Jim Fehlig [Fri, 26 Aug 2011 18:10:27 +0000 (12:10 -0600)]
Use max bandwidth from qemuDomainObjPrivate struct when migrating
Adjust qemuMigrationRun() to use migMaxBandwidth in qemuDomainObjPrivate
structure when setting qemu migration speed. Caller-specified 'resource'
parameter overrides migMaxBandwidth.
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.
Jim Fehlig [Fri, 26 Aug 2011 18:10:22 +0000 (12:10 -0600)]
Store max migration bandwidth in qemuDomainObjPrivate struct
The maximum bandwidth that can be consumed when migrating a domain
is better classified as an operational vs configuration parameter of
the dommain. As such, store this parameter in qemuDomainObjPrivate
structure.
Eric Blake [Tue, 13 Sep 2011 20:21:10 +0000 (14:21 -0600)]
snapshot: ABI stability must include memory sizing
Commit 973fcd8f introduced the ability for qemu to reject snapshot
reversion on an ABI incompatibility; but the very example that was
first proposed on-list[1] as a demonstration of an ABI incompatibility,
namely that of changing the max memory allocation, was not being
checked for, resulting in a cryptic failure when running with larger
max mem than what the snapshot was created with:
error: operation failed: Error -22 while loading VM state
This commit merely protects the three variables within mem that are
referenced by qemu_command.c, rather than all 7 (the other 4 variables
affect cgroup handling, but as far as I can tell, have no visible effect
to the qemu guest). This also affects migration and save file handling,
which are other places where we perform ABI compatibility checks.
Peter Krempa [Wed, 14 Sep 2011 14:17:57 +0000 (16:17 +0200)]
xml: Clean up rest of virtual XML document names for XML strings
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
Peter Krempa [Wed, 14 Sep 2011 12:20:07 +0000 (14:20 +0200)]
make: Fix 'make syntax-check' failing.
Commit 2a0d75e5 added file python/libvirt-qemu-override.c that contains
code that does not pass "make syntax-check". This patch adds an
exception for this file and the check.
prohibit_always_true_header_tests
python/libvirt-qemu-override.c:17:#undef HAVE_PTHREAD_H
maint.mk: do not test the above HAVE_<header>_H symbol(s);
with the corresponding gnulib module, they are always true
make: *** [sc_prohibit_always_true_header_tests] Error 1
Peter Krempa [Tue, 13 Sep 2011 15:16:45 +0000 (17:16 +0200)]
virsh: Use old API if remote libvirtd does not support new
Commit ffe28ab74b821c916ec4ba8efb5c992454e4bd24 introduced regression
while communicating with older libvirtd command 'domblkstat' used the new
API and did not check for VIR_ERR_RPC error code signalling the remote
server does not support this API and did not fall back to older API.
Thereafter 'domblkstat' ended with "error: unknown procedure: 243".
Regression introduced in commit 3881a470, due to an improper rebase
of a cleanup written beforehand but only applied after a rebased of
a refactoring that created a new function in commit 25fb3ef.
Also avoids passing NULL to printf %s.
* src/qemu/qemu_driver.c: In qemuDomainSnapshotForEachQcow2()
it free up the memory of qemu_driver->qemuImgBinary in the
cleanup tag which leads to the garbage value of qemuImgBinary
in qemu_driver struct and libvirtd crash when running
"virsh snapshot-create" command a second time.
Daniel Veillard [Tue, 13 Sep 2011 10:24:13 +0000 (18:24 +0800)]
Do not log invalid operations in libvirtd logs
This is a bit painful for example when starting virt-manager
it tends to clutter libvirtd.log with invalid operation on cpu pinning
for defined but not running domains. A priori those kind of errors
don't indicate an error when executing the command but on a precondition
for running the API, and honnestly while the application should report
it, logging it as an error in libvirtd.log is not really useful,
Related bug: https://bugzilla.redhat.com/show_bug.cgi?id=590807
* daemon/libvirtd.c: extend daemonErrorLogFilter() to filter out
errors of type VIR_ERR_OPERATION_INVALID
Philipp Hahn [Thu, 8 Sep 2011 14:34:10 +0000 (16:34 +0200)]
Fix URL-escaping for domainDefine
'+' in strings get translated to ' ' when editing domains.
While xenDaemonDomainCreateXML() did URL-escape the sexpr,
xenDaemonDomainDefineXML() did not.
Remove the explicit urlencode() in xenDaemonDomainCreateXML() and add
the direct encoding calls to xend_op_ext() because it calls xend_post()
which uses "Content-Type: application/x-www-form-urlencoded". According
to <http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1> this
requires all parameters to be url-encoded as specified in rfc1738.
Notice: virBufferAsprintf(..., "%s=%s", ...) is again replaced by three
calls to virBufferURIEncodeString() and virBufferAddChar() because '='
is a "reserved" character, which would get escaped by
virBufferURIEncodeString(), which - by the way - escapes anything not
c_isalnum().
