A vCPU thread always reaches 100% utilization when:
- guest uses idle=poll
- disable HLT vm-exit
- enable MWAIT
Add new guest agent command 'guest-get-cpustats' to get guest CPU
statistics, we can know the guest workload and how busy the CPU is.
Signed-off-by: zhenwei pi <pizhen...@bytedance.com>
---
qga/commands-posix.c | 72 ++++++++++++++++++++++++++++++++++++++++++++
qga/commands-win32.c | 6 ++++
qga/qapi-schema.json | 49 ++++++++++++++++++++++++++++++
3 files changed, 127 insertions(+)
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 0469dc409d..2847023876 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -2893,6 +2893,73 @@ GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error
**errp)
return guest_get_diskstats(errp);
}
+GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
+{
+ GuestCpuStatsList *head = NULL, **tail = &head;
+ const char *cpustats = "/proc/stat";
+ FILE *fp;
+ size_t n;
+ char *line = NULL;
+
+ fp = fopen(cpustats, "r");
+ if (fp == NULL) {
+ error_setg_errno(errp, errno, "open(\"%s\")", cpustats);
+ return NULL;
+ }
+
+ while (getline(&line, &n, fp) != -1) {
+ GuestCpuStats *cpustat = NULL;
+ int i;
+ unsigned long user, system, idle, iowait, irq, softirq, steal, guest;
+ unsigned long nice, guest_nice;
+ char name[64];
+
+ i = sscanf(line, "%s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu",
+ name, &user, &nice, &system, &idle, &iowait, &irq, &softirq,
+ &steal, &guest, &guest_nice);
+
+ /* drop "cpu 1 2 3 ...", get "cpuX 1 2 3 ..." only */
+ if (strncmp(name, "cpu", 3) || (name[3] == '\0')) {
+ continue;
+ }
+
+ cpustat = g_new0(GuestCpuStats, 1);
+ cpustat->cpu = atoi(&name[3]);
+ cpustat->has_user = true;
+ cpustat->user = user * 10;
+ cpustat->has_system = true;
+ cpustat->system = system * 10;
+ cpustat->has_idle = true;
+ cpustat->idle = idle * 10;
+
+ /* Linux version >= 2.6 */
+ if (i > 5) {
+ cpustat->has_iowait = true;
+ cpustat->iowait = iowait * 10;
+ cpustat->has_irq = true;
+ cpustat->irq = irq * 10;
+ cpustat->has_softirq = true;
+ cpustat->softirq = softirq * 10;
+ }
+
+ if (i > 8) {
+ cpustat->has_steal = true;
+ cpustat->steal = steal * 10;
+ }
+
+ if (i > 9) {
+ cpustat->has_guest = true;
+ cpustat->guest = guest * 10;
+ }
+
+ QAPI_LIST_APPEND(tail, cpustat);
+ }
+
+ free(line);
+ fclose(fp);
+ return head;
+}
+
#else /* defined(__linux__) */
void qmp_guest_suspend_disk(Error **errp)
@@ -3247,6 +3314,11 @@ GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error
**errp)
return NULL;
}
+GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
+{
+ error_setg(errp, QERR_UNSUPPORTED);
+ return NULL;
+}
#endif /* CONFIG_FSFREEZE */
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 36f94c0f9c..7ed7664715 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -2543,3 +2543,9 @@ GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error
**errp)
error_setg(errp, QERR_UNSUPPORTED);
return NULL;
}
+
+GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
+{
+ error_setg(errp, QERR_UNSUPPORTED);
+ return NULL;
+}
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 9fa20e791b..4859c887b2 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -1576,3 +1576,52 @@
{ 'command': 'guest-get-diskstats',
'returns': ['GuestDiskStatsInfo']
}
+
+##
+# @GuestCpuStats:
+#
+# Get statistics of each CPU in millisecond.
+#
+# @cpu: CPU index in guest OS
+#
+# @user: CPU time of user mode
+#
+# @system: CPU time of system mode
+#
+# @idle: CPU time of idle state
+#
+# @iowait: CPU time waiting IO
+#
+# @irq: CPU time of hardware interrupt
+#
+# @softirq: CPU time of soft interrupt
+#
+# @steal: CPU time stolen by host
+#
+# @guest: CPU time of running guest mode
+#
+# Since: 7.1
+##
+{ 'struct': 'GuestCpuStats',
+ 'data': {'cpu': 'int',
+ '*user': 'uint64',
+ '*system': 'uint64',
+ '*idle': 'uint64',
+ '*iowait': 'uint64',
+ '*irq': 'uint64',
+ '*softirq': 'uint64',
+ '*steal': 'uint64',
+ '*guest': 'uint64'
+ } }
+
+##
+# @guest-get-cpustats:
+#
+# Retrieve information about CPU stats.
+# Returns: List of CPU stats of guest.
+#
+# Since: 7.1
+##
+{ 'command': 'guest-get-cpustats',
+ 'returns': ['GuestCpuStats']
+}
--
2.20.1
