* [PATCH 1/2] qga-win: implement a 'guest-get-load' command
2025-03-14 11:38 [PATCH 0/2] qga: Add 'guest-get-load' command Konstantin Kostiuk
@ 2025-03-14 11:38 ` Konstantin Kostiuk
2025-03-19 15:02 ` Daniel P. Berrangé
2025-03-14 11:38 ` [PATCH 2/2] qga: Add tests for guest-get-load command Konstantin Kostiuk
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: Konstantin Kostiuk @ 2025-03-14 11:38 UTC (permalink / raw)
To: qemu-devel; +Cc: Marc-André Lureau, Daniel P . Berrangé, Michael Roth
Windows has no native equivalent API, but it would be possible to
simulate it as illustrated here (BSD-3-Clause):
https://github.com/giampaolo/psutil/pull/1485
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
---
qga/commands-win32.c | 140 +++++++++++++++++++++++++++++++++++++++++
qga/guest-agent-core.h | 10 +++
qga/main.c | 39 ++++++++++++
qga/meson.build | 2 +-
qga/qapi-schema.json | 4 +-
5 files changed, 192 insertions(+), 3 deletions(-)
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 749fdf8895..9ded44c2f7 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -27,6 +27,7 @@
#include <lm.h>
#include <wtsapi32.h>
#include <wininet.h>
+#include <pdh.h>
#include "guest-agent-core.h"
#include "vss-win32.h"
@@ -119,6 +120,28 @@ static OpenFlags guest_file_open_modes[] = {
{"a+b", FILE_GENERIC_APPEND | GENERIC_READ, OPEN_ALWAYS }
};
+/*
+ * We use an exponentially weighted moving average, just like Unix systems do
+ * https://en.wikipedia.org/wiki/Load_(computing)#Unix-style_load_calculation
+ *
+ * These constants serve as the damping factor and are calculated with
+ * 1 / exp(sampling interval in seconds / window size in seconds)
+ *
+ * This formula comes from linux's include/linux/sched/loadavg.h
+ * https://github.com/torvalds/linux/blob/345671ea0f9258f410eb057b9ced9cefbbe5dc78/include/linux/sched/loadavg.h#L20-L23
+ */
+#define LOADAVG_FACTOR_1F 0.9200444146293232478931553241
+#define LOADAVG_FACTOR_5F 0.9834714538216174894737477501
+#define LOADAVG_FACTOR_15F 0.9944598480048967508795473394
+/*
+ * The time interval in seconds between taking load counts, same as Linux
+ */
+#define LOADAVG_SAMPLING_INTERVAL 5
+
+double load_avg_1m;
+double load_avg_5m;
+double load_avg_15m;
+
#define debug_error(msg) do { \
char *suffix = g_win32_error_message(GetLastError()); \
g_debug("%s: %s", (msg), suffix); \
@@ -2448,3 +2471,120 @@ char *qga_get_host_name(Error **errp)
return g_utf16_to_utf8(tmp, size, NULL, NULL, NULL);
}
+
+
+static VOID CALLBACK load_avg_callback(PVOID hCounter, BOOLEAN timedOut)
+{
+ PDH_FMT_COUNTERVALUE displayValue;
+ double currentLoad;
+ PDH_STATUS err;
+
+ err = PdhGetFormattedCounterValue(
+ (PDH_HCOUNTER)hCounter, PDH_FMT_DOUBLE, 0, &displayValue);
+ /* Skip updating the load if we can't get the value successfully */
+ if (err != ERROR_SUCCESS) {
+ slog("PdhGetFormattedCounterValue failed to get load value with 0x%lx",
+ err);
+ return;
+ }
+ currentLoad = displayValue.doubleValue;
+
+ load_avg_1m = load_avg_1m * LOADAVG_FACTOR_1F + currentLoad * \
+ (1.0 - LOADAVG_FACTOR_1F);
+ load_avg_5m = load_avg_5m * LOADAVG_FACTOR_5F + currentLoad * \
+ (1.0 - LOADAVG_FACTOR_5F);
+ load_avg_15m = load_avg_15m * LOADAVG_FACTOR_15F + currentLoad * \
+ (1.0 - LOADAVG_FACTOR_15F);
+}
+
+static BOOL init_load_avg_counter(Error **errp)
+{
+ CONST WCHAR *szCounterPath = L"\\System\\Processor Queue Length";
+ PDH_STATUS status;
+ BOOL ret;
+ HQUERY hQuery;
+ HCOUNTER hCounter;
+ HANDLE event;
+ HANDLE waitHandle;
+
+ status = PdhOpenQueryW(NULL, 0, &hQuery);
+ if (status != ERROR_SUCCESS) {
+ /*
+ * If the function fails, the return value is a system error code or
+ * a PDH error code. error_setg_win32 cant translate PDH error code
+ * properly, so just report it as is.
