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[libvirt] [RFC] making (newly public) EventImpl interface more consistent
by David Lively 14 Nov '08

14 Nov '08

Hi Folks - Since virEventRegisterImpl is now public (in libvirt.h), a nagging concern of mine has become more urgent. Essentially this callback gives clients a way of registering their own "handle (fd) watcher" and "timer" functionality for use by libvirt. What bugs me is the inconsistency between the handle-watcher and timer interfaces: the timer "add" function returns a timer id, which is then used to identify the timer to the "update" and "remove" functions. But the handle-watcher add / update / remove functions identify the watcher by the handle (fd). The semantics of registering the same handle twice aren't specified (what happens when we pass that same fd in a subsequent "update" or "remove"?). Even worse, this doesn't allow one to manage multiple watches on the same handle reasonably. So why not make the handle "add" function return a "watch id" (analogous to the "timer id" returned by the timer "add" fn)? And then use this watch id to specify the handle-watcher in the "update" and "remove" functions. This conveniently handles multiple watches on the same handle, and also makes the "handle-watching" interface more consistent with the "timer" interface (which is registered at the same time). We'd pass both the watch id and the handle (fd) into the watch-handler callback. I'd like to implement and submit this (along with fixups to the event test code) if there are no objections. Thanks, Dave P.S. I'm currently working on Java bindings to the new event code ...

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[libvirt] [PATCH] avoid format string warnings
by Jim Meyering 14 Nov '08

14 Nov '08

>From f06595fb110e1e5a4c4f6ea8c729da3341f89ac4 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering(a)redhat.com> Date: Fri, 14 Nov 2008 13:19:29 +0100 Subject: [PATCH] avoid format string warnings * src/openvz_driver.c (ADD_ARG_LIT): Add "%s" arg before _(...). * src/qemu_driver.c (PCI_ATTACH_OK_MSG): Likewise. * src/util.c (virExec, virRun): Likewise. --- src/openvz_driver.c | 4 ++-- src/qemu_driver.c | 2 +- src/util.c | 4 ++-- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/src/openvz_driver.c b/src/openvz_driver.c index 48ffa13..95631ee 100644 --- a/src/openvz_driver.c +++ b/src/openvz_driver.c @@ -426,7 +426,7 @@ openvzDomainSetNetwork(virConnectPtr conn, const char *vpsid, dev_name_ve = openvzGenerateContainerVethName(veid); if (dev_name_ve == NULL) { openvzError(conn, VIR_ERR_INTERNAL_ERROR, - _("Could not generate eth name for container")); + "%s", _("Could not generate eth name for container")); rc = -1; goto exit; } @@ -437,7 +437,7 @@ openvzDomainSetNetwork(virConnectPtr conn, const char *vpsid, net->ifname = openvzGenerateVethName(veid, dev_name_ve); if (net->ifname == NULL) { openvzError(conn, VIR_ERR_INTERNAL_ERROR, - _("Could not generate veth name")); + "%s", _("Could not generate veth name")); rc = -1; VIR_FREE(dev_name_ve); goto exit; diff --git a/src/qemu_driver.c b/src/qemu_driver.c index 8291bfe..47167b7 100644 --- a/src/qemu_driver.c +++ b/src/qemu_driver.c @@ -2611,7 +2611,7 @@ static int qemudDomainAttachPciDiskDevice(virDomainPtr dom, virDomainDeviceDefPt s += strlen(PCI_ATTACH_OK_MSG); if (virStrToLong_i ((const char*)s, &dummy, 10, &dev->data.disk->slotnum) == -1) - qemudLog(QEMUD_WARN, _("Unable to parse slot number\n")); + qemudLog(QEMUD_WARN, "%s", _("Unable to parse slot number\n")); } else { qemudReportError (dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED, _("adding %s disk failed"), type); diff --git a/src/util.c b/src/util.c index 6141847..9b1c5f4 100644 --- a/src/util.c +++ b/src/util.c @@ -406,7 +406,7 @@ virExec(virConnectPtr conn, char *argv_str; if ((argv_str = virArgvToString(argv)) == NULL) { - ReportError(conn, VIR_ERR_NO_MEMORY, _("command debug string")); + ReportError(conn, VIR_ERR_NO_MEMORY, "%s", _("command debug string")); return -1; } DEBUG0(argv_str); @@ -523,7 +523,7 @@ virRun(virConnectPtr conn, char *argv_str = NULL; if ((argv_str = virArgvToString(argv)) == NULL) { - ReportError(conn, VIR_ERR_NO_MEMORY, _("command debug string")); + ReportError(conn, VIR_ERR_NO_MEMORY, "%s", _("command debug string")); goto error; } DEBUG0(argv_str); -- 1.6.0.4.911.gc990

