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[Libvir] Remote patch 20070514
by Richard W.M. Jones 15 May '07

15 May '07

This is the current remote patch, against current CVS: http://annexia.org/tmp/libvirt-remote-20070514.patch and a patch against the previous patch so you can see what changed (not very much): http://annexia.org/tmp/libvirt-remote-20070505-to-20070514.patch My To-Do list at the moment: (a) Disable Nagle (https://www.redhat.com/archives/libvir-list/2007-May/msg00142.html) (b) Implement Mark's sensible client certificate checks (https://www.redhat.com/archives/libvir-list/2007-May/msg00152.html) (c) Update TLS certificate documentation to reflect (b). And I'm hoping with those done we may be able to apply this one? It would be great if others could test this. Rich. -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903

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[Libvir] How libvirt handles QEMU?
by Jun Koi 14 May '07

14 May '07

Hello, I am new to libvirt, so have a question. My concern is: libvirt can manage QEMU VMs. The point is thatI QEMU doesnt not export monitor interface to outside (at least that is what I know about older version of QEMU, not sure if anything changed recently). So how can libvirt does something like: pause, resume or extract internal information about a QEMU VM? Thank you, Jun

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[Libvir] [PATCH] Remote 0/8: Plan
by Richard W.M. Jones 14 May '07

14 May '07

Below is the plan for delivering the remote patch for review in stages. More details about in each email. I only expect to get through the first two emails today. Rich. 1 Additional error handling --------------------------- M include/libvirt/virterror.h M src/virterror.c 2 Client-server protocol ------------------------ A qemud/remote_protocol.x A qemud/rpcgen_fix.pl A qemud/remote_protocol.c A qemud/remote_protocol.h 3 Client-side ------------- A src/remote_internal.c A src/remote_internal.h M src/driver.h M src/libvirt.c 4 Server-side call dispatch --------------------------- A qemud/remote.c A qemud/remote_generate_stubs.pl A qemud/remote_dispatch_localvars.h A qemud/remote_dispatch_proc_switch.h A qemud/remote_dispatch_prototypes.h 5 Client-side QEMUD modifications --------------------------------- M src/qemu_internal.c 6 Server-side QEMUD modifications --------------------------------- A qemud/protocol.x A qemud/protocol.c M qemud/protocol.h M qemud/Makefile.am M qemud/conf.c M qemud/dispatch.c M qemud/dispatch.h M qemud/internal.h M qemud/qemud.c M qemud/uuid.c 7 Documentation updates ----------------------- M docs/libvir.html M docs/remote.html 8 Build system -------------- M .cvsignore M configure.in A libvirtd.conf M src/Makefile.am A RENAMES -- Emerging Technologies, Red Hat http://et.redhat.com/~rjones/ 64 Baker Street, London, W1U 7DF Mobile: +44 7866 314 421 Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Directors: Michael Cunningham (USA), Charlie Peters (USA) and David Owens (Ireland)

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[Libvir] gl_COMPILER_FLAGS gives an error
by Richard W.M. Jones 14 May '07

14 May '07

./configure: line 21215: syntax error near unexpected token `-fprofile-arcs' ./configure: line 21215: ` gl_COMPILER_FLAGS(-fprofile-arcs)' The only solution I can seem to find is to comment out the calls to gl_COMPILER_FLAGS in configure.in. Can't very much on Google about what gl_COMPILER_FLAGS is supposed to do. Rich. -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903

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[Libvir] PATCH: Fix uninitialized variable & bridge setup
by Daniel P. Berrange 11 May '07

11 May '07

Two crazy bugs - I forgot an =0 initialization in a recent patch to deal with qemu startup - If you don't have any virtual networks defined, then libvirt_qemud will never called brctlInit() so trying to start a guest using bridged network will get EINVAL. 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] [PATCH] Three cleanup patches
by Richard W.M. Jones 11 May '07

11 May '07

* Add some extra generated files to .cvsignore * Remove an unused header in qemud/uuid.c * Log an error if xenHypervisorOpen fails because xenHypervisorInit has failed. Rich. -- Emerging Technologies, Red Hat http://et.redhat.com/~rjones/ 64 Baker Street, London, W1U 7DF Mobile: +44 7866 314 421 Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Directors: Michael Cunningham (USA), Charlie Peters (USA) and David Owens (Ireland)

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[Libvir] Making QEMU use the real internal driver API
by Daniel P. Berrange 09 May '07

