When a client which started non-p2p migration dies in a bad time, the
source libvirtd never clears the migration job and almost nothing can be
done with the domain without restarting the daemon. This patch makes use
of connection close callbacks and ensures that migration job is properly
discarded when the client disconnects.
Destination daemon should not rely on the client or source daemon
(depending on the type of migration) to call Finish when migration
fails, because the client may crash before it can do so. The domain
prepared for incoming migration is set to be destroyed (and migration
job cleaned up) when connection with the client closes but this is not
enough. If the associated qemu process crashes after Prepare step and
the domain is cleaned up before the connection gets closed, autodestroy
is not called for the domain and migration jobs remains set. In case the
domain is defined on destination host (i.e., it is not completely
removed once destroyed) we keep the job set for ever. To fix this, we
register a cleanup callback which is responsible to clean migration-in
job when a domain dies anywhere between Prepare and Finish steps. Note
that we can't blindly clean any job when spotting EOF on monitor since
normally an API is running at that time.
This reverts commit 61f2b6ba5f and most of
commit d8916dc8e2, which effectively
brings back commit ef1065cf5a written by
Jim Fehlig:
The qemu migration speed default is 32MiB/s as defined in migration.c
/* Migration speed throttling */
static int64_t max_throttle = (32 << 20);
There's no need to throttle migration when targeting a file, so set
migration speed to unlimited prior to migration, and restore to libvirt
default value after migration.
Default units is MB for migrate_set_speed monitor command, so
(INT64_MAX / (1024 * 1024)) is used for unlimited migration speed.
This was reverted because migration to file could not be canceled and
even monitored since qemu was not processing any monitor commands until
the migration finished. This is now different as we make sure the
file descriptor we pass to qemu is able to properly report EAGAIN.
Recent qemu changes might have helped as well.
I tested managedsave with this patch in and indeed, it is 10x faster
while I can still monitor its progress.
When host-model and host-passthrouh CPU modes were introduced, qemu
driver was properly modify to update guest CPU definition during
migration so that we use the right CPU at the destination. However,
similar treatment is needed for (managed)save and snapshots since they
need to save the exact CPU so that a domain can be properly restored.
To avoid repetition of such situation, all places that need live XML
share the code which generates it.
As a side effect, this patch fixes error reporting from
qemuDomainSnapshotWriteMetadata().
Currently, startupPolicy='requisite' was determining cold boot
by migrateFrom != NULL. That means, if domain was started up
with migrateFrom set we didn't require disk source path and allowed
it to be dropped. However, on snapshot-revert domain wasn't migrated
but according to documentation, requisite should drop disk source
as well.
This patch includes the following changes to virnetdevmacvlan.c and
virnetdevvportprofile.c:
- removes some netlink functions which are now available in
virnetdev.c
- Adds a vf argument to all port profile functions.
For 802.1Qbh devices, the port profile calls can use a vf argument if
passed by the caller. If the vf argument is -1 it will try to derive the vf
if the device passed is a virtual function.
For 802.1Qbg devices, This patch introduces a null check for the device
argument because during port profile assignment on a hostdev, this argument
can be null.
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
No matter what cache mode is used, readonly disks are always safe wrt
migration. Shared disks are required to be readonly or to disable
host-side cache, which makes them safe as well.
Add de-association handling for 802.1qbg (vepa) via lldpad
netlink messages. Also adds the possibility to perform an
association request without waiting for a confirmation.
Signed-off-by: D. Herrendoerfer <d.herrendoerfer@herrendoerfer.name>
Function xmlParseURI does not remove square brackets around IPv6
address when parsing. One of the solutions is making wrappers around
functions working with xmlURI*. This assures that uri->server will be
always properly assigned and it doesn't have to be changed when used
on some new place in the code.
For this purpose, functions virParseURI and virSaveURI were
added. These function are wrappers around xmlParseURI and xmlSaveUri
respectively.
Also there is one new syntax check function to prohibit these functions
anywhere else.
