Re: [libvirt] [PATCHv4 02/10] conf: support backend domain name in disk and network devices

From: Marek Marczykowski <marmarek(a)invisiblethingslab.com&gt; At least Xen supports backend drivers in another domain (aka "driver domain"). This patch introduces XML config option for such setting as 'domain' attribute of 'source' element. Verification its content is left for the driver. In the future same option will be needed for USB devices (hostdev objects), but for now libxl doesn't have support for PVUSB. Signed-off-by: Marek Marczykowski-Górecki <marmarek(a)invisiblethingslab.com&gt; --- Changes in v2: - describe in docs/formatdomain.html.in - enforce empty domain tag (only 'name' attribute allowed) Changes in v3: - change <domain name='xx'/> element to domain='' attribute of source element - this is more logical place - grammar of docs Changes in v4: - revert back to separate element, named <backenddomain name='xx'/> docs/formatdomain.html.in | 29 +++++++++++++++++++++++++++++ docs/schemas/domaincommon.rng | 16 ++++++++++++++++ src/conf/domain_conf.c | 21 +++++++++++++++++++++ src/conf/domain_conf.h | 2 ++ 4 files changed, 68 insertions(+) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index c5ad6f4..16d8b5c 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -2357,6 +2357,13 @@ </li> </ul> </dd> + <dt><code>backenddomain</code></dt> + <dd>The optional <code>backenddomain</code> element allows specifying a backend + domain (aka driver domain) for the device. If the real device/file resides + in some other domain on the same host, use the <code>name</code> + attribute to specify its name.

+ <span class="since">Since 1.2.13 (Xen only)</span> + </dd> <dt><code>boot</code></dt> <dd>Specifies that the disk is bootable. The <code>order</code> attribute determines the order in which devices will be tried during @@ -4235,6 +4242,28 @@ qemu-kvm -net nic,model=? /dev/null network device. <span class="since">Since 0.9.10 (QEMU and KVM only)</span>. </p> + <h5><a name="elementDomain">Setting up a network backend in a driver domain</a></h5> +<pre> + ... + &lt;devices&gt; + ... + &lt;interface type='bridge'&gt; + &lt;source bridge='br0'/&gt; + <b>&lt;backenddomain name='netvm'/&gt;</b> + &lt;/interface&gt; + ... + &lt;/devices&gt; + ...</pre> + + <p> + The optional <code>backenddomain</code> element allows specifying a backend + domain (aka driver domain) for the device. Use the <code>name</code> attribute + to specify its name. You can use it to create a direct network link between + domains (so data will not go through host system). Use with type 'ethernet' + to create plain network link, or with 'bridge' to connect to some bridge + inside the driver domain.

+ <span class="since">Since 1.2.13 (Xen only)</span> + </p> <h5><a name="elementQoS">Quality of service</a></h5> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index d467dce..6721431 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -1127,6 +1127,14 @@ </optional> <ref name="target"/> <optional> + <element name="backenddomain"> + <attribute name="name"> + <ref name="domainName"/> + </attribute> + <empty/> + </element> + </optional> + <optional>