09 May '07

So currently, as we all know, the QEMU driver is just a shim through to the QEMU daemon. Looking at the code for Rich's remote driver I quite like the way the remote driver / server works like, and don't like the ugliness of having the special case QEMU code in there. We always had a long term plan to try & make the QEMU driver fit into the regular driver API more cleanly but not really tackled it yet. Similarly we've periodically brought up the idea of having asynchronous notifications of 'interesting' state changes in the drivers, to eliminate the need for polling. After a little thinking I have an idea that may let us address both issues in one go. Or to be more precise, put infrastructure in place to let us move closer to allowing async notiifcations. First let me consider the files under qemud/ .... Self-contained helper routines, ignore for rest of discussion bridge.c bridge.h iptables.c iptables.h uuid.c uuid.h buf.c buf.h The on the wire protcol definition, this is the bit we want to kill in favour of the generic remote wire protocol: protocol.h The code to convert from wire -> function calls. Again this ought to die in favour of the generic remote dispatcher. dispatch.c dispatch.h The QEMU config handling routines. conf.c conf.h The impl of core APIs: driver.c driver.h Finally the 'server': internal.h qemud.c The end-goal is that 'qemud/driver.c' would become 'src/qemu_internal.c' implementing the official internal driver API. The 'qemud/conf.c' would likely become 'src/qemu_config.c'. The key difference between the internal driver API, and the QEMU specific driver 'API' inside the daemon is the prescense of some global state via the 'qemud_server' struct. If we can figure out a way to store this state inside the regular driver API we can refactor that without much problem. Then there is the need for an event loop for monitoring the file handles of the QEMU processes, which at the moment is fairly tied into the event loop used to monitor the client/server socket handles. This existing code is rather ugly & has bad structure IMHO. The result is that code which ought to be isolated in driver.c, is instead part of qemud.c because of event loop integration. Finally, there is some code which runs on startup, and shutdown of the daemon, to do stuff like auto-start of VMs / networks, and clean shutdown of the same. Oh, and we need to make sure the QEMU driver is never activated locally, only when libvirt.so is being used as part of 'libvirtd'. So at a high level what I think we'd need to add to the internal driver API to make this possible is In driver.h: typedef int (*virDrvStartup)(void); typedef int (*virDrvShutdown)(void); Adding these to the 'virDriver' struct. Regular apps using libvirt.so would never trigger these APIs - they're only intended for the daemon, so I figure we'd have to private APIs in the libivrt.so (but not in the libvirt.h) __virStartup(void); __virShutdown(void); Since these are only called by the daemon, we now conveniently also have a way to stop the QEMU driver being locally activated. Next up, event loops. First, we don't want to mandate a particular impl of an event loop. If you get into the argument about QT vs GLib vs libevent and libvirt picks one, then you make it hard for libvirt to integrate with apps using the other. Second, we don't want to assume that 1 connection == 1 file handle. We also don't want to assume that the number of file handles used by a driver stays the same over time. Basically we need to expect that any single driver connection will have zero or more file handles that it is interested in. The DBus library deals with this exact same issue & the solution is very simple. The app using the libvirt registers a callback which the internal driver than then use to (un)register file handles. So in src/internal.h we'd add methods for internal drivers to call to add / remove file handles to/from the event loop: /* * @fd: the file handle on which the event occurred * @event: bitset of one or more of POLLxxx constants from poll.h * @opaque: data associated with 'fd' * * Return 0 to continue monitoring, -1 if an error occurred * and the handle should no longer be monitored */ typedef int (*virEventCallback)(int fd, int events, void *opaque); /* * @fd: the file handle to start monitoring * @events: bitset of POLLxxx contants to monitor * @cb: callback to invoke when an event ocurrs * @opaque: data to pass into callback's opaque parameter */ int virEventAddHandle(int fd, int events, virEventCallback cb, void *opaque); /* * @fd: the file handle to stop monitoring */ int virEventRemoveHandle(int fd); And we'd also add methods for a user of libvirt to register an event loop implementation: typedef int (*virEventAddHandleImpl)(int fd, int events, opaque); typedef int (*virEventRemoveHandleImpl)(int fd); void virEventInitialize(virEventAddHandleImpl add, virEventRemoveHandleImpl remove); If we want to add support for async events into the public API, then the virEventInitialize method could instead be in libvirt.h, and exported in the libvirt.so. Otherwise we could mark it private __virEventInitialize in libvirt.so. That I think should be enough to let us move QEMU into a regular style libvirt driver. NB, what follows now is a quick brain-dump - I'm not suggesting implementing this yet - its really a rough idea of general architecture. We'd definitely want to prototype it in a test app before committing to something like this. There's also many many scenarios to be thought about beyond just watching create/destroy events Thinking about a public API we could have: enum { VIR_CONN_DOMAIN_CREATED, VIR_CONN_DOMAIN_DESTROYED; } virConnectEvent; typedef int (*virConnectNotifyCallback)(virConnectPtr dom, unsigned char uuid[16], int event); virConnectNotify(virConnectPtr conn, virConnectNofifyCallback cb); An application using this would thus be able to do something like /* Assume there's a convenient libvirtglib.so addon providing these for apps */ extern virEventAddHandleImpl virGLibEventAddHandle; extern virEventRemoveHandleImpl virGLibEventRemoveHandle; int domainWatcher(virConnectPtr dom, unsigned char uuid[16], int event) { ... do something ... } int main () { virConnectPtr con; con = virConnectOpen(NULL); /* Setup an event loop via glib */ virEventInitilize(virGLibEventAddHandle, virGLibEventRemoveHandle); virConnectNotify(conn, domainWatcher); 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] [PATCH] Fields in virDomainPtr which appear to be never used
by Richard W.M. Jones 08 May '07

