[libvirt] [PATCH v4 3/7] blockcopy: add qemu implementation of new tunables

Eric Blake eblake at redhat.com
Fri Sep 12 03:55:37 UTC 2014


Upstream qemu 1.4 added some drive-mirror tunables not present
when it was first introduced in 1.3.  Management apps may want
to set these in some cases (for example, without tuning
granularity down to sector size, a copy may end up occupying
more bytes than the original because an entire cluster is
copied even when only a sector within the cluster is dirty,
although tuning it down results in more CPU time to do the
copy).  I haven't personally needed to use the parameters, but
since they exist, and since the new API supports virTypedParams,
we might as well expose them.

Since the tuning parameters aren't often used, and omitted from
the QMP command when unspecified, I think it is safe to rely on
qemu 1.3 to issue an error about them being unsupported, rather
than trying to create a new capability bit in libvirt.

Meanwhile, all versions of qemu from 1.4 to 2.1 have a bug where
a bad granularity (such as non-power-of-2) gives a poor message:
error: internal error: unable to execute QEMU command 'drive-mirror': Invalid parameter 'drive-virtio-disk0'

because of abuse of QERR_INVALID_PARAMETER (which is supposed to
name the parameter that was given a bad value, rather than the
value passed to some other parameter).  I don't see that a
capability check will help, so we'll just live with it (and it
has since been improved in upstream qemu).

* src/qemu/qemu_monitor.h (qemuMonitorDriveMirror): Add
parameters.
* src/qemu/qemu_monitor.c (qemuMonitorDriveMirror): Likewise.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDriveMirror):
Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDriveMirror):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainBlockCopyCommon): Likewise.
(qemuDomainBlockRebase, qemuDomainBlockCopy): Adjust callers.
* src/qemu/qemu_migration.c (qemuMigrationDriveMirror): Likewise.
* tests/qemumonitorjsontest.c (qemuMonitorJSONDriveMirror): Likewise.

Signed-off-by: Eric Blake <eblake at redhat.com>
---
 src/qemu/qemu_driver.c       | 18 +++++-------------
 src/qemu/qemu_migration.c    |  2 +-
 src/qemu/qemu_monitor.c      |  8 +++++---
 src/qemu/qemu_monitor.h      |  2 ++
 src/qemu/qemu_monitor_json.c |  4 ++++
 src/qemu/qemu_monitor_json.h |  2 ++
 tests/qemumonitorjsontest.c  |  2 +-
 7 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 6895b23..1673c7b 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15287,6 +15287,8 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
                           const char *path,
                           virStorageSourcePtr mirror,
                           unsigned long long bandwidth,
+                          unsigned int granularity,
+                          unsigned long long buf_size,
                           unsigned int flags)
 {
     virQEMUDriverPtr driver = conn->privateData;
@@ -15432,7 +15434,7 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
     /* Actually start the mirroring */
     qemuDomainObjEnterMonitor(driver, vm);
     ret = qemuMonitorDriveMirror(priv->mon, device, mirror->path, format,
-                                 bandwidth, flags);
+                                 bandwidth, granularity, buf_size, flags);
     virDomainAuditDisk(vm, NULL, mirror, "mirror", ret >= 0);
     qemuDomainObjExitMonitor(driver, vm);
     if (ret < 0) {
@@ -15528,7 +15530,7 @@ qemuDomainBlockRebase(virDomainPtr dom, const char *path, const char *base,
     flags &= (VIR_DOMAIN_BLOCK_REBASE_SHALLOW |
               VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT);
     ret = qemuDomainBlockCopyCommon(vm, dom->conn, path, dest,
-                                    bandwidth, flags);
+                                    bandwidth, 0, 0, flags);
     vm = NULL;
     dest = NULL;

@@ -15596,23 +15598,13 @@ qemuDomainBlockCopy(virDomainPtr dom, const char *disk, const char *destxml,
             buf_size = param->value.ul;
         }
     }
-    if (granularity) {
-        virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
-                       _("granularity tuning not supported yet"));
-        goto cleanup;
-    }
-    if (buf_size) {
-        virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
-                       _("buffer size tuning not supported yet"));
-        goto cleanup;
-    }

     if (!(dest = virDomainDiskDefSourceParse(destxml, vm->def, driver->xmlopt,
                                              VIR_DOMAIN_XML_INACTIVE)))
         goto cleanup;

     ret = qemuDomainBlockCopyCommon(vm, dom->conn, disk, dest,
-                                    bandwidth, flags);
+                                    bandwidth, granularity, buf_size, flags);
     vm = NULL;