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[libvirt] RFC: Add a 'reason' argument for domain events ?
by Daniel P. Berrange 14 Nov '08

14 Nov '08

We currently have a set of domain lifecycle events VIR_DOMAIN_EVENT_ADDED = 0, VIR_DOMAIN_EVENT_REMOVED = 1, VIR_DOMAIN_EVENT_STARTED = 2, VIR_DOMAIN_EVENT_SUSPENDED = 3, VIR_DOMAIN_EVENT_RESUMED = 4, VIR_DOMAIN_EVENT_STOPPED = 5, VIR_DOMAIN_EVENT_SAVED = 6, VIR_DOMAIN_EVENT_RESTORED = 7, And a couple more I proposed last week to allow distinguishing of new domains which are transient vs persistent VIR_DOMAIN_EVENT_DEFINED = 8, VIR_DOMAIN_EVENT_UNDEFINED = 9, Previously Stefan has suggested we should consider having an event for migration, and though I rejected that at the time, I'm now inclined to agree that this info would be useful here. I'm also thinking I'd like to have more information about STOPPED & STARTED events in general. eg, there are a number of reasons why an domain may have started - explicitly booted on the host - restored from a saved image - incoming migration operation and there are a number of reasons why a domain might have stopped - forcably destroyed by host admin - shutdown by host admin - shutdown by guest admin - host emulator process crashed - killed by mgmt after host emulation hung - migrated to another host - saved to a memory image We have explicit events for the SAVED/RESTORED reasons, but what should we do about the other reasons ? One option is to add alot more events VIR_DOMAIN_MIGRATED_IN (migrated to another node) VIR_DOMAIN_MIGRATED_OUT (migrated from another node) VIR_DOMAIN_SHUTDOWN (graceful shutdown by host admin) VIR_DOMAIN_DESTROYED (force destroyed by host admin) VIR_DOMAIN_CRASHED (guest kernel crashed) VIR_DOMAIN_HUNG (host emulator hung) leaving STOPPED to just be a generic stop event, with no particular reason. The downside with this, is if an application just wants to know about whether a domain shutdown, not why, then they have to track lots and lots of events. Also, not every driver would be able to provide all of these events, so would often have to fallback on a generic STOPPED event So one alternative is to provide a generic 'char * reason' with each event with provides scope on the cause of the lifecycle operation. So you'd get VIR_DOMAIN_STOPPED ("crashed", "shutdown", "destroyed", "quit", "hung", "migrated", "saved") VIR_DOMAIN_STARTED ("booted", "migrated", "restored") nb, we could remove the explicit SAVED and RESTORED events in this style. With such a 'reason' arg, we could possibly avoid adding the DEFINED and UNDEFINED events I suggested. Instead, adding a reason for ADDED and REMOVED events, VIR_DOMAIN_ADDED ("started", "defined") VIR_DOMAIN_REMOVED ("shutdown", "undefined") which lets you distinguish transient from persistent domains. The downside of this though, is that we can't explicitly track when a configuration file is 're-defined', eg adding a config file for an existing running guest. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|

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[libvirt] [PATCH]: Implement Qemu/KVM live migration
by Chris Lalancette 14 Nov '08

14 Nov '08

All, Attached is a patch to implement Qemu/KVM live migration in libvirt. Now that upstream Qemu has settled on an interface that is friendly to libvirt (i.e. one that doesn't block the monitor on -incoming), we can implement it here. Note that the bulk of this patch was written by Rich Jones quite a while ago. My hand in it has mostly been to forward port it to current libvirt CVS, tweak it for the new Qemu style, and test it out with a recent KVM (kvm-78, in particular). Note that there is a FIXME in the code. When testing this out with kvm-78, I found that if I let the source side kill the source VM immediately after the "migrate" monitor command completed, the migration to the destination would never complete. This seems to be a bug in Qemu; the migrate monitor command shouldn't return until the migrate is really, truly complete. I'm posting this now so I can get reviews, and start to address review comments while I try to figure out what's going on with Qemu. With my temporary hack of the sleep() call in there, though, I was able to successfully live migrate an F-9 guest between two machines. Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] [PATCH] add the check whether the domain has already used a disk which attach
by S.Sakamoto 14 Nov '08

