Re: [libvirt] [PATCH v3 2/5] xml: add disk driver metadata_cache_size option

The options specifies metadata cache size policy for a disk. This is going to be used only for QEMU and only for qcow2 images in next patch to set qcow2 L2 cache size. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy(a)virtuozzo.com&gt; --- docs/formatdomain.html.in | 11 ++++++ docs/schemas/domaincommon.rng | 11 ++++++ src/conf/domain_conf.c | 17 +++++++++ src/conf/domain_conf.h | 9 +++++ .../qemuxml2argvdata/disk-metadata_cache_size.xml | 35 ++++++++++++++++++ .../disk-metadata_cache_size.xml | 41 ++++++++++++++++++++++ tests/qemuxml2xmltest.c | 2 ++ 7 files changed, 126 insertions(+) create mode 100644 tests/qemuxml2argvdata/disk-metadata_cache_size.xml create mode 100644 tests/qemuxml2xmloutdata/disk-metadata_cache_size.xml diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 7f07bb7..fcffa9c 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -3608,6 +3608,17 @@ virt queues for virtio-blk. (<span class="since">Since 3.9.0</span>) </li> <li> + The optional <code>metadata_cache_size</code> attribute specifies + metadata cache size policy. Possible values are "default" and + "maximum". Using "default" leaves setting cache size to the hypervisor,

+ Using "maximum" ensures entire disk cache remains in memory, increasing + IO but utilizing more memory. This policy helps if workload's + disk working set (the amount of disk data used intensively) is too large + to be covered by cache size by "default" policy. + (<span class="since">Since 5.0.0, QEMU 3.0</span>). The option makes

+ sense only for non raw images and supported for qcow2 only now. + </li> + <li> For virtio disks, <a href="#elementsVirtio">Virtio-specific options</a> can also be set. (<span class="since">Since 3.5.0</span>) diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index aa50eac..aa8b8ff 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -2003,6 +2003,9 @@ <ref name="detect_zeroes"/> </optional> <optional> + <ref name="metadata_cache_size"/> + </optional> + <optional> <attribute name='queues'> <ref name="positiveInteger"/> </attribute> @@ -2103,6 +2106,14 @@ </choice> </attribute> </define> + <define name="metadata_cache_size"> + <attribute name='metadata_cache_size'> + <choice> + <value>default</value> + <value>maximum</value> + </choice> + </attribute> + </define> <define name="controller"> <element name="controller"> <optional> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 222bb8c..9488c35 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -889,6 +889,11 @@ VIR_ENUM_IMPL(virDomainDiskDetectZeroes, VIR_DOMAIN_DISK_DETECT_ZEROES_LAST, "on", "unmap") +VIR_ENUM_IMPL(virDomainDiskMetadataCacheSize, + VIR_DOMAIN_DISK_METADATA_CACHE_SIZE_LAST, + "default", + "maximum") + VIR_ENUM_IMPL(virDomainDiskMirrorState, VIR_DOMAIN_DISK_MIRROR_STATE_LAST, "none", "yes", @@ -9419,6 +9424,14 @@ virDomainDiskDefDriverParseXML(virDomainDiskDefPtr def, } VIR_FREE(tmp); + if ((tmp = virXMLPropString(cur, "metadata_cache_size")) && + (def->metadata_cache_size = virDomainDiskMetadataCacheSizeTypeFromString(tmp)) < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown driver metadata_cache_size value '%s'"), tmp); + goto cleanup; + } + VIR_FREE(tmp); + ret = 0; cleanup: @@ -24193,6 +24206,10 @@ virDomainDiskDefFormatDriver(virBufferPtr buf, if (disk->queues) virBufferAsprintf(&driverBuf, " queues='%u'", disk->queues); + if (disk->metadata_cache_size) + virBufferAsprintf(&driverBuf, " metadata_cache_size='%s'", + virDomainDiskMetadataCacheSizeTypeToString(disk->metadata_cache_size)); + virDomainVirtioOptionsFormat(&driverBuf, disk->virtio); return virXMLFormatElement(buf, "driver", &driverBuf, NULL); diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index fae1306..31ce9ab 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -567,6 +567,13 @@ typedef enum { VIR_DOMAIN_DISK_DETECT_ZEROES_LAST } virDomainDiskDetectZeroes; +typedef enum { + VIR_DOMAIN_DISK_METADATA_CACHE_SIZE_DEFAULT = 0,

+ VIR_DOMAIN_DISK_METADATA_CACHE_SIZE_MAXIMUM, + + VIR_DOMAIN_DISK_METADATA_CACHE_SIZE_LAST +} virDomainDiskMetadataCacheSize; +