June 2020 - Devel - libvirt List Archives

[libvirt] [PATCH] Fix python error reporting for some storage operations
by Cole Robinson 07 Mar '25

07 Mar '25

In the python bindings, all vir* classes expect to be passed a virConnect object when instantiated. Before the storage stuff, these classes were only instantiated in virConnect methods, so the generator is hardcoded to pass 'self' as the connection instance to these classes. Problem is there are some methods that return pool or vol instances which aren't called from virConnect: you can lookup a storage volume's associated pool, and can lookup volumes from a pool. In these cases passing 'self' doesn't give the vir* instance a connection, so when it comes time to raise an exception crap hits the fan. Rather than rework the generator to accomodate this edge case, I just fixed the init functions for virStorage* to pull the associated connection out of the passed value if it's not a virConnect instance. Thanks, Cole diff --git a/python/generator.py b/python/generator.py index 01a17da..c706b19 100755 --- a/python/generator.py +++ b/python/generator.py @@ -962,8 +962,12 @@ def buildWrappers(): list = reference_keepers[classname] for ref in list: classes.write(" self.%s = None\n" % ref[1]) - if classname in [ "virDomain", "virNetwork", "virStoragePool", "virStorageVol" ]: + if classname in [ "virDomain", "virNetwork" ]: classes.write(" self._conn = conn\n") + elif classname in [ "virStorageVol", "virStoragePool" ]: + classes.write(" self._conn = conn\n" + \ + " if not isinstance(conn, virConnect):\n" + \ + " self._conn = conn._conn\n") classes.write(" if _obj != None:self._o = _obj;return\n") classes.write(" self._o = None\n\n"); destruct=None

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Re: [libvirt] [Qemu-devel] Qemu migration with vhost-user-blk on top of local storage
by Stefan Hajnoczi 27 Oct '23

27 Oct '23

On Wed, Jan 09, 2019 at 06:23:42PM +0800, wuzhouhui wrote: > Hi everyone, > > I'm working qemu with vhost target (e.g. spdk), and I attempt to migrate VM with > 2 local storages. One local storage is a regular file, e.g. /tmp/c74.qcow2, and > the other is a malloc bdev that spdk created. This malloc bdev will exported to > VM via vhost-user-blk. When I execute following command: > > virsh migrate --live --persistent --unsafe --undefinesource --copy-storage-all \ > --p2p --auto-converge --verbose --desturi qemu+tcp://<uri>/system vm0 > > The libvirt reports: > > qemu-2.12.1: error: internal error: unable to execute QEMU command \ > 'nbd-server-add': Cannot find device=drive-virtio-disk1 nor \ > node_name=drive-virtio-disk1 Please post your libvirt domain XML. > Does it means that qemu with spdk on top of local storage don't support migration? > > QEMU: 2.12.1 > SPDK: 18.10 vhost-user-blk bypasses the QEMU block layer, so NBD storage migration at the QEMU level will not work for the vhost-user-blk disk. Stefan

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[libvirt] [PATCH v3] openvswitch: Add new port VLAN mode "dot1q-tunnel"
by luzhipeng＠uniudc.com 27 Oct '23

