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[libvirt] New wiki pages with libvirt SSH setup instructions
by Justin Clift 14 Sep '10

14 Sep '10

Hi all, Just added some new pages to the wiki, this time covering how to configure remote access to libvirt through SSH, not using root: http://wiki.libvirt.org/page/SSHSetup <--- entry page http://wiki.libvirt.org/page/SSHPolicyKitSetup This has details for several different Linux distributions: * RHEL 5 & 6 * Fedora 11-13 * Centos 5 & 6 * Ubuntu 10.04 Server & Desktop * openSUSE 11.2 onwards Does anyone have info they'd like to include for other distributions? :) Regards and best wishes, Justin Clift

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[libvirt] [PATCH] Rebuild network filter for UML guests on updates
by Soren Hansen 14 Sep '10

14 Sep '10

When nwfilter support was added to UML, I didn't realise the UML driver needed instrumentation to make updating nwfilters on the fly work. This patch adds this bit of glue. Signed-off-by: Soren Hansen <soren(a)linux2go.dk> --- src/uml/uml_driver.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/src/uml/uml_driver.c b/src/uml/uml_driver.c index 40345d5..9101928 100644 --- a/src/uml/uml_driver.c +++ b/src/uml/uml_driver.c @@ -2198,6 +2198,18 @@ static virDriver umlDriver = { NULL, /* qemuDomainMonitorCommand */ }; +static int +umlVMFilterRebuild(virConnectPtr conn ATTRIBUTE_UNUSED, + virHashIterator iter, void *data) +{ + struct uml_driver *driver = uml_driver; + + umlDriverLock(driver); + virHashForEach(uml_driver->domains.objs, iter, data); + umlDriverUnlock(driver); + + return 0; +} static virStateDriver umlStateDriver = { .name = "UML", @@ -2207,8 +2219,14 @@ static virStateDriver umlStateDriver = { .active = umlActive, }; +static virNWFilterCallbackDriver umlCallbackDriver = { + .name = "UML", + .vmFilterRebuild = umlVMFilterRebuild, +}; + int umlRegister(void) { virRegisterDriver(&umlDriver); virRegisterStateDriver(&umlStateDriver); + virNWFilterRegisterCallbackDriver(&umlCallbackDriver); return 0; } -- 1.7.1

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[libvirt] [PATCH] virsh: Use virBuffer for generating XML
by Jiri Denemark 14 Sep '10

