A block commit moves data in the opposite direction of block pull.
Block pull reduces the chain length by dropping backing files after
data has been pulled into the top overlay, and is always safe; block
commit reduces the chain length by dropping overlays after data has
been committed into the backing file, and any files that depended
on base but not on top are invalidated at any point where they have
unallocated data that is now pointing to changed contents in base.
Both directions are useful, however: a qcow2 layer that is more than
50% allocated will typically be faster with a pull operation, while
a qcow2 layer with less than 50% allocation will be faster as a
commit operation. Committing across multiple layers can be more
efficient than repeatedly committing one layer at a time, but
requires extra support from the hypervisor.
This API matches Jeff Cody's proposed qemu command 'block-commit':
https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg02226.html
Jeff's command is still in the works for qemu 1.3, and may gain
further enhancements, such as the ability to control on-error
handling (it will be comparable to the error handling Paolo is
adding to 'drive-mirror', so a similar solution will be needed
when I finally propose virDomainBlockCopy with more functionality
than the basics supported by virDomainBlockRebase). However, even
without qemu support, this API will be useful for _offline_ block
commits, by wrapping qemu-img calls and turning them into a block
job, so this API is worth committing now.
For some examples of how this will be implemented, all starting
with the chain: base <- snap1 <- snap2 <- active
+ These are equivalent:
virDomainBlockCommit(dom, disk, NULL, NULL, 0, 0)
virDomainBlockCommit(dom, disk, NULL, "active", 0, 0)
virDomainBlockCommit(dom, disk, "base", NULL, 0, 0)
virDomainBlockCommit(dom, disk, "base", "active", 0, 0)
but cannot be implemented for online qemu with round 1 of
Jeff's patches; and for offline images, it would require
three back-to-back qemu-img invocations unless qemu-img
is patched to allow more efficient multi-layer commits;
the end result would be 'base' as the active disk with
contents from all three other files, where 'snap1' and
'snap2' are invalid right away, and 'active' is invalid
once any further changes to 'base' are made.
+ These are equivalent:
virDomainBlockCommit(dom, disk, "snap2", NULL, 0, 0)
virDomainBlockCommit(dom, disk, NULL, NULL, 0, _SHALLOW)
they cannot be implemented for online qemu, but for offline,
it is a matter of 'qemu-img commit active', so that 'snap2'
is now the active disk with contents formerly in 'active'.
+ Similarly:
virDomainBlockCommit(dom, disk, "snap2", NULL, 0, _DELETE)
for an offline domain will merge 'active' into 'snap2', then
delete 'active' to avoid leaving a potentially invalid file
around.
+ This version:
virDomainBlockCommit(dom, disk, NULL, "snap2", 0, _SHALLOW)
can be implemented online with 'block-commit' passing a base of
snap1 and a top of snap2; and can be implemented offline by
'qemu-img commit snap2' followed by 'qemu-img rebase -u
-b snap1 active'
* include/libvirt/libvirt.h.in (virDomainBlockCommit): New API.
* src/libvirt.c (virDomainBlockCommit): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.10.2): Export it.
* src/driver.h (virDrvDomainBlockCommit): New driver callback.
* docs/apibuild.py (CParser.parseSignature): Add exception.
Upstream qemu has raised a concern about whether dumping guest
memory by reading guest paging tables is a security hole:
https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg02607.html
While auditing libvirt to see if we would be impacted, I noticed
that we had some dead code. It is simpler to nuke the dead code
and limit our monitor code to just the subset we make use of.
* src/qemu/qemu_monitor.h (QEMU_MONITOR_DUMP): Drop poorly named
and mostly-unused enum.
* src/qemu/qemu_monitor.c (qemuMonitorDumpToFd): Drop arguments.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDump): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDump): Likewise.
