This one's nasty. Ever since we fixed virHashForEach to prevent
nested hash iterations for safety reasons (commit fba550f6),
virDomainSnapshotDelete with VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN
has been broken for qemu: it deletes children, while leaving
grandchildren intact but pointing to a no-longer-present parent.
But even before then, the code would often appear to succeed to
clean up grandchildren, but risked memory corruption if you have
a large and deep hierarchy of snapshots.
For acting on just children, a single virHashForEach is sufficient.
But for acting on an entire subtree, it requires iteration; and
since we declared recursion as invalid, we have to switch to a
while loop. Doing this correctly requires quite a bit of overhaul,
so I added a new helper function to isolate the algorithm from the
actions, so that callers do not have to reinvent the iteration.
Note that this _still_ does not handle CHILDREN correctly if one
of the children is the current snapshot; that will be next.
* src/conf/domain_conf.h (_virDomainSnapshotDef): Add mark.
(virDomainSnapshotForEachDescendant): New prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainSnapshotMarkDescendant)
(virDomainSnapshotActOnDescendant)
(virDomainSnapshotForEachDescendant): New functions.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiscardChildren):
Replace...
(qemuDomainSnapshotDiscardDescenent): ...with callback that
doesn't nest hash traversal.
(qemuDomainSnapshotDelete): Use new function.
For a system checkpoint of a running or paused domain, it's fairly
easy to honor new flags for altering which state to use after the
revert. For an inactive snapshot, the revert has to be done while
there is no qemu process, so do back-to-back transitions; this also
lets us revert to inactive snapshots even for transient domains.
* src/qemu/qemu_driver.c (qemuDomainRevertToSnapshot): Support new
flags.
Commit 5e47785 broke reverts to offline system checkpoint snapshots
with older qemu, since there is no longer any code path to use
qemu -loadvm on next boot. Meanwhile, reverts to offline system
checkpoints have been broken for newer qemu, both before and
after that commit, since -loadvm no longer works to revert to
disk state without accompanying vm state. Fix both of these by
using qemu-img to revert disk state.
Meanwhile, consolidate the (now 3) clients of a qemu-img iteration
over all disks of a VM into one function, so that any future
algorithmic fixes to the FIXMEs in that function after partial
loop iterations are dealt with at once. That does mean that this
patch doesn't handle partial reverts very well, but we're not
making the situation any worse in this patch.
* src/qemu/qemu_driver.c (qemuDomainRevertToSnapshot): Use
qemu-img rather than 'qemu -loadvm' to revert to offline snapshot.
(qemuDomainSnapshotRevertInactive): New helper.
(qemuDomainSnapshotCreateInactive): Factor guts...
(qemuDomainSnapshotForEachQcow2): ...into new helper.
(qemuDomainSnapshotDiscard): Use it.
If you take a checkpoint snapshot of a running domain, then pause
qemu, then restore the snapshot, the result should be a running
domain, but the code was leaving things paused. Furthermore, if
you take a checkpoint of a paused domain, then run, then restore,
there was a brief but non-deterministic window of time where the
domain was running rather than paused. Fix both of these
discrepancies by always pausing before restoring.
Also, check that the VM is active every time lock is dropped
between two monitor calls.
Finally, straighten out the events that get emitted on each
transition.
* src/qemu/qemu_driver.c (qemuDomainRevertToSnapshot): Always
pause before reversion, and improve events.
Implement the new running/paused overrides for saved state management.
Unfortunately, for virDomainSaveImageDefineXML, the saved state
updates are write-only - I don't know of any way to expose a way
to query the current run/pause setting of an existing save image
file to the user without adding a new API or modifying the domain
xml of virDomainSaveImageGetXMLDesc to include a new element to
reflect the state bit encoded into the save image. However, I
don't think this is a show-stopper, since the API is designed to
leave the state bit alone unless an explicit flag is used to
change it.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemuDomainSaveImageOpen): Adjust signature.
(qemuDomainSaveFlags, qemuDomainManagedSave)
(qemuDomainRestoreFlags, qemuDomainSaveImageGetXMLDesc)
(qemuDomainSaveImageDefineXML, qemuDomainObjRestore): Adjust
callers.