14 Nov '08

Hi, "attach-disk" does not give an error, when the domain which is attached has already used the source which attach. This has danger of the data corruption. I make the patch to add the check of this. This patch outputs an error, when the domain which is attached has already used the source which attach. Thanks, Shigeki Sakamoto. Index: src/virsh.c =================================================================== RCS file: /data/cvs/libvirt/src/virsh.c,v retrieving revision 1.170 diff -u -p -r1.170 virsh.c --- src/virsh.c 13 Oct 2008 16:46:29 -0000 1.170 +++ src/virsh.c 4 Nov 2008 07:28:20 -0000 @@ -4993,6 +4993,11 @@ cmdAttachDisk(vshControl *ctl, const vsh char *source, *target, *driver, *subdriver, *type, *mode; int isFile = 0, ret = FALSE; char *buf = NULL, *tmp = NULL; + xmlDocPtr xml = NULL; + xmlXPathObjectPtr obj = NULL; + xmlXPathContextPtr ctxt = NULL; + char *doc; + char xpath[PATH_MAX]; if (!vshConnectionUsability(ctl, ctl->conn, TRUE)) goto cleanup; @@ -5034,6 +5039,35 @@ cmdAttachDisk(vshControl *ctl, const vsh } } + if (source) { + doc = virDomainGetXMLDesc(dom, 0); + if (!doc) + goto cleanup; + + xml = xmlReadDoc((const xmlChar *) doc, "domain.xml", NULL, + XML_PARSE_NOENT | XML_PARSE_NONET | + XML_PARSE_NOWARNING); + free(doc); + if (!xml) + goto cleanup; + ctxt = xmlXPathNewContext(xml); + if (!ctxt) + goto cleanup; + + sprintf(xpath, "string(/domain/devices/disk/source[@dev='%s']/@dev)", source); + obj = xmlXPathEval(BAD_CAST xpath, ctxt); + if (!strcmp(obj->stringval, source)) { + vshError(ctl, FALSE, _("Disk %s is already in use by own guest"), source); + goto cleanup; + } + sprintf(xpath, "string(/domain/devices/disk/source[@file='%s']/@file)", source); + obj = xmlXPathEval(BAD_CAST xpath, ctxt); + if (!strcmp(obj->stringval, source)) { + vshError(ctl, FALSE, _("Disk %s is already in use by own guest"), source); + goto cleanup; + } + } + /* Make XML of disk */ tmp = vshMalloc(ctl, 1); if (!tmp) goto cleanup; @@ -5123,6 +5157,10 @@ cmdAttachDisk(vshControl *ctl, const vsh ret = TRUE; cleanup: + xmlXPathFreeObject(obj); + xmlXPathFreeContext(ctxt); + if (xml) + xmlFreeDoc(xml); if (dom) virDomainFree(dom); free(buf);

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[libvirt] [PATCH] Register storage backends in test driver
by Cole Robinson 12 Nov '08

12 Nov '08

The refactored storage backend registering broke the test driver. The attached patch makes everything work again by explicitly registering the backends on driver startup. Thanks, Cole diff --git a/src/test.c b/src/test.c index 30dc52a..a785f04 100644 --- a/src/test.c +++ b/src/test.c @@ -43,6 +43,11 @@ #include "network_conf.h" #include "domain_conf.h" #include "storage_conf.h" +#include "storage_backend.h" +#include "storage_backend_logical.h" +#include "storage_backend_iscsi.h" +#include "storage_backend_disk.h" +#include "storage_backend_fs.h" #include "xml.h" #define MAX_CPUS 128 @@ -663,6 +668,17 @@ static int testOpen(virConnectPtr conn, return VIR_DRV_OPEN_ERROR; } + if (virStorageBackendRegister(&virStorageBackendDirectory) < 0 || + virStorageBackendRegister(&virStorageBackendFileSystem) < 0 || + virStorageBackendRegister(&virStorageBackendNetFileSystem) < 0 || + virStorageBackendRegister(&virStorageBackendLogical) < 0 || + virStorageBackendRegister(&virStorageBackendISCSI) < 0 || + virStorageBackendRegister(&virStorageBackendDisk) < 0) { + testError(NULL, VIR_ERR_INTERNAL_ERROR, + _("Failed to register storage backends.")); + return VIR_DRV_OPEN_DECLINED; + } + if (STREQ(uri->path, "/default")) ret = testOpenDefault(conn); else