27 Oct '23

From: ZhiPeng Lu <luzhipeng(a)uniudc.com> Signed-off-by: ZhiPeng Lu <luzhipeng(a)uniudc.com> --- v1->v2: 1. Fix "make syntax-check" failure v2->v3: 1. remove other_config when updating vlan docs/formatnetwork.html.in | 17 +++++++++-------- docs/schemas/networkcommon.rng | 1 + src/conf/netdev_vlan_conf.c | 2 +- src/util/virnetdevopenvswitch.c | 7 +++++++ src/util/virnetdevvlan.h | 1 + 5 files changed, 19 insertions(+), 9 deletions(-) diff --git a/docs/formatnetwork.html.in b/docs/formatnetwork.html.in index 363a72b..3c1ae62 100644 --- a/docs/formatnetwork.html.in +++ b/docs/formatnetwork.html.in @@ -688,16 +688,17 @@ For network connections using Open vSwitch it is also possible - to configure 'native-tagged' and 'native-untagged' VLAN modes + to configure 'native-tagged' and 'native-untagged' and 'dot1q-tunnel' + VLAN modes. Since 1.1.0. This is done with the - optional <code>nativeMode</code> attribute on - the <code><tag></code> subelement: <code>nativeMode</code> - may be set to 'tagged' or 'untagged'. The <code>id</code> - attribute of the <code><tag></code> subelement - containing <code>nativeMode</code> sets which VLAN is considered - to be the "native" VLAN for this interface, and + optional <code>nativeMode</code> attribute on the + <code><tag></code> subelement: <code>nativeMode</code> + may be set to 'tagged' or 'untagged' or 'dot1q-tunnel'. + The <code>id</code> attribute of the <code><tag></code> + subelement containing <code>nativeMode</code> sets which VLAN is + considered to be the "native" VLAN for this interface, and the <code>nativeMode</code> attribute determines whether or not - traffic for that VLAN will be tagged. + traffic for that VLAN will be tagged or QinQ. <code><vlan></code> elements can also be specified in diff --git a/docs/schemas/networkcommon.rng b/docs/schemas/networkcommon.rng index 2699555..11c48ff 100644 --- a/docs/schemas/networkcommon.rng +++ b/docs/schemas/networkcommon.rng @@ -223,6 +223,7 @@ <choice> <value>tagged</value> <value>untagged</value> + <value>dot1q-tunnel</value> </choice> </attribute> </optional> diff --git a/src/conf/netdev_vlan_conf.c b/src/conf/netdev_vlan_conf.c index dff49c6..79710d9 100644 --- a/src/conf/netdev_vlan_conf.c +++ b/src/conf/netdev_vlan_conf.c @@ -29,7 +29,7 @@ #define VIR_FROM_THIS VIR_FROM_NONE VIR_ENUM_IMPL(virNativeVlanMode, VIR_NATIVE_VLAN_MODE_LAST, - "default", "tagged", "untagged") + "default", "tagged", "untagged", "dot1q-tunnel") int virNetDevVlanParse(xmlNodePtr node, xmlXPathContextPtr ctxt, virNetDevVlanPtr def) diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c index 8fe06fd..9fec30b 100644 --- a/src/util/virnetdevopenvswitch.c +++ b/src/util/virnetdevopenvswitch.c @@ -91,6 +91,11 @@ virNetDevOpenvswitchConstructVlans(virCommandPtr cmd, virNetDevVlanPtr virtVlan) virCommandAddArg(cmd, "vlan_mode=native-untagged"); virCommandAddArgFormat(cmd, "tag=%d", virtVlan->nativeTag); break; + case VIR_NATIVE_VLAN_MODE_DOT1Q_TUNNEL: + virCommandAddArg(cmd, "vlan_mode=dot1q-tunnel"); + virCommandAddArg(cmd, "other_config:qinq-ethtype=802.1q"); + virCommandAddArgFormat(cmd, "tag=%d", virtVlan->nativeTag); + break; case VIR_NATIVE_VLAN_MODE_DEFAULT: default: break; @@ -504,6 +509,8 @@ int virNetDevOpenvswitchUpdateVlan(const char *ifname, "--", "--if-exists", "clear", "Port", ifname, "tag", "--", "--if-exists", "clear", "Port", ifname, "trunk", "--", "--if-exists", "clear", "Port", ifname, "vlan_mode", + "--", "--if-exists", "remove", "Port", ifname, "other_config", + "qinq-ethtype", NULL, "--", "--if-exists", "set", "Port", ifname, NULL); if (virNetDevOpenvswitchConstructVlans(cmd, virtVlan) < 0) diff --git a/src/util/virnetdevvlan.h b/src/util/virnetdevvlan.h index be85f59..0667f9d 100644 --- a/src/util/virnetdevvlan.h +++ b/src/util/virnetdevvlan.h @@ -29,6 +29,7 @@ typedef enum { VIR_NATIVE_VLAN_MODE_DEFAULT = 0, VIR_NATIVE_VLAN_MODE_TAGGED, VIR_NATIVE_VLAN_MODE_UNTAGGED, + VIR_NATIVE_VLAN_MODE_DOT1Q_TUNNEL, VIR_NATIVE_VLAN_MODE_LAST } virNativeVlanMode; -- 1.8.3.1

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[libvirt] [PATCH] Fix compile error for stable 1.2.9
by Yang hongyang 27 Oct '23

27 Oct '23

Seems a backport miss. An extra member is passed to struct virLXCBasicMountInfo. Signed-off-by: Yang hongyang <hongyang.yang(a)easystack.cn> --- src/lxc/lxc_container.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 28dabec..1c65fa9 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -760,7 +760,7 @@ typedef struct { static const virLXCBasicMountInfo lxcBasicMounts[] = { { "proc", "/proc", "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, false, false }, - { "/proc/sys", "/proc/sys", NULL, MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false, false, false }, + { "/proc/sys", "/proc/sys", NULL, MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false, false }, { "sysfs", "/sys", "sysfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false, false }, { "securityfs", "/sys/kernel/security", "securityfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true, true }, #if WITH_SELINUX -- 1.7.1

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[libvirt] [PATCH] web docs -- macvtap mode explanation
by Stefan Berger 27 Oct '23

27 Oct '23

This adds more information about the different macvtap device modes. Regards, Stefan

