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[Libvir] Question about XML
by Juan Walker 20 Jul '06

20 Jul '06

Hi, I have a question regarding the XML format that libvir uses for domain configuration. I was wondering if there is a way to use the configuration format that xm uses or if a tool exists to convert to XML. I'm writing an app to help users manage their Xen domains but I'm hoping to be able to use any .sxp files that the user already has. I suspect I missed something in the documentation about why the XML format is better, but if there is no such tool maybe I should volunteer to write one? Thanks.

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[Libvir] just a question about libvirt evolution
by Philippe Berthault 20 Jul '06

20 Jul '06

Hello, Several major modifications will appear this year in future Xen releases (3.0.3 and 3.0.4) that may have impacts on libvirt. These modifications (see xen roadmap edited by Ian Pratt in july 2006) are : - Introduction of XML-RPC, - Xen configuration files in XML format, - Suppression of S-Expressions, - etc.. What is the libvirt position about these points ? Is the initial goal of libvirt to mask Xen evolutions will be always possible ? The most problematic problem would be the configurations files in XML format. Libvirt already supports its own XML format of configuration files. It seems to me that it would be interesting to use the same XML format (or a compatible format) in libvirt and in Xen. Is there a plan in this direction ? Thanks.

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[Libvir] Patch to correct spelling
by Daniel P. Berrange 20 Jul '06

20 Jul '06

The attached patch changes 'informations' to 'information' throughout the codebase to fix up the English grammer. I assume its ok to commit ? Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|

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[Libvir] possible bug in virDomainLookupByID
by Bryan D. Payne 19 Jul '06

19 Jul '06

I'm experiencing an odd problem in virDomainLookupByID when using 0.1.3 that does not exist when using 0.1.1. Perhaps this is a side effect of switching the backend connection? I'm curious is anyone else has seen this and/or if you have any suggestions for fixing it. The attached code generates the problem that I'm seeing. Specifically, after upgrading to 0.1.3, calling virDomainLookupByID twice results in a failure on the second call. This behavior was not seen in 0.1.1. Any thoughts? Thanks, bryan PS... This problem is seen in XenAccess. Thanks to Daniele Sgandurra for bringing it to my attention. #include <stdio.h> #include <string.h> #include <libvirt/libvirt.h> #include <libvirt/virterror.h> #include <libxml/parser.h> #include <libxml/tree.h> char *get_xml_info (int id) { virConnectPtr conn = NULL; virDomainPtr dom = NULL; char *xml_data = NULL; /* NULL means connect to local Xen hypervisor */ conn = virConnectOpenReadOnly(NULL); if (NULL == conn) { printf("ERROR: Failed to connect to hypervisor\n"); goto error_exit; } /* Find the domain of the given id */ dom = virDomainLookupByID(conn, id); if (NULL == dom) { virErrorPtr error = virConnGetLastError(conn); printf("(%d) %s\n", error->code, error->message); printf("ERROR: Failed to find Domain %d\n", id); goto error_exit; } xml_data = virDomainGetXMLDesc(dom, 0); error_exit: if (NULL!= dom) virDomainFree(dom); if (NULL!= conn) virConnectClose(conn); return xml_data; } int main () { char *xml = NULL; xml = get_xml_info(1); if (!xml){ printf("Failed on first try\n"); return 0; } free(xml); xml = get_xml_info(1); if (!xml){ printf("Failed on second try\n"); return 0; } free(xml); return 1; }

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[Libvir] virDomainLookupByID problem when Root
by Daniele Sgandurra 17 Jul '06

17 Jul '06

Hi all! I've tried to compile and execute info1.c both as user and as root. As user I have no problem, but as root I get: Failed to find Domain 0 I've traced back the problem to the function: virDomainLookupByID(virConnectPtr conn, int id) at the line: path = xs_get_domain_path(conn->xshandle, (unsigned int) id); When root I get path != NULL, otherwise path==NULL; if path==NULL then the block after it is executed and everything is ok, otherwise at the end of the function name=null. (I manually changed path to NULL so that I can run it when root and it works even if info.maxMem it's different from when the program is run as a normal user: it shows -4 instead of 464896). It could be a configuration problem of mine (of Xen Store for example)? Thanks! Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com

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[Libvir] announce: gnome-applet-vm-0.1.0rc1
by Karel Zak 14 Jul '06

14 Jul '06

I have just pushed out a new version of the VM Applet. The changes/features are: - D-BUS support and integration with virt-manager - console helper support for privileged operations - fixed a lot of bugs - new icons - better GUI - the applet internally supports multiple libvirt connection (in future it will be useful for monitoring remote virtual machines) Web page (with screenshot of course:-): http://people.redhat.com/kzak/gnome-applet-vm/ Please, help me found bugs and improve this application. Karel -- Karel Zak <kzak(a)redhat.com>

