July 2013 - 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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[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] libvirt-php: 0.4.8 tag is missing
by Doug Goldstein 20 Apr '14

20 Apr '14

The libvirt-php 0.4.8 tar is missing from the git repo [1]. Hopefully someone who created the tarball can create the tag as well and push it. [1] http://libvirt.org/git/?p=libvirt-php.git Thanks. -- Doug Goldstein

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[libvirt] [PATCH] qemu: add PCI-multibus support for ppc
by Olivia Yin 05 Mar '14

05 Mar '14

Signed-off-by: Olivia Yin <hong-hua.yin(a)freescale.com> --- src/qemu/qemu_capabilities.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 7bc1ebc..7d7791d 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -2209,6 +2209,11 @@ virQEMUCapsInitHelp(virQEMUCapsPtr qemuCaps, uid_t runUid, gid_t runGid) virQEMUCapsClear(qemuCaps, QEMU_CAPS_NO_ACPI); } + /* ppc support PCI-multibus */ + if (qemuCaps->arch == VIR_ARCH_PPC) { + virQEMUCapsSet(qemuCaps, QEMU_CAPS_PCI_MULTIBUS); + } + /* virQEMUCapsExtractDeviceStr will only set additional caps if qemu * understands the 0.13.0+ notion of "-device driver,". */ if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE) && @@ -2450,6 +2455,11 @@ virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps, virQEMUCapsSet(qemuCaps, QEMU_CAPS_NO_ACPI); } + /* ppc support PCI-multibus */ + if (qemuCaps->arch == VIR_ARCH_PPC) { + virQEMUCapsSet(qemuCaps, QEMU_CAPS_PCI_MULTIBUS); + } + if (virQEMUCapsProbeQMPCommands(qemuCaps, mon) < 0) goto cleanup; if (virQEMUCapsProbeQMPEvents(qemuCaps, mon) < 0) -- 1.6.4

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[libvirt] Warnings messages in logs from DHCP snooping code
by Daniel P. Berrange 31 Jan '14

31 Jan '14

I'm noticing that VMs which have nwfilters associated with them will apparently always cause the following errors to appear in the logs upon VM shutdown: 2013-02-27 17:02:18.709+0000: 9669: error : virNWFilterDHCPSnoopEnd:2131 : internal error ifname "vnet0" not in key map 2013-02-27 17:02:18.715+0000: 9669: error : virNetDevGetIndex:653 : Unable to get index for interface vnet0: No such device Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|

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[libvirt] Add patches to allow users to join running containers.
by dwalsh＠redhat.com 02 Jan '14

02 Jan '14

[PATCH 1/2] Add virGetUserDirectoryByUID to retrieve users homedir [PATCH 2/2] virt-login-shell joins users into lxc container. This patch implements most of the changes suggested by Dan Berrange and Eric Blake. Some replies to suggested changes. Removed mingw-libvirt.spec.in changes since virt lxc probably can not be supported in Windows. Not sure if I need to make changes so my code will not build on that platform. Did not make the changes to install virt-login-shell as 4755 automatically. I guess I want a more firm, make that change request... I did not make a helper function to parse a list of strings out of conf file. The getuid and getgid calls return the user that executed the program, when the app is setuid geteuid and getegid return "0". I believe getuid and getgid are correct. Added virt-login-shell --help, not sure what --program would do? The program is hard coded to LXC because there is no way that I know of for a ZZ process to join a running qemu instance. I have heard back from one security review from Miloslav Trmac, who had similar comments as Eric.

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[libvirt] JNA Error Callback could cause core dump.
by Benjamin Wang (gendwang) 20 Dec '13

20 Dec '13

Hi, When I changed code as following: public class Connect { // Load the native part static { Libvirt.INSTANCE.virInitialize(); try { ErrorHandler.processError(Libvirt.INSTANCE); } catch (Exception e) { e.printStackTrace(); } + Libvirt.INSTANCE.virSetErrorFunc(null, new ErrorCallback()); } The server will generate the following core dump: Program terminated with signal 6, Aborted. #0 0x0000003f9b030265 in raise () from /lib64/libc.so.6 (gdb) where #0 0x0000003f9b030265 in raise () from /lib64/libc.so.6 #1 0x0000003f9b031d10 in abort () from /lib64/libc.so.6 #2 0x0000003f9b06a84b in __libc_message () from /lib64/libc.so.6 #3 0x0000003f9b07230f in _int_free () from /lib64/libc.so.6 #4 0x0000003f9b07276b in free () from /lib64/libc.so.6 #5 0x00002aaaacf46868 in ?? () #6 0x0000000000000000 in ?? () The problem was caused that when JNA call setErrorFunc, it will create ErrorCallback object. But when GC is executed, the object is GCed. But even I change code as following. When GC is excuted, the callback object will be moved. Then C can't find this object. Both of scenarios will cause core dump. It seems that JNA mustn't provide ErrorCallback Class, Because nobody can use this. Please correct me. public class Connect { + private static final ErrorCallback callback = new ErrorCallback(); // Load the native part static { Libvirt.INSTANCE.virInitialize(); try { ErrorHandler.processError(Libvirt.INSTANCE); } catch (Exception e) { e.printStackTrace(); } + Libvirt.INSTANCE.virSetErrorFunc(null, callback); } B.R. Benjamin Wang

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[libvirt] [PATCH 0/4] Support for integrating cgroups with systemd
by Daniel P. Berrange 16 Dec '13

16 Dec '13

From: "Daniel P. Berrange" <berrange(a)redhat.com> This is a much changed / expanded version of my previous work to create cgroups via systemd. The difference is that this time it actually works :-) I'm not proposing this for merge until after the 1.1.1 release. Daniel P. Berrange (4): Add APIs for formatting systemd slice/scope names Add support for systemd cgroup mount Cope with races while killing processes Enable support for systemd-machined in cgroups creation src/libvirt_private.syms | 2 + src/lxc/lxc_process.c | 10 +- src/qemu/qemu_cgroup.c | 1 + src/util/vircgroup.c | 270 +++++++++++++++++++++++++++++++++++++++++------ src/util/vircgroup.h | 2 + src/util/virsystemd.c | 96 ++++++++++++++++- src/util/virsystemd.h | 5 + tests/vircgrouptest.c | 9 ++ tests/virsystemdtest.c | 48 +++++++++ 9 files changed, 403 insertions(+), 40 deletions(-) -- 1.8.1.4

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[libvirt] configuring a disconnected <interface>
by Dan Kenigsberg 23 Aug '13

23 Aug '13

Hi List, Like most of us, I've bought my actual computer with an Ethernet interface card, that I can connect to a wall jack at will. It's quite easy to disconnect the Ethernet cable from the wall, as well. I would like to expose this behavior to virtual computers, too. Via libvirt, of course. That's useful, since an admin may need to disconnect a running VM from a network temporarily, without resorting to hot-unplugging its nic. How should the domxml represent this situation? An interface that is connected to a specific LAN1 bridge is <interface type='bridge'> <source bridge='LAN1'> <target dev='vnet1'/> <model type='virtio'/> </interface> Would the following make sense for an interface with no bridge at the source? <interface type='bridge'> <source/> <target dev='vnet1'/> <model type='virtio'/> </interface> And how about the recommended config for <interface>s, which is type='network'? Would it make sense to predefine <network> <name>null-bridge-network</name> <forward mode='bridge'> <bridge/> </network> so that <interface type='network'> <source network='null-bridge-network'/> </interface> means "keep this interface dangling out there"? Regards, Dan.

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