<ref name="deviceBoot"/> </optional> <optional> @@ -2328,6 +2336,14 @@ </element> </optional> <optional> + <element name="backenddomain"> + <attribute name="name"> + <ref name="domainName"/> + </attribute> + <empty/> + </element> + </optional> + <optional> <element name="model"> <attribute name="type"> <data type="string"> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 4251b13..657b71f 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -1260,6 +1260,7 @@ virDomainDiskDefFree(virDomainDiskDefPtr def) VIR_FREE(def->wwn); VIR_FREE(def->vendor); VIR_FREE(def->product); + VIR_FREE(def->domain_name); virDomainDeviceInfoClear(&def->info); VIR_FREE(def); @@ -1442,6 +1443,7 @@ void virDomainNetDefFree(virDomainNetDefPtr def) VIR_FREE(def->backend.vhost); VIR_FREE(def->virtPortProfile); VIR_FREE(def->script); + VIR_FREE(def->domain_name); VIR_FREE(def->ifname); VIR_FREE(def->ifname_guest); VIR_FREE(def->ifname_guest_actual); @@ -5725,6 +5727,7 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt, char *discard = NULL; char *mirrorFormat = NULL; char *mirrorType = NULL; + char *domain_name = NULL; int expected_secret_usage = -1; int auth_secret_usage = -1; int ret = 0; @@ -5790,6 +5793,9 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt, if (target && STRPREFIX(target, "ioemu:")) memmove(target, target+6, strlen(target)-5); + } else if (!domain_name && + xmlStrEqual(cur->name, BAD_CAST "backenddomain")) { + domain_name = virXMLPropString(cur, "name"); } else if (xmlStrEqual(cur->name, BAD_CAST "geometry")) { if (virXPathUInt("string(./geometry/@cyls)", ctxt, &def->geometry.cylinders) < 0) { @@ -6514,6 +6520,8 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt, driverName = NULL; def->src->encryption = encryption; encryption = NULL; + def->domain_name = domain_name; + domain_name = NULL; def->serial = serial; serial = NULL; def->wwn = wwn; @@ -6576,6 +6584,7 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt, VIR_FREE(product); VIR_FREE(mirrorType); VIR_FREE(mirrorFormat); + VIR_FREE(domain_name); ctxt->node = save_ctxt; return def; @@ -7365,6 +7374,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, char *mode = NULL; char *linkstate = NULL; char *addrtype = NULL; + char *domain_name = NULL; char *vhostuser_mode = NULL; char *vhostuser_path = NULL; char *vhostuser_type = NULL; @@ -7503,6 +7513,9 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, } else if (!script && xmlStrEqual(cur->name, BAD_CAST "script")) { script = virXMLPropString(cur, "path"); + } else if (!domain_name && + xmlStrEqual(cur->name, BAD_CAST "backenddomain")) { + domain_name = virXMLPropString(cur, "name"); } else if (xmlStrEqual(cur->name, BAD_CAST "model")) { model = virXMLPropString(cur, "type"); } else if (xmlStrEqual(cur->name, BAD_CAST "driver")) { @@ -7802,6 +7815,10 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, def->script = script; script = NULL; } + if (domain_name != NULL) { + def->domain_name = domain_name; + domain_name = NULL; + } if (ifname != NULL) { def->ifname = ifname; ifname = NULL; @@ -8059,6 +8076,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, VIR_FREE(mode); VIR_FREE(linkstate); VIR_FREE(addrtype); + VIR_FREE(domain_name); VIR_FREE(trustGuestRxFilters); VIR_FREE(ips); virNWFilterHashTableFree(filterparams); @@ -16820,6 +16838,8 @@ virDomainDiskDefFormat(virBufferPtr buf, def->src->backingStoreRaw, 1) < 0) return -1; + virBufferEscapeString(buf, "<backenddomain name='%s'/>\n", def->domain_name); + virDomainDiskGeometryDefFormat(buf, def); virDomainDiskBlockIoDefFormat(buf, def); @@ -17786,6 +17806,7 @@ virDomainNetDefFormat(virBufferPtr buf, virBufferEscapeString(buf, "<script path='%s'/>\n", def->script); + virBufferEscapeString(buf, "<backenddomain name='%s'/>\n", def->domain_name); if (def->ifname && !((flags & VIR_DOMAIN_DEF_FORMAT_INACTIVE) && (STRPREFIX(def->ifname, VIR_NET_GENERATED_PREFIX)))) { diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 93f2314..b2ef8db 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -700,6 +700,7 @@ struct _virDomainDiskDef { int sgio; /* enum virDomainDeviceSGIO */ int discard; /* enum virDomainDiskDiscard */ unsigned int iothread; /* unused = 0, > 0 specific thread # */ + char *domain_name; /* backend domain name */ }; @@ -995,6 +996,7 @@ struct _virDomainNetDef { unsigned long sndbuf; } tune; char *script; + char *domain_name; /* backend domain name */ char *ifname; char *ifname_guest; char *ifname_guest_actual;