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[libvirt] Supporting vhost-net and macvtap in libvirt for QEMU
by Anthony Liguori 27 Oct '23

27 Oct '23

Disclaimer: I am neither an SR-IOV nor a vhost-net expert, but I've CC'd people that are who can throw tomatoes at me for getting bits wrong :-) I wanted to start a discussion about supporting vhost-net in libvirt. vhost-net has not yet been merged into qemu but I expect it will be soon so it's a good time to start this discussion. There are two modes worth supporting for vhost-net in libvirt. The first mode is where vhost-net backs to a tun/tap device. This is behaves in very much the same way that -net tap behaves in qemu today. Basically, the difference is that the virtio backend is in the kernel instead of in qemu so there should be some performance improvement. Current, libvirt invokes qemu with -net tap,fd=X where X is an already open fd to a tun/tap device. I suspect that after we merge vhost-net, libvirt could support vhost-net in this mode by just doing -net vhost,fd=X. I think the only real question for libvirt is whether to provide a user visible switch to use vhost or to just always use vhost when it's available and it makes sense. Personally, I think the later makes sense. The more interesting invocation of vhost-net though is one where the vhost-net device backs directly to a physical network card. In this mode, vhost should get considerably better performance than the current implementation. I don't know the syntax yet, but I think it's reasonable to assume that it will look something like -net tap,dev=eth0. The effect will be that eth0 is dedicated to the guest. On most modern systems, there is a small number of network devices so this model is not all that useful except when dealing with SR-IOV adapters. In that case, each physical device can be exposed as many virtual devices (VFs). There are a few restrictions here though. The biggest is that currently, you can only change the number of VFs by reloading a kernel module so it's really a parameter that must be set at startup time. I think there are a few ways libvirt could support vhost-net in this second mode. The simplest would be to introduce a new tag similar to <source network='br0'>. In fact, if you probed the device type for the network parameter, you could probably do something like <source network='eth0'> and have it Just Work. Another model would be to have libvirt see an SR-IOV adapter as a network pool whereas it handled all of the VF management. Considering how inflexible SR-IOV is today, I'm not sure whether this is the best model. Has anyone put any more thought into this problem or how this should be modeled in libvirt? Michael, could you share your current thinking for -net syntax? -- Regards, Anthony Liguori

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[libvirt] Semantic change in v4.3 slows down image creation and snapshots (on ZFS)
by Christian Ehrhardt 31 Jul '22

31 Jul '22

Hi, when discussing bug [1] triggered by [2] Daniel and I have found that the change [3] which is in since v4.3 was a semantic change to the behavior of libvirt. virt-manager used and still does issue a volume XML like: <volume> <name>disk.qcow2</name> <capacity>16106127360</capacity> <allocation>16106127360</allocation> <target> <format type="qcow2"/> <features> <lazy_refcounts/> </features> </target> </volume> Up until the commit above that was using preallocation=metadata, but now uses preallocation=falloc. In many cases (read: Fileystems) that won't be very user-visible, but if you are running on ZFS (or anything else that can't fallocate well) this is made worse by [4] slowing down these operations a lot. After the POV for virt-manager seems to have settled on the bug [1] referenced the remaining question is if libvirt should revert/modify the change [3] - and that we agreed required a wider discussion to be had here, hence this mail. [1]: https://bugzilla.redhat.com/show_bug.cgi?id=1759454 [2]: https://bugs.launchpad.net/virt-manager/+bug/1847105 [3]: https://libvirt.org/git/?p=libvirt.git;a=commit;h=c9ec7088c7a3f4cd26bb471f1… [4]: https://github.com/zfsonlinux/zfs/issues/326 -- Christian Ehrhardt Software Engineer, Ubuntu Server Canonical Ltd

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[PATCH] virt-aa-helper: disallow graphics socket read permissions
by Simon Arlott 02 Jan '21

02 Jan '21

The VM does not need read permission for its own sockets to create(), bind(), accept() connections or to recv(), send(), etc. on connections. This was fixed in ab9569e5460d1e4737fe8b625c67687dc2204665 (virt-aa-helper: disallow VNC socket read permissions), but then b6465e1aa49397367a9cd0f27110b9c2280a7385 (graphics: introduce new listen type 'socket') and acc83afe333bfadd3f7f79091d38ca3d7da1eeb2 (acc83afe333bfadd3f7f79091d38ca3d7da1eeb2) reverted it. Unless the read permission is omitted, VMs can connect to each other's VNC/graphics sockets. Signed-off-by: Simon Arlott <libvirt(a)octiron.net> --- src/security/virt-aa-helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 6e6dd1b1db..fddbdafc41 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -1053,7 +1053,7 @@ get_files(vahControl * ctl) if (listenObj.type == VIR_DOMAIN_GRAPHICS_LISTEN_TYPE_SOCKET && listenObj.socket && - vah_add_file(&buf, listenObj.socket, "rw")) + vah_add_file(&buf, listenObj.socket, "w")) goto cleanup; } } -- 2.17.1 -- Simon Arlott