Peter Krempa [Thu, 8 Sep 2011 13:25:01 +0000 (15:25 +0200)]
xml: Change virtual file names of xml documents parsed in memory
While parsing XML strings from memory, the previous convention in
libvirt was to set the virtual file name to "domain.xml" or something
similar. This could potentialy trick the user into looking for a file
named domain.xml on the disk in an attempt to fix the error.
This patch changes these filenames to something that can't be as easily
confused for a valid filename.
Examples of error messages:
---------------------------
Error while loading file from disk:
15:07:59.015: 527: error : catchXMLError:709 : /path/to/domain.xml:1: StartTag: invalid element name
<domain type='kvm'><
--------------------^
Eric Blake [Thu, 8 Sep 2011 13:06:45 +0000 (14:06 +0100)]
snapshot: fix regression with system checkpoints
Regression introduced in commit d6f6b2d194c. Running
'virsh snapshot-create dom' would mistakenly report that
disks can only be specified for disk snapshots.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString): Only
give error about no disk support when <disk> was found.
Eric Blake [Thu, 8 Sep 2011 11:19:25 +0000 (12:19 +0100)]
snapshot: new APIs for inspecting snapshot object
These functions access internals of the opaque object, and do
not need any rpc counterpart. It could be argued that we should
have provided these when snapshot objects were first introduced,
since all the other vir*Ptr objects have at least a GetName accessor.
Don't treat pci_system_init failure as fatal if no PCI bus is present
Xen PV domU's have no PCI bus. node_device_udev.c calls pci_system_init
which looks for /sys/bus/pci. If it does not find /sys/bus/pci (which it
won't in a Xen PV domU) it returns unsuccesfully (ENOENT), which libvirt
considers fatal. This makes libvirt unusable in this environment, even
though there are plenty of valid virtualisation options that work
there (LXC, UML, and QEmu spring to mind)
Alex Jia [Sun, 4 Sep 2011 15:48:42 +0000 (23:48 +0800)]
rpc: avoid memory leak on virNetTLSContextValidCertificate
* src/rpc/virnettlscontext.c: fix memory leak on
virNetTLSContextValidCertificate.
* Detected in valgrind run:
==25667==
==25667== 6,085 (44 direct, 6,041 indirect) bytes in 1 blocks are definitely
lost in loss record 326 of 351
==25667== at 0x4005447: calloc (vg_replace_malloc.c:467)
==25667== by 0x4F2791F3: _asn1_add_node_only (structure.c:53)
==25667== by 0x4F27997A: _asn1_copy_structure3 (structure.c:421)
==25667== by 0x4F276A50: _asn1_append_sequence_set (element.c:144)
==25667== by 0x4F2743FF: asn1_der_decoding (decoding.c:1194)
==25667== by 0x4F22B9CC: gnutls_x509_crt_import (x509.c:229)
==25667== by 0x805274B: virNetTLSContextCheckCertificate
(virnettlscontext.c:1009)
==25667== by 0x804DE32: testTLSSessionInit (virnettlscontexttest.c:693)
==25667== by 0x804F14D: virtTestRun (testutils.c:140)
==25667==
==25667== 23,188 (88 direct, 23,100 indirect) bytes in 11 blocks are definitely
lost in loss record 346 of 351
==25667== at 0x4005447: calloc (vg_replace_malloc.c:467)
==25667== by 0x4F22B841: gnutls_x509_crt_init (x509.c:50)
==25667== by 0x805272B: virNetTLSContextCheckCertificate
(virnettlscontext.c:1003)
==25667== by 0x804DDD1: testTLSSessionInit (virnettlscontexttest.c:673)
==25667== by 0x804F14D: virtTestRun (testutils.c:140)
* How to reproduce?
% cd libvirt && ./configure && make && make -C tests valgrind
or
% valgrind -v --leak-check=full ./tests/virnettlscontexttest
Alex Jia [Sun, 4 Sep 2011 15:48:41 +0000 (23:48 +0800)]
tests: avoid memory leak on testTLSSessionInit
* tests/virnettlscontexttest: fix memory leak on virnettlscontext test case.
* Detected in valgrind run:
==25667==
==25667== 86,651 (34,680 direct, 51,971 indirect) bytes in 10 blocks are
definitely lost in loss record 350 of 351
==25667== at 0x4005447: calloc (vg_replace_malloc.c:467)
==25667== by 0x4F1F515D: gnutls_init (gnutls_state.c:270)
==25667== by 0x8053432: virNetTLSSessionNew (virnettlscontext.c:1181)
==25667== by 0x804DD24: testTLSSessionInit (virnettlscontexttest.c:624)
==25667== by 0x804F14D: virtTestRun (testutils.c:140)
==25667==
==25667== 100,578 (38,148 direct, 62,430 indirect) bytes in 11 blocks are
definitely lost in loss record 351 of 351
==25667== at 0x4005447: calloc (vg_replace_malloc.c:467)
==25667== by 0x4F1F515D: gnutls_init (gnutls_state.c:270)
==25667== by 0x8053432: virNetTLSSessionNew (virnettlscontext.c:1181)
==25667== by 0x804DD3C: testTLSSessionInit (virnettlscontexttest.c:625)
==25667== by 0x804F14D: virtTestRun (testutils.c:140)
* How to reproduce?
