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[Libvir] PATCH: Fix remote driver to handle network API for local non-QEMU
by Daniel P. Berrange 04 Jul '07

04 Jul '07

The remote_internal.c code is basically a no-op in its remoteNetworkOpen method. This means the remote driver will only handle the networking APIs, if it is also handling the main domain APIs. This works fine if connecting to a remote URI, or if using QEMU URIs, but it does not work if using the test or Xen drivers. To make this work the remoteNetworkOpen method needs to open a connection to the remote daemon IIF the remoteOpen method did not already open one. So the attached patch adds the neccessary logic in remoteNetworkOpen. It also adds code to remoteNetworkClose to make it shutdown& free the connection IIF it was opened by the remoteNetworkOpen method. This is what the extra 'networkOnly' field in the 'struct private_data' is used to check. Second, all of the implementations of virNetwork* APIs in the remote_internal.c driver must use the 'struct private_data *' from networkPrivateData field in virConnectPtr, not the 'privateData' field. This is because the 'privateData' field is probably storing data related to the Xen or Test drivers. Third, this also fixes the qemu_driver.c which incorrectly used the privateData field insteadof the networkPrivateData field for 2 of the networking APIs, and finally makes sure the qemu_driver.c also acccepts the use of qemu:///session APIs for root user. 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] Proposal: libvirt should remove or rename a save file after a successful restore
by Richard W.M. Jones 02 Jul '07

02 Jul '07

Chris Lalancette found this problem: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=246105 <quote> Once an "xm restore" has successfully completed, the -save file that it came from should really be deleted. Restoring a domain a second time from the same save file will result in disk corruption; the kernel VM state (in the saved file) will be in an inconsistent state with respect to what is actually on disk (in the domain disk file). The only valid use I can see for the -save file after a restore is possibly for some crash analysis, but even that could be worked around by renaming the save file after a success. In particular, I just ran into this situation (and I'm worried customers might do the same): [and then he goes on to describe a scenario in which you can commonly hit this situation] </quote> So the obvious and simple solution, it seems to me, is just to change libvirt.c:virDomainRestore so that if the driver underneath it returns from the restore without error, then we either remove or rename the restore file. It's a trivial patch -- what do people think? My thoughts: * Removing the file might seem quite abrupt/unexpected, and there is the possibility of data loss. * You have to rename the file as a hidden file (dotfile) in order for xendomains to ignore it. However these files are big and having large, hidden files which build up in number over time sounds like it could be a bad thing. * This might be considered a significant behaviour change. * It's easier to handle this for the remote case if we make the change inside libvirt, rather than in virsh etc. 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] Cleanup patch
by Daniel Veillard 29 Jun '07

29 Jun '07

Enclosed is a cleanup patch I applied, it corrects the XML api generation, fixes warning in the XSLT stylesheet, add comments to a number of internal functions, makes most function of the QEmu back-end static, fixes a few bugs found in the way. Daniel -- Red Hat Virtualization group http://redhat.com/virtualization/ Daniel Veillard | virtualization library http://libvirt.org/ 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: hvsupport html page
by Philippe Berthault 29 Jun '07

29 Jun '07

A great work ! This new help page will be very useful for all developers :-) Thanks a lot. P.Berthault.

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[Libvir] [PATCH] Do check the UUID in __virGetDomain()
by Masayuki Sunou 29 Jun '07

