Random write IOPS will drop dramatically if qcow2 l2 cache could not cover the whole disk. This patch give libvirt user a chance to adjust the qcow2 cache configuration. Signed-off-by: Liu Qing <liuqing(a)huayun.com&gt; --- src/conf/domain_conf.c | 30 ++++++++++++++++++++++++++++++ src/qemu/qemu_command.c | 6 ++++++ src/util/virstoragefile.c | 3 +++ src/util/virstoragefile.h | 4 ++++ 4 files changed, 43 insertions(+) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index d97aab4..06ca1de 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -8590,6 +8590,30 @@ virDomainDiskDefDriverParseXML(virDomainDiskDefPtr def, VIR_FREE(tmp); } + if ((tmp = virXMLPropString(cur, "l2-cache-size")) && + (virStrToLong_ui(tmp, NULL, 10, &def->src->l2_cache_size) < 0)) { + virReportError(VIR_ERR_XML_ERROR, + _("Invalid l2-cache-size attribute in disk driver element: %s"), + tmp); + goto cleanup; + } + + if ((tmp = virXMLPropString(cur, "refcount-cache-size")) && + (virStrToLong_ui(tmp, NULL, 10, &def->src->refcount_cache_size) < 0)) { + virReportError(VIR_ERR_XML_ERROR, + _("Invalid refcount-cache-size attribute in disk driver element: %s"), + tmp); + goto cleanup; + } + + if ((tmp = virXMLPropString(cur, "cache-clean-interval")) && + (virStrToLong_ui(tmp, NULL, 10, &def->src->cache_clean_interval) < 0)) { + virReportError(VIR_ERR_XML_ERROR, + _("Invalid cache-clean-interval attribute in disk driver element: %s"), + tmp); + goto cleanup; + } + if ((tmp = virXMLPropString(cur, "detect_zeroes")) && (def->detect_zeroes = virDomainDiskDetectZeroesTypeFromString(tmp)) <= 0) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, @@ -21887,6 +21911,12 @@ virDomainDiskDefFormat(virBufferPtr buf, virBufferAsprintf(&driverBuf, " iothread='%u'", def->iothread); if (def->detect_zeroes) virBufferAsprintf(&driverBuf, " detect_zeroes='%s'", detect_zeroes); + if (def->src->l2_cache_size > 0) + virBufferAsprintf(&driverBuf, " l2-cache-size='%u'", def->src->l2_cache_size); + if (def->src->refcount_cache_size > 0) + virBufferAsprintf(&driverBuf, " refcount-cache-size='%u'", def->src->refcount_cache_size); + if (def->src->cache_clean_interval > 0) + virBufferAsprintf(&driverBuf, " cache-clean-interval='%u'", def->src->cache_clean_interval); virDomainVirtioOptionsFormat(&driverBuf, def->virtio); diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9a27987..7996eed 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -1430,6 +1430,12 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk, qemuformat = "luks"; virBufferAsprintf(buf, "format=%s,", qemuformat); } + if (disk->src->format == VIR_STORAGE_FILE_QCOW2 && disk->src->l2_cache_size > 0) + virBufferAsprintf(buf, "l2-cache-size=%u,", disk->src->l2_cache_size); + if (disk->src->format == VIR_STORAGE_FILE_QCOW2 && disk->src->refcount_cache_size > 0) + virBufferAsprintf(buf, "refcount-cache-size=%u,", disk->src->refcount_cache_size); + if (disk->src->format == VIR_STORAGE_FILE_QCOW2 && disk->src->cache_clean_interval > 0) + virBufferAsprintf(buf, "cache-clean-interval=%u,", disk->src->cache_clean_interval); ret = 0; diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index fbc8245..c685331 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -2038,6 +2038,9 @@ virStorageSourceCopy(const virStorageSource *src, ret->physical = src->physical; ret->readonly = src->readonly; ret->shared = src->shared; + ret->l2_cache_size = src->l2_cache_size; + ret->refcount_cache_size = src->refcount_cache_size; + ret->cache_clean_interval = src->cache_clean_interval; /* storage driver metadata are not copied */ ret->drv = NULL; diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h index 6c388b1..e7889d9 100644 --- a/src/util/virstoragefile.h +++ b/src/util/virstoragefile.h @@ -280,6 +280,10 @@ struct _virStorageSource { /* metadata that allows identifying given storage source */ char *nodeformat; /* name of the format handler object */ char *nodestorage; /* name of the storage object */ + + unsigned l2_cache_size; /* qcow2 l2 cache size */ + unsigned refcount_cache_size; /* qcow2 reference count table cache size */ + unsigned cache_clean_interval; /* clean unused cache entries interval */ }; -- 1.8.3.1