7:02 a.m.
Just set l2-cache-size to INT64_MAX for all format nodes of
qcow2 type in block node graph.
-drive configuration is not supported because we can not
set l2 cache size down the backing chain in this case.
Note that imlementation sets l2-cache-size and not cache-size.
Unfortunately at time of this patch setting cache-size to INT64_MAX
fails and as guest performance depends only on l2 cache size
and not refcount cache size (which is documented in recent qemu)
we can set l2 directly.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy(a)virtuozzo.com>
---
src/qemu/qemu_block.c | 5 ++++-
src/qemu/qemu_command.c | 23 +++++++++++++++++++++++
src/qemu/qemu_domain.c | 2 ++
src/util/virstoragefile.c | 1 +
src/util/virstoragefile.h | 1 +
5 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 5321dda..8771cc1 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -1322,7 +1322,6 @@ qemuBlockStorageSourceGetFormatQcow2Props(virStorageSourcePtr src,
* 'pass-discard-snapshot'
* 'pass-discard-other'
* 'overlap-check'
- * 'l2-cache-size'
* 'l2-cache-entry-size'
* 'refcount-cache-size'
* 'cache-clean-interval'
@@ -1331,6 +1330,10 @@ qemuBlockStorageSourceGetFormatQcow2Props(virStorageSourcePtr src,
if (qemuBlockStorageSourceGetFormatQcowGenericProps(src, "qcow2", props)
< 0)
return -1;
+ if (src->metadata_cache_size == VIR_DOMAIN_DISK_METADATA_CACHE_SIZE_MAXIMUM
&&
+ virJSONValueObjectAdd(props, "I:l2-cache-size", INT64_MAX, NULL) <
0)
+ return -1;
+
return 0;
}
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index f59cbf5..12b2c8d 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1330,6 +1330,20 @@ qemuCheckDiskConfig(virDomainDiskDefPtr disk,
return -1;
}
+ if (disk->metadata_cache_size) {
+ if (disk->src->format != VIR_STORAGE_FILE_QCOW2) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("metadata_cache_size can only be set for qcow2
disks"));
+ return -1;
+ }
+
+ if (disk->metadata_cache_size != VIR_DOMAIN_DISK_METADATA_CACHE_SIZE_MAXIMUM)
{
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("metadata_cache_size can only be set to
'maximum'"));
+ return -1;
+ }
+ }
+
if (qemuCaps) {
if (disk->serial &&
disk->bus == VIR_DOMAIN_DISK_BUS_SCSI &&
@@ -1353,6 +1367,15 @@ qemuCheckDiskConfig(virDomainDiskDefPtr disk,
_("detect_zeroes is not supported by this QEMU
binary"));
return -1;
}
+
+ if (disk->metadata_cache_size &&
+ !(virQEMUCapsGet(qemuCaps, QEMU_CAPS_BLOCKDEV) &&
+ virQEMUCapsGet(qemuCaps, QEMU_CAPS_QCOW2_L2_CACHE_SIZE))) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("setting metadata_cache_size is not supported by
"
+ "this QEMU binary"));
+ return -1;
+ }
}
if (disk->serial &&
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 045a7b4..23d9348 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -9074,6 +9074,7 @@ qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,
/* "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);
+ CHECK_EQ(metadata_cache_size, "metadata_cache_size", true);
/* Note: For some address types the address auto generation for
* @disk has still not happened at this point (e.g. driver
@@ -13244,6 +13245,7 @@ qemuDomainPrepareDiskSourceData(virDomainDiskDefPtr disk,
src->iomode = disk->iomode;
src->cachemode = disk->cachemode;
src->discard = disk->discard;
+ src->metadata_cache_size = disk->metadata_cache_size;
if (disk->device == VIR_DOMAIN_DISK_DEVICE_FLOPPY)
src->floppyimg = true;
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 94c32d8..9089e2f 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -2210,6 +2210,7 @@ virStorageSourceCopy(const virStorageSource *src,
ret->cachemode = src->cachemode;
ret->discard = src->discard;
ret->detect_zeroes = src->detect_zeroes;
+ ret->metadata_cache_size = src->metadata_cache_size;
/* storage driver metadata are not copied */
ret->drv = NULL;
diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
index 3ff6c4f..8b57399 100644
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@@ -331,6 +331,7 @@ struct _virStorageSource {
int cachemode; /* enum virDomainDiskCache */
int discard; /* enum virDomainDiskDiscard */
int detect_zeroes; /* enum virDomainDiskDetectZeroes */
+ int metadata_cache_size; /* enum virDomainDiskImageMetadataCacheSize */
bool floppyimg; /* set to true if the storage source is going to be used
as a source for floppy drive */
--
1.8.3.1