There are two classes of management apps that track events - one
that only cares about on/off (and only needs to track EVENT_STARTED
and EVENT_STOPPED), and one that cares about paused/running (also
tracks EVENT_SUSPENDED/EVENT_RESUMED). To keep both classes happy,
any transition that can go from inactive to paused must emit two
back-to-back events - one for started and one for suspended (since
later resuming of the domain will only send RESUMED, but the first
class isn't tracking that).
This also fixes a bug where virDomainCreateWithFlags with the
VIR_DOMAIN_START_PAUSED flag failed to start paused when restoring
from a managed save image.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_EVENT_SUSPENDED_RESTORED)
(VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT)
(VIR_DOMAIN_EVENT_RESUMED_FROM_SNAPSHOT): New sub-events.
* src/qemu/qemu_driver.c (qemuDomainRevertToSnapshot): Use them.
(qemuDomainSaveImageStartVM): Likewise, and add parameter.
(qemudDomainCreate, qemuDomainObjStart): Send suspended event when
starting paused.
(qemuDomainObjRestore): Add parameter.
(qemuDomainObjStart, qemuDomainRestoreFlags): Update callers.
* examples/domain-events/events-c/event-test.c
(eventDetailToString): Map new detail strings.
QEMU uses USB bus name "usb.0" when using the legacy -usb argument.
If we want to allow USB devices to specify their addresses with legacy
-usb, we should either in case of legacy bus name drop the 0 from the
address bus, or just drop the 0 from device id. This patch does the
later.
Another solution would be to permit addressing on non-legacy USB
controllers only.
So that devices can be attached to hubs. Example, to attach to first
port of a usb-hub on port 1.
<hub type='usb'>
<address type='usb' bus='0' port='1'/>
</hub>
<input type='mouse' type='usb'>
<address type='usb' bus='0' port='1.1'/>
</hub>
also add a test entry
Commit 6766ff10 introduced a corner case bug with snapshot creation:
if a snapshot is created, but then we hit OOM while trying to
create the return value of the function, then we have polluted the
internal directory with the snapshot metadata with no way to clean
it up from the running libvirtd.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Don't
write metadata file on OOM condition.
Newer QEMU introduced cache=directsync for -drive, this patchset
is to expose it in libvirt layer.
* Introduced a new QEMU capability flag ($prefix_CACHE_DIRECTSYNC),
As even $prefix_CACHE_V2 is set, we can't known if directsync
is supported.
Several users have reported problems with 'virsh start' failing because
it was encountering a managed save situation where the managed save file
was incomplete. Be more robust to this by using two different magic
numbers, so that newer libvirt can gracefully handle an incomplete file
differently than a complete one, while older libvirt will at least fail
up front rather than trying to load only to have qemu fail at the end.
Managed save is a convenience - it exists to preserve as much state
as possible; if the state was not preserved, it is reasonable to just
log that fact, then proceed with a fresh boot. On the other hand,
user saves are under user control, so we must fail, but by making
the failure message distinct, the user can better decide how to handle
the situation of an incomplete save file.
* src/qemu/qemu_driver.c (QEMUD_SAVE_PARTIAL): New define.
(qemuDomainSaveInternal): Use it to mark incomplete images.
(qemuDomainSaveImageOpen, qemuDomainObjRestore): Add parameter
that controls what to do with partial images.
(qemuDomainRestoreFlags, qemuDomainSaveImageGetXMLDesc)
(qemuDomainSaveImageDefineXML, qemuDomainObjStart): Update callers.
Based on an initial idea by Osier Yang.
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.
After supporting multi function pci device, we only reserve function 1 on slot 1.
The user can use the other function on slot 1 in the xml config file. We should
detect this wrong usage.
The libvirt BlockPull API supports the use of an initial bandwidth limit but the
qemu block_stream API does not. To get the desired behavior we use the two APIs
strung together: first BlockPull, then BlockJobSetSpeed. We can do this at the
driver level to avoid duplicated code in each monitor path.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Due to an unfortunate precedent in qemu, the units for the bandwidth parameter
to block_job_set_speed are different between the text monitor and the qmp
monitor. While the qmp monitor uses bytes/s, the text monitor expects MB/s.