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[libvirt] [PATCH] 0/7 host ("node") device enumeration - completed submission
by David Lively 12 Nov '08

12 Nov '08

Since the version of this I posted last week still had some outstaning TODO items that I have since finished, I'm re-submitting the whole thing. I consider this a "complete submission" since I don't think it's necessary to implement any additional functionality to make this acceptable. (The two remaining unimplemented items are virNodeDeviceCreate / Destroy and a real Devkit impl, neither of which needs to be done immediately, for reasons discussed earlier.) These patches implement the node device enumeration functionality, as discussed here: https://www.redhat.com/archives/libvir-list/2008-September/msg00398.html I've broken it into the following pieces: 1-public-api additions to the public API 2-internal-api additions to the internal API 3-local-node-drivers the HAL & DeviceKit implementations 4-remote-node-driver the remote driver 5-virsh-support virsh support 6-python-bindings python bindings 7-java-bindings Java bindings (for libvirt-java) Dave

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Re: >>: [libvirt] OpenVZ capabilites in LibVIRT
by Ivan Vovk 11 Nov '08

11 Nov '08

Hi, Anton. > You can specify an IP address and a netmask like this: >> http://libvirt.org/formatnetwork.html#elementsAddress >> Such bridge will be automatically set up. >> > - thanks for the hint. I assigned 0.0.0.0 as I don't need IP on bridges at the moment. > 2) there is a default network "Default" with enabled 'Autostart'. Is >>> there any way to remove this network completely? >>> >> Yes, >> # virsh net-destroy defaul >> > correct answer is > # virsh net-undefine default > - you were correct in both cases: you can't undefine active network so it should be destroyed and after that undefine. So it worked! > Short answer: it doesn't work now. Wait for nex libvirt release > (libvirt-4.6-alt2). I will try to make it as soon as possible. > For details see > http://www.redhat.com/archives/libvir-list/2008-October/msg00323.html > - yeah, i've already read that thread and known it was a bug. Just needed a confirmation that it was going to be fixed in next release. So may be my question will be a bit indelicate, but is there a hope to see this release by the end of november? > 5) Is there any way to destroy domain completely like it can be done via >> 'vzctl destroy <ID>'? >> > Yes, > # virsh destroy <domain-name> > >> And here too, if domain was previously defined, command must be: > # virsh undefine <domain-name> > - got the idea. And noticed the following: virsh # define ovz.xml Domain 3005 defined from ovz.xml virsh # start 3005 Domain 3005 started virsh # shutdown 3005 Domain 3005 is being shutdown virsh # undefine 3005 libvir: OpenVZ error : Domain not found Domain 3005 has been undefined It really removes domain from file system, but why does it throw that error message? 6) Where does libvirt store info about already created domains? I can't >> create a new domain with ID 3005 after I completely destroy previous one via >> 'vzctl destroy 3005'. >> > And what does it saying? > - if i simply destroy domain via vzctl (without undefining it via virsh): [root@alt-03 ~]# vzctl destroy 3005 Destroying container private area: /var/lib/vz/private/3005 Container private area was destroyed - and then try to create another one (this time via virsh) virsh # create ovz.xml libvir: OpenVZ error : operation failed: Already an OPENVZ VM defined with the id '3005' error: Failed to create domain from ovz.xml It seems domain is still defined from LibVirt's point of view but actually it doesn't exist any more. It was removed via native OpenVZ tool. In case I try to undefine it: virsh # undefine 3005 libvir: OpenVZ error : Domain not found libvir: error : vzctl exited with non-zero status 14 and signal 0 libvir: OpenVZ error : internal error Could not exec vzctl error: Failed to undefine domain 3005 And from this moment it is imposible to create domain with ID 3005. So how can I obtain a list of already defined domains? And how can it be purged? 7) Is there any way to publish domain's console on a host system so that I > can connect via telnet to HW node on some TCP/4567 and get into domain's > console? > vzctl enter <domain ID> > - yeah, that for sure is true wheh you are on HW node itself. But I need to organize access into domain's consoles from remote mashines. In my case there is no network connectivity between real lan and domains. I believed, this XML definition could help me: http://libvirt.org/formatdomain.html#elementsCharTCP - "*The character device acts as a TCP client connecting to a remote server, or as a server waiting for a client connection*", so when you connect to HW node on some TCP port you get into domain's console. But it seems I got it in a wrong way because is didn't work in case of OpenVZ. P.S. You can ask ALT-specific questions to me directly. > - thanks, will keep that in mind. ___________ Best regards, Ivan V.