  cleanup:
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 4819c04..ce1a5cd 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -1461,7 +1461,7 @@ qemuMigrationDriveMirror(virQEMUDriverPtr driver,
                                            QEMU_ASYNC_JOB_MIGRATION_OUT) < 0)
             goto error;
         mon_ret = qemuMonitorDriveMirror(priv->mon, diskAlias, nbd_dest,
-                                         NULL, speed, mirror_flags);
+                                         NULL, speed, 0, 0, mirror_flags);
         qemuDomainObjExitMonitor(driver, vm);

         if (mon_ret < 0)
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 702404a..6059133 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -3189,17 +3189,19 @@ int
 qemuMonitorDriveMirror(qemuMonitorPtr mon,
                        const char *device, const char *file,
                        const char *format, unsigned long long bandwidth,
+                       unsigned int granularity, unsigned long long buf_size,
                        unsigned int flags)
 {
     int ret = -1;

     VIR_DEBUG("mon=%p, device=%s, file=%s, format=%s, bandwidth=%lld, "
-              "flags=%x",
-              mon, device, file, NULLSTR(format), bandwidth, flags);
+              "granularity=%#x, buf_size=%lld, flags=%x",
+              mon, device, file, NULLSTR(format), bandwidth, granularity,
+              buf_size, flags);

     if (mon->json)
         ret = qemuMonitorJSONDriveMirror(mon, device, file, format, bandwidth,
-                                         flags);
+                                         granularity, buf_size, flags);
     else
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
                        _("drive-mirror requires JSON monitor"));
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index ced198e..c32001d 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -650,6 +650,8 @@ int qemuMonitorDriveMirror(qemuMonitorPtr mon,
                            const char *file,
                            const char *format,
                            unsigned long long bandwidth,
+                           unsigned int granularity,
+                           unsigned long long buf_size,
                            unsigned int flags)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
 int qemuMonitorDrivePivot(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 30f9ffb..0c4832a 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -3422,6 +3422,8 @@ int
 qemuMonitorJSONDriveMirror(qemuMonitorPtr mon,
                            const char *device, const char *file,
                            const char *format, unsigned long long speed,
+                           unsigned int granularity,
+                           unsigned long long buf_size,
                            unsigned int flags)
 {
     int ret = -1;
@@ -3434,6 +3436,8 @@ qemuMonitorJSONDriveMirror(qemuMonitorPtr mon,
                                      "s:device", device,
                                      "s:target", file,
                                      "Y:speed", speed,
+                                     "z:granularity", granularity,
+                                     "P:buf-size", buf_size,
                                      "s:sync", shallow ? "top" : "full",
                                      "s:mode", reuse ? "existing" : "absolute-paths",
                                      "S:format", format,
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index a6d05b5..b5c61ca 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -249,6 +249,8 @@ int qemuMonitorJSONDriveMirror(qemuMonitorPtr mon,
                                const char *file,
                                const char *format,
                                unsigned long long speed,
+                               unsigned int granularity,
+                               unsigned long long buf_size,
                                unsigned int flags)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
 int qemuMonitorJSONDrivePivot(qemuMonitorPtr mon,
diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c
index e3fb4f7..afbf13a 100644
--- a/tests/qemumonitorjsontest.c
+++ b/tests/qemumonitorjsontest.c
@@ -1176,7 +1176,7 @@ GEN_TEST_FUNC(qemuMonitorJSONRemoveNetdev, "net0")
 GEN_TEST_FUNC(qemuMonitorJSONDelDevice, "ide0")
 GEN_TEST_FUNC(qemuMonitorJSONAddDevice, "some_dummy_devicestr")
 GEN_TEST_FUNC(qemuMonitorJSONSetDrivePassphrase, "vda", "secret_passhprase")
-GEN_TEST_FUNC(qemuMonitorJSONDriveMirror, "vdb", "/foo/bar", NULL, 1024,
+GEN_TEST_FUNC(qemuMonitorJSONDriveMirror, "vdb", "/foo/bar", NULL, 1024, 0, 0,
               VIR_DOMAIN_BLOCK_REBASE_SHALLOW | VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT)
 GEN_TEST_FUNC(qemuMonitorJSONBlockCommit, "vdb", "/foo/bar1", "/foo/bar2", NULL, 1024)
 GEN_TEST_FUNC(qemuMonitorJSONDrivePivot, "vdb", NULL, NULL)
-- 
1.9.3




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