% cd libvirt && ./configure && make && make -C tests valgrind
or
% valgrind -v --leak-check=full ./tests/virnettlscontexttest
Alex Jia [Sun, 4 Sep 2011 17:01:03 +0000 (01:01 +0800)]
libxl: avoid a dereference of a null pointer
Variable 'l_disk' initialized to a null pointer value, control jumps to 'case
VIR_DOMAIN_DISK_DEVICE_DISK and then taking false branch, Within the expansion
of the macro 'libxlError': Field access results in a dereference of a null
pointer (loaded from variable 'l_disk').
* src/libxl/libxl_driver.c: Field access results in a dereference of a null
pointer (loaded from variable 'l_disk')
Although we were initializing worker threads during pool creating,
we missed this during virThreadPoolSendJob. This bug led to segmenation
fault as worker thread free() given argument.
Peter Krempa [Tue, 6 Sep 2011 08:31:59 +0000 (16:31 +0800)]
link-state: virsh: Add wrapper commands for changing link state
Two new commands are added to virsh that wrap usage of
virDomainUpdateDeviceFlags for changing link state of domain's network
interfaces. These wrappers extract network devices's xml configuration
and modify the link state for easy manipulation from an user's perspective.
- domif-setlink - set link state of a domains virtual network interface
- domif-getlink - get link state
Peter Krempa [Tue, 6 Sep 2011 08:23:47 +0000 (16:23 +0800)]
link-state: qemu: Add net intf modification to virUpdateDeviceFlags
This patch enables modifying network device configuration using the
virUpdateDeviceFlags API method. Matching of devices is accomplished
using MAC addresses.
While updating live configuration of a running domain, the user is
allowed only to change link state of the interface. Additional
modifications may be added later. For now the code checks for
unsupported changes and thereafter changes the link state, if
applicable.
When updating persistent configuration of guest's network interface the
whole configuration (except for the MAC address) may be modified and
is stored for the next startup.
* src/qemu/qemu_driver.c - Add dispatching of virUpdateDevice for
network devices update (live/config)
* src/qemu/qemu_hotplug.c - add setting of initial link state on live
device addition
- add function to change network device
configuration. By now it supports only
changing of link state
* src/qemu/qemu_hotplug.h - Headers to above functions
* src/qemu/qemu_process.c - set link states before virtual machine
start. Qemu does not support setting of
this on the command line.
Peter Krempa [Tue, 6 Sep 2011 08:18:57 +0000 (16:18 +0800)]
link-state: qemu: Add monitor handling for link state modification
This patch adds handlers for modification of guest's interface
link state. Both HMP and QMP commands are supported, but as the
link state functionality is from the beginning supported in QMP
the HMP code will probably never be used.
Peter Krempa [Tue, 6 Sep 2011 08:08:15 +0000 (16:08 +0800)]
link-state: conf: Add element to XML for controling link state
A new element is introduced to XML that allows to control
state of virtual network interfaces in hypervisors.
Live modification of the link state allows networking tools
propagate topology changes to guest OS or testing of
scenarios in complex (virtual) networks.
This patch adds elements to XML grammars and parsing and generating
code.
Peter Krempa [Tue, 6 Sep 2011 08:05:53 +0000 (16:05 +0800)]
link-state: util: Add equality comparison functions for structures
This patch adds functions to compare structures containing network
device configuration for equality. They serve for the purpose of
disallowing unsupported changes to live network devices.
Peter Krempa [Tue, 6 Sep 2011 07:48:22 +0000 (15:48 +0800)]
XML: Improve XML parsing error messages
This patch modifies error handling function for the XML parser provided
by libxml2.
Originaly only a line number and error message were logged. With this
new error handler function, the user is provided with a more complex
description of the parsing error.
Context of the error is printed in libXML2 style and filename of the
file, that caused the error is printed. Example of an parse error:
13:41:36.262: 16032: error : catchXMLError:706 :
/etc/libvirt/qemu/rh_bad.xml:58: Opening and ending tag mismatch: name
line 2 and domain
</domain>
---------^
Context of the error gives the user hints that may help to quickly
locate a corrupt xml file.
fixes BZs:
----------
Bug 708735 - [RFE] Show column and line on XML parsing error
https://bugzilla.redhat.com/show_bug.cgi?id=708735
Bug 726771 - libvirt does not specify problem file if persistent xml is
invalid
https://bugzilla.redhat.com/show_bug.cgi?id=726771
It is important to be able to attach USB redirected devices to a
particular controller (one that supports USB2 for instance).
Without this patch, only the default bus was used.
Osier Yang [Mon, 5 Sep 2011 08:24:51 +0000 (16:24 +0800)]
latency: Update virsh command domblkstat to use new API
The modified function fallbacks to use virDomainBlockStats if
virDomainBlockStatsFlags is not supported by the hypervisor driver.
If the new API is supported, it will be invoked instead of the
old API.