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[libvirt] Weird permissions error
by Darryl Pierce 11 Nov '08

11 Nov '08

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I have a startup script that runs a second script to do some work on the system. This second script calls: virsh -c qemu:///system --readonly nodeinfo and then scrapes from that the amount of free memory. When I run this from my init script, I get: libvir: Remote error : unable to connect to '/var/run/libvirt/libvirt-sock-ro': Permission denied But if I run the second script itself directly (outside of the init script) it works correctly. Any ideas? - -- Darryl L. Pierce <dpierce(a)redhat.com> : GPG KEYID: 6C4E7F1B -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iEYEARECAAYFAkkYsEEACgkQjaT4DmxOfxuwzACgzYNQ7ku5P0YGr4jdHaDzf6Pq MicAoJ5nB7e+TSwE2Vfd9YrCgiahKXwo =01FA -----END PGP SIGNATURE-----

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[libvirt] OpenVZ capabilites in LibVIRT
by Anton Protopopov 10 Nov '08

10 Nov '08

Hi! > > I faced with several difficulties / misunderstandings and I hope someone > could clarify me (at the moment I use 'virsh' for testing). > > 1) after creating network via 'virsh # net-create network.xml' i get vzbr0 > bridge in down state and have to make ip up manually. Is there any way to > automatically make it up? > You can specify an IP address and a netmask like this: http://libvirt.org/formatnetwork.html#elementsAddress Such bridge will be automatically set up. > 2) there is a default network "Default" with enabled 'Autostart'. Is there > any way to remove this network completely? > Yes, # virsh net-destroy defaul > 3) after creating domain via 'virsh # create ovz.xml' i get a new > container, but it doesn't work as it should do: > - at first, it has 'vzbr0' veth interface inside and its pair on a HW node > is added into default bridge vmbr0. I believed tag <source bridge='vzbr0'/> > should point to a bridge name on a HW node, but instead it created veth > interface with such name. In openvz config file for created domain i see > this: > [root@alt-03 ~]# cat /etc/vz/conf/3005.conf | grep NETIF > > NETIF="ifname=vzbr0,mac=52:54:00:35:10:6D,host_ifname=veth3005.0,host_mac=52:54:00:35:10:6D" > Short answer: it doesn't work now. Wait for nex libvirt release (libvirt-4.6-alt2). I will try to make it as soon as possible. For details see http://www.redhat.com/archives/libvir-list/2008-October/msg00323.html > 4) Is there any way to specify config file for created domain like it can > be done via 'vzctl create <ID> --oostemplate <templname> --config > <confname>'? > No > 5) Is there any way to destroy domain completely like it can be done via > 'vzctl destroy <ID>'? > Yes, # virsh destroy <domain-name> > 6) Where does libvirt store info about already created domains? I can't > create a new domain with ID 3005 after I completely destroy previous one via > 'vzctl destroy 3005'. > And what does it saying? 7) Is there any way to publish domain's console on a host system so that I > can connect via telnet to HW node on some TCP/4567 and get into domain's > console? > vzctl enter <domain ID> > 8) Does libvirt use some OpenVZ bindings or simply executes vzctl and other > stuff? > simply executes vzctl and reading/writing <veid>.conf P.S. You can ask ALT-specific questions to me directly.

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