File changes:
- src/util/viruri.h -- declaration
- src/util/viruri.c -- definition
- src/libvirt_private.syms -- symbol export
- src/Makefile.am -- added source and header files
- cfg.mk -- added sc_prohibit_xmlURI
- all others -- ID name and include fixes
Migrating domains with disks using cache != none is unsafe unless the
disk images are stored on coherent clustered filesystem. Thus we forbid
migrating such domains unless VIR_MIGRATE_UNSAFE flags is used.
When migrating a qemu domain, we enter the monitor, send some commands,
try to connect to destination qemu, send other commands, end exit the
monitor. However, if we couldn't connect to destination qemu we forgot
to exit the monitor.
Bug introduced by commit d9d518b1c8.
Calling qemuDomainMigrateGraphicsRelocate notifies spice clients to
connect to destination qemu so that they can seamlessly switch streams
once migration is done. Unfortunately, current qemu is not able to
accept any connections while incoming migration connection is open.
Thus, we need to delay opening the migration connection to the point
spice client is already connected to the destination qemu.
Commit 5d784bd6d7 was a nice attempt to
clarify the semantics by requiring domain name from dxml to either match
original name or dname. However, setting dxml domain name to dname
doesn't really work since destination host needs to know the original
domain name to be able to use it in migration cookies. This patch
requires domain name in dxml to match the original domain name. The
change should be safe and backward compatible since migration would fail
just a bit later in the process.
When sVirt is integrated with the LXC driver, it will be neccessary
to invoke the security driver APIs using only a virDomainDefPtr
since the lxc_container.c code has no virDomainObjPtr available.
Aside from two functions which want obj->pid, every bit of the
security driver code only touches obj->def. So we don't need to
pass a virDomainObjPtr into the security drivers, a virDomainDefPtr
is sufficient. Two functions also gain a 'pid_t pid' argument.
* src/qemu/qemu_driver.c, src/qemu/qemu_hotplug.c,
src/qemu/qemu_migration.c, src/qemu/qemu_process.c,
src/security/security_apparmor.c,
src/security/security_dac.c,
src/security/security_driver.h,
src/security/security_manager.c,
src/security/security_manager.h,
src/security/security_nop.c,
src/security/security_selinux.c,
src/security/security_stack.c: Change all security APIs to use a
virDomainDefPtr instead of virDomainObjPtr
A generic error code was returned, if the user aborted a migration job.
This made it hard to distinguish between a user requested abort and an
error that might have occured. This patch introduces a new error code,
which is returned in the specific case of a user abort, while leaving
all other failures with their existing code. This makes it easier to
distinguish between failure while mirgrating and an user requested
abort.
* include/libvirt/virterror.h: - add new error code
* src/util/virterror.c: - add message for the new error code
* src/qemu/qemu_migration.h: - Emit operation aborted error instead of
operation failed, on migration abort
The virTimestamp and virTimeMs functions in src/util/util.h
duplicate functionality from virtime.h, in a non-async signal
safe manner. Remove them, and convert all code over to the new
APIs.
* src/util/util.c, src/util/util.h: Delete virTimeMs and virTimestamp
* src/lxc/lxc_driver.c, src/qemu/qemu_domain.c,
src/qemu/qemu_driver.c, src/qemu/qemu_migration.c,
src/qemu/qemu_process.c, src/util/event_poll.c: Convert to use
virtime APIs
If a connection to destination host is lost during peer-to-peer
migration (because keepalive protocol timed out), we won't be able to
finish the migration and it doesn't make sense to wait for qemu to
transmit all data. This patch automatically cancels such migration
without waiting for virDomainAbortJob to be called.