Osier Yang [Mon, 5 Sep 2011 08:22:17 +0000 (16:22 +0800)]
latency: Update monitor functions for new latency fields
The mainly changes are:
1) Update qemuMonitorGetBlockStatsInfo and it's children (Text/JSON)
functions to return the value of new latency fields.
2) Add new function qemuMonitorGetBlockStatsParamsNumber, which is
to count how many parameters the underlying QEMU supports.
3) Update virDomainBlockStats in src/qemu/qemu_driver.c to be
compatible with the changes by 1).
Michal Privoznik [Tue, 16 Aug 2011 10:51:36 +0000 (12:51 +0200)]
qemu: Deal with stucked qemu on daemon startup
If libvirt daemon gets restarted and there is (at least) one
unresponsive qemu, the startup procedure hangs up. This patch creates
one thread per vm in which we try to reconnect to monitor. Therefore,
blocking in one thread will not affect other APIs.
Michal Privoznik [Fri, 12 Aug 2011 13:29:37 +0000 (15:29 +0200)]
qemu: Introduce job queue size limit
This patch creates an optional BeginJob queue size limit. When
active, all other attempts above level will fail. To set this
feature assign desired value to max_queued variable in qemu.conf.
Setting it to 0 turns it off.
Michal Privoznik [Fri, 12 Aug 2011 12:04:31 +0000 (14:04 +0200)]
daemon: Create priority workers pool
This patch annotates APIs with low or high priority.
In low set MUST be all APIs which might eventually access monitor
(and thus block indefinitely). Other APIs may be marked as high
priority. However, some must be (e.g. domainDestroy).
For high priority calls (HPC), there are some high priority workers
(HPW) created in the pool. HPW can execute only HPC, although normal
worker can process any call regardless priority. Therefore, only those
APIs which are guaranteed to end in reasonable small amount of time
can be marked as HPC.
The size of this HPC pool is static, because HPC are expected to end
quickly, therefore jobs assigned to this pool will be served quickly.
It can be configured in libvirtd.conf via prio_workers variable.
Default is set to 5.
To mark API with low or high priority, append priority:{low|high} to
it's comment in src/remote/remote_protocol.x. This is similar to
autogen|skipgen. If not marked, the generator assumes low as default.
Eric Blake [Tue, 23 Aug 2011 23:14:55 +0000 (17:14 -0600)]
snapshot: use SELinux and lock manager with external snapshots
With this, it is now possible to create external snapshots even
when SELinux is enforcing, and to protect the new file with a
lock manager.
* src/qemu/qemu_driver.c
(qemuDomainSnapshotCreateSingleDiskActive): Create and register
new file with proper permissions and locks.
(qemuDomainSnapshotCreateDiskActive): Update caller.
Eric Blake [Sat, 20 Aug 2011 04:33:13 +0000 (22:33 -0600)]
snapshot: wire up live qemu disk snapshots
Lots of earlier patches led up to this point - the qemu snapshot_blkdev
monitor command can now be controlled by libvirt! Well, insofar as
SELinux doesn't prevent qemu from open(O_CREAT) on the files. There's
still some followup work before things work with SELinux enforcing,
but this patch is big enough to post now.
There's still room for other improvements, too (for example, taking a
disk snapshot of an inactive domain, by using qemu-img for both internal
and external snapshots; wiring up delete and revert control, including
additional flags from my RFC; supporting active QED disk snapshots;
supporting per-storage-volume snapshots such as LVM or btrfs snapshots;
etc.). But this patch is the one that proves the new XML works!
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Wire in
active disk snapshots.
(qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateDiskActive)
(qemuDomainSnapshotCreateSingleDiskActive): New functions.
Eric Blake [Mon, 15 Aug 2011 23:25:54 +0000 (17:25 -0600)]
snapshot: wire up new qemu monitor command
No one uses this yet, but it will be important once
virDomainSnapshotCreateXML learns a VIR_DOMAIN_SNAPSHOT_DISK_ONLY
flag, and the xml allows passing in the new file names.
Eric Blake [Mon, 22 Aug 2011 19:49:10 +0000 (13:49 -0600)]
snapshot: make it possible to audit external snapshot
Snapshots alter the set of disk image files opened by qemu, so
they must be audited. But they don't involve a full disk definition
structure, just the new filename. Make the next patch easier by
refactoring the audit routines to just operate on file name.
Eric Blake [Mon, 22 Aug 2011 20:26:52 +0000 (14:26 -0600)]
snapshot: reject unimplemented disk snapshot features
My RFC for snapshot support [1] proposes several rules for when it is
safe to delete or revert to an external snapshot, predicated on
the existence of new API flags. These will be incrementally added
in future patches, but until then, blindly mishandling a disk
snapshot risks corrupting internal state, so it is better to
outright reject the attempts until the other pieces are in place,
thus incrementally relaxing the restrictions added in this patch.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCountExternal): New
function.
(qemuDomainUndefineFlags, qemuDomainSnapshotDelete): Use it to add
safety valve.
(qemuDomainRevertToSnapshot, qemuDomainSnapshotCreateXML): Add safety
valve.