* src/qemu/qemu_driver.c (qemuDumpToFd): Update caller.
virNetworkAssignDef was allocating a new network object, initing and
grabbing its lock, then potentially freeing it without unlocking or
destroying the lock. In practice 1) this will probably never happen,
and 2) even if it did, the lock implementation used on most (all?)
platforms doesn't actually hold any resources for an initialized or
held lock, but it still bothered me, so I moved the realloc that could
lead to this bad situation earlier in the function, and now the mutex
isn't inited or locked until we are assured of complete success.
These two objects were previously always parsed as a part of an IpDef,
but we will now need to be able to parse them on their own for
virNetworkUpdate(). Split the parsing functions out, with no
functional changes.
The final patch in Hu Tao's series to enhance virBitmap actually
removes virDomainCpuSetParse and virDomainCpuSetFormat as "no longer
used", and the rest of the series hadn't taken care of two uses of
virDomainCpuSetParse in the xen code.
This patch replaces those with appropriate virBitmap functions. It
should be pushed prior to the patch removing virDomainCpuSetParse.
In many places we store bitmap info in a chunk of data
(pointed to by a char *), and have redundant codes to
set/unset bits. This patch extends virBitmap, and convert
those codes to use virBitmap in subsequent patches.
New command node-memory-tune to get/set the node memory parameters,
only two parameters are allowed to set (pages_to_scan, and sleep_millisecs,
see documents in this patch for more details).
Example of node-memory-tune's output:
Shared memory:
pages_to_scan 100
sleep_millisecs 20
pages_shared 0
pages_sharing 0
pages_unshared 0
pages_volatile 0
full_scans 0
Only implemented for linux platform.
* src/nodeinfo.h: (Declare node{Get,Set}MemoryParameters)
* src/nodeinfo.c: (Implement node{Get,Set}MemoryParameters)
* src/libvirt_private.syms: (Export those two new internal APIs to
private symbols)
* src/rpc/gendispatch.pl: (virNodeSetMemoryParameters is the
the special one which needs a connection object as the first
argument, improve the generator to support it).
* daemon/remote.c: (Implement the server side handler for
virDomainGetMemoryParameters)
* src/remote/remote_driver.c: (Implement the client side handler
for virDomainGetMemoryParameters)
* src/remote/remote_protocol.x: (New RPC procedures for the two
new APIs and structs to represent the args and ret for it)
* src/remote_protocol-structs: Likewise
* include/libvirt/libvirt.h.in: (Add macros for the param fields,
declare the APIs).
* src/driver.h: (New methods for the driver struct)
* src/libvirt.c: (Implement the public APIs)
* src/libvirt_public.syms: (Export the public symbols)
This introduces four new options for secret-list, to filter the
returned secrets by whether it's ephemeral or not, and/or by
whether it's private or not.
* tools/virsh-secret.c: (New helper vshSecretSorter,
vshSecretListFree, and vshCollectSecretList; Use the new
API for secret-list; error out if flags are specified,
because there is no way to filter the results when using
old APIs (no APIs to get the properties (ephemeral, private)
of a secret yet).
* tools/virsh.pod: Document the 4 new options.
The implementation is done manually as the generator does not support
wrapping lists of C pointers into Python objects.
python/libvirt-override-api.xml: Document
python/libvirt-override-virConnect.py: Implementation for listAllSecrets.
python/libvirt-override.c: Implementation for the wrapper.
Simply returns the object list. Supports to filter the secrets
by its storage location, and whether it's private or not.
src/secret/secret_driver.c: Implement listAllSecrets
The RPC generator doesn't support returning list of object yet, this patch
does the work manually.
* daemon/remote.c:
Implement the server side handler remoteDispatchConnectListAllSecrets.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllSecrets.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_SECRETS and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
This is to list the secret objects. Supports to filter the secrets
by its storage location, and whether it's private or not.
include/libvirt/libvirt.h.in: Declare enum virConnectListAllSecretFlags
and virConnectListAllSecrets.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllSecrets)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public
tools/virsh-nwfilter.c:
* vshNWFilterSorter to sort network filters by name
* vshNWFilterListFree to free the network filter objects list.