29 Jun '07

Hi This patch adds checking the UUID in __virGetDomain(). Now, the UUID of domain is wrong in the following operations. 1. Start virsh in interactive mode. 2. Execute domuuid to the domain 3. Execute undefine to the domain which executed domuuid in 2. 4. Create the domain whose name is same as the domain that executed undefine. 5. Execute domuuid for the new domain This patch can fix it. Signed-off-by: Masayuki Sunou <fj1826dm(a)aa.jp.fujitsu.com> Thanks, Masayuki Sunou. -------------------------------------------------------------------------------- Index: src/hash.c =================================================================== RCS file: /data/cvs/libvirt/src/hash.c,v retrieving revision 1.22 diff -u -p -r1.22 hash.c --- src/hash.c 8 May 2007 10:53:27 -0000 1.22 +++ src/hash.c 7 Jun 2007 02:08:41 -0000 @@ -758,8 +758,14 @@ __virGetDomain(virConnectPtr conn, const ret = (virDomainPtr) virHashLookup(conn->domains, name); if (ret != NULL) { - /* TODO check the UUID */ - goto done; + if (memcmp(ret->uuid, uuid, 16)) { + if (virFreeDomain(conn, ret, 0) < 0) { + xmlMutexUnlock(conn->hashes_mux); + return(NULL); + } + } else { + goto done; + } } /* @@ -813,7 +819,7 @@ error: * Returns the reference count or -1 in case of failure. */ int -virFreeDomain(virConnectPtr conn, virDomainPtr domain) { +virFreeDomain(virConnectPtr conn, virDomainPtr domain, int lock) { int ret = 0; if ((!VIR_IS_CONNECT(conn)) || (!VIR_IS_CONNECTED_DOMAIN(domain)) || @@ -821,7 +827,8 @@ virFreeDomain(virConnectPtr conn, virDom virHashError(conn, VIR_ERR_INVALID_ARG, __FUNCTION__); return(-1); } - xmlMutexLock(conn->hashes_mux); + if (lock) + xmlMutexLock(conn->hashes_mux); /* * decrement the count for the domain @@ -853,13 +860,14 @@ virFreeDomain(virConnectPtr conn, virDom if (conn->domains != NULL) virHashFree(conn->domains, (virHashDeallocator) virDomainFreeName); - if (conn->hashes_mux != NULL) + if (conn->hashes_mux != NULL && lock) xmlFreeMutex(conn->hashes_mux); free(conn); return(0); done: - xmlMutexUnlock(conn->hashes_mux); + if (lock) + xmlMutexUnlock(conn->hashes_mux); return(ret); } Index: src/internal.h =================================================================== RCS file: /data/cvs/libvirt/src/internal.h,v retrieving revision 1.41 diff -u -p -r1.41 internal.h --- src/internal.h 8 May 2007 10:53:27 -0000 1.41 +++ src/internal.h 7 Jun 2007 02:08:41 -0000 @@ -202,7 +202,7 @@ virDomainPtr __virGetDomain (virConnectP const char *name, const unsigned char *uuid); int virFreeDomain (virConnectPtr conn, - virDomainPtr domain); + virDomainPtr domain, int lock); virDomainPtr virGetDomainByID(virConnectPtr conn, int id); virNetworkPtr __virGetNetwork (virConnectPtr conn, Index: src/libvirt.c =================================================================== RCS file: /data/cvs/libvirt/src/libvirt.c,v retrieving revision 1.73 diff -u -p -r1.73 libvirt.c --- src/libvirt.c 5 Jun 2007 12:06:08 -0000 1.73 +++ src/libvirt.c 7 Jun 2007 02:08:41 -0000 @@ -730,7 +730,7 @@ virDomainFree(virDomainPtr domain) virLibDomainError(domain, VIR_ERR_INVALID_DOMAIN, __FUNCTION__); return (-1); } - if (virFreeDomain(domain->conn, domain) < 0) + if (virFreeDomain(domain->conn, domain, 1) < 0) return (-1); return(0); } Index: src/qemu_internal.c =================================================================== RCS file: /data/cvs/libvirt/src/qemu_internal.c,v retrieving revision 1.25 diff -u -p -r1.25 qemu_internal.c --- src/qemu_internal.c 5 Jun 2007 12:06:08 -0000 1.25 +++ src/qemu_internal.c 7 Jun 2007 02:08:42 -0000 @@ -906,7 +906,7 @@ static int qemuUndefine(virDomainPtr dom } cleanup: - if (virFreeDomain(dom->conn, dom) < 0) + if (virFreeDomain(dom->conn, dom, 1) < 0) ret = -1; return ret; Index: src/xend_internal.c =================================================================== RCS file: /data/cvs/libvirt/src/xend_internal.c,v retrieving revision 1.116 diff -u -p -r1.116 xend_internal.c --- src/xend_internal.c 5 Jun 2007 12:06:09 -0000 1.116 +++ src/xend_internal.c 7 Jun 2007 02:08:42 -0000 @@ -1900,7 +1900,7 @@ error: virXendError(conn, VIR_ERR_INTERNAL_ERROR, _("failed to parse Xend domain information")); if (ret != NULL) - virFreeDomain(conn, ret); + virFreeDomain(conn, ret, 1); return(NULL); } #endif /* !PROXY */ @@ -3055,7 +3055,7 @@ xenDaemonCreateLinux(virConnectPtr conn, /* Make sure we don't leave a still-born domain around */ if (dom != NULL) { xenDaemonDomainDestroy(dom); - virFreeDomain(dom->conn, dom); + virFreeDomain(dom->conn, dom, 1); } if (name != NULL) free(name);