Eric Blake [Mon, 22 Aug 2011 23:12:56 +0000 (17:12 -0600)]
snapshot: wire up disk-only flag to snapshot-create
Expose the disk-only flag through virsh. Additionally, make
virsh snapshot-create-as take an arbitrary number of diskspecs,
which can be used to build up the xml for <domainsnapshot>.
* tools/virsh.c (cmdSnapshotCreate): Add --disk-only.
(cmdSnapshotCreateAs): Likewise, and add argv diskspec.
(vshParseSnapshotDiskspec): New helper function.
(vshCmddefGetOption): Allow naming of argv field.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
them.
* tests/virsh-optparse: Test snapshot-create-as parsing.
Eric Blake [Sat, 20 Aug 2011 04:03:38 +0000 (22:03 -0600)]
snapshot: add flag for requesting disk snapshot
Prior to this patch, <domainsnapshot>/<disks> was ignored. This
changes it to be an error unless an explicit disk snapshot is
requested (a future patch may relax things if it turns out to
be useful to have a <disks> specification alongside a system
checkpoint).
* include/libvirt/libvirt.h.in
(VIR_DOMAIN_SNAPSHOT_CREATE_DISK_ONLY): New flag.
* src/libvirt.c (virDomainSnapshotCreateXML): Document it.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML): Disk
snapshots not supported yet.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Likewise.
Eric Blake [Sat, 20 Aug 2011 13:04:24 +0000 (07:04 -0600)]
snapshot: add virsh domblklist command
This adds a convenience function to virsh that parses out block
information from the domain xml, making it much easier to see
what strings can be used in all other contexts that demand a
specific block name, especially when given the previous patch
that allows using either target or unique source name.
As an example on a domain with one disk and an empty cdrom drive:
Eric Blake [Sat, 20 Aug 2011 02:38:36 +0000 (20:38 -0600)]
snapshot: also support disks by path
I got confused when 'virsh domblkinfo dom disk' required the
path to a disk (which can be ambiguous, since a single file
can back multiple disks), rather than the unambiguous target
device name that I was using in disk snapshots. So, in true
developer fashion, I went for the best of both worlds - all
interfaces that operate on a disk (aka block) now accept
either the target name or the unambiguous path to the backing
file used by the disk.
* src/conf/domain_conf.h (virDomainDiskIndexByName): Add
parameter.
(virDomainDiskPathByName): New prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainDiskIndexByName): Also allow
searching by path, and decide whether ambiguity is okay.
(virDomainDiskPathByName): New function.
(virDomainDiskRemoveByName, virDomainSnapshotAlignDisks): Update
callers.
* src/qemu/qemu_driver.c (qemudDomainBlockPeek)
(qemuDomainAttachDeviceConfig, qemuDomainUpdateDeviceConfig)
(qemuDomainGetBlockInfo, qemuDiskPathToAlias): Likewise.
* src/qemu/qemu_process.c (qemuProcessFindDomainDiskByPath):
Likewise.
* src/libxl/libxl_driver.c (libxlDomainAttachDeviceDiskLive)
(libxlDomainDetachDeviceDiskLive, libxlDomainAttachDeviceConfig)
(libxlDomainUpdateDeviceConfig): Likewise.
* src/uml/uml_driver.c (umlDomainBlockPeek): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainBlockPeek): Likewise.
* docs/formatsnapshot.html.in: Update documentation.
* tools/virsh.pod (domblkstat, domblkinfo): Likewise.
* docs/schemas/domaincommon.rng (diskTarget): Tighten pattern on
disk targets.
* docs/schemas/domainsnapshot.rng (disksnapshot): Update to match.
* tests/domainsnapshotxml2xmlin/disk_snapshot.xml: Update test.
Eric Blake [Thu, 18 Aug 2011 23:33:36 +0000 (17:33 -0600)]
snapshot: add <disks> to snapshot xml
Adds an optional element to <domainsnapshot>, which will be used
to give user control over external snapshot filenames on input,
and specify generated filenames on output.
For now, no driver accepts this element; that will come later.
Eric Blake [Fri, 19 Aug 2011 00:14:40 +0000 (18:14 -0600)]
snapshot: support extra state in snapshots
In order to distinguish disk snapshots from system checkpoints, a
new state value that is only valid for snapshots is helpful.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_LAST): New placeholder.
* src/conf/domain_conf.h (virDomainSnapshotState): New enum mapping.
(VIR_DOMAIN_DISK_SNAPSHOT): New internal enum value.
* src/conf/domain_conf.c (virDomainState): Use placeholder.
(virDomainSnapshotState): Extend mapping by one for use in snapshot.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Handle new state.
(virDomainObjSetState, virDomainStateReasonToString)
(virDomainStateReasonFromString): Avoid compiler warnings.
* tools/virsh.c (vshDomainState, vshDomainStateReasonToString):
Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new functions.
* docs/schemas/domainsnapshot.rng: Tighten state definition.
* docs/formatsnapshot.html.in: Document it.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: New test.
