[libvirt] [PATCHv2 03/11] qemu: add helper to get the block stats

Add an helper function to get the block stats of a disk. This helper is meant to be used by the bulk stats API. Signed-off-by: Francesco Romani <fromani(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 41 +++++++++++++++ src/qemu/qemu_monitor.c | 23 +++++++++ src/qemu/qemu_monitor.h | 18 +++++++ src/qemu/qemu_monitor_json.c | 118 +++++++++++++++++++++++++++++-------------- src/qemu/qemu_monitor_json.h | 4 ++ 5 files changed, 165 insertions(+), 39 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 1842e60..39e2c1b 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -178,6 +178,12 @@ static int qemuDomainHelperGetVcpus(virDomainObjPtr vm, unsigned char *cpumaps, int maplen); +static int qemuDomainGetBlockStats(virQEMUDriverPtr driver, + virDomainObjPtr vm, + struct qemuBlockStats *stats, + int nstats); + + virQEMUDriverPtr qemu_driver = NULL; @@ -9672,6 +9678,41 @@ qemuDomainBlockStats(virDomainPtr dom, return ret; } + +/* + * returns at most the first `nstats' stats, then stops. + * Returns the number of stats filled. + */ +static int +qemuDomainGetBlockStats(virQEMUDriverPtr driver, + virDomainObjPtr vm, + struct qemuBlockStats *stats, + int nstats) +{ + int ret = -1; + qemuDomainObjPrivatePtr priv; + + if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0) + goto cleanup; + + priv = vm->privateData; + + qemuDomainObjEnterMonitor(driver, vm); + + ret = qemuMonitorGetAllBlockStatsInfo(priv->mon, NULL, + stats, nstats); + + qemuDomainObjExitMonitor(driver, vm); + + if (!qemuDomainObjEndJob(driver, vm)) + vm = NULL; + + cleanup: + if (vm) + virObjectUnlock(vm); + return ret; +} + static int qemuDomainBlockStatsFlags(virDomainPtr dom, const char *path, diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 5b2952a..8aadba5 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -1754,6 +1754,29 @@ int qemuMonitorGetBlockStatsInfo(qemuMonitorPtr mon, return ret; } +int qemuMonitorGetAllBlockStatsInfo(qemuMonitorPtr mon, + const char *dev_name, + struct qemuBlockStats *stats, + int nstats) +{ + int ret; + VIR_DEBUG("mon=%p dev=%s", mon, dev_name); + + if (!mon) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("monitor must not be NULL")); + return -1; + } + + if (mon->json) + ret = qemuMonitorJSONGetAllBlockStatsInfo(mon, dev_name, + stats, nstats); + else + ret = -1; /* not supported */ + + return ret; +} + /* Return 0 and update @nparams with the number of block stats * QEMU supports if success. Return -1 if failure. */ diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 4fd6f01..1b7d00b 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -346,6 +346,24 @@ int qemuMonitorGetBlockStatsInfo(qemuMonitorPtr mon, long long *flush_req, long long *flush_total_times, long long *errs); + +struct qemuBlockStats { + long long rd_req; + long long rd_bytes; + long long wr_req; + long long wr_bytes; + long long rd_total_times; + long long wr_total_times; + long long flush_req; + long long flush_total_times; + long long errs; /* meaningless for QEMU */ +}; + +int qemuMonitorGetAllBlockStatsInfo(qemuMonitorPtr mon, + const char *dev_name, + struct qemuBlockStats *stats, + int nstats); + int qemuMonitorGetBlockStatsParamsNumber(qemuMonitorPtr mon, int *nparams); diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 62e7d5d..68c5cf8 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -1712,13 +1712,9 @@ int qemuMonitorJSONGetBlockStatsInfo(qemuMonitorPtr mon, long long *flush_total_times, long long *errs) { - int ret; - size_t i; - bool found = false; - virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("query-blockstats", - NULL); - virJSONValuePtr reply = NULL; - virJSONValuePtr devices; + struct qemuBlockStats stats; + int nstats = 1; + int ret = -1; *rd_req = *rd_bytes = -1; *wr_req = *wr_bytes = *errs = -1; @@ -1732,9 +1728,45 @@ int qemuMonitorJSONGetBlockStatsInfo(qemuMonitorPtr mon, if (flush_total_times) *flush_total_times = -1; + if (qemuMonitorJSONGetAllBlockStatsInfo(mon, dev_name, &stats, nstats) != nstats) + goto cleanup; + + *rd_req = stats.rd_req; + *rd_bytes = stats.rd_bytes; + *rd_total_times = stats.rd_total_times; + *wr_req = stats.wr_req; + *wr_bytes = stats.wr_bytes; + *wr_total_times = stats.wr_total_times; + *flush_req = stats.flush_req; + *flush_total_times = stats.flush_total_times; + *errs = stats.errs; + + ret = 0; + + cleanup: + return ret; +} + + +int qemuMonitorJSONGetAllBlockStatsInfo(qemuMonitorPtr mon, + const char *dev_name, + struct qemuBlockStats *blockstats, + int nstats) +{ + int ret; + size_t i; + bool found = false; + virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("query-blockstats", + NULL); + virJSONValuePtr reply = NULL; + virJSONValuePtr devices; + if (!cmd) return -1; + if (!blockstats || nstats <= 0) + return -1; + ret = qemuMonitorJSONCommand(mon, cmd, &reply); if (ret == 0) @@ -1750,33 +1782,41 @@ int qemuMonitorJSONGetBlockStatsInfo(qemuMonitorPtr mon, goto cleanup; } + ret = 0; for (i = 0; i < virJSONValueArraySize(devices); i++) { virJSONValuePtr dev = virJSONValueArrayGet(devices, i); virJSONValuePtr stats; - const char *thisdev; if (!dev || dev->type != VIR_JSON_TYPE_OBJECT) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("blockstats device entry was not in expected format")); goto cleanup; } - if ((thisdev = virJSONValueObjectGetString(dev, "device")) == NULL) { - virReportError(VIR_ERR_INTERNAL_ERROR, "%s", - _("blockstats device entry was not in expected format")); - goto cleanup; + if (ret > nstats) { + break; } - /* New QEMU has separate names for host & guest side of the disk - * and libvirt gives the host side a 'drive-' prefix. The passed - * in dev_name is the guest side though - */ - if (STRPREFIX(thisdev, QEMU_DRIVE_HOST_PREFIX)) - thisdev += strlen(QEMU_DRIVE_HOST_PREFIX); + if (dev_name != NULL) { + const char *thisdev; + if ((thisdev = virJSONValueObjectGetString(dev, "device")) == NULL) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("blockstats device entry was not in expected format")); + goto cleanup; + } - if (STRNEQ(thisdev, dev_name)) - continue; + /* New QEMU has separate names for host & guest side of the disk + * and libvirt gives the host side a 'drive-' prefix. The passed + * in dev_name is the guest side though + */ + if (STRPREFIX(thisdev, QEMU_DRIVE_HOST_PREFIX)) + thisdev += strlen(QEMU_DRIVE_HOST_PREFIX); + + if (STRNEQ(thisdev, dev_name)) + continue; + + found = true; + } - found = true; if ((stats = virJSONValueObjectGet(dev, "stats")) == NULL || stats->type != VIR_JSON_TYPE_OBJECT) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", @@ -1784,74 +1824,74 @@ int qemuMonitorJSONGetBlockStatsInfo(qemuMonitorPtr mon, goto cleanup; } - if (virJSONValueObjectGetNumberLong(stats, "rd_bytes", rd_bytes) < 0) { + if (virJSONValueObjectGetNumberLong(stats, "rd_bytes", &blockstats->rd_bytes) < 0) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "rd_bytes"); goto cleanup; } - if (virJSONValueObjectGetNumberLong(stats, "rd_operations", rd_req) < 0) { + if (virJSONValueObjectGetNumberLong(stats, "rd_operations", &blockstats->rd_req) < 0) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "rd_operations"); goto cleanup; } - if (rd_total_times && - virJSONValueObjectHasKey(stats, "rd_total_time_ns") && + if (virJSONValueObjectHasKey(stats, "rd_total_time_ns") && (virJSONValueObjectGetNumberLong(stats, "rd_total_time_ns", - rd_total_times) < 0)) { + &blockstats->rd_total_times) < 0)) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "rd_total_time_ns"); goto cleanup; } - if (virJSONValueObjectGetNumberLong(stats, "wr_bytes", wr_bytes) < 0) { + if (virJSONValueObjectGetNumberLong(stats, "wr_bytes", &blockstats->wr_bytes) < 0) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "wr_bytes"); goto cleanup; } - if (virJSONValueObjectGetNumberLong(stats, "wr_operations", wr_req) < 0) { + if (virJSONValueObjectGetNumberLong(stats, "wr_operations", &blockstats->wr_req) < 0) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "wr_operations"); goto cleanup; } - if (wr_total_times && - virJSONValueObjectHasKey(stats, "wr_total_time_ns") && + if (virJSONValueObjectHasKey(stats, "wr_total_time_ns") && (virJSONValueObjectGetNumberLong(stats, "wr_total_time_ns", - wr_total_times) < 0)) { + &blockstats->wr_total_times) < 0)) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "wr_total_time_ns"); goto cleanup; } - if (flush_req && - virJSONValueObjectHasKey(stats, "flush_operations") && + if (virJSONValueObjectHasKey(stats, "flush_operations") && (virJSONValueObjectGetNumberLong(stats, "flush_operations", - flush_req) < 0)) { + &blockstats->flush_req) < 0)) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "flush_operations"); goto cleanup; } - if (flush_total_times && - virJSONValueObjectHasKey(stats, "flush_total_time_ns") && + if (virJSONValueObjectHasKey(stats, "flush_total_time_ns") && (virJSONValueObjectGetNumberLong(stats, "flush_total_time_ns", - flush_total_times) < 0)) { + &blockstats->flush_total_times) < 0)) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot read %s statistic"), "flush_total_time_ns"); goto cleanup; } + blockstats->errs = -1; /* meaningless for QEMU */ + + ret++; + blockstats++; } - if (!found) { + if (dev_name != NULL && !found) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot find statistics for device '%s'"), dev_name); + ret = 0; goto cleanup; } - ret = 0; cleanup: virJSONValueFree(cmd); diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index d8c9308..79058c1 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -79,6 +79,10 @@ int qemuMonitorJSONGetBlockStatsInfo(qemuMonitorPtr mon, long long *flush_req, long long *flush_total_times, long long *errs); +int qemuMonitorJSONGetAllBlockStatsInfo(qemuMonitorPtr mon, + const char *dev_name, + struct qemuBlockStats *stats, + int nstats); int qemuMonitorJSONGetBlockStatsParamsNumber(qemuMonitorPtr mon, int *nparams); int qemuMonitorJSONGetBlockExtent(qemuMonitorPtr mon, -- 1.9.3