Hi Daniel,
On Tue, 2014-04-15 at 12:04 +0100, Daniel P. Berrange wrote:
> On Tue, Apr 15, 2014 at 06:31:09PM +0800, Chen Fan wrote:
> > Current virsh migrate command require specfying migration URI with
> > command option.
> >
> > Here is current step.
> > 1) If user specifies --migrateuri on virsh migrate command, then the command
> > transfers the data to specified host.
> > 2) If --migrateuri is not specified, the command transfers the data to host
> > whose name is resolved by DNS or /etc/hosts.
> >
> > but we are able to use virsh migrate command more usefull.
> > User can specify a constant destination by definition file.
> > if user want to specify other temporary destination, command option
> > is good for it.
> >
> > Signed-off-by: Chen Fan <chen.fan.fnst@xxxxxxxxxxxxxx>
> > ---
> > daemon/remote.c | 11 ++++++++++-
> > src/driver.h | 1 +
> > src/libvirt.c | 12 +++++++++++-
> > src/libvirt.conf | 7 +++++++
> > src/libvirt_internal.h | 1 +
> > src/qemu/qemu_driver.c | 37 ++++++++++++++++++++++++++++++++++---
> > src/remote/remote_driver.c | 13 +++++++++++++
> > src/remote/remote_protocol.x | 1 +
> > 8 files changed, 78 insertions(+), 5 deletions(-)
> >
> > diff --git a/daemon/remote.c b/daemon/remote.c
> > index 8476961..693f460 100644
> > --- a/daemon/remote.c
> > +++ b/daemon/remote.c
> > @@ -5331,6 +5331,7 @@ remoteDispatchDomainMigrateBegin3Params(virNetServerPtr server ATTRIBUTE_UNUSED,
> > int nparams = 0;
> > char *cookieout = NULL;
> > int cookieoutlen = 0;
> > + char **uri_out = NULL;
> > int rv = -1;
> > struct daemonClientPrivate *priv =
> > virNetServerClientGetPrivateData(client);
> > @@ -5355,21 +5356,29 @@ remoteDispatchDomainMigrateBegin3Params(virNetServerPtr server ATTRIBUTE_UNUSED,
> > 0, &nparams)))
> > goto cleanup;
> >
> > + /* Wacky world of XDR ... */
> > + if (VIR_ALLOC(uri_out) < 0)
> > + goto cleanup;
> > +
> > if (!(xml = virDomainMigrateBegin3Params(dom, params, nparams,
> > &cookieout, &cookieoutlen,
> > + uri_out,
> > args->flags)))
> > goto cleanup;
> >
> > ret->cookie_out.cookie_out_len = cookieoutlen;
> > ret->cookie_out.cookie_out_val = cookieout;
> > + ret->uri_out = !*uri_out ? NULL : uri_out;
> > ret->xml = xml;
> >
> > rv = 0;
> >
> > cleanup:
> > virTypedParamsFree(params, nparams);
> > - if (rv < 0)
> > + if (rv < 0) {
> > virNetMessageSaveError(rerr);
> > + VIR_FREE(uri_out);
> > + }
> > if (dom)
> > virDomainFree(dom);
> > return rv;
> > diff --git a/src/driver.h b/src/driver.h
> > index e66fc7a..738ab3a 100644
> > --- a/src/driver.h
> > +++ b/src/driver.h
> > @@ -1094,6 +1094,7 @@ typedef char *
> > int nparams,
> > char **cookieout,
> > int *cookieoutlen,
> > + char **uri_out,
> > unsigned int flags);
> >
> > typedef int
> > diff --git a/src/libvirt.c b/src/libvirt.c
> > index f8d5240..257adbd 100644
> > --- a/src/libvirt.c
> > +++ b/src/libvirt.c
> > @@ -4738,7 +4738,7 @@ virDomainMigrateVersion3Full(virDomainPtr domain,
> > VIR_DEBUG("Begin3 %p", domain->conn);
> > if (useParams) {
> > dom_xml = domain->conn->driver->domainMigrateBegin3Params
> > - (domain, params, nparams, &cookieout, &cookieoutlen,
> > + (domain, params, nparams, &cookieout, &cookieoutlen, &uri_out,
> > flags | protection);
> > } else {
> > dom_xml = domain->conn->driver->domainMigrateBegin3
> > @@ -4748,6 +4748,14 @@ virDomainMigrateVersion3Full(virDomainPtr domain,
> > if (!dom_xml)
> > goto done;
> >
> > + /* Does domainMigrateBegin3Params() change URI? */
> > + if (uri_out) {
> > + if (virTypedParamsReplaceString(¶ms, &nparams,
> > + VIR_MIGRATE_PARAM_URI,
> > + uri_out) < 0)
> > + goto done;
> > + }
> > +
> > if (useParams) {
> > /* If source is new enough to support extensible migration parameters,
> > * it's certainly new enough to support virDomainGetState. */
> > @@ -6778,6 +6786,7 @@ virDomainMigrateBegin3Params(virDomainPtr domain,
> > int nparams,
> > char **cookieout,
> > int *cookieoutlen,
> > + char **uri_out,
> > unsigned int flags)
> > {
> > virConnectPtr conn;
> > @@ -6798,6 +6807,7 @@ virDomainMigrateBegin3Params(virDomainPtr domain,
> > char *xml;
> > xml = conn->driver->domainMigrateBegin3Params(domain, params, nparams,
> > cookieout, cookieoutlen,
> > + uri_out,
> > flags);
> > VIR_DEBUG("xml %s", NULLSTR(xml));
> > if (!xml)
> > diff --git a/src/libvirt.conf b/src/libvirt.conf
> > index 016cd24..9cef343 100644
> > --- a/src/libvirt.conf
> > +++ b/src/libvirt.conf
> > @@ -16,3 +16,10 @@
> > # driver when no URI is supplied by the application.