14 Sep '10

cmdAttachInterface and cmdAttachDisk still used vshRealloc and sprintf for generating XML, which is hardly maintainable. Let's get rid of this old code. --- tools/virsh.c | 152 ++++++++++++++++++++------------------------------------ 1 files changed, 54 insertions(+), 98 deletions(-) diff --git a/tools/virsh.c b/tools/virsh.c index 57ea618..9eb1e51 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -7874,8 +7874,9 @@ cmdAttachInterface(vshControl *ctl, const vshCmd *cmd) virDomainPtr dom = NULL; char *mac, *target, *script, *type, *source; int typ, ret = FALSE; - char *buf = NULL, *tmp = NULL; unsigned int flags; + virBuffer buf = VIR_BUFFER_INITIALIZER; + char *xml; if (!vshConnectionUsability(ctl, ctl->conn)) goto cleanup; @@ -7903,52 +7904,40 @@ cmdAttachInterface(vshControl *ctl, const vshCmd *cmd) } /* Make XML of interface */ - tmp = vshMalloc(ctl, 1); - buf = vshMalloc(ctl, strlen(type) + 25); - sprintf(buf, " <interface type='%s'>\n" , type); + virBufferVSprintf(&buf, "<interface type='%s'>\n" , type); - tmp = vshRealloc(ctl, tmp, strlen(source) + 28); - if (typ == 1) { - sprintf(tmp, " <source network='%s'/>\n", source); - } else if (typ == 2) { - sprintf(tmp, " <source bridge='%s'/>\n", source); - } - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); + if (typ == 1) + virBufferVSprintf(&buf, " <source network='%s'/>\n", source); + else if (typ == 2) + virBufferVSprintf(&buf, " <source bridge='%s'/>\n", source); - if (target != NULL) { - tmp = vshRealloc(ctl, tmp, strlen(target) + 24); - sprintf(tmp, " <target dev='%s'/>\n", target); - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); - } + if (target != NULL) + virBufferVSprintf(&buf, " <target dev='%s'/>\n", target); + if (mac != NULL) + virBufferVSprintf(&buf, " <mac address='%s'/>\n", mac); + if (script != NULL) + virBufferVSprintf(&buf, " <script path='%s'/>\n", script); - if (mac != NULL) { - tmp = vshRealloc(ctl, tmp, strlen(mac) + 25); - sprintf(tmp, " <mac address='%s'/>\n", mac); - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); - } + virBufferAddLit(&buf, "</interface>\n"); - if (script != NULL) { - tmp = vshRealloc(ctl, tmp, strlen(script) + 25); - sprintf(tmp, " <script path='%s'/>\n", script); - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); + if (virBufferError(&buf)) { + vshPrint(ctl, "%s", _("Failed to allocate XML buffer")); + return FALSE; } - buf = vshRealloc(ctl, buf, strlen(buf) + 19); - strcat(buf, " </interface>\n"); + xml = virBufferContentAndReset(&buf); if (vshCommandOptBool(cmd, "persistent")) { flags = VIR_DOMAIN_DEVICE_MODIFY_CONFIG; if (virDomainIsActive(dom) == 1) flags |= VIR_DOMAIN_DEVICE_MODIFY_LIVE; - ret = virDomainAttachDeviceFlags(dom, buf, flags); + ret = virDomainAttachDeviceFlags(dom, xml, flags); } else { - ret = virDomainAttachDevice(dom, buf); + ret = virDomainAttachDevice(dom, xml); } + VIR_FREE(xml); + if (ret != 0) { vshError(ctl, "%s", _("Failed to attach interface")); ret = FALSE; @@ -7960,8 +7949,7 @@ cmdAttachInterface(vshControl *ctl, const vshCmd *cmd) cleanup: if (dom) virDomainFree(dom); - VIR_FREE(buf); - VIR_FREE(tmp); + virBufferFreeAndReset(&buf); return ret; } @@ -8126,9 +8114,10 @@ cmdAttachDisk(vshControl *ctl, const vshCmd *cmd) virDomainPtr dom = NULL; char *source, *target, *driver, *subdriver, *type, *mode; int isFile = 0, ret = FALSE; - char *buf = NULL, *tmp = NULL; unsigned int flags; char *stype; + virBuffer buf = VIR_BUFFER_INITIALIZER; + char *xml; if (!vshConnectionUsability(ctl, ctl->conn)) goto cleanup; @@ -8167,77 +8156,45 @@ cmdAttachDisk(vshControl *ctl, const vshCmd *cmd) } /* Make XML of disk */ - tmp = vshMalloc(ctl, 1); - buf = vshMalloc(ctl, 23); - if (isFile) { - sprintf(buf, " <disk type='file'"); - } else { - sprintf(buf, " <disk type='block'"); - } - - if (type) { - tmp = vshRealloc(ctl, tmp, strlen(type) + 13); - sprintf(tmp, " device='%s'>\n", type); - } else { - tmp = vshRealloc(ctl, tmp, 3); - sprintf(tmp, ">\n"); - } - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); - - if (driver) { - tmp = vshRealloc(ctl, tmp, strlen(driver) + 22); - sprintf(tmp, " <driver name='%s'", driver); - } else { - tmp = vshRealloc(ctl, tmp, 25); - sprintf(tmp, " <driver name='phy'"); - } - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); - - if (subdriver) { - tmp = vshRealloc(ctl, tmp, strlen(subdriver) + 12); - sprintf(tmp, " type='%s'/>\n", subdriver); - } else { - tmp = vshRealloc(ctl, tmp, 4); - sprintf(tmp, "/>\n"); - } - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); - - tmp = vshRealloc(ctl, tmp, strlen(source) + 25); - if (isFile) { - sprintf(tmp, " <source file='%s'/>\n", source); - } else { - sprintf(tmp, " <source dev='%s'/>\n", source); - } - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); - - tmp = vshRealloc(ctl, tmp, strlen(target) + 24); - sprintf(tmp, " <target dev='%s'/>\n", target); - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); + virBufferVSprintf(&buf, "<disk type='%s'", + (isFile) ? "file" : "block"); + if (type) + virBufferVSprintf(&buf, " device='%s'", type); + virBufferAddLit(&buf, ">\n"); + + virBufferVSprintf(&buf, " <driver name='%s'", + (driver) ? driver : "phy"); + if (subdriver) + virBufferVSprintf(&buf, " type='%s'", subdriver); + virBufferAddLit(&buf, "/>\n"); + + virBufferVSprintf(&buf, " <source %s='%s'/>\n", + (isFile) ? "file" : "dev", + source); + virBufferVSprintf(&buf, " <target dev='%s'/>\n", target); + if (mode) + virBufferVSprintf(&buf, " <%s/>\n", mode); + + virBufferAddLit(&buf, "</disk>\n"); - if (mode != NULL) { - tmp = vshRealloc(ctl, tmp, strlen(mode) + 11); - sprintf(tmp, " <%s/>\n", mode); - buf = vshRealloc(ctl, buf, strlen(buf) + strlen(tmp) + 1); - strcat(buf, tmp); + if (virBufferError(&buf)) { + vshPrint(ctl, "%s", _("Failed to allocate XML buffer")); + return FALSE; } - buf = vshRealloc(ctl, buf, strlen(buf) + 13); - strcat(buf, " </disk>\n"); + xml = virBufferContentAndReset(&buf); if (vshCommandOptBool(cmd, "persistent")) { flags = VIR_DOMAIN_DEVICE_MODIFY_CONFIG; if (virDomainIsActive(dom) == 1) flags |= VIR_DOMAIN_DEVICE_MODIFY_LIVE; - ret = virDomainAttachDeviceFlags(dom, buf, flags); + ret = virDomainAttachDeviceFlags(dom, xml, flags); } else { - ret = virDomainAttachDevice(dom, buf); + ret = virDomainAttachDevice(dom, xml); } + VIR_FREE(xml); + if (ret != 0) { vshError(ctl, "%s", _("Failed to attach disk")); ret = FALSE; @@ -8249,8 +8206,7 @@ cmdAttachDisk(vshControl *ctl, const vshCmd *cmd) cleanup: if (dom) virDomainFree(dom); - VIR_FREE(buf); - VIR_FREE(tmp); + virBufferFreeAndReset(&buf); return ret; } -- 1.7.2.3