Correct the units for the text interface.
Signed-off-by: Adam Litke <agl@us.ibm.com>
It is not possible to change the label of a TCP socket once it
has been opened. When creating a TCP socket care must be taken
to ensure the socket creation label is set & then cleared.
Remove the bogus call to virSecurityManagerSetProcessFDLabel
from the lock driver guest setup code and instead make use of
virSecurityManagerSetSocketLabel
There is no reason to forbid pausing an autodestroy domain
(not to mention that 'virsh start --paused --autodestroy'
succeeds in creating a paused autodestroy domain).
Meanwhile, qemu was failing to enforce the API documentation that
autodestroy domains cannot be saved. And while the original
documentation only mentioned save/restore, snapshots are another
form of saving that are close enough in semantics as to make no
sense on one-shot domains.
* src/qemu/qemu_driver.c (qemudDomainSuspend): Drop bogus check.
(qemuDomainSaveInternal, qemuDomainSnapshotCreateXML): Forbid
saves of autodestroy domains.
* src/libvirt.c (virDomainCreateWithFlags, virDomainCreateXML):
Document snapshot interaction.
According to qemu-kvm/qerror.c all messages start with a capital
"Device ", but the current code only scans for the lower case "device ".
This results in "virDomainUpdateDeviceFlags()" to not detect locked
CD-ROMs and reporting success even in the case of a failure:
# virsh qemu-monitor-command "$VM" change\ drive-ide0-0-0\ \"/var/lib/libvirt/images/ucs_2.4-0-sec4-20110714145916-dvd-amd64.iso\"
Device 'drive-ide0-0-0' is locked
# virsh update-device "$VM" /dev/stdin <<<"<disk type='file' device='cdrom'><driver name='qemu' type='raw'/><source file='/var/lib/libvirt/images/ucs_2.4-0-sec4-20110714145916-dvd-amd64.iso'/><target dev='hda' bus='ide'/><readonly/><alias name='ide0-0-0'/><address type='drive' controller='0' bus='0' unit='0'/></disk>"
Device updated successfully
Signed-off-by: Philipp Hahn <hahn@univention.de>
There have been several instances of people having problems with
a broken managed save file, and not aware that they could use
'virsh managedsave-remove dom' to fix things. Making it possible
to do this as part of starting a domain makes the same functionality
easier to find, and one less API call.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_START_FORCE_BOOT): New
flag.
* src/libvirt.c (virDomainCreateWithFlags): Document it.
* src/qemu/qemu_driver.c (qemuDomainObjStart): Alter signature.
(qemuAutostartDomain, qemuDomainStartWithFlags): Update callers.
* tools/virsh.c (cmdStart): Expose it in virsh.
* tools/virsh.pod (start): Document it.
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.
On success, the 'sendkey' command does not return any data, so
any data in the reply should be considered to be an error
message
* src/qemu/qemu_monitor_text.c: Treat non-"" reply data as an
error message for 'sendkey' command
The QEMU 'sendkey' command expects keys to be encoded in the same
way as the RFB extended keycode set. Specifically it wants extended
keys to have the high bit of the first byte set, while the Linux
XT KBD driver codeset uses the low bit of the second byte. To deal
with this we introduce a new keymap 'RFB' and use that in the QEMU
driver
* include/libvirt/libvirt.h.in: Add VIR_KEYCODE_SET_RFB
* src/qemu/qemu_driver.c: Use RFB keycode set instead of XT KBD
* src/util/virkeycode-mapgen.py: Auto-generate the RFB keycode
set from the XT KBD set
* src/util/virkeycode.c: Add RFB keycode entry to table. Add a
verify check on cardinality of the codeOffset table
The APIs are designed to label a socket in a way that the libvirt daemon
itself is able to access it (i.e., in SELinux the label is virtd_t based
as opposed to svirt_* we use for labeling resources that need to be
accessed by a vm). The new name reflects this.
Audit all changes to the qemu vm->current_snapshot, and make them
update the saved xml file for both the previous and the new
snapshot, so that there is always at most one snapshot with
<active>1</active> in the xml, and that snapshot is used as the
current snapshot even across libvirtd restarts.
