Re: [libvirt PATCH 1/2] conf: add killpriv v2 attribute for virtiofs

Add a new attribute to control the killpriv feature: <filesystem> ... <binary> <killpriv v2='off'/> </binary> </filesystem>

https://bugzilla.redhat.com/show_bug.cgi?id=1972571 Signed-off-by: Ján Tomko <jtomko(a)redhat.com&gt; --- docs/formatdomain.rst | 4 ++++ docs/schemas/domaincommon.rng | 7 +++++++ src/conf/domain_conf.c | 15 +++++++++++++++ src/conf/domain_conf.h | 1 + .../qemuxml2argvdata/vhost-user-fs-fd-memory.xml | 1 + 5 files changed, 28 insertions(+) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index d4f30bb8af..73ff8bce51 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -3313,6 +3313,7 @@ A directory on the host that can be accessed directly from the guest. <binary path='/usr/libexec/virtiofsd' xattr='on'> <cache mode='always'/> <sandbox mode='namespace'/> + <killpriv v2='on'/> <lock posix='on' flock='on'/> </binary> <source dir='/path'/> @@ -3447,6 +3448,9 @@ A directory on the host that can be accessed directly from the guest. ``chroot``, see the `virtiofsd documentation <https://qemu.readthedocs.io/en/latest/tools/virtiofsd.html>`__ for more details. ( :since:`Since 7.2.0` ) + The ``killpriv`` element with the attribute ``v2`` (values: ``on`` or ``off``) + can be used to disable the killpriv capability which is used to improve performance + by expecting writes to reset some security attributes. ( :since:`Since 8.0.0` ) ``source`` The resource on the host that is being accessed in the guest. The ``name`` attribute must be used with ``type='template'``, and the ``dir`` attribute diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 7fa5c2b8b5..5701bbe193 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -3057,6 +3057,13 @@ </optional> </element> </optional> + <optional> + <element name="killpriv"> + <attribute name="v2"> + <ref name="virOnOff"/> + </attribute> + </element> + </optional> </interleave> </element> </define> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 5691b8d2d5..2a1802a3d5 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -9874,6 +9874,7 @@ virDomainFSDefParseXML(virDomainXMLOption *xmlopt, g_autofree char *sandbox = virXPathString("string(./binary/sandbox/@mode)", ctxt); g_autofree char *posix_lock = virXPathString("string(./binary/lock/@posix)", ctxt); g_autofree char *flock = virXPathString("string(./binary/lock/@flock)", ctxt); + g_autofree char *killpriv_v2 = virXPathString("string(./binary/killpriv/@v2)", ctxt); int val; if (queue_size && virStrToLong_ull(queue_size, NULL, 10, &def->queue_size) < 0) { @@ -9932,6 +9933,15 @@ virDomainFSDefParseXML(virDomainXMLOption *xmlopt, } def->flock = val; } + + if (killpriv_v2) { + if ((val = virTristateSwitchTypeFromString(killpriv_v2)) <= 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown killpriv_v2 value '%s'"), killpriv_v2); + goto error; + } + def->killpriv_v2 = val; + } } if (source == NULL && def->type != VIR_DOMAIN_FS_TYPE_RAM @@ -24197,6 +24207,11 @@ virDomainFSDefFormat(virBuffer *buf, virTristateSwitchTypeToString(def->flock)); } + if (def->killpriv_v2 != VIR_TRISTATE_SWITCH_ABSENT) { + virBufferAsprintf(&binaryBuf, "<killpriv v2='%s'/>\n", + virTristateSwitchTypeToString(def->killpriv_v2)); + } + virXMLFormatElement(&binaryBuf, "lock", &lockAttrBuf, NULL); } diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 144ba4dd12..4619fcbfd1 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -892,6 +892,7 @@ struct _virDomainFSDef { virTristateSwitch posix_lock; virTristateSwitch flock; virDomainFSSandboxMode sandbox; + virTristateSwitch killpriv_v2; virDomainVirtioOptions *virtio; virObject *privateData; }; diff --git a/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml b/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml index abddf0870b..2f44a1593a 100644 --- a/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml +++ b/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml @@ -31,6 +31,7 @@ <binary path='/usr/libexec/virtiofsd' xattr='on'> <cache mode='always'/> <sandbox mode='chroot'/> + <killpriv v2='on'/> <lock posix='off' flock='off'/> </binary> <source dir='/path'/> -- 2.31.1