April 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] [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] 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] libxl: allow an <emulator> to be selected in the domain config XML
by David Scott 01 Jun '13

01 Jun '13

The emulator path supplied can be any valid path on the system. Note that when setting a device_model, libxl needs us to set the device_model_version too. The device_model_version can be either ...QEMU_XEN: meaning "upstream qemu", the default in xen-4.3 onwards ...QEMU_XEN_TRADITIONAL: the old xen-specific fork We detect the device_model_version by examining the qemu filename: if it is "qemu-dm" then it's the old xen-specific fork. If anything else then we assume "upstream qemu" (whose filename may change in future). Note that if you are using a wrapper script to (eg) adjust the arguments of the old qemu during development, you will have to ensure the wrapper script also has the name "qemu-dm", by placing it in a separate directory. Signed-off-by: David Scott <dave.scott(a)eu.citrix.com> --- src/libxl/libxl_conf.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 44 insertions(+), 0 deletions(-) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index 7e0753a..2aa5a62 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -788,6 +788,46 @@ libxlMakeCapabilities(libxl_ctx *ctx) } int +libxlMakeEmulator(virDomainDefPtr def, libxl_domain_config *d_config) +{ + /* No explicit override means use the default */ + if (!def->emulator) { + return 0; + } + + if (!virFileExists(def->emulator)) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("emulator '%s' not found"), + def->emulator); + return -1; + } + + VIR_FREE(d_config->b_info.device_model); + if ((d_config->b_info.device_model = strdup(def->emulator)) == NULL) { + virReportOOMError(); + return -1; + } + + /* N.B. from xen/tools/libxl/libxl_types.idl: + * "If setting device_model you must set device_model_version too." + * + * The xen-4.3 and later default is "upstream qemu" (QEMU_XEN) + * so we make that the default and special-case the old-style + * "traditional qemu" (QEMU_XEN_TRADITIONAL) + */ + + d_config->b_info.device_model_version = + LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN; + + if (STREQ(basename(def->emulator), "qemu-dm")) + d_config->b_info.device_model_version = + LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL; + + return 0; +} + + +int libxlBuildDomainConfig(libxlDriverPrivatePtr driver, virDomainDefPtr def, libxl_domain_config *d_config) { @@ -811,6 +851,10 @@ libxlBuildDomainConfig(libxlDriverPrivatePtr driver, goto error; } + if (libxlMakeEmulator(def, d_config) < 0) { + goto error; + } + d_config->on_reboot = def->onReboot; d_config->on_poweroff = def->onPoweroff; d_config->on_crash = def->onCrash; -- 1.7.1

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[libvirt] [PATCH 00/12] A bunch of extensions to libxl driver
by Marek Marczykowski 31 May '13

31 May '13

This are some additional features to libxl driver. Some of them require change in domain config structures/syntax. Details described with each patch. The last two patches are bugfix for deadlock during daemon startup. Marek Marczykowski (12): libxl: allow script for any network interface, not only bridge libxl: PCI passthrough support libxl: nodeDevice* support for PCI devices libxl: populate xenstore memory entries at startup conf: add 'script' attribute to disk specification libxl: use disk 'script' attribute conf: support backend domain name in disk and network devices libxl: support backend domain setting for disk and net devices libxl: fill HVM SDL and VNC settings based on <graphics/> entries RFC: libxl: special 'stubdom-dm' emulator to use qemu in stub domain conf: virDomainObjListRemoveLocked function libxl: fix deadlock in libxlReconnectDomain docs/schemas/domaincommon.rng | 14 ++ src/conf/domain_conf.c | 54 ++++++++ src/conf/domain_conf.h | 5 + src/libvirt_private.syms | 1 + src/libxl/libxl_conf.c | 297 +++++++++++++++++++++++++++++++++--------- src/libxl/libxl_conf.h | 6 +- src/libxl/libxl_driver.c | 253 +++++++++++++++++++++++++++++++---- 7 files changed, 545 insertions(+), 85 deletions(-) -- 1.8.1.4

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[libvirt] [PATCH] nwfilter: Remove error report in virNWFilterDHCPSnoopEnd
by Stefan Berger 24 May '13

24 May '13

Remove error reporting when calling the virNWFilterDHCPSnoopEnd function with an interface for which no thread is snooping traffic. Document the usage of this function. Signed-off-by: Stefan Berger <stefanb(a)linux.vnet.ibm.com> --- src/nwfilter/nwfilter_dhcpsnoop.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) Index: libvirt/src/nwfilter/nwfilter_dhcpsnoop.c =================================================================== --- libvirt.orig/src/nwfilter/nwfilter_dhcpsnoop.c +++ libvirt/src/nwfilter/nwfilter_dhcpsnoop.c @@ -2117,6 +2117,16 @@ err_exit: return -1; } +/** + * End a DHCP snoop thread on the given interface or end all + * DHCP snoop threads. + * + * @ifname: Name of an interface or NULL to stop all snoop threads + * + * It is not an error to call this function with an interface name + * for which no thread is snooping traffic. In this case the call will + * be a no-op. + */ void virNWFilterDHCPSnoopEnd(const char *ifname) { @@ -2130,11 +2140,8 @@ virNWFilterDHCPSnoopEnd(const char *ifna if (ifname) { ifkey = (char *)virHashLookup(virNWFilterSnoopState.ifnameToKey, ifname); - if (!ifkey) { - virReportError(VIR_ERR_INTERNAL_ERROR, - _("ifname \"%s\" not in key map"), ifname); + if (!ifkey) goto cleanup; - } ignore_value(virHashRemoveEntry(virNWFilterSnoopState.ifnameToKey, ifname));

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[libvirt] [PATCH 0/2] qemu: Rework CD/DVD changing
by Michal Privoznik 21 May '13

21 May '13

The first patch is bare bug fix (without any bug reported though). The second is again a bug fix, but not so easy to spot. Basically, when we change a media, we should issue 'eject' first, then wait until the tray gets open, after which we can finally issue 'change' command. Even for bare 'eject' we ought to check status, shouldn't we? Michal Privoznik (2): qemu_monitor: Fix tray-open attribute in query-block qemu_hotplug: Rework media changing process src/qemu/qemu_hotplug.c | 51 +++++++++++++++++++++++++++++++++++++++++--- src/qemu/qemu_monitor_json.c | 2 +- src/qemu/qemu_monitor_text.c | 6 +++--- 3 files changed, 52 insertions(+), 7 deletions(-) -- 1.8.0.2

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