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[Libvir] Patch: Fix for UUIDs in XML parser
by Peter Vetere 13 Jul '06

13 Jul '06

Hi all. Here's a pretty straightforward patch that fixes a bug I found where, if <uuid>...</uuid> is specified in the XML on the call createLinux, it is not propagated down to Xend. The result is an instance with a different UUID than the one requested. Pete

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[Libvir] Re: Proposal : add 3 functions to Libvirt API, for virtual CPUs
by michel.ponceau＠bull.net 13 Jul '06

13 Jul '06

I imagined that each Libvirt user could choose its own MAX number of CPU. If it is not possible, at least can we reserve the extended cpumap for future development (TODO, same as NULL domain pointer) ? Veuillez répondre à veillard(a)redhat.com Pour : michel.ponceau(a)bull.net cc : libvir-list(a)redhat.com Objet : Re: Proposal : add 3 functions to Libvirt API, for virtual CPUs On Thu, Jul 13, 2006 at 01:12:47PM +0200, michel.ponceau(a)bull.net wrote: > I don't understand. Libvirt users must of course compile API and > application with the same libvirt.h, after updating the value of > VIR_MAX_CPUS when necessary. And go from first info element to next one by > (info+1), which adds sizeof(virVcpuInfo) to address, including correct > length of cpumap according to: > unsigned char cpumap[(VIR_MAX_CPUS + 7) / 8]; /* Bit map of usable > real CPUs. > For alignment constraints, compiler rounds up the sizeof(virVcpuInfo)when > needed. Well if you need to recompile the library to use a larger set of CPU you don't garantee API and ABI, by definition. And you will need to recompile the library because the structures passed between the app and the library change size, this will also likely affect the proxy since I expect vCPU informations to be provided (so communication between the library and proxy must change). There is certainly solutions to the scalability problem, but suggesting a change of header and recompilation of the whole software stack is really not one I would like to propose, it breaks basically all expectations an enterprise customer would have w.r.t. using the library. Unless I really misunderstood what you were suggesting, which is possible in that case reformulating it might be a good idea, because I really understood you want to make the MAX number of CPU a compile time setting. Daniel -- Daniel Veillard | Red Hat http://redhat.com/ veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/

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[Libvir] Re: Proposal : add 3 functions to Libvirt API, for virtual CPUs
by michel.ponceau＠bull.net 13 Jul '06

13 Jul '06

I don't understand. Libvirt users must of course compile API and application with the same libvirt.h, after updating the value of VIR_MAX_CPUS when necessary. And go from first info element to next one by (info+1), which adds sizeof(virVcpuInfo) to address, including correct length of cpumap according to: unsigned char cpumap[(VIR_MAX_CPUS + 7) / 8]; /* Bit map of usable real CPUs. For alignment constraints, compiler rounds up the sizeof(virVcpuInfo)when needed. Veuillez répondre à veillard(a)redhat.com Pour : michel.ponceau(a)bull.net cc : libvir-list(a)redhat.com Objet : Re: Proposal : add 3 functions to Libvirt API, for virtual CPUs On Tue, Jul 11, 2006 at 05:29:52PM +0200, michel.ponceau(a)bull.net wrote: > 2) CPU map cut into standard + extension : It would be more simple to let > each Libvirt user modify the value of VIR_MAX_CPUS in private libvirt.h. > It could be similar to the version number update, from libvirt.h.in to > libvirt.h : > #define LIBVIR_VERSION_NUMBER @LIBVIRT_VERSION_NUMBER@ No, I do think it is instead very hard. You start to get into very annoying problems from an API point of view. How do you go from the first element in the info array to the next one ? in the client it's already not nice, you must do pointer arithmetic (and I really don't want to push an API which forces that to most users), it expose potential serious problem like alignment and packing, problems between versions of compilers and tools. In a nutshell I don't want an API where one need to access an array of structure where the size of the structure is not defined by the API itself. What I suggested did that in both case, either low number of CPUs and fixed size records like you initial solutions, or high number of CPUs and you work on a two dimentional array of bytes. Daniel -- Daniel Veillard | Red Hat http://redhat.com/ veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/

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[Libvir] Connecting to remote hypervisors?
by Nick Devito 13 Jul '06

13 Jul '06

I might be overlooking something, but, I don't see anything on the libvirt site about it. Does libvirt support connecting to a remote hypervisor, if so, how? Thanks, Nick Devito

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