From: Konstantin Kostiuk Date: Mon, 24 Mar 2025 13:17:28 +0000 (+0200) Subject: qga-win: implement a 'guest-get-load' command X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6f0273d6ae21bb2e4222789af0e6d480aa9430b1;p=thirdparty%2Fqemu.git qga-win: implement a 'guest-get-load' command 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 Reviewed-by: Daniel P. Berrangé Tested-by: Dehan Meng Reviewed-by: Yan Vugenfirer Signed-off-by: Konstantin Kostiuk --- diff --git a/qga/commands-win32.c b/qga/commands-win32.c index d4482538ec..8227480810 100644 --- a/qga/commands-win32.c +++ b/qga/commands-win32.c @@ -27,6 +27,7 @@ #include #include #include +#include #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); \ @@ -2444,3 +2467,128 @@ 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) +{ + /* + * The load average logic calls PerformaceCounterAPI, which can result + * in a performance penalty. This avoids running the load average logic + * until a management application actually requests it. The load average + * will not initially be very accurate, but assuming that any interested + * management application will request it repeatedly throughout the lifetime + * of the VM, this seems like a good mitigation. + */ + 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 +#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 +#include #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 5316bfacbf..6d770f7b8e 100644 --- a/qga/qapi-schema.json +++ b/qga/qapi-schema.json @@ -1880,7 +1880,7 @@ 'load5m': 'number', 'load15m': 'number' }, - 'if': 'CONFIG_GETLOADAVG' + 'if': { 'any': ['CONFIG_WIN32', 'CONFIG_GETLOADAVG'] } } ## @@ -1888,13 +1888,18 @@ # # Retrieve CPU process load information # +# .. note:: Windows does not have load average API, so QGA emulates it by +# calculating the average CPU usage in the last 1, 5, 15 minutes +# similar as Linux does this. +# Calculation starts from the first time this command is called. +# # Returns: load information # # Since: 10.0 ## { 'command': 'guest-get-load', 'returns': 'GuestLoadAverage', - 'if': 'CONFIG_GETLOADAVG' + 'if': { 'any': ['CONFIG_WIN32', 'CONFIG_GETLOADAVG'] } } ##