+ */
+ error_setg_win32(errp, (DWORD)status,
+ "PdhOpenQueryW failed with 0x%lx", status);
+ return FALSE;
+ }
+
+ status = PdhAddEnglishCounterW(hQuery, szCounterPath, 0, &hCounter);
+ if (status != ERROR_SUCCESS) {
+ error_setg_win32(errp, (DWORD)status,
+ "PdhAddEnglishCounterW failed with 0x%lx. Performance counters may be disabled.",
+ status);
+ PdhCloseQuery(hQuery);
+ return FALSE;
+ }
+
+ event = CreateEventW(NULL, FALSE, FALSE, L"LoadUpdateEvent");
+ if (event == NULL) {
+ error_setg_win32(errp, GetLastError(), "Create LoadUpdateEvent failed");
+ PdhCloseQuery(hQuery);
+ return FALSE;
+ }
+
+ status = PdhCollectQueryDataEx(hQuery, LOADAVG_SAMPLING_INTERVAL, event);
+ if (status != ERROR_SUCCESS) {
+ error_setg_win32(errp, (DWORD)status,
+ "PdhCollectQueryDataEx failed with 0x%lx", status);
+ CloseHandle(event);
+ PdhCloseQuery(hQuery);
+ return FALSE;
+ }
+
+ ret = RegisterWaitForSingleObject(
+ &waitHandle,
+ event,
+ (WAITORTIMERCALLBACK)load_avg_callback,
+ (PVOID)hCounter,
+ INFINITE,
+ WT_EXECUTEDEFAULT);
+
+ if (ret == 0) {
+ error_setg_win32(errp, GetLastError(),
+ "RegisterWaitForSingleObject failed");
+ CloseHandle(event);
+ PdhCloseQuery(hQuery);
+ return FALSE;
+ }
+
+ ga_set_load_avg_wait_handle(ga_state, waitHandle);
+ ga_set_load_avg_event(ga_state, event);
+ ga_set_load_avg_pdh_query(ga_state, hQuery);
+
+ return TRUE;
+}
+
+GuestLoadAverage *qmp_guest_get_load(Error **errp)
+{
+ if (ga_get_load_avg_pdh_query(ga_state) == NULL) {
+ /* set initial values */
+ load_avg_1m = 0;
+ load_avg_5m = 0;
+ load_avg_15m = 0;
+
+ if (init_load_avg_counter(errp) == false) {
+ return NULL;
+ }
+ }
+
+ GuestLoadAverage *ret = NULL;
+
+ ret = g_new0(GuestLoadAverage, 1);
+ ret->load1m = load_avg_1m;
+ ret->load5m = load_avg_5m;
+ ret->load15m = load_avg_15m;
+ return ret;
+}
diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h
index a536d07d0d..d9f3922adf 100644
--- a/qga/guest-agent-core.h
+++ b/qga/guest-agent-core.h
@@ -13,6 +13,10 @@
#ifndef GUEST_AGENT_CORE_H
#define GUEST_AGENT_CORE_H
+#ifdef _WIN32
+#include <pdh.h>
+#endif
+
#include "qapi/qmp-registry.h"
#include "qga-qapi-types.h"
@@ -41,6 +45,12 @@ void ga_set_response_delimited(GAState *s);
bool ga_is_frozen(GAState *s);
void ga_set_frozen(GAState *s);
void ga_unset_frozen(GAState *s);
+#ifdef _WIN32
+void ga_set_load_avg_event(GAState *s, HANDLE event);
+void ga_set_load_avg_wait_handle(GAState *s, HANDLE wait_handle);
+void ga_set_load_avg_pdh_query(GAState *s, HQUERY query);
+HQUERY ga_get_load_avg_pdh_query(GAState *s);
+#endif
const char *ga_fsfreeze_hook(GAState *s);
int64_t ga_get_fd_handle(GAState *s, Error **errp);
int ga_parse_whence(GuestFileWhence *whence, Error **errp);
diff --git a/qga/main.c b/qga/main.c
index 72c39b042f..6c02f3ec38 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -33,6 +33,7 @@
#include "qemu-version.h"
#ifdef _WIN32
#include <dbt.h>
+#include <pdh.h>
#include "qga/service-win32.h"
#include "qga/vss-win32.h"
#endif
@@ -105,6 +106,9 @@ struct GAState {
GAService service;
HANDLE wakeup_event;
HANDLE event_log;
+ HANDLE load_avg_wait_handle;
+ HANDLE load_avg_event;
+ HQUERY load_avg_pdh_query;
#endif
bool delimit_response;
bool frozen;
@@ -582,6 +586,25 @@ const char *ga_fsfreeze_hook(GAState *s)
}
#endif
+#ifdef _WIN32
+void ga_set_load_avg_wait_handle(GAState *s, HANDLE wait_handle)
+{
+ s->load_avg_wait_handle = wait_handle;
+}
+void ga_set_load_avg_event(GAState *s, HANDLE event)
+{
+ s->load_avg_event = event;
+}
+void ga_set_load_avg_pdh_query(GAState *s, HQUERY query)
+{
+ s->load_avg_pdh_query = query;
+}
+HQUERY ga_get_load_avg_pdh_query(GAState *s)
+{
+ return s->load_avg_pdh_query;
+}
+#endif
+
static void become_daemon(const char *pidfile)
{
#ifndef _WIN32
