Re: [libvirt PATCHv1 4/8] conf: add idmap element to filesystem

Let unprivileged virtiofs use user namespace. Signed-off-by: Ján Tomko <jtomko(a)redhat.com&gt; --- docs/formatdomain.rst | 7 +++ src/conf/domain_conf.c | 51 +++++++++++++++++++ src/conf/domain_conf.h | 1 + src/conf/schemas/domaincommon.rng | 3 ++ .../vhost-user-fs-fd-memory.xml | 4 ++ 5 files changed, 66 insertions(+) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index bc469e5f9f..0f10b3043f 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -3501,6 +3501,10 @@ A directory on the host that can be accessed directly from the guest. </binary> <source dir='/path'/> <target dir='mount_tag'/> + <idmap> + <uid start='0' target='100000' count='65535'/> + <gid start='0' target='100000' count='65535'/> + </idmap> </filesystem> <filesystem type='mount'> <driver type='virtiofs' queue='1024'/> @@ -3650,6 +3654,9 @@ A directory on the host that can be accessed directly from the guest. Where the ``source`` can be accessed in the guest. For most drivers this is an automatic mount point, but for QEMU/KVM this is merely an arbitrary string tag that is exported to the guest as a hint for where to mount. +``idmap`` + For ``virtiofs``, an ``idmap`` element can be specified to map IDs in the user + namespace. See the `Container boot`_ section for the syntax of the element.

``readonly`` Enables exporting filesystem as a readonly mount for guest, by default read-write access is given (currently only works for QEMU/KVM driver). diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index dd67e7f21b..2379a9204f 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -2585,6 +2585,8 @@ void virDomainFSDefFree(virDomainFSDef *def) virObjectUnref(def->privateData); g_free(def->binary); g_free(def->sock); + g_free(def->idmap.uidmap); + g_free(def->idmap.gidmap); g_free(def); } @@ -8767,6 +8769,8 @@ virDomainFSDefParseXML(virDomainXMLOption *xmlopt, xmlNodePtr binary_lock_node = virXPathNode("./binary/lock", ctxt); xmlNodePtr binary_cache_node = virXPathNode("./binary/cache", ctxt); xmlNodePtr binary_sandbox_node = virXPathNode("./binary/sandbox", ctxt); + ssize_t n; + xmlNodePtr *nodes = NULL; if (queue_size && virStrToLong_ull(queue_size, NULL, 10, &def->queue_size) < 0) { virReportError(VIR_ERR_XML_ERROR, @@ -8812,6 +8816,30 @@ virDomainFSDefParseXML(virDomainXMLOption *xmlopt, VIR_XML_PROP_NONZERO, &def->sandbox) < 0) goto error; + + if ((n = virXPathNodeSet("./idmap/uid", ctxt, &nodes)) < 0) + return NULL; + + if (n) { + def->idmap.uidmap = virDomainIdmapDefParseXML(ctxt, nodes, n); + if (!def->idmap.uidmap) + return NULL;

+ + def->idmap.nuidmap = n; + } + VIR_FREE(nodes);

+ + if ((n = virXPathNodeSet("./idmap/gid", ctxt, &nodes)) < 0) + return NULL; + + if (n) { + def->idmap.gidmap = virDomainIdmapDefParseXML(ctxt, nodes, n); + if (!def->idmap.gidmap) + return NULL;

+ + def->idmap.ngidmap = n; + } + VIR_FREE(nodes); } if (source == NULL && def->type != VIR_DOMAIN_FS_TYPE_RAM @@ -23164,6 +23192,29 @@ virDomainFSDefFormat(virBuffer *buf, virXMLFormatElement(buf, "driver", &driverAttrBuf, &driverBuf); virXMLFormatElement(buf, "binary", &binaryAttrBuf, &binaryBuf); + if (def->idmap.uidmap) { + size_t i; + + virBufferAddLit(buf, "<idmap>\n"); + virBufferAdjustIndent(buf, 2); + for (i = 0; i < def->idmap.nuidmap; i++) { + virBufferAsprintf(buf, + "<uid start='%u' target='%u' count='%u'/>\n", + def->idmap.uidmap[i].start, + def->idmap.uidmap[i].target, + def->idmap.uidmap[i].count); + } + for (i = 0; i < def->idmap.ngidmap; i++) { + virBufferAsprintf(buf, + "<gid start='%u' target='%u' count='%u'/>\n", + def->idmap.gidmap[i].start, + def->idmap.gidmap[i].target, + def->idmap.gidmap[i].count); + } + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</idmap>\n"); + } + switch (def->type) { case VIR_DOMAIN_FS_TYPE_MOUNT: case VIR_DOMAIN_FS_TYPE_BIND: diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 8937968e3b..b84719b01d 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -925,6 +925,7 @@ struct _virDomainFSDef { virTristateSwitch flock; virDomainFSSandboxMode sandbox; int thread_pool_size; + virDomainIdMapDef idmap; virDomainVirtioOptions *virtio; virObject *privateData; }; diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng index 2f9ba31c0a..2ca0e92f00 100644 --- a/src/conf/schemas/domaincommon.rng +++ b/src/conf/schemas/domaincommon.rng @@ -3052,6 +3052,9 @@ </choice> <empty/> </element> + <optional> + <ref name="idmap"/> + </optional> <ref name="filesystemCommon"/> </interleave> </group> diff --git a/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml b/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml index 81de8c0dd7..1d0bc26c46 100644 --- a/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml +++ b/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml @@ -34,6 +34,10 @@ <lock posix='off' flock='off'/> <thread_pool size='16'/> </binary> + <idmap> + <uid start='0' target='100000' count='65535'/> + <gid start='0' target='100000' count='65535'/> + </idmap> <source dir='/path'/> <target dir='mount_tag'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>