<sys/syslimits.h> is not standardized, so portable programs should
not need to rely on it. If there really is something that we need
where <sys/syslimits.h> provided the limit but <limits.h> did not,
then that would be a candidate for fixing in gnulib. But this patch
did not turn up any compilation failures on Linux.
* src/internal.h (includes): Drop unused header.
* daemon/libvirtd.h (includes): Likewise.
* configure.ac (AC_CHECK_HEADERS): Likewise.
Based on a report by Matthias Bolte.
POSIX allows sysconf(_SC_GETPW_R_SIZE_MAX) to return -1 if there
is no fixed limit, and requires ERANGE errors to track real size.
Model our behavior after the example in POSIX itself:
http://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid_r.html
Also, on error for get*_r functions, errno is undefined, and the
real error was the return value.
* src/util/util.c (virGetUserEnt, virGetUserID, virGetGroupID)
(virSetUIDGID): Cope with sysconf failure or too small buffer.
Reported by Matthias Bolte.
virRunWithHook is now unused, so we can drop it. Tested w/ raw + qcow2
volume creation and copying.
v2:
Use opaque data to skip hook second time around
Simply command building
v3:
Drop explicit FindFileInPath
virStreamNew needs to dispatch the error that virGetStream reports
on failure.
remoteCreateClientStream can fail due to virStreamNew or due to
VIR_ALLOC. Report OOM error for VIR_ALLOC failure to report errors
in all error cases.
Remove OOM error reporting from remoteCreateClientStream callers.
When the session has expired then multiple threads can race while
reestablishing it.
This race condition is not that critical as it requires a special usage
pattern to be triggered. It can only happen when an application doesn't
do API calls for quite some time (the session expires after 30 min
inactivity) and then multiple threads doing simultaneous API calls and
end up doing simultaneous calls to esxVI_EnsureSession.
virsh didn't call virInitialize(), which (among other things)
initializes virLastErr thread local variable. As a result of that, virsh
could just segfault in virEventRegisterDefaultImpl() since that is the
first call that touches (resets) virLastErr.
I have no idea what lucky coincidence made this bug visible but I was
able to reproduce it in 100% cases but only in one specific environment
which included building in sandbox.
Mingw execve() has a broken signature. Disable this
function until gnulib fixes the signature, since we
don't really need this on Win32 anyway.
* src/util/command.c: Disable virCommandExec on Win32
When failing to marshall an XDR message, include the
full program/version/status/proc/type info, to allow
easier debugging & diagnosis of the problem.
* src/remote/remote_driver.c: Improve error when marshalling
fails
By running the doTunnelSendAll code in a separate thread, the
main thread can do qemuMigrationWaitForCompletion as with
normal migration. This in turn ensures that job signals work
correctly and that progress monitoring can be done
* src/qemu/qemu_migration.c: Run tunnelled migration in
separate thread
Cancelling the QEMU migration may cause QEMU to flush pending
data on the migration socket. This may in turn block QEMU if
nothing reads from the other end of the socket. Closing the
socket before cancelling QEMU migration avoids this possible
deadlock.
* src/qemu/qemu_migration.c: Close sockets before cancelling
migration on failure
The 'nbytes' variable was not re-initialized to the
buffer size on each iteration of the tunnelled migration
loop. While saferead() will ensure a full read, except
on EOF, it is clearer to use the real buffer size
* src/qemu/qemu_migration.c: Always read full buffer of data
The qemuMigrationWaitForCompletion method contains a loop which
repeatedly queries QEMU to check migration progress, and also
processes job signals (pause, setspeed, setbandwidth, cancel).
The tunnelled migration loop does not currently support this
functionality, but should. Refactor the code to allow it to
be used with tunnelled migration.
Implement the v3 migration protocol, which has two extra
steps, 'begin' on the source host and 'confirm' on the
source host. All other methods also gain both input and
output cookies to allow bi-directional data passing at
all stages.
The QEMU peer2peer migration method gains another impl
to provide the v3 migration. This finally allows migration
cookies to work with tunnelled migration, which is required
for Spice seamless migration & the lock manager transfer
* src/qemu/qemu_driver.c: Wire up migrate v3 APIs
* src/qemu/qemu_migration.c, src/qemu/qemu_migration.h: Add
begin & confirm methods, and peer2peer impl of v3
Merge the doNonTunnelMigrate2 and doTunnelMigrate2 methods
into one doPeer2PeerMigrate2 method, since they are substantially
the same. With the introduction of v3 migration, this will be
even more important, to avoid massive code duplication.