Eric Blake [Thu, 18 Aug 2011 14:37:26 +0000 (08:37 -0600)]
snapshot: expose halt-after-creation in virsh
Easy enough to emulate even with older servers.
* tools/virsh.c (cmdSnapshotCreate, cmdSnapshotCreateAs): Add
--halt flag.
(vshSnapshotCreate): Emulate halt when flag is unsupported.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
it.
Eric Blake [Thu, 1 Sep 2011 23:23:29 +0000 (17:23 -0600)]
snapshot: allow halting after snapshot
Since a snapshot is fully recoverable, it is useful to have a
snapshot as a means of hibernating a guest, then reverting to
the snapshot to wake the guest up. This mode of usage is
similar to 'virsh save/virsh restore', except that virsh
save uses an external file while virsh snapshot keeps the
vm state internal to a qcow2 file. However, it only works on
persistent domains.
In the usage pattern of snapshot/revert for hibernating a guest,
there is no need to keep the guest running between the two points
in time, especially since that would generate runtime state that
would just be discarded. Add a flag to make it possible to
stop the domain after the snapshot has completed.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_SNAPSHOT_CREATE_HALT):
New flag.
* src/libvirt.c (virDomainSnapshotCreateXML): Document it.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotCreateActive): Implement it.
Eric Blake [Tue, 16 Aug 2011 22:48:04 +0000 (16:48 -0600)]
snapshot: expose new delete flag in virsh
It would technically be possible to have virsh compute the list
of descendants of a given snapshot, then delete those one at
a time. But it's complex, and not worth writing for a first
cut at implementing the new flags.
Eric Blake [Tue, 16 Aug 2011 22:23:45 +0000 (16:23 -0600)]
snapshot: introduce new deletion flag
Reverting to a state prior to an external snapshot risks
corrupting any other branches in the snapshot hierarchy that
were using the snapshot as a read-only backing file. So
disk snapshot code will default to preventing reverting to
a snapshot that has any children, meaning that deleting just
the children of a snapshot becomes a useful operation in
preparing that snapshot for being a future reversion target.
The code for the new flag is simple - it's one less deletion,
plus a tweak to keep the current snapshot correct.
* include/libvirt/libvirt.h.in
(VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY): New flag.
* src/libvirt.c (virDomainSnapshotDelete): Document it, and
enforce mutual exclusion.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDelete): Implement
it.
Eric Blake [Sat, 13 Aug 2011 21:42:48 +0000 (15:42 -0600)]
snapshot: reject transient disks where code is not ready
The previous patch introduced new config, but if a hypervisor does
not support that new config, someone can write XML that does not
behave as documented. This prevents some of those cases by
explicitly rejecting transient disks for several hypervisors.
Disk snapshots will require a new flag to actually affect a snapshot
creation, so there's not much to reject there.
Eric Blake [Sat, 13 Aug 2011 19:20:21 +0000 (13:20 -0600)]
snapshot: additions to domain xml for disks
As discussed here:
https://www.redhat.com/archives/libvir-list/2011-August/msg00361.html
https://www.redhat.com/archives/libvir-list/2011-August/msg00552.html
Adds snapshot attribute and transient sub-element:
* docs/schemas/domaincommon.rng (snapshot): New define.
(disk): Add snapshot and persistent attributes.
* docs/formatdomain.html.in: Document them.
* src/conf/domain_conf.h (virDomainDiskSnapshot): New enum.
(_virDomainDiskDef): New fields.
* tests/qemuxml2argvdata/qemuxml2argv-disk-transient.xml: New
test of rng, no args counterpart until qemu support is complete.
* tests/qemuxml2argvdata/qemuxml2argv-disk-snapshot.args: New
file, snapshot attribute does not affect args.
* tests/qemuxml2argvdata/qemuxml2argv-disk-snapshot.xml: Likewise.
* tests/qemuxml2argvtest.c (mymain): Run new test.
Philipp Hahn [Mon, 5 Sep 2011 06:22:36 +0000 (14:22 +0800)]
Fix localtime handling for Xen-PV domains
At least Xen-3.4.3 translates the /vm/localtime SXPR value to
/domain/platform/localtime and /domain/image/{linux,hvm}/localtime when
the domain is defined. When reading back that information libvirt only
handles HVM domains, but not PV domains: This results in libvirtd always
returning
<clock offset="utc"/>
while Xend used (localtime 1).
Eric Blake [Sat, 13 Aug 2011 03:20:04 +0000 (21:20 -0600)]
snapshot: store qemu domain details in xml
When reverting to a snapshot, the inactive domain configuration
has to be rolled back to what it was at the time of the snapshot.
Additionally, if the VM is active and the snapshot was active,
this now adds a failure if the two configurations are ABI
incompatible, rather than risking qemu confusion.
A future patch will add a VIR_DOMAIN_SNAPSHOT_FORCE flag, which
will be required for two risky code paths - reverting to an
older snapshot that lacked full domain information, and reverting
from running to a live snapshot that requires starting a new qemu
process. Any reverting that stops a running vm is also a form
of data loss (discarding the current running state to go back in
time), but as that is what reversion usually implies, it is
probably not worth requiring a force flag.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Copy out
domain.
