[libvirt] [PATCH v3 17/18] blockcopy: add qemu implementation of new tunables

Eric Blake eblake at redhat.com
Sun Aug 31 04:02:35 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 |  6 +++++-
 src/qemu/qemu_monitor_json.h |  2 ++
 tests/qemumonitorjsontest.c  |  2 +-
 7 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index d93e184..e597d68 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15356,6 +15356,8 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
                           const char *path,
                           virStorageSourcePtr dest,
                           unsigned long long bandwidth,
+                          unsigned int granularity,
+                          unsigned long long buf_size,
                           unsigned int flags)
 {
     virQEMUDriverPtr driver = conn->privateData;
@@ -15505,7 +15507,7 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
     /* Actually start the mirroring */
     qemuDomainObjEnterMonitor(driver, vm);
     ret = qemuMonitorDriveMirror(priv->mon, device, dest->path, format,
-                                 bandwidth, flags);
+                                 bandwidth, granularity, buf_size, flags);
     virDomainAuditDisk(vm, NULL, mirror, "mirror", ret >= 0);
     qemuDomainObjExitMonitor(driver, vm);
     if (ret < 0) {
@@ -15601,7 +15603,7 @@ 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;

  cleanup:
@@ -15668,23 +15670,13 @@ 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 6bdee4e..3a506f8 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -1279,7 +1279,7 @@ 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 d96b1b8..e481ec1 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -3183,17 +3183,19 @@ 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 9012ad4..cb88e6e 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 8130f92..2ccf9cb 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -3397,6 +3397,8 @@ 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;
@@ -3408,7 +3410,9 @@ qemuMonitorJSONDriveMirror(qemuMonitorPtr mon,
     cmd = qemuMonitorJSONMakeCommand("drive-mirror",
                                      "s:device", device,
                                      "s:target", file,
-                                     "U:speed", speed,
+                                     "P: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 4595eae..a325463 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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