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[Libvir] request for libvirt documentation improvement
by Philippe Berthault 29 Jun '07

29 Jun '07

The documentation of libvirt doesn't indicate which functions are for Xen or QEMU or both. The only way to know that, is by searching in libvirt sources. It would be interesting for libvirt users to add in the documentation, for each function, a mention such as "QEMU only", "Xen(TM) only", "QEMU and Xen(TM)", etc.. Regards. Libvirt 0.2.3 functions dedicated to QEMU only: virConnectListDefinedNetworks virConnectListNetworks virConnectNumOfDefinedNetworks virConnectNumOfNetworks virDomainGetAutostart virDomainSetAutostart virNetworkCreate virNetworkCreateXML virNetworkDefineXML virNetworkDestroy virNetworkFree virNetworkGetAutostart virNetworkGetBridgeName virNetworkGetName virNetworkGetUUID virNetworkGetUUIDString virNetworkGetXMLDesc virNetworkLookupByName virNetworkLookupByUUID virNetworkLookupByUUIDString virNetworkSetAutostart virNetworkUndefine Libvirt 0.2.3 functions dedicated to Xen(TM) only: virConnectGetMaxVcpus virConnectGetType virDomainAttachDevice virDomainCoreDump virDomainDetachDevice virDomainGetMaxMemory virDomainGetSchedulerParameters virDomainGetSchedulerType virDomainPinVcpu virDomainReboot virDomainSetMaxMemory virDomainSetMemory virDomainSetSchedulerParameters virDomainSetVcpus

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[Libvir] Proposal: New virDomainLookup function to indicate Not found vs Error
by Richard W.M. Jones 29 Jun '07