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot): Perform
ABI compatibility checks.
Eric Blake [Sat, 13 Aug 2011 01:33:15 +0000 (19:33 -0600)]
snapshot: update rng to support full domain in xml
This patch will probably cause merge conflicts to those trying
to do backports. The end goal is simple - domaincommon.rng
should be the state of domain.rng pre-patch, with a few lines
tweaked in the header, while domain.rng post-patch is now just
a shell that includes domaincommon.rng and sets the <start>.
* docs/schemas/domain.rng: Move guts...
* docs/schemas/domaincommon.rng: ...to new file.
* docs/schemas/domainsnapshot.rng: Allow new xml.
* docs/schemas/Makefile.am (schema_DATA): Distribute new file.
* tests/domainsnapshotxml2xmlout/full_domain.xml: New test.
* libvirt.spec.in (%files client): Ship new file. Sort lines.
* mingw32-libvirt.spec.in: Likewise.
Eric Blake [Fri, 19 Aug 2011 16:56:57 +0000 (10:56 -0600)]
snapshot: correctly escape generated xml
Commit 69278878 fixed one direction of arbitrarily-named snapshots,
but not the round trip path. While auditing domain_conf, I found
a couple other instances that weren't escaping arbitrary strings.
Eric Blake [Sat, 13 Aug 2011 01:19:47 +0000 (19:19 -0600)]
snapshot: allow full domain xml in snapshot
Just like VM saved state images (virsh save), snapshots MUST
track the inactive domain xml to detect any ABI incompatibilities.
The indentation is not perfect, but functionality comes before form.
Later patches will actually supply a full domain; for now, this
wires up the storage to support one, but doesn't ever generate one
in dumpxml output.
Happily, libvirt.c was already rejecting use of VIR_DOMAIN_XML_SECURE
from read-only connections, even though before this patch, there was
no information to be secured by the use of that flag.
And while we're at it, mark the libvirt snapshot metadata files
as internal-use only.
* src/libvirt.c (virDomainSnapshotGetXMLDesc): Document flag.
* src/conf/domain_conf.h (_virDomainSnapshotDef): Add member.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Update signature.
* src/conf/domain_conf.c (virDomainSnapshotDefFree): Clean up.
(virDomainSnapshotDefParseString): Optionally parse domain.
(virDomainSnapshotDefFormat): Output full domain.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML)
(esxDomainSnapshotGetXMLDesc): Update callers.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML)
(vboxDomainSnapshotGetXMLDesc): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotLoad, qemuDomainSnapshotGetXMLDesc)
(qemuDomainSnapshotWriteMetadata): Likewise.
* docs/formatsnapshot.html.in: Rework doc example.
Based on a patch by Philipp Hahn.
Eric Blake [Fri, 12 Aug 2011 19:23:09 +0000 (13:23 -0600)]
snapshot: prevent migration from stranding snapshot data
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.
Eric Blake [Fri, 12 Aug 2011 16:20:24 +0000 (10:20 -0600)]
snapshot: support new undefine flags in qemu
A nice benefit of deleting all snapshots at undefine time is that
you don't have to do any reparenting or subtree identification - since
everything goes, this is an O(n) process, whereas using multiple
virDomainSnapshotDelete calls would be O(n^2) or worse. But it is
only doable for snapshot metadata, where we are in control of the
data being deleted; for the actual snapshots, there's too much
likelihood of something going wrong, and requiring even more API
calls to figure out what failed in the meantime, so callers are
better off deleting the snapshot data themselves one snapshot at
a time where they can deal with failures as they happen.
* src/qemu/qemu_driver.c (qemuDomainUndefineFlags): Honor new flags.
Eric Blake [Fri, 12 Aug 2011 16:12:47 +0000 (10:12 -0600)]
snapshot: cache qemu-img location
As more clients start to want to know this information, doing
a PATH stat walk and malloc for every client adds up.
We are only caching the location, not the capabilities, so even
if qemu-img is updated in the meantime, it will still probably
live in the same location. So there is no need to worry about
clearing this particular cache.
Eric Blake [Fri, 12 Aug 2011 02:24:19 +0000 (20:24 -0600)]
snapshot: teach virsh about new undefine flags
Similar to 'undefine --managed-save' (commit 83e849c1), we must
assume that the old API is unsafe; however, we cannot emulate
metadata-only deletion on older servers. Additionally, we have
the wrinkle that while virDomainUndefineFlags and managed save
cleanup were introduced in 0.9.4, it wasn't until 0.9.5 that
snapshots block undefine of a domain. Do the best we can given
the server we are talking to.