* src/qemu/qemu_migration.c: Merge tunnel & non-tunnel migration
The v2 migration protocol was accidentally missing out the
finish step, when prepare succeeded, but returned an invalid
URI
* src/libvirt.c: Teardown VM if prepare returns invalid URI
To facilitate the introduction of the v3 migration protocol,
the doTunnelMigrate method is refactored into two pieces. One
piece is intended to mirror the flow of virDomainMigrateVersion2,
while the other is the helper for setting up sockets and processing
the data.
Previously socket setup would be done before the 'prepare' step,
so errors could be dealt with immediately, avoiding need to shut
off the destination QEMU. In the new split, socket setup is done
after the 'prepare' step. This is not a serious problem, since
the control flow already requires calling 'finish' to tear down
the destination QEMU upon several errors.
* src/qemu/qemu_migration.c:
Use the graphics information from the QEMU migration cookie to
issue a 'client_migrate_info' monitor command to QEMU. This causes
the SPICE client to automatically reconnect to the target host
when migration completes
* src/qemu/qemu_migration.c: Set data for SPICE client relocation
before starting migration on src
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
new qemuMonitorGraphicsRelocate() command
Extend the QEMU migration cookie structure to allow information
about the destination host graphics setup to be passed by to
the source host. This will enable seamless migration of any
connected graphics clients
* src/qemu/qemu_migration.c: Add graphics info to migration
cookies
* daemon/libvirtd.c: Always initialize gnutls to enable
x509 cert parsing in QEMU
The migration protocol has support for a 'cookie' parameter which
is an opaque array of bytes as far as libvirt is concerned. Drivers
may use this for passing around arbitrary extra data they might
need during migration. The QEMU driver needs to do a few things:
- Pass hostname/uuid to allow strict protection against localhost
migration attempts
- Pass SPICE/VNC server port from the target back to the source to
allow seamless relocation of client sessions
- Pass lock driver state from source to destination
This patch introduces the basic glue for handling cookies
but only includes the host/guest UUID & name.
* src/libvirt_private.syms: Export virXMLParseStrHelper
* src/qemu/qemu_migration.c, src/qemu/qemu_migration.h: Parsing
and formatting of migration cookies
* src/qemu/qemu_driver.c: Pass in cookie parameters where possible
* src/remote/remote_protocol.h, src/remote/remote_protocol.x: Change
cookie max length to 16384 bytes
The qemuMigrationPrepareTunnel method should not unlock the
qemu driver, since that is the caller's job.
* src/qemu/qemu_migration.c: Fix qemuMigrationPrepareTunnel
unlocking of QEMU driver
Migration just seems to go from bad to worse. We already had to
introduce a second migration protocol when adding the QEMU driver,
since the one from Xen was insufficiently flexible to cope with
passing the data the QEMU driver required.
It turns out that this protocol still has some flaws that we
need to address. The current sequence is
* Src: DumpXML
- Generate XML to pass to dst
* Dst: Prepare
- Get ready to accept incoming VM
- Generate optional cookie to pass to src
* Src: Perform
- Start migration and wait for send completion
- Kill off VM if successful, resume if failed
* Dst: Finish
- Wait for recv completion and check status
- Kill off VM if unsuccessful
The problems with this are:
- Since the first step is a generic 'DumpXML' call, we can't
add in other migration specific data. eg, we can't include
any VM lease data from lock manager plugins
- Since the first step is a generic 'DumpXML' call, we can't
emit any 'migration begin' event on the source, or have
any hook that runs right at the start of the process
- Since there is no final step on the source, if the Finish
method fails to receive all migration data & has to kill
the VM, then there's no way to resume the original VM
on the source
This patch attempts to introduce a version 3 that uses the
improved 5 step sequence
* Src: Begin
- Generate XML to pass to dst
- Generate optional cookie to pass to dst
* Dst: Prepare
- Get ready to accept incoming VM
- Generate optional cookie to pass to src
* Src: Perform
- Start migration and wait for send completion
- Generate optional cookie to pass to dst
* Dst: Finish
- Wait for recv completion and check status
- Kill off VM if failed, resume if success
- Generate optional cookie to pass to src
* Src: Confirm
- Kill off VM if success, resume if failed
The API is designed to allow both input and output cookies
in all methods where applicable. This lets us pass around
arbitrary extra driver specific data between src & dst during
migration. Combined with the extra 'Begin' method this lets
us pass lease information from source to dst at the start of
migration
Moving the killing of the source VM out of Perform and
into Confirm, means we can now recover if the dst host
can't successfully Finish receiving migration data.