29 Jun '07

virt-install has some code which waits for a domain to appear just after it has been created. It looks like the loop attached to the end of this email, and is functional but has two problems. Problem (1) is that self.conn.lookupByName doesn't distinguish between a "Not found" domain and an actual error. For example there is no way to tell the difference between being unable to contact xend (an actual error), and being able to contact xend, but xend not being able to find the domain (not found). As shown here: >>> import libvirt >>> conn = libvirt.open ("xen+tls:///") >>> d = conn.lookupByName ("Domain-0") >>> d = conn.lookupByName ("doesnotexist") [...] libvirt.libvirtError: virDomainLookupByName() failed then I deliberately kill the remote daemon: >>> d = conn.lookupByName ("doesnotexist") libvir: Remote error : Error in the push function. [...] The first exception is a Not found condition (not an error) whereas the second is an error. Problem (2) is that virterror is over anxious to print error messages to stderr, even if the caller can handle them and even if (as in the Not found case) they don't indicate errors. In practical terms this means that the virt-install loop attached below may print out 1 or 2 error messages even when it is functioning normally. You'll see an error like this appearing [sic]: libvir: Xen Daemon error : GET operation failed: Since it's difficult to change the LookupBy* functions without changing the ABI, I suspect that the best thing to do is going to be to add a new call with better semantics. Therefore I suggest: virDomainPtr * virDomainLookup (virConnectPtr conn, int flags, int id, char *str, int *error); where flags is one of: VIR_LOOKUP_BY_ID, VIR_LOOKUP_BY_NAME, VIR_LOOKUP_BY_UUID or VIR_LOOKUP_BY_UUID_STRING The return values are: ret = domain, *error = 0 => found it ret = NULL, *error = 0 => not found ret = NULL, *error = 1 => error (check virterror) Addition 1: There would be a similar function virNetworkLookup, but without needing the 'id' parameter because networks don't have IDs. Addition 2: Change the driver internals so that they don't call virterror in the not found case. (This requires quite a bit of rejigging in xend_internal, but is not too hard). Addition 3: Language bindings could be modified to detect this function and if present change their existing LookupBy* functions to use the new interface. Thoughts? Rich. ---------------------------------------------------- This is the troublesome loop: logging.debug("Created guest, looking to see if it is running") # sleep in .25 second increments until either a) we find # our domain or b) it's been 5 seconds. this is so that # we can try to gracefully handle domain creation failures num = 0 d = None while num < (5 / .25): # 5 seconds, .25 second sleeps try: d = self.conn.lookupByName(self.name) break except libvirt.libvirtError, e: logging.debug("No guest running yet " + str(e)) pass num += 1 time.sleep(0.25) -- 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 0/20: Re-factor libvirtd / QEMU driver
by Daniel P. Berrange 28 Jun '07

28 Jun '07

The work to refactor the QEMU driver to use the regular libvirt driver API is now complete. The next 20 (!) patches provide fairly fine-grained steps refactoring the code. Aside from that which adds an event loop, and the very last one, they should all be pretty much straightforward refactoring with no functional change. With this patch series fully applied there is now only a single daemon which can serve both remote & QEMU drivers in one go, with no deadlock issues. 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] libvirt 0.1.8 Help
by Omer Khalid 27 Jun '07

27 Jun '07

Hi, I have the following code working on libvirt 0.1.9: ######################################## conn = libvirt.openReadOnly(None) if conn == None: print 'Failed to open connection to the hypervisor' #sys.exit(1) try: domains = conn.listDomainsID() num = conn.numOfDomains() except: print 'Failed to find the list of domains' for i in range(num): try: dom0 = conn.lookupByID(domains[i]) domInfo = dom0.info() except: print "Unexpected error:", sys.exc_info() ############################################## For legacy reason, I have to get it working on libvirt 0.1.8 but I am constantly getting the following error: Unexpected error: (<class libvirt.libvirtError at 0xb7f49f2c>, < libvirt.libvirtError instance at 0xb7f4f2cc>, <traceback object at 0xb7f44c5c>) Any help would be much appreciated! Cheers Omer -- ---------------------------------------------------------- CERN – European Organization for Nuclear Research, IT Department, CH-1211 Geneva 23, Switzerland Phone: +41 (0) 22 767 2224 Fax: +41 (0) 22 766 8683 E-mail : Omer.Khalid(a)cern.ch Homepage: http://cern.ch/Omer.Khalid

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[Libvir] [PATCH] Move common buffer code to lib/ directory
by Richard W.M. Jones 26 Jun '07

26 Jun '07

I haven't quite got to my goal of removing _GNU_SOURCE (yet), but this patch along the way creates a lib/ subdirectory and moves the common buffer code (from qemud/buf.[ch] and in src/xml.[ch]) there. There are many, many places which call the buffer functions without checking the return value. I have manually verified / fixed up the calls which do bother to check return values, but not added any more checks where they don't. 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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