@@ -1402,6 +1425,10 @@ static GAState *initialize_agent(GAConfig *config, int socket_activation)
g_debug("Guest agent version %s started", QEMU_FULL_VERSION);
#ifdef _WIN32
+ s->load_avg_wait_handle = INVALID_HANDLE_VALUE;
+ s->load_avg_event = INVALID_HANDLE_VALUE;
+ s->load_avg_pdh_query = NULL;
+
s->event_log = RegisterEventSource(NULL, "qemu-ga");
if (!s->event_log) {
g_autofree gchar *errmsg = g_win32_error_message(GetLastError());
@@ -1506,6 +1533,18 @@ static void cleanup_agent(GAState *s)
#ifdef _WIN32
CloseHandle(s->wakeup_event);
CloseHandle(s->event_log);
+
+ if (s->load_avg_wait_handle != INVALID_HANDLE_VALUE) {
+ UnregisterWait(s->load_avg_wait_handle);
+ }
+
+ if (s->load_avg_event != INVALID_HANDLE_VALUE) {
+ CloseHandle(s->load_avg_event);
+ }
+
+ if (s->load_avg_pdh_query) {
+ PdhCloseQuery(s->load_avg_pdh_query);
+ }
#endif
if (s->command_state) {
ga_command_state_cleanup_all(s->command_state);
diff --git a/qga/meson.build b/qga/meson.build
index 587ec4e5e8..89a4a8f713 100644
--- a/qga/meson.build
+++ b/qga/meson.build
@@ -95,7 +95,7 @@ gen_tlb = []
qga_libs = []
if host_os == 'windows'
qga_libs += ['-lws2_32', '-lwinmm', '-lpowrprof', '-lwtsapi32', '-lwininet', '-liphlpapi', '-lnetapi32',
- '-lsetupapi', '-lcfgmgr32', '-luserenv']
+ '-lsetupapi', '-lcfgmgr32', '-luserenv', '-lpdh' ]
if have_qga_vss
qga_libs += ['-lole32', '-loleaut32', '-lshlwapi', '-lstdc++', '-Wl,--enable-stdcall-fixup']
subdir('vss-win32')
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 995594aaf4..cdab3872ea 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -1863,7 +1863,7 @@
'load5m': 'number',
'load15m': 'number'
},
- 'if': 'CONFIG_GETLOADAVG'
+ 'if': { 'any': ['CONFIG_WIN32', 'CONFIG_GETLOADAVG'] }
}
##
@@ -1877,7 +1877,7 @@
##
{ 'command': 'guest-get-load',
'returns': 'GuestLoadAverage',
- 'if': 'CONFIG_GETLOADAVG'
+ 'if': { 'any': ['CONFIG_WIN32', 'CONFIG_GETLOADAVG'] }
}
##
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/2] qga: Add tests for guest-get-load command
2025-03-14 11:38 [PATCH 0/2] qga: Add 'guest-get-load' command Konstantin Kostiuk
2025-03-14 11:38 ` [PATCH 1/2] qga-win: implement a " Konstantin Kostiuk
@ 2025-03-14 11:38 ` Konstantin Kostiuk
2025-03-18 13:47 ` [PATCH 0/2] qga: Add 'guest-get-load' command Dehan Meng
2025-03-19 14:57 ` Yan Vugenfirer
3 siblings, 0 replies; 7+ messages in thread
From: Konstantin Kostiuk @ 2025-03-14 11:38 UTC (permalink / raw)
To: qemu-devel; +Cc: Marc-André Lureau, Daniel P . Berrangé, Michael Roth
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
---
tests/unit/test-qga.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/tests/unit/test-qga.c b/tests/unit/test-qga.c
index 541b08a5e7..587e30c7e4 100644
--- a/tests/unit/test-qga.c
+++ b/tests/unit/test-qga.c
@@ -332,6 +332,22 @@ static void test_qga_get_fsinfo(gconstpointer fix)
}
}
+static void test_qga_get_load(gconstpointer fix)
+{
+ const TestFixture *fixture = fix;
+ g_autoptr(QDict) ret = NULL;
+ QDict *load;
+
+ ret = qmp_fd(fixture->fd, "{'execute': 'guest-get-load'}");
+ g_assert_nonnull(ret);
+ qmp_assert_no_error(ret);
+
+ load = qdict_get_qdict(ret, "return");
+ g_assert(qdict_haskey(load, "load1m"));
+ g_assert(qdict_haskey(load, "load5m"));
+ g_assert(qdict_haskey(load, "load15m"));
+}
+
static void test_qga_get_memory_block_info(gconstpointer fix)
{
const TestFixture *fixture = fix;
@@ -1105,6 +1121,7 @@ int main(int argc, char **argv)
g_test_add_data_func("/qga/get-vcpus", &fix, test_qga_get_vcpus);
}
g_test_add_data_func("/qga/get-fsinfo", &fix, test_qga_get_fsinfo);
+ g_test_add_data_func("/qga/get-load", &fix, test_qga_get_load);
g_test_add_data_func("/qga/get-memory-block-info", &fix,
test_qga_get_memory_block_info);
g_test_add_data_func("/qga/get-memory-blocks", &fix,
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread