Re: [libvirt] [PATCH] qemu:Add support L2 table cache for qcow2 disk

The patch add support L2 table cache for qcow2 disk. L2 table cache can improve IO read and write performance for qcow2 img. Diff follows:  src/conf/domain_conf.c                               | 47 +++++++++++++++++++++++++++++++++++++++++++++++  src/conf/domain_conf.h                               |  5 +++++  src/qemu/qemu_command.c                              |  7 +++++++  src/qemu/qemu_domain.c                               |  6 ++++++  tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.args |  2 +-  tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml  |  3 ++-  6 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index beca0be..0a6afca 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -8058,6 +8058,8 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,      char *domain_name = NULL;      int expected_secret_usage = -1;      int auth_secret_usage = -1; +    char *disk_l2_cache_size = NULL; +    char *disk_cache_clean_interval = NULL;      if (!(def = virDomainDiskDefNew(xmlopt)))          return NULL; @@ -8233,6 +8235,27 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,              }          } else if (xmlStrEqual(cur->name, BAD_CAST "boot")) {              /* boot is parsed as part of virDomainDeviceInfoParseXML */ +        } else if (xmlStrEqual(cur->name, BAD_CAST "diskCache")) { +            disk_l2_cache_size = +                virXMLPropString(cur, "disk_l2_cache_size"); +            if (disk_l2_cache_size && +                virStrToLong_ui(disk_l2_cache_size, NULL, 0, +                                &def->disk_cache.disk_l2_cache_size) < 0) { +                virReportError(VIR_ERR_INTERNAL_ERROR, +                               _("invalid disk L2 cache size '%s'"), +                               disk_l2_cache_size); +                goto error; +            } +            disk_cache_clean_interval = +                virXMLPropString(cur, "disk_cache_clean_interval"); +            if (disk_cache_clean_interval && +                virStrToLong_ui(disk_cache_clean_interval, NULL, 0, +                                &def->disk_cache.disk_cache_clean_interval) < 0) { +                virReportError(VIR_ERR_INTERNAL_ERROR, +                               _("invalid disk cache clean interval '%s'"), +                               disk_cache_clean_interval); +                goto error; +            }          }      } @@ -8472,6 +8495,8 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,      VIR_FREE(vendor);      VIR_FREE(product);      VIR_FREE(domain_name); +    VIR_FREE(disk_l2_cache_size); +    VIR_FREE(disk_cache_clean_interval);      ctxt->node = save_ctxt;      return def; @@ -20646,6 +20671,27 @@ virDomainDiskBlockIoDefFormat(virBufferPtr buf,      }  } +static void +virDomainDiskCacheDefFormat(virBufferPtr buf, +                              virDomainDiskDefPtr def) +{ +    if (def->disk_cache.disk_l2_cache_size > 0 || +        def->disk_cache.disk_cache_clean_interval > 0) { +        virBufferAddLit(buf, "<diskCache"); +        if (def->disk_cache.disk_l2_cache_size > 0) { +            virBufferAsprintf(buf, +                              " disk_l2_cache_size='%u'", +                              def->disk_cache.disk_l2_cache_size); +        } +        if (def->disk_cache.disk_cache_clean_interval > 0) { +            virBufferAsprintf(buf, +                              " disk_cache_clean_interval='%u'", +                              def->disk_cache.disk_cache_clean_interval); +        } +        virBufferAddLit(buf, "/>\n"); +    } +} +  /* virDomainSourceDefFormatSeclabel:   * @@ -20990,6 +21036,7 @@ virDomainDiskDefFormat(virBufferPtr buf,      virDomainDiskGeometryDefFormat(buf, def);      virDomainDiskBlockIoDefFormat(buf, def); +    virDomainDiskCacheDefFormat(buf, def);      /* For now, mirroring is currently output-only: we only output it       * for live domains, therefore we ignore it on input except for diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 91a33cb..83ea9d3 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -647,6 +647,11 @@ struct _virDomainDiskDef {          unsigned int physical_block_size;      } blockio; +    struct { +        unsigned int disk_l2_cache_size; +        unsigned int disk_cache_clean_interval; +    } disk_cache; +      virDomainBlockIoTuneInfo blkdeviotune;      char *serial; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index e087891..7c47cd3 100755 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -1662,6 +1662,13 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk,      if (qemuBuildDriveSourceStr(disk, cfg, &opt, qemuCaps) < 0)          goto error; +    if (disk->disk_cache.disk_l2_cache_size > 0) +        virBufferAsprintf(&opt, "l2-cache-size=%u,", +                disk->disk_cache.disk_l2_cache_size); +    if (disk->disk_cache.disk_cache_clean_interval > 0) +        virBufferAsprintf(&opt, "cache-clean-interval=%u,", +                disk->disk_cache.disk_cache_clean_interval); +      if (emitDeviceSyntax)          virBufferAddLit(&opt, "if=none");      else diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 9f165c1..de334a7 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -5408,6 +5408,12 @@ qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,      CHECK_EQ(ioeventfd, "ioeventfd", true);      CHECK_EQ(event_idx, "event_idx", true);      CHECK_EQ(copy_on_read, "copy_on_read", true); + +    CHECK_EQ(disk_cache.disk_l2_cache_size, +             "diskCache disk_l2_cache_size", true); +    CHECK_EQ(disk_cache.disk_cache_clean_interval, +             "diskCache disk_cache_clean_interval", true); +      /* "snapshot" is a libvirt internal field and thus can be changed */      /* startupPolicy is allowed to be updated. Therefore not checked here. */      CHECK_EQ(transient, "transient", true); diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.args index b405242..b968302 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.args @@ -22,7 +22,7 @@ QEMU_AUDIO_DRV=none \  -drive file=/dev/HostVG/QEMUGuest2,format=raw,if=none,media=cdrom,\  id=drive-ide0-1-0,readonly=on \  -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 \ --drive file=/tmp/data.img,format=raw,if=none,id=drive-virtio-disk0 \ +-drive file=/tmp/data.img,format=qcow2,l2-cache-size=536870912,cache-clean-interval=900,if=none,id=drive-virtio-disk0 \  -device virtio-blk-pci,bus=pci.0,addr=0x3,drive=drive-virtio-disk0,\  id=virtio-disk0 \  -drive file=/tmp/logs.img,format=raw,if=none,id=drive-virtio-disk1 \ diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml index b843878..43298fb 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml @@ -28,8 +28,9 @@        <address type='drive' controller='0' bus='1' target='0' unit='0'/>      </disk>      <disk type='file' device='disk'> -      <driver name='qemu' type='raw'/> +      <driver name='qemu' type='qcow2'/>        <source file='/tmp/data.img'/> +      <diskCache disk_l2_cache_size='53687' disk_cache_clean_interval='900' />        <target dev='vda' bus='virtio'/>      </disk>      <disk type='file' device='disk'> Thanks -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list