
+ size_desc * header->num_desc, ret);
+ goto exit;
+ }
+
+ for (i = 0; i < header->num_desc; ++i) {
+ struct kvm_stats_desc *pdesc = (void *)stats_desc + i * size_desc;
+ size_data = pdesc->size * sizeof(uint64_t);
+ uint64_t *stats_data = g_malloc(size_data);
+
+ ret = pread(stats_fd, stats_data, size_data,
+ header->data_offset + pdesc->offset);
+
+ if (ret != pdesc->size * sizeof(*stats_data)) {
+ error_setg(&local_err, "KVM stats: failed to read data: "
+ "expected %zu actual %zu",
+ pdesc->size * sizeof(*stats_data), ret);
+ g_free(stats_data);
+ goto exit;
+ }
+
+ if (kvm_stat_args->filter) {
+ if (g_strcmp0(kvm_stat_args->filter, pdesc->name)) {
+ g_free(stats_data);
+ continue;
+ }
+ }
+
+ /* Add stats entry to the list */
+ data_list = add_kvmstat_entry(pdesc, stats_data, data_list,
&local_err);
+ g_free(stats_data);
+ }
+ kvm_stat_args->kvm_stat->stats = data_list;
+
+exit:
+ error_propagate(kvm_stat_args->errp, local_err);
+ g_free(stats_desc);
+ g_free(id);
+ g_free(header);
+}
+
+static void query_kvmstats_vcpu(CPUState *cpu, run_on_cpu_data data)
+{
+ KvmStatsArgs *kvm_stats_args = (KvmStatsArgs *) data.host_ptr;
+ int stats_fd = kvm_vcpu_ioctl(cpu, KVM_GET_STATS_FD, NULL);
+ Error *local_err = NULL;
+
+ if (stats_fd == -1) {
+ error_setg(&local_err, "KVM stats: ioctl failed");
+ error_propagate(kvm_stats_args->errp, local_err);
+ return;
+ }
+ query_kvmstats(kvm_stats_args, stats_fd);
+ close(stats_fd);
+}
+
+KvmStatsList *qmp_query_kvmstats(bool has_filter, const char *filter,
+ Error **errp)
+{
+ KvmStatsList *stats_list_head, **stats_list_tail = &stats_list_head;
+ KvmStatsArgs *stats_args;
+ CPUState *cpu;
+ KVMState *s = kvm_state;
+ KvmStats *value;
+ int stats_fd;
+
+ if (!kvm_enabled()) {
+ error_setg(errp, "KVM stats: KVM not enabled");
+ return NULL;
+ }
+
+ if (!kvm_check_extension(s, KVM_CAP_BINARY_STATS_FD)) {
+ error_setg(errp, "KVM stats: not supported");
+ return NULL;
+ }
+
+ stats_args = g_malloc0(sizeof(*stats_args));
+ stats_args->errp = errp;
+
+ if (has_filter) {
+ stats_args->filter = g_strdup(filter);
+ }
+
+ /* Query vm stats */
+ stats_fd = kvm_vm_ioctl(s, KVM_GET_STATS_FD, NULL);
+ if (stats_fd == -1) {
+ error_setg(errp, "KVM stats: ioctl failed");
+ g_free(stats_args);
+ return NULL;
+ }
+ value = g_malloc0(sizeof(*value));
+ value->name = g_strdup("vm");
+ QAPI_LIST_APPEND(stats_list_tail, value);
+
+ stats_args->kvm_stat = value;
+ query_kvmstats(stats_args, stats_fd);
+ close(stats_fd);
+
+ /* Query vcpu stats */
+ CPU_FOREACH(cpu) {
+ KvmStats *value = g_malloc0(sizeof(*value));
+ value->name = g_strdup_printf("vcpu_%d", cpu->cpu_index);
+ QAPI_LIST_APPEND(stats_list_tail, value);
+
+ stats_args->kvm_stat = value;
+ run_on_cpu(cpu, query_kvmstats_vcpu, RUN_ON_CPU_HOST_PTR(stats_args));
+ }
+
+ g_free(stats_args);
+ return stats_list_head;
+}
+
int kvm_create_device(KVMState *s, uint64_t type, bool test)
{
int ret;
diff --git a/qapi/misc.json b/qapi/misc.json
index 5c2ca3b556..0ced6a856c 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -523,3 +523,76 @@
'data': { '*option': 'str' },
'returns': ['CommandLineOptionInfo'],
'allow-preconfig': true }
+
+##
+# @KvmStatType:
+#
+# Enumeration of KVM stat types
+# @cumulative: stat is cumulative; value can only increase.
+# @instant: stat is instantaneous; value can increase or decrease.
+# @peak: stat is the peak value; value can only increase.
+#
+# Since: 6.2
+##
+{ 'enum' : 'KvmStatType',
+ 'data' : [ 'cumulative', 'instant', 'peak' ] }
+
+##
+# @KvmStatUnit:
+#
+# Enumeration of KVM stat units
+# @bytes: stat reported in bytes.
+# @seconds: stat reported in seconds.
+# @cycles: stat reported in clock cycles.
+# @none: no unit for this stat.
+#
+# Since: 6.2
+##
+{ 'enum' : 'KvmStatUnit',
+ 'data' : [ 'bytes', 'seconds', 'cycles', 'none' ] }
+
+##
+# @KvmStatData:
+#
+# Individual KVM stat
+# @name: Stat name
+# @type: @KvmStatType
+# @unit: @KvmStatUnit
+# @base: Exponent base (2 or 10)
+# @exponent: Used together with @base
+# @val: List of uint64 values
+#
+# Since: 6.2
+##
+{ 'struct': 'KvmStatData',
+ 'data': { 'name': 'str',
+ 'type': 'KvmStatType',
+ 'unit': 'KvmStatUnit',
+ 'base': 'uint8',
+ 'exponent': 'int16',
+ 'val': [ 'uint64' ] } }
+
+##
+# @KvmStats:
+#
+# KvmStats per vm or vcpu
+# @name: vm or vcpu_<number>
+# @stats: List of @KvmStatData
+#
+# Since: 6.2
+##
+{ 'struct': 'KvmStats',
+ 'data': {'name': 'str',
+ 'stats': [ 'KvmStatData' ] } }
+
+##
+# @query-kvmstats:
+#
+# @filter: KVM stat name (optional)
+# Returns: List of @KvmStats
+#
+# Since: 6.2
+##
+{ 'command': 'query-kvmstats',
+ 'data': { '*filter': 'str' },
+ 'returns': [ 'KvmStats' ] }
--
2.26.2