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[libvirt] [PATCH] Use SED variable for `sed` binary in src/Makefile
by Mitchell Hashimoto 14 Sep '10

14 Sep '10

Hi, I've been trying to get libvirt (client) to cleanly/easily compile on BSD-based systems (in this case OS X). "./configure" runs fine but the "make" caused an error with `sed` since BSD sed was reporting some sort of regex error. I realized that the "SED" variable was populated with "gsed" which worked properly. This made the make continue (failed again later, will address that when I can). This is my first contribution to a C-based project and I don't have much experience with autotools other than using them as a consumer. Let me know if anything can be improved. Thank you, Mitchell

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[libvirt] [PATCH 0/3] test cases for spoofing prevention
by gstenzel＠linux.vnet.ibm.com 14 Sep '10

14 Sep '10

The following patches add a set of test cases to verify that several spoofing attacks are prevented by the nwfilter subsystem. In order to have a well defined test machine a virtual disk is installed from scratch over the network. I am currently trying to find a suitable location for the kickstart file. -- Best regards, Gerhard Stenzel, ----------------------------------------------------------------------------------------------------------------------------------- IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Martin Jetter Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294

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Re: [libvirt] Question, how to use virDomainQemuMonitorCommand()
by Chris Lalancette 14 Sep '10

14 Sep '10

On 09/07/10 - 04:08:13PM, Lai Jiangshan wrote: > Hi, Chris, > > I saw virDomainQemuMonitorCommand() in libvirt-qemu.c, > I think it will help me to send arbitrary qemu-monitor command to > qemu via libvirtd. > > But how can I use virDomainQemuMonitorCommand()? > Can I use it by just using current tools(virsh or other) without writing any code? Unfortunately, no. There is a bug in the current virsh command that prevents it from properly parsing the command-lines necessary to send monitor commands to the qemu monitor. Until we fix that bug, we won't push the support into virsh. For that reason you will need to write a custom program to call virDomainQemuMonitorCommand as appropriate. The absolute easiest program you can write looks something like (untested): #include <stdio.h> #include <stdlib.h> #include <libvirt/libvirt.h> int main() { virConnectPtr conn; virDomainPtr dom; char *reply; conn = virConnectOpen(NULL); dom = virDomainLookupByName(conn, "mydomain"); virDomainQemuMonitorCommand(dom, "info cpus", &reply, 0); fprintf(stderr, "Reply: %s\n", reply); free(reply); virConnectClose(conn); return 0; } -- Chris Lalancette

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[libvirt] Remote access form windows - Java bindings
by Gandhiraj Natarajan 14 Sep '10

14 Sep '10

Hi I am developing tool to collect information on XenServer which is on Opensuse 11. I am using libvirt-0.4.6.jar and and jna-3.2.4 jar files. I tried to connect from Remote system(Windows) to server, but could not get the connection object. Any configuration needs to be done for remote access ? conn = new Connect("xen+tcp://192.168.10.22/"); it shows the exception Exception in thread "main" java.lang.UnsatisfiedLinkError: Unable to load library 'virt': The specified module could not be found. at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:164) at com.sun.jna.NativeLibrary.getInstance(NativeLibrary.java:237) at com.sun.jna.Library$Handler.<init>(Library.java:140) at com.sun.jna.Native.loadLibrary(Native.java:374) at com.sun.jna.Native.loadLibrary(Native.java:359) at org.libvirt.jna.Libvirt.<clinit>(Unknown Source) at org.libvirt.Connect.<clinit>(Unknown Source) at LibvirtCon.main(LibvirtCon.java:29) Help me Regards Gandhiraj Natarajan

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[libvirt] [PATCH] docs: improve wording for the dev guide
by Justin Clift 13 Sep '10

13 Sep '10

Wording tweak suggested by David Jorm, author of the libvirt App Dev Guide. --- docs/devguide.html.in | 14 +++++++------- docs/downloads.html.in | 14 +++++++------- 2 files changed, 14 insertions(+), 14 deletions(-) diff --git a/docs/devguide.html.in b/docs/devguide.html.in index 409952e..6c51c36 100644 --- a/docs/devguide.html.in +++ b/docs/devguide.html.in @@ -4,16 +4,16 @@ <h1>libvirt Application Development Guide</h1> <p> - This is both a guide to developing with libvirt, and a useful - reference document. It is a work in progress, contributed to by the - members of the libvirt team and being authored by a professional - author. + The guide is both a learning tool for developing with libvirt and an + API reference document. It is a work in progress, composed by a + professional author from contributions written by members of the + libvirt team. </p> <p> - Contributors to this are <b>VERY</b> welcome, so if you'd like to - get your name in this and demonstrate your virtualisation prowess, - contributing solidly to the content here will do it. :) + Contributions to the guide are <b>VERY</b> welcome. If you'd like to get + your name on this and demonstrate your virtualisation prowess, a solid + contribution to the content here will do it. :) </p> <h2>Browsable online</h2> diff --git a/docs/downloads.html.in b/docs/downloads.html.in index 66b99e1..2ce1048 100644 --- a/docs/downloads.html.in +++ b/docs/downloads.html.in @@ -49,16 +49,16 @@ <h1>libvirt Application Development Guide</h1> <p> - This is both a guide to developing with libvirt, and a useful - reference document. It is a work in progress, contributed to by the - members of the libvirt team and being authored by a professional - author. + The guide is both a learning tool for developing with libvirt and an + API reference document. It is a work in progress, composed by a + professional author from contributions written by members of the + libvirt team. </p> <p> - Contributors to this are <b>VERY</b> welcome, so if you'd like to - get your name in this and demonstrate your virtualisation prowess, - contributing solidly to the content here will do it. :) + Contributions to the guide are <b>VERY</b> welcome. If you'd like to get + your name on this and demonstrate your virtualisation prowess, a solid + contribution to the content here will do it. :) </p> <h2>Downloadable PDF</h2> -- 1.7.2.2