> >
> > #uri_default = "qemu:///system"
> > +
> > +#
> > +# This can be used to provide the default migrate URI when
> > +# migrate to target host. if migrate URI had been specified
> > +# in command line, this URI was ignored.
> > +
> > +#uri_migrate = "tcp://dest-uri-example"
>
> This is a client side configuration file...
>
> > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> > index 1d08951..c82fbca 100644
> > --- a/src/qemu/qemu_driver.c
> > +++ b/src/qemu/qemu_driver.c
>
>
> > +
> > + if (!uri_in) {
> > + if (virConnectGetConfigFile(&conf) < 0) {
> > + goto cleanup;
> > + }
> > +
> > + if ((value = virConfGetValue(conf, "uri_migrate"))) {
> > + if (value->type != VIR_CONF_STRING) {
> > + VIR_WARN("Expected a string for 'uri_migrate' config parameter");
> > + } else {
> > + if (VIR_STRDUP(*uri_out, value->str) < 0)
> > + goto cleanup;
> > + }
> > + }
> > + virConfFree(conf);
>
> ...which you're attempting to read from the server side.
Oh, I'm sorry for this low-level mistake.
>
> > diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
> > index ed7dde6..3df59da 100644
> > --- a/src/remote/remote_driver.c
> > +++ b/src/remote/remote_driver.c
> > @@ -6970,6 +6970,7 @@ remoteDomainMigrateBegin3Params(virDomainPtr domain,
> > int nparams,
> > char **cookieout,
> > int *cookieoutlen,
> > + char **uri_out,
> > unsigned int flags)
> > {
> > char *rv = NULL;
> > @@ -7017,15 +7018,27 @@ remoteDomainMigrateBegin3Params(virDomainPtr domain,
> > *cookieoutlen = ret.cookie_out.cookie_out_len;
> > }
> >
> > + if (ret.uri_out) {
> > + if (!uri_out) {
> > + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> > + _("caller ignores uri_out"));
> > + goto error;
> > + }
> > + *uri_out = *ret.uri_out; /* Caller frees. */
> > + }
> > +
> > rv = ret.xml; /* caller frees */
> >
> > cleanup:
> > remoteFreeTypedParameters(args.params.params_val, args.params.params_len);
> > + VIR_FREE(ret.uri_out);
> > remoteDriverUnlock(priv);
> > return rv;
> >
> > error:
> > VIR_FREE(ret.cookie_out.cookie_out_val);
> > + if (ret.uri_out)
> > + VIR_FREE(*ret.uri_out);
> > goto cleanup;
> > }
> >
> > diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x
> > index 6c445cc..202a0eb 100644
> > --- a/src/remote/remote_protocol.x
> > +++ b/src/remote/remote_protocol.x
> > @@ -2860,6 +2860,7 @@ struct remote_domain_migrate_begin3_params_args {
> >
> > struct remote_domain_migrate_begin3_params_ret {
> > opaque cookie_out<REMOTE_MIGRATE_COOKIE_MAX>;
> > + remote_string uri_out;
> > remote_nonnull_string xml;
> > };
>
> NACK, this breaks wire protocol compatibility. Changing any existing
> APIs is absolutely forbidden.
>
>
> IMHO the idea of storing the 'migration_uri' parameter in a configuration
> file is just plain wrong. This value is inherantly associated with the
> host that you're migrating to. So if you set 'migration_uri' to one host
> in the config, but then invoke virDomainMigrate with a virConnectPtr that
> is associated with a different host, this just crashes and burns.
how about add a optional 'migrate_uri'(or 'data_migrate_uri') in
libvirtd.conf as secondary network interface?
if so, when user add a new NIC in host A, then user can store this NIC
address to 'migrate_uri' parameter in the configuration file, then when
doing migration from other host B to this host A, we can get the
'migrate_uri' address in host A and pass this uri back to host B as the
new 'uri_out' value at domainMigratePrepare3Params(). then we don't need
to change any existing APIs. and the new NIC used to transfer migrate
data will be more useful.
Thanks,
Chen
>
> Regards,
> Daniel
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