7:50 a.m.
QEMU blockdev allows to configure cachemode, discard and detect-zeroes
for blockdev-add. The benefit of allowing to change cachemode is copying
a shared storage (RBD, writeback) to a local device mapping (SAN, none
cache) and still allows live migration. Allowing changing detect-zeroes
could be beneficial while copying from SAN to RBD without taking too
much space.
Signed-off-by: jshen28 <yshxxsjt715(a)163.com>
---
src/conf/domain_conf.c | 11 +++++++++++
src/conf/storage_source_conf.h | 6 +++---
src/qemu/qemu_blockjob.c | 13 +++++++++++++
src/qemu/qemu_driver.c | 14 ++++++++++++++
4 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index ff1c78ecd1..0533a770c3 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -13962,6 +13962,17 @@ virDomainDiskDefParseSource(const char *xmlStr,
if ((driverNode = virXPathNode("./driver", ctxt))) {
if (virDomainDiskDefDriverSourceParseXML(src, driverNode, ctxt) < 0)
return NULL;
+ if (virXMLPropEnum(driverNode, "cache",
virDomainDiskCacheTypeFromString,
+ VIR_XML_PROP_NONE, &src->cachemode) < 0)
+ return NULL;
+ if (virXMLPropEnum(driverNode, "detect_zeroes",
+ virDomainDiskDetectZeroesTypeFromString,
+ VIR_XML_PROP_NONE, &src->detect_zeroes) < 0)
+ return NULL;
+ if (virXMLPropEnum(driverNode, "discard",
+ virDomainDiskDiscardTypeFromString,
+ VIR_XML_PROP_NONE, &src->discard) < 0)
+ return NULL;
}
if (virStorageSourceIsEmpty(src)) {
diff --git a/src/conf/storage_source_conf.h b/src/conf/storage_source_conf.h
index 14a6825d54..bed3b6570d 100644
--- a/src/conf/storage_source_conf.h
+++ b/src/conf/storage_source_conf.h
@@ -392,9 +392,9 @@ struct _virStorageSource {
* These instances are currently just copies from the parent definition and
* are not mapped back to the XML */
int iomode; /* enum virDomainDiskIo */
- int cachemode; /* enum virDomainDiskCache */
- int discard; /* enum virDomainDiskDiscard */
- int detect_zeroes; /* enum virDomainDiskDetectZeroes */
+ unsigned int cachemode; /* enum virDomainDiskCache */
+ unsigned int discard; /* enum virDomainDiskDiscard */
+ unsigned int detect_zeroes; /* enum virDomainDiskDetectZeroes */
bool floppyimg; /* set to true if the storage source is going to be used
as a source for floppy drive */
diff --git a/src/qemu/qemu_blockjob.c b/src/qemu/qemu_blockjob.c
index cb2d05d71d..f6b85772be 100644
--- a/src/qemu/qemu_blockjob.c
+++ b/src/qemu/qemu_blockjob.c
@@ -1240,6 +1240,19 @@ qemuBlockJobProcessEventConcludedCopyPivot(virQEMUDriver *driver,
qemuBlockJobEventProcessConcludedRemoveChain(driver, vm, asyncJob,
job->disk->src);
virObjectUnref(job->disk->src);
job->disk->src = g_steal_pointer(&job->disk->mirror);
+
+ /* reset cachemode, discard, detect_zeroes to reflect the enforced setting */
+ if (job->disk->src->cachemode) {
+ job->disk->cachemode = job->disk->src->cachemode;
+ }
+
+ if (job->disk->src->discard) {
+ job->disk->discard = job->disk->src->discard;
+ }
+
+ if (job->disk->src->detect_zeroes) {
+ job->disk->detect_zeroes = job->disk->src->detect_zeroes;
+ }
}
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 6154fe9bfe..4058cdfafe 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -14552,6 +14552,7 @@ qemuDomainBlockCopyCommon(virDomainObj *vm,
bool existing = mirror_reuse;
qemuBlockJobData *job = NULL;
g_autoptr(virStorageSource) mirror = mirrorsrc;
+ g_autoptr(virStorageSource) mirror_cpy = virStorageSourceCopy(mirror, false);
bool supports_create = false;
bool supports_access = false;
bool supports_detect = false;
@@ -14725,6 +14726,19 @@ qemuDomainBlockCopyCommon(virDomainObj *vm,
* to modify all callers of 'qemuDomainPrepareStorageSourceBlockdev' */
mirror->detect_zeroes = disk->detect_zeroes;
+ /* respect input disk configuration */
+ if (mirror_cpy->detect_zeroes) {
+ mirror->detect_zeroes = mirror_cpy->detect_zeroes;
+ }
+
+ if (mirror_cpy->cachemode) {
+ mirror->cachemode = mirror_cpy->cachemode;
+ }
+
+ if (mirror_cpy->discard) {
+ mirror->discard = mirror_cpy->discard;
+ }
+
/* If reusing an external image that includes a backing file but the user
* did not enumerate the chain in the XML we need to detect the chain */
if (mirror_reuse &&
--
2.17.1