08 May '07

Below is the definition of struct _virDomain from internal.h. I may be missing something big (well, it wouldn't be the first time), but as far as I can see some of these fields are never used, and some are set but can never be read. struct _virDomain { unsigned int magic; /* specific value to check */ OK int uses; /* reference count */ OK virConnectPtr conn; /* pointer back to the connection */ OK char *name; /* the domain external name */ OK char *path; /* the domain internal path */ This field is set in src/xs_internal.c, but nowhere in libvirt does it appear to be read. The only other time it is reference is in hash.c where it is freed if non-NULL. int id; /* the domain ID */ OK int flags; /* extra flags */ Apparently this field could be set to DOMAIN_IS_SHUTDOWN or DOMAIN_IS_DEFINED. However neither of these symbols are used, and moreover this structure field looks like it is never written or read. unsigned char uuid[VIR_UUID_BUFLEN]; /* the domain unique identifier */ OK char *xml; /* the XML description for defined domains */ This field is, as far as I can tell, never set anywhere. However the code in hash.c does check whether it is set and will free it upon destruction of the _virDomain object. }; With this analysis in mind, attached is a patch which removes these three fields (path, flags, xml) and the unused virDomainFlags, with no apparent ill-effects. Rich. -- Emerging Technologies, Red Hat http://et.redhat.com/~rjones/ 64 Baker Street, London, W1U 7DF Mobile: +44 7866 314 421 Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Directors: Michael Cunningham (USA), Charlie Peters (USA) and David Owens (Ireland)

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[Libvir] [PATCH] Fix the value of XEN_V2_OP_GETDOMAININFOLIST
by Saori Fukuta 08 May '07

08 May '07

Hi, The value of "Max memory" shown by using "virsh dominfo" is different from xm command. # virsh dominfo HVM_RH5_sda6 | grep mem Max memory: 300000 kB Used memory: 264064 kB # xm li -l HVM_RH5_sda6 | grep mem (maxmem 450) (memory 292) (shadow_memory 5) So, I changed the definition as follows, (before) #define XEN_V2_OP_GETDOMAININFOLIST 6 (changed) #define XEN_V2_OP_GETDOMAININFOLIST 5 and I could get the value that I want. # ./virsh dominfo HVM_RH5_sda6 | grep mem Max memory: 460800 kB Used memory: 299008 kB # xm li -l HVM_RH5_sda6 | grep mem (maxmem 450) (memory 292) (shadow_memory 5) I think that is not mistake because the XEN_V2_OP_GETDOMAININFOLIST is a system operation, so the definition is not exactly wrong. /usr/include/xen/sysctl.h:#define XEN_SYSCTL_getdomaininfolist 6 Do you know any reason for this? Signed-off-by: Saori Fukuta <fukuta.saori(a)jp.fujitsu.com> Thanks, Saori Fukuta. Index: xen_internal.c =================================================================== RCS file: /data/cvs/libvirt/src/xen_internal.c,v retrieving revision 1.71 diff -u -p -r1.71 xen_internal.c --- xen_internal.c 13 Apr 2007 00:43:57 -0000 1.71 +++ xen_internal.c 26 Apr 2007 11:41:03 -0000 @@ -117,7 +117,7 @@ static regex_t xen_cap_rec; #define XEN_V0_OP_GETDOMAININFOLIST 38 #define XEN_V1_OP_GETDOMAININFOLIST 38 -#define XEN_V2_OP_GETDOMAININFOLIST 6 +#define XEN_V2_OP_GETDOMAININFOLIST 5 struct xen_v0_getdomaininfo { domid_t domain; /* the domain number */

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[Libvir] Request for minimum memory level of dom0 (xen)
by Jan Michael 07 May '07

07 May '07

Hi LibVirt-Mailreaders, Is it possible to provide information about the minimum memory level of domain 0 (xen)? The value is located in the xen deamon config file as "dom0-min-mem". I would like to calculate on the basis of this value if there is enough memory left to create additional domains. Thanks in advance, Jan Michael

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