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[libvirt] [PATCH]: Fix VIR_ALLOC_N for 0 byte arrays
by Chris Lalancette 19 Jun '08

19 Jun '08

Hello, For 0.4.3, danpb's new memory management scheme went into libvirt. This is fine, except that is subtly alters the semantics of malloc(), calloc(), and realloc(). In particular, if you say: foo = malloc(0); glibc will happily return a non-NULL pointer to you. However, with the new memory management stuff, if you say: foo = VIR_ALLOC(0); you will actually get a NULL pointer back. Personally, I think this is a dangerous deviation from malloc() semantics that everyone is used to, and is indeed causing problems with the remote driver. The short of it is that the remote driver allocates memory on behalf of the remote side using VIR_ALLOC_N, and this call is returning NULL so that the NULL checks elsewhere in the code fire and return failure. The attached patch fixes this situation by removing the 0 checks from the memory allocation paths, and just lets them fall through to the normal malloc(), calloc(), or realloc() routines, restoring old semantics. Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] How does libvirt access kvm infomation?
by Akio Takebe 19 Jun '08

19 Jun '08

Hi, AFAIK kvm has only an interface of qemu console when we use device hotplug, migration and so on. How does libvirt access the interface of qemu console? Best Regards, Akio Takebe

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[libvirt] Cherokee+Libvirt+Avahi = Cool Libre Application
by Stefan de Konink 18 Jun '08

18 Jun '08

Hi, As I have told on the mailinglist before I'm working on a webbased implementation of the libvirt API. Using Avahi as messaging protocol, some extra tools were written: - Domumdns (Tool that puts every domain on the network (scanning interval of 10s connecting to the local hypervisor), refering back to the hostname of libvirtd) - Cherokee Avahi Handler, Cherokee Virt Handler (implements HTTP API) So basically: http://xen.bot.nu/avahi/ Shows the available vms on my network, every 10 seconds updated by domudmns. My proposal would be to add this functionality by default to libvirtd. 1) it is useful 2) it implements something of the todo list: events. http://xen.bot.nu/virt/klant1/gentoo/virDomainGetID http://xen.bot.nu/virt/klant1/gentoo/virDomainGetName http://xen.bot.nu/virt/klant1/gentoo/virDomainGetMaxMemory http://xen.bot.nu/virt/klant1/gentoo/virDomainGetMaxVcpus http://xen.bot.nu/virt/klant1/gentoo/virDomainGetOSType http://xen.bot.nu/virt/klant1/gentoo/virDomainGetUUID <-- that's odd http://xen.bot.nu/virt/klant1/gentoo/virDomainGetUUIDString http://xen.bot.nu/virt/klant1/gentoo/virDomainGetXMLDesc Are implemented now, the updates as attach/detach devices will be added soon, but that is not something I'm going to demo without some basic authentication ;) Stefan

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[libvirt] [PATCH 5/5]: Rewrite findLuns function
by Chris Lalancette 17 Jun '08

17 Jun '08

This rather large patch rewrites the virStorageBackendISCSIFindLUNs() function to only rely on sysfs for finding LUNs, given a session number. Along the way, it also fixes the bug where we wouldn't find LUNs for older kernels (with the block:sda format), and also (possibly) fixes a race condition where we could try to find the LUN before udev has finished connecting it. I say it "possibly" fixes it because I haven't been able to hit it so far, but I definitely need more testing to try and confirm. Changes since last time: 1) Don't blindly ignore the 0'th LUN (thanks Stefan). Instead, look if the LUNs are Direct-Access devices (as defined by the kernel); if so, they are LUNs we can use. 2) Fix up whitespace damage. 3) Check the return value of the scsidev strdup as pointed out by Jim. 4) Change all ISCSIADM commands to be const char *const as pointed out by Jim. Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] [PATCH 4/5]: Move the sendtarget command into the login command
by Chris Lalancette 17 Jun '08

17 Jun '08

A small bugfix; we only need to call the iscsiadm sendtarget command when we are first logging in; we don't need to do it for logout. Move the sendtarget command into the Login() function. Changes since last time: 1) Make const char *cmdsendtarget into const char *const cmdsendtarget based on feedback from Jim. Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] [PATCH 3/5]: Fix up the call to iscsiadm --mode session
by Chris Lalancette 17 Jun '08