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[libvirt] [PATCH] tests: Fix preprocessor indentation
by Jiri Denemark 13 Sep '10

13 Sep '10

--- Pushed as obvious to fix make syntax-check failure. tests/virbuftest.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/tests/virbuftest.c b/tests/virbuftest.c index d8258fc..db08fc4 100644 --- a/tests/virbuftest.c +++ b/tests/virbuftest.c @@ -70,7 +70,7 @@ mymain(int argc ATTRIBUTE_UNUSED, int ret = 0; -# define DO_TEST(msg, cb, data) \ +#define DO_TEST(msg, cb, data) \ do { \ struct testInfo info = { data }; \ if (virtTestRun("Buf: " msg, 1, cb, &info) < 0) \ -- 1.7.2.2

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[libvirt] QEMU interfaces for image streaming and post-copy block migration
by Anthony Liguori 12 Sep '10

12 Sep '10

Hi, We've got copy-on-read and image streaming working in QED and before going much further, I wanted to bounce some interfaces off of the libvirt folks to make sure our final interface makes sense. Here's the basic idea: Today, you can create images based on base images that are copy on write. With QED, we also support copy on read which forces a copy from the backing image on read requests and write requests. In additional to copy on read, we introduce a notion of streaming a block device which means that we search for an unallocated region of the leaf image and force a copy-on-read operation. The combination of copy-on-read and streaming means that you can start a guest based on slow storage (like over the network) and bring in blocks on demand while also having a deterministic mechanism to complete the transfer. The interface for copy-on-read is just an option within qemu-img create. Streaming, on the other hand, requires a bit more thought. Today, I have a monitor command that does the following: stream <device> <sector offset> Which will try to stream the minimal amount of data for a single I/O operation and then return how many sectors were successfully streamed. The idea about how to drive this interface is a loop like: offset = 0; while offset < image_size: wait_for_idle_time() count = stream(device, offset) offset += count Obviously, the "wait_for_idle_time()" requires wide system awareness. The thing I'm not sure about is 1) would libvirt want to expose a similar stream interface and let management software determine idle time 2) attempt to detect idle time on it's own and provide a higher level interface. If (2), the question then becomes whether we should try to do this within qemu and provide libvirt a higher level interface. A related topic is block migration. Today we support pre-copy migration which means we transfer the block device and then do a live migration. Another approach is to do a live migration, and on the source, run a block server using image streaming on the destination to move the device. With QED, to implement this one would: 1) launch qemu-nbd on the source while the guest is running 2) create a qed file on the destination with copy-on-read enabled and a backing file using nbd: to point to the source qemu-nbd 3) run qemu -incoming on the destination with the qed file 4) execute the migration 5) when migration completes, begin streaming on the destination to complete the copy 6) when the streaming is complete, shut down the qemu-nbd instance on the source This is a bit involved and we could potentially automate some of this in qemu by launching qemu-nbd and providing commands to do some of this. Again though, I think the question is what type of interfaces would libvirt prefer? Low level interfaces + recipes on how to do high level things or higher level interfaces? Regards, Anthony Liguori

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