Rename the macvtap.c file to virnetdevmacvlan.c to reflect its
functionality. Move the port profile association code out into
virnetdevvportprofile.c. Make the APIs available unconditionally
to callers
* src/util/macvtap.h: rename to src/util/virnetdevmacvlan.h,
* src/util/macvtap.c: rename to src/util/virnetdevmacvlan.c
* src/util/virnetdevvportprofile.c, src/util/virnetdevvportprofile.h:
Pull in vport association code
* src/Makefile.am, src/conf/domain_conf.h, src/qemu/qemu_conf.c,
src/qemu/qemu_conf.h, src/qemu/qemu_driver.c: Update include
paths & remove conditional compilation
In preparation for code re-organization, rename the Macvtap
management APIs to have the following patterns
virNetDevMacVLanXXXXX - macvlan/macvtap interface management
virNetDevVPortProfileXXXX - virtual port profile management
* src/util/macvtap.c, src/util/macvtap.h: Rename APIs
* src/conf/domain_conf.c, src/network/bridge_driver.c,
src/qemu/qemu_command.c, src/qemu/qemu_command.h,
src/qemu/qemu_driver.c, src/qemu/qemu_hotplug.c,
src/qemu/qemu_migration.c, src/qemu/qemu_process.c,
src/qemu/qemu_process.h: Update for renamed APIs
This reverts commit ef1065cf5ac; see also this bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=751900
In qemu 0.15.1 and earlier, during migration to file, the
qemu_savevm_state_begin and qemu_savevm_state_iterate methods
will both process as much migration data as possible until either
1. The file descriptor returns EAGAIN
2. The bandwidth rate limit is reached
If we set the rate limit to ULONG_MAX, test 2 never becomes true. We're
passing a plain file descriptor to QEMU and POSIX does not support EAGAIN on
regular files / block devices, so test 1 never becomes true either.
In the 'virsh save --bypass-cache' case, we pass a pipe instead of a
regular fd, but using a pipe adds I/O overhead, so always passing a
pipe just so qemu can see EAGAIN doesn't seem nice.
The ultimate fix needs to come from qemu - background migration must
respect asynchronous abort requests, or else periodically return
control to the main handling loop without an EAGAIN and without
waiting to hit an insanely large amount of data. But until a
version of qemu is fixed to support "unlimited" data rates while
still allowing cancellation, the best we can do is avoid the
automatic use of unlimited rates from within libvirt (users can
still explicitly change the migration rates, if they are aware that
they are giving up the ability to cancel a job).
Reverting the lone use of QEMU_DOMAIN_FILE_MIG_BANDWIDTH_MAX is
the simplest patch; this slows migration back down to a default
32M/sec cap, but also ensures that the main qemu processing loop
will still be responsive to cancellation requests. Hopefully
upstream qemu will provide us a means of safely using unlimited
speed, including a runtime probe of that capability.
* src/qemu/qemu_migration.c (qemuMigrationToFile): Revert attempt
to use unlimited migration bandwidth when migrating to file.
Signed-off-by: Daniel Veillard <veillard@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
- changed some return 1's to return -1
- changed if (rc) error checks to if (rc < 0)
- fixed some other minor convention violations
I might have missed some. Can fix in another patch or can respin
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Reported-by: Eric Blake <eblake@redhat.com>
Reported-by: Laine Stump <laine@laine.org>
Signed-off-by: Eric Blake <eblake@redhat.com>
<domainsnapshot> is the first public instance of <domain> being
used as a sub-element, although we have two other private uses
(runtime state, and migration cookie). Although indentation has
no effect on XML parsing, using it makes the output more consistent.
This uses virBuffer auto-indentation to obtain the effect, for all
but the portions of <domain> that are not generated a line at a
time into the same virBuffer. Further patches will clean up the
remaining problems.
* src/conf/domain_conf.h (virDomainDefFormatInternal): New prototype.
* src/conf/domain_conf.c (virDomainDefFormatInternal): Export.
(virDomainObjFormat, virDomainSnapshotDefFormat): Update callers.
* src/libvirt_private.syms (domain_conf.h): Add new export.
* src/qemu/qemu_migration.c (qemuMigrationCookieXMLFormat): Use
new function.
(qemuMigrationCookieXMLFormatStr): Update caller.