17 Jun '08

Older versions of iscsiadm didn't support the "-P 0" flag to the "iscsiadm --mode session" command. However, just running "iscsiadm --mode session" seems to work on all version of iscsiadm commands back to FC-6, so just use that. Changes since last time: None Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] [PATCH 2/5]: Cleanup carriage returns in util.c
by Chris Lalancette 17 Jun '08

17 Jun '08

In src/util.c, virLog is just a wrapper around fprintf(stderr). Make sure to put line breaks at the end of lines that use virLog() (noticed during testing). Changes since last time: None Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] [PATCH 1/5]: Return exitstatus from virStorageBackendRunProgRegex
by Chris Lalancette 17 Jun '08

17 Jun '08

This patch changes things around so that virStorageBackendRunProgRegex() does *not* virStorageReportError() if the fork()/exec() process it spawned returned a != 0 exit code. Rather, it returns the exitcode in this case, and it is up to the higher level to determine whether this is a fatal error or not. The use case for this change is in the iSCSI stuff; older versions of iscsiadm tools would return a failure when getting the session number, despite the command succeeding. Changes since last time: 1) Fix up whitespace damage Signed-off-by: Chris Lalancette <clalance(a)redhat.com>

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[libvirt] [PATCH 0/5]: Rework iSCSI lun handling
by Chris Lalancette 17 Jun '08

17 Jun '08

These patches are now better tested, so I'm sending them for review again. To recap, these patches: 1) Do minor cleanup of the existing code 2) Fix a bug where we aren't properly finding the LUNs on pre 2.6.24 kernels 3) Fix a bug seen in oVirt where we race between libvirtd scanning the sysfs path and udev actually making the sysfs path in the first place 4) Further lessen our dependence on direct calls to iscsiadm, in case they change the output in the future. Changes since last time include: 1) Fixing the 0th LUN problem as pointed out by Stefan de Konink. We now use a sysfs file to determine whether this is a valid LUN for us to have. 2) Fix all my whitespace damage 3) Small cleanups based on feedback from the list. Also, I'm putting a build through koji, available here: http://koji.fedoraproject.org/koji/taskinfo?taskID=663583 Chris Lalancette

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[libvirt] [PATCH] Pass syntax check for block devices to XenD.
by Hiroyuki Kaguchi 17 Jun '08

17 Jun '08

Hi, libvirt doesn't pass disk information that the device type isn't specified to XenD and doesn't show the error message either. However, the error message should be displayed, and XenD should show it. On this account, I change libvirt that libvirt passes the disk information that the device type isn't specified to XenD and XenD shows error message. The related patch: After Xen Cset17617, XenD check the syntax of the device type of the disk information. Thanks, Signed-off-by: Hiroyuki Kaguchi <fj7025cf(a)aa.jp.fujitsu.com> Index: src/xm_internal.c =================================================================== RCS file: /data/cvs/libvirt/src/xm_internal.c,v retrieving revision 1.79 diff -u -p -r1.79 xm_internal.c --- src/xm_internal.c 29 May 2008 19:20:23 -0000 1.79 +++ src/xm_internal.c 3 Jun 2008 07:48:02 -0000 @@ -767,12 +767,10 @@ char *xenXMDomainFormatXML(virConnectPtr if (!src[0]) { strcpy(drvName, "phy"); tmp = &src[0]; - } else if (!(tmp = strchr(src, ':')) || !tmp[0]) { - goto skipdisk; - } else { - strncpy(drvName, src, (tmp-src)); - drvName[tmp-src] = '\0'; - } + } else if (tmp = strchr(src, ':')) { + strncpy(drvName, src, (tmp-src)); + drvName[tmp-src] = '\0'; + } /* And the source driver sub-type */ if (STRPREFIX(drvName, "tap")) { @@ -782,7 +780,7 @@ char *xenXMDomainFormatXML(virConnectPtr memmove(src, src+(tmp1-src)+1, strlen(src)-(tmp1-src)); } else { drvType[0] = '\0'; - if (src[0]) + if (src[0] && tmp) memmove(src, src+(tmp-src)+1, strlen(src)-(tmp-src)); }

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