This patch does not fix the case of virDomainSnapshotDelete(,CHILDREN)
where one of the children is the current snapshot; that will be later.
* src/conf/domain_conf.h (_virDomainSnapshotDef): Alter member
type and name.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString)
(virDomainSnapshotDefFormat): Update clients.
* docs/schemas/domainsnapshot.rng: Tighten rng.
* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad): Reload current
snapshot.
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDiscard): Track current snapshot.
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.
https://bugzilla.redhat.com/show_bug.cgi?id=727709
mentions that if qemu fails to create the snapshot (such as what
happens on Fedora 15 qemu, which has qmp but where savevm is only
in hmp, and where libvirt is old enough to not try the hmp fallback),
then 'virsh snapshot-list dom' will show a garbage snapshot entry,
and the libvirt internal directory for storing snapshot metadata
will have a bogus file.
This fixes the fallout bug of polluting the snapshot-list with
garbage on failure (the root cause of the F15 bug of not having
fallback to hmp has already been fixed in newer libvirt releases).
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Allocate
memory before making snapshot, and cleanup on failure. Don't
dereference NULL if transient domain exited during snapshot creation.
* 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,
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pciDeviceListSteal(pcidevs, dev) removes dev from pcidevs reducing
the length of pcidevs, so moving onto what was the next dev is wrong.
Instead callers should pop entry 0 repeatedly until pcidevs is empty.
Signed-off-by: Steve Hodgson <shodgson@solarflare.com>
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
* src/qemu/qemu_monitor_json.c: Handle error "CommandNotFound" and
report the error.
* src/qemu/qemu_monitor_text.c: If a sub info command is not found,
it prints the output of "help info", for other commands,
"unknown command" is printed.
Without this patch, libvirt always report:
An error occurred, but the cause is unknown
This patch was adapted from a patch by Osier Yang <jyang@redhat.com> to
break out detection of unrecognized text monitor commands into a separate
function.
Signed-off-by: Adam Litke <agl@us.ibm.com>
* src/qemu/qemu_monitor_text.c: BALLOON_PREFIX was defined as
"balloon: actual=", which cause "actual=" is stripped early before
the real parsing. This patch changes BALLOON_PREFIX into "balloon: ",
and modifies related functions, also renames
"qemuMonitorParseExtraBalloonInfo" to "qemuMonitorParseBalloonInfo",
as after the changing, it parses all the info returned by "info balloon".
A virsh command like:
migrate --live --copy-storage-all Guest qemu+ssh://user@host/system
--persistent --verbose
shows
Migration: [ 0 %]
during the storage copy and does not start counting
until the ram transfer starts
Fix this by scraping optional disk transfer status, and adding it
into the progress meter.
Otherwise the device will still be bound to pci-stub driver even
it's set as "managed=yes" when do detaching. Of course, it won't
triger any driver reprobing too.
In some versions of qemu, both virtio-blk-pci and virtio-net-pci
devices can have an event_idx setting that determines some details of
event processing. When it is enabled, it "reduces the number of
interrupts and exits for the guest". qemu will automatically enable
this feature when it is available, but there may be cases where this
new feature could actually make performance worse (NB: no such case
has been found so far).
As a safety switch in case such a situation is encountered in the
field, this patch adds a new attribute "event_idx" to the <driver>
element of both disk and interface devices. event_idx can be set to
"on" (to force event_idx on in case qemu has it disabled by default)
or "off" (for force event_idx off). In the case that event_idx support
isn't present in qemu, the attribute is ignored (this on the advice of
the qemu developer).
docs/formatdomain.html.in: document the new flag (marking it as
"don't mess with this!"
docs/schemas/domain.rng: add event_idx in appropriate places
src/conf/domain_conf.[ch]: add event_idx to parser and formatter
src/libvirt_private.syms: export
virDomainVirtioEventIdx(From|To)String
src/qemu/qemu_capabilities.[ch]: detect and report event_idx in
disk/net
src/qemu/qemu_command.c: add event_idx parameter to qemu commandline
when appropriate.
tests/qemuxml2argvdata/qemuxml2argv-event_idx.args,
tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml,
tests/qemuxml2argvtest.c,
tests/qemuxml2xmltest.c: test cases for event_idx.