Eric Blake [Fri, 12 Aug 2011 15:07:08 +0000 (09:07 -0600)]
snapshot: prevent stranding snapshot data on domain destruction
Just as leaving managed save metadata behind can cause problems
when creating a new domain that happens to collide with the name
of the just-deleted domain, the same is true of leaving any
snapshot metadata behind. For safety sake, extend the semantic
change of commit b26a9fa9 to also cover snapshot metadata as a
reason to reject undefining an inactive domain. A future patch
will make sure that shutdown of a transient domain automatically
deletes snapshot metadata (whether by destroy, shutdown, or
guest-initiated action). Management apps of transient domains
should take care to capture xml of snapshots, if it is necessary
to recreate the snapshot metadata on a later transient domain
with the same name and uuid.
This also documents a new flag that hypervisors can choose to
support as a shortcut for taking care of the metadata as part of
the undefine process; however, nontrivial driver support for these
flags will be deferred to future patches.
Note that ESX and VBox can never be transient; therefore, they
do not have to worry about automatic cleanup after shutdown
(the persistent domain still remains); likewise they never
store snapshot metadata, so the undefine flag is trivial.
The nontrivial work remaining is thus in the qemu driver.
* include/libvirt/libvirt.h.in
(VIR_DOMAIN_UNDEFINE_SNAPSHOTS_METADATA): New flag.
* src/libvirt.c (virDomainUndefine, virDomainUndefineFlags):
Document new limitations and flag.
* src/esx/esx_driver.c (esxDomainUndefineFlags): Trivial
implementation.
* src/vbox/vbox_tmpl.c (vboxDomainUndefineFlags): Likewise.
* src/qemu/qemu_driver.c (qemuDomainUndefineFlags): Enforce
the limitations.
Eric Blake [Thu, 1 Sep 2011 22:50:17 +0000 (16:50 -0600)]
snapshot: add qemu snapshot redefine support
Redefining a qemu snapshot requires a bit of a tweak to the common
snapshot parsing code, but the end result is quite nice.
Be careful that redefinitions do not introduce circular parent
chains. Also, we don't want to allow conversion between online
and offline existing snapshots. We could probably do some more
validation for snapshots that don't already exist to make sure
they are even feasible, by parsing qemu-img output, but that
can come later.
* src/conf/domain_conf.h (virDomainSnapshotParseFlags): New
internal flags.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString): Alter
signature to take internal flags.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML): Update caller.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Support
new public flags.
Eric Blake [Thu, 1 Sep 2011 21:47:03 +0000 (15:47 -0600)]
snapshot: add qemu snapshot creation without metadata
Supporting NO_METADATA on snapshot creation is interesting - we must
still return a valid opaque snapshot object, but the user can't get
anything out of it (unless we add a virDomainSnapshotGetName()),
since it is no longer registered with the domain.
Also, virsh now tries to query for secure xml, in anticipation of
when we store <domain> xml inside <domainsnapshot>; for now, we
can trivially support it, since we have nothing secure.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Support
new flag.
(qemuDomainSnapshotGetXMLDesc): Trivially support VIR_DOMAIN_XML_SECURE.
Wire up the new snapshot creation flags in virsh. For convenience,
teach 'snapshot-current' how to make an existing snapshot become
current (can be used after upgrading to newer libvirt to recover
from the fact that the older libvirt lost track of the current
snapshot after a restart). The snapshot-create-as command is
intentionally not taught --redefine or --current, as this would
imply adding a lot of other options for everything else that can
appear in the <domainsnapshot> xml, but which is normally read-only.
Besides, redefining will usually be done on files created by
snapshot-dumpxml, rather than something built up by hand on the
command line. And now that we can redefine, we can edit.
* tools/virsh.c (cmdSnapshotCreate): Add --redefine, --current,
and --no-metadata.
(cmdSnapshotCreateAs): Add --no-metadata.
(cmdSnapshotCurrent): Add snapshotname to alter current snapshot.
(cmdSnapshotEdit): New command.
* tools/virsh.pod (snapshot-create, snapshot-create-as)
(snapshot-current, snapshot-edit): Document these.
Eric Blake [Wed, 31 Aug 2011 01:02:46 +0000 (19:02 -0600)]
snapshot: allow recreation of metadata
The first two flags are essential for being able to replicate
snapshot hierarchies across multiple hosts, which will come in
handy for supervised migrations. It also allows a management app
to take a snapshot of a transient domain, save the metadata, stop
the domain, recreate a new transient domain by the same name,
redefine the snapshot, then revert to it.
This is not quite as convenient as leaving the metadata behind
after a domain is no longer around, but doing that has a few
problems: 1. the libvirt API can only delete snapshot metadata
if there is a valid domain handle to use to get to that snapshot
object - if stale data is left behind without a domain, there is
no way to request that the data be cleaned up. 2. creating a new
domain with the same name but different uuid than the older
domain where a snapshot existed cannot use the older snapshot
data; this risks confusing libvirt, and forbidding the stale
data is similar to the recent patch to forbid stale managed save.
The first two flags might be useful on hypervisors with no metadata,
but only for modifying the notion of the current snapshot;
however, I don't know how to do that for ESX or VBox.
The third flag is a convenience option, to combine a creation with
a delete metadata into one step. It is trivial for hypervisors
with no metadata.
The qemu changes will be involved enough to warrant a separate patch.
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