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Races / crashes in shutdown of libvirtd daemon
by Daniel P. Berrangé 13 Nov '20

13 Nov '20

We got a new BZ filed about a libvirtd crash in shutdown https://bugzilla.redhat.com/show_bug.cgi?id=1828207 We can see from the stack trace that the "interface" driver is in the middle of servicing an RPC call for virConnectListAllInterfaces() Meanwhile the libvirtd daemon is doing virObjectUnref(dmn) on the virNetDaemonPtr object. The fact that it is doing this unref, means that it must have already call virStateCleanup(), given the code sequence: /* Run event loop. */ virNetDaemonRun(dmn); ret = 0; virHookCall(VIR_HOOK_DRIVER_DAEMON, "-", VIR_HOOK_DAEMON_OP_SHUTDOWN, 0, "shutdown", NULL, NULL); cleanup: /* Keep cleanup order in inverse order of startup */ virNetDaemonClose(dmn); virNetlinkEventServiceStopAll(); if (driversInitialized) { /* NB: Possible issue with timing window between driversInitialized * setting if virNetlinkEventServerStart fails */ driversInitialized = false; virStateCleanup(); } virObjectUnref(adminProgram); virObjectUnref(srvAdm); virObjectUnref(qemuProgram); virObjectUnref(lxcProgram); virObjectUnref(remoteProgram); virObjectUnref(srv); virObjectUnref(dmn); Unless I'm missing something non-obvious, this cleanup code path is inherantly broken & racy. When virNetDaemonRun() returns the RPC worker threads are all still active. They are all liable to still be executing RPC calls, which means any of the drivers may be in use. So calling virStateCleanup() is an inherantly dangerous thing to do. There is the further complication that once we have exitted the main loop we may prevent the RPC calls from ever completing, as they may be waiting on an event to be dispatched. I know we're had various patch proposals in the past to improve the robustness of shutdown cleanup but I can't remember the outcome of the reviews. Hopefully people involved in those threads can jump in here... IMHO the key problem here is the virNetDeamonRun() method which just looks at the "quit" flag and immediately returns if it is set. This needs to be changed so that when it sees quit == true, it takes the following actions 1. Call virNetDaemonClose() to drop all RPC clients and thus prevent new RPC calls arriving 2. Flush any RPC calls which are queued but not yet assigned to a worker thread 3. Tell worker threads to exit after finishing their current job 4. Wait for all worker threads to exit 5. Now virNetDaemonRun may return At this point we can call virStateCleanup and the various other things, as we know no drivers are still active in RPC calls. Having said that, there could be background threads in the the drivers which are doing work that uses the event loop thread. So we probably need a virStateClose() method that we call from virNetDaemonRun, *after* all worker threads are gone, which would cleanup any background threads while the event loop is still running. The issue is that step 4 above ("Wait for all worker threads to exit") may take too long, or indeed never complete. To deal with this, it will need a timeout. In the remote_daemon.c cleanup code path, if there are still worker threads present, then we need to skip all cleanup and simply call _exit(0) to terminate the process with no attempt at cleanup, since it would be unsafe to try anything else. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|

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[PATCH v1] qemu: monitor: substitute missing model name for host-passthrough
by Collin Walling 23 Sep '20

23 Sep '20

When executing the hypervisor-cpu-compare/baseline commands and the XML file contains a CPU definition using host-passthrough and no model name, the commands will fail and return an error message from the QMP response. Let's fix this by checking for host-passthrough and a missing model name when converting a CPU definition to a JSON object. If these conditions are matched, then the JSON object will be constructed using "host" as the model name. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1850680 Signed-off-by: Collin Walling <walling(a)linux.ibm.com> --- src/qemu/qemu_monitor_json.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 3070c1e6b3..448a3a9356 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -5804,9 +5804,20 @@ qemuMonitorJSONMakeCPUModel(virCPUDefPtr cpu, { virJSONValuePtr model = virJSONValueNewObject(); virJSONValuePtr props = NULL; + const char *model_name = cpu->model; size_t i; - if (virJSONValueObjectAppendString(model, "name", cpu->model) < 0) + if (!model_name) { + if (cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) { + model_name = "host"; + } else { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("cpu parameter is missing a model name")); + goto error; + } + } + + if (virJSONValueObjectAppendString(model, "name", model_name) < 0) goto error; if (cpu->nfeatures || !migratable) { -- 2.26.2

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