* vshNWFilterListCollect to collect the network filter objects, trying
to use new API first, fall back to older APIs if it's not supported.
The implementation is done manually as the generator does not support
wrapping lists of C pointers into Python objects.
python/libvirt-override-api.xml: Document
python/libvirt-override-virConnect.py:
* Implementation for listAllNWFilters.
python/libvirt-override.c: Implementation for the wrapper.
The RPC generator doesn't support returning list of object yet, this patch
do the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchConnectListAllNWFilters.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllNWFilters.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_NWFILTERS and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
This is to list the network filter objects. No flags are supported
include/libvirt/libvirt.h.in: Declare enum virConnectListAllNWFilterFlags
and virConnectListAllNWFilters.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllNWFilters)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public
tools/virsh-nodedev.c:
* vshNodeDeviceSorter to sort node devices by name
* vshNodeDeviceListFree to free the node device objects list.
* vshNodeDeviceListCollect to collect the node device objects, trying
to use new API first, fall back to older APIs if it's not supported.
* Change option --cap to accept multiple capability types.
tools/virsh.pod
* Update document for --cap
This improve helper vshStringToArray to accept const string as
argument instead. To not convert the const string when using
vshStringToArray, and thus avoid motifying it.
The implementation is done manually as the generator does not support
wrapping lists of C pointers into Python objects.
python/libvirt-override-api.xml: Document
python/libvirt-override-virConnect.py:
* Implementation for listAllNodeDevices.
python/libvirt-override.c: Implementation for the wrapper.
src/conf/node_device_conf.h:
* New macro VIR_CONNECT_LIST_NODE_DEVICES_FILTERS_CAP
* Declare virNodeDeviceList
src/conf/node_device_conf.c:
* New helpers virNodeDeviceCapMatch, virNodeDeviceMatch.
virNodeDeviceCapMatch looks up the list of all the caps the device
support, to see if the device support the cap type.
* Implement virNodeDeviceList
src/libvirt_private.syms:
* Export virNodeDeviceList
* Export virNodeDevCapTypeFromString
The RPC generator doesn't support returning list of object yet, this patch
does the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchConnectListAllNodeDevices.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllNodeDevices.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_INTERFACES and
This is to list the node device objects, supports to filter the results
by capability types.
include/libvirt/libvirt.h.in: Declare enum virConnectListAllNodeDeviceFlags
and virConnectListAllNodeDevices.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllNodeDevices)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public
virNWFilterSnoopAdjustPoll() uses a struct pollfd but poll.h is never included
nwfilter/nwfilter_dhcpsnoop.c:1297: error: 'struct pollfd' declared inside parameter list
If the qemuBuildCommandLine method raised an error before the
virCommandPtr instance was created, the local var would not
be initialized, resulting in a possible SEGV in the error
cleanup branch. Also add some debugging of the method params
Introduce a qemuCapsNewForBinary() API which creates a new
QEMU capabilities object, populated with data relating to
a specific QEMU binary. The qemuCaps object is also given
a timestamp, which makes it possible to detect when the
cached capabilities for a binary are out of date
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Don't bother checking for the existance of the HMP passthrough
command. Just try to execute it, and propagate the failure.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The qemuMonitorHMPCommand() API and things it calls will report
a wide variety of errors. The QEMU text monitor should not be
overwriting these errors
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This patch adds full support for EOI setting for domains. Because this
is CPU feature (flag), the model needs to be added even when it's not
specified. Fortunately this problem was already solved with kvmclock,
so this patch simply abuses that.
And due to the size of the patch (17 lines) I dared to include the tests.
New options is added to support EOI (End of Interrupt) exposure for
guests. As it makes sense only when APIC is enabled, I added this into
the <apic> element in <features> because this should be tri-state
option (cannot be handled as standalone feature).