Destination libvirtd remembers the original name in the prepare phase
and clears it in the finish phase. The original name is used when
comparing domain name in migration cookie.
* src/qemu/qemu_migration.c: if 'vmdef' is NULL, the function
virDomainSaveConfig still dereferences it, it doesn't make
sense, so should add return value check to make sure 'vmdef'
is non-NULL before calling virDomainSaveConfig, in addition,
in order to debug later, also should record error information
into log.
Signed-off-by: Alex Jia <ajia@redhat.com>
If a domain has inactive XML we want to transfer it to destination
when migrating with VIR_MIGRATE_PERSIST_DEST. In order to harm
the migration protocol as least as possible, a optional cookie was
chosen.
Commit 282fe1f0 documented that transient domains will auto-delete
any snapshot metadata when the last reference to the domain is
removed, and that management apps are in charge of grabbing any
snapshot metadata prior to that point. However, this was not
actually implemented for qemu until now.
* src/qemu/qemu_driver.c (qemudDomainCreate)
(qemuDomainDestroyFlags, qemuDomainSaveInternal)
(qemudDomainCoreDump, qemuDomainRestoreFlags, qemudDomainDefine)
(qemuDomainUndefineFlags, qemuDomainMigrateConfirm3)
(qemuDomainRevertToSnapshot): Clean up snapshot metadata.
* src/qemu/qemu_migration.c (qemuMigrationPrepareAny)
(qemuMigrationPerformJob, qemuMigrationPerformPhase)
(qemuMigrationFinish): Likewise.
* src/qemu/qemu_process.c (qemuProcessHandleMonitorEOF)
(qemuProcessReconnect, qemuProcessReconnectHelper)
(qemuProcessAutoDestroyDom): Likewise.
Adjust qemuMigrationRun() to use migMaxBandwidth in qemuDomainObjPrivate
structure when setting qemu migration speed. Caller-specified 'resource'
parameter overrides migMaxBandwidth.
The qemu migration speed default is 32MiB/s as defined in migration.c
/* Migration speed throttling */
static int64_t max_throttle = (32 << 20);
There's no need to throttle migration when targeting a file, so set migration
speed to unlimited prior to migration, and restore to libvirt default value
after migration.
Default units is MB for migrate_set_speed monitor command, so
(INT64_MAX / (1024 * 1024)) is used for unlimited migration speed.
Tested with both json and text monitors.
Commit 498d783 cleans up some of virtual file names for parsing strings
in memory. This patch cleans up (hopefuly) the rest forgotten by the
first patch.
This patch also changes all of the previously modified "filenames" to
valid URI's replacing spaces for underscores.
Changes to v1:
- Replace all spaces for underscores, so that the strings form valid
URI's
- Replace spaces in places changed by commit 498d783
Migration is another case of stranding metadata. And since
snapshot metadata is arbitrarily large, there's no way to
shoehorn it into the migration cookie of migration v3.
This patch consolidates two existing locations for migration
validation into one helper function, then enhances that function
to also do the new checks. If we could always trust the source
to validate migration, then the destination would not have to
do anything; but since older servers that did not do checking
can migrate to newer destinations, we have to repeat some of
the same checks on the destination; meanwhile, we want to
detect failures as soon as possible. With migration v2, this
means that validation will reject things at Prepare on the
destination if the XML exposes the problem, otherwise at Perform
on the source; with migration v3, this means that validation
will reject things at Begin on the source, or if the source
is old and the XML exposes the problem, then at Prepare on the
destination.
This patch is necessarily over-strict. Once a later patch
properly handles auto-cleanup of snapshot metadata on the
death of a transient domain, then the only time we actually
need snapshots to prevent migration is when using the
--undefinesource flag on a persistent source domain.
It is possible to recreate snapshot metadata on the destination
with VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE and
VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT. But for now, that is limited,
since if we delete the snapshot metadata prior to migration,
then we won't know the name of the current snapshot to pass
along; and if we delete the snapshot metadata after migration
and use the v3 migration cookie to pass along the name of the
current snapshot, then we need a way to bypass the fact that
this patch refuses migration with snapshot metadata present.
So eventually, we may have to introduce migration protocol v4
that allows feature negotiation and an arbitrary number of
handshake exchanges, so as to pass as many rpc calls as needed
to transfer all the snapshot xml hierarchy.
But all of that is thoughts for the future; for now, the best
course of action is to quit early, rather than get into a
funky state of stale metadata; then relax restrictions later.
* src/qemu/qemu_migration.h (qemuMigrationIsAllowed): Make static.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Alter
signature, and allow checks for both outgoing and incoming.
(qemuMigrationBegin, qemuMigrationPrepareAny)
(qemuMigrationPerformJob): Update callers.
In a SELinux or root-squashing NFS environment, libvirt has to go
through some hoops to create a new file that qemu can then open()
by name. Snapshots are a case where we want to guarantee an empty
file that qemu can open; also, reopening a save file to convert it
from being marked partial to complete requires a reopen to avoid
O_DIRECT headaches. Refactor some existing code to make it easier
to reuse in later patches.
* src/qemu/qemu_migration.h (qemuMigrationToFile): Drop parameter.
* src/qemu/qemu_migration.c (qemuMigrationToFile): Let cgroup do
the stat, rather than asking caller to do it and pass info down.
* src/qemu/qemu_driver.c (qemuOpenFile): New function, pulled from...
(qemuDomainSaveInternal): ...here.
(doCoreDump, qemuDomainSaveImageOpen): Use it here as well.
Commit 3261761 made it possible to use pipes instead of sockets
for outgoing tunneled migration; however, it caused a regression
because the pipe was never given a SELinux label.
* src/qemu/qemu_migration.c (doTunnelMigrate): Label outgoing pipe.
When a user migrates a domain by command as
libvirt saves vm's domain XML config in destination host after migration.
But it saves vm->def. Then, the saved XML contains some garbage.
<domain type='kvm' id='50'>
^^^^^^^^
...
<console type='pty' tty='/dev/pts/5'>
^^^^^^^^^^^^^^^^^
Avoid saving unnecessary things by saving persistent vm definition.
Changing the current vm, and writing that change to the file
system, all before a new qemu starts, is risky; it's hard to
roll back if starting the new qemu fails for some reason.
Instead of abusing vm->current_snapshot and making the command
line generator decide whether the current snapshot warrants
using -loadvm, it is better to just directly pass a snapshot all
the way through the call chain if it is to be loaded.
This frees up the last use of snapshot->def->active for qemu's
use, so the next patch can repurpose that field for tracking
which snapshot is current.
* src/qemu/qemu_command.c (qemuBuildCommandLine): Don't use active
field of snapshot.
* src/qemu/qemu_process.c (qemuProcessStart): Add a parameter.
* src/qemu/qemu_process.h (qemuProcessStart): Update prototype.
* src/qemu/qemu_migration.c (qemuMigrationPrepareAny): Update
callers.
* src/qemu/qemu_driver.c (qemudDomainCreate)
(qemuDomainSaveImageStartVM, qemuDomainObjStart)
(qemuDomainRevertToSnapshot): Likewise.
(qemuDomainSnapshotSetCurrentActive)
(qemuDomainSnapshotSetCurrentInactive): Delete unused functions.
* src/qemu/qemu_migration.c: avoid dead 'ret' assignment and silence
clang warning.
Detected by ccc-analyzer:
CC libvirt_driver_qemu_la-qemu_migration.lo
qemu/qemu_migration.c:2046:5: warning: Value stored to 'ret' is never read
ret = qemuMigrationConfirm(driver, sconn, vm,
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
By opening a connection to remote qemu process ourselves and passing the
socket to qemu we get much better errors than just "migration failed"
when the connection is opened by qemu.
The core of these two functions is very similar and most of it is even
exactly the same. Factor out the core functionality into a separate
function to remove code duplication and make further changes easier.
