xenUnifiedDomainEventRegister() calls out to
virDomainEventCallbackListAdd(), which increments the reference
count on the connection. That is fine, but then
xenUnifiedDomainEventRegister() increments the usage count again,
leading to a usage count leak. Remove the increment in the xen
register, and the UnrefConnect in the xen unregister.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Most of the hash iterators need to modify either payload of
data args. The const annotation prevents this.
* src/util/hash.h, src/util/hash.c: Remove const-ness from
virHashForEach/Iterator
* src/xen/xm_internal.c: Remove bogus casts
If one has e.g.
<guest>
<os_type>hvm</os_type>
<arch name='x86_64'>
<wordsize>64</wordsize>
<emulator>/usr/bin/qemu-system-x86_64</emulator>
<machine>pc-0.11</machine>
<machine canonical='pc-0.11'>pc</machine>
<machine>pc-0.10</machine>
<machine>isapc</machine>
<domain type='qemu'>
</domain>
<domain type='kvm'>
<emulator>/usr/bin/kvm</emulator>
<machine>pc</machine>
<machine>isapc</machine>
</domain>
</arch>
</guest>
and start a guest with:
<domain type='kvm'>
...
<os>
<type arch='x86_64'>hvm</type>
...
</os>
</domain>
then the default machine type should be 'pc' and not 'pc-0.11'
Issue was reported by Anton Protopopov.
* src/capabilities.[ch]: pass the domain type to
virCapabilitiesDefaultGuestArch() and use it to look up the default
machine type from a specific guest domain if needed.
* src/conf/domain_conf.c, src/xen/xm_internal.c: update
* tests/qemuxml2argvdata/qemuxml2argv-machine-aliases2.xml: update
the domain type to 'kvm' and remove the machine type to check
that the default gets looked up correctly
Introduces several new public API options for migration
- VIR_MIGRATE_PEER2PEER: With this flag the client only
invokes the virDomainMigratePerform method, expecting
the source host driver to do whatever is required to
complete the entire migration process.
- VIR_MIGRATE_TUNNELLED: With this flag the actual data
for migration will be tunnelled over the libvirtd RPC
channel. This requires that VIR_MIGRATE_PEER2PEER is
also set.
- virDomainMigrateToURI: This is variant of the existing
virDomainMigrate method which does not require any
virConnectPtr for the destination host. Given suitable
driver support, this allows for all the same modes as
virDomainMigrate()
The URI for VIR_MIGRATE_PEER2PEER must be a valid libvirt
URI. For non-p2p migration a hypervisor specific migration
URI is used.
virDomainMigrateToURI without a PEER2PEER flag is only
support for Xen currently, and it involves XenD talking
directly to XenD, no libvirtd involved at all.
* include/libvirt/libvirt.h.in: Add VIR_MIGRATE_PEER2PEER
flag for migration
* src/libvirt_internal.h: Add feature flags for peer to
peer migration (VIR_FEATURE_MIGRATE_P2P) and direct
migration (VIR_MIGRATE_PEER2PEER mode)
* src/libvirt.c: Implement support for VIR_MIGRATE_PEER2PEER
and virDomainMigrateToURI APIs.
* src/xen/xen_driver.c: Advertise support for DIRECT migration
* src/xen/xend_internal.c: Add TODO item for p2p migration
* src/libvirt_public.syms: Export virDomainMigrateToURI
method
* src/qemu/qemu_driver.c: Add support for PEER2PEER and
migration, and adapt TUNNELLED migration.
* tools/virsh.c: Add --p2p and --direct args and use the
new virDomainMigrateToURI method where possible.
Implementation of tunnelled migration, using a Unix Domain Socket
on the qemu backend. Note that this requires very new versions of
qemu (0.10.7 at least) in order to get the appropriate bugfixes.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Add the virStrncpy function, which takes a dst string, source string,
the number of bytes to copy and the number of bytes available in the
dest string. If the source string is too large to fit into the
destination string, including the \0 byte, then no data is copied and
the function returns NULL. Otherwise, this function copies n bytes
from source into dst, including the \0, and returns a pointer to the
dst string. This function is intended to replace all unsafe uses
of strncpy in the code base, since strncpy does *not* guarantee that
the buffer terminates with a \0.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
The commit cb51aa48a7 "Fix up connection
reference counting." changed the driver closing and virConnectPtr
unref-logic in virConnectClose().
Before this commit virConnectClose() closed all drivers of the given
virConnectPtr and virUnrefConnect()'ed it afterwards. After this
commit the driver-closing is done in virUnrefConnect() if and only if
the ref-count of the virConnectPtr dropped to zero.
This change in execution order leads to a virConnectPtr leak, at least
for connections to Xen.
The relevant call sequences:
virConnectOpen() -> xenUnifiedOpen() ...
... xenInotifyOpen() -> virConnectRef(conn)
... xenStoreOpen() -> xenStoreAddWatch() -> conn->refs++
virConnectClose() -> xenUnifiedClose() ...
... xenInotifyClose() -> virUnrefConnect(conn)
... xenStoreClose() -> xenStoreRemoveWatch() -> virUnrefConnect(conn)
Before the commit this additional virConnectRef/virUnrefConnect calls
where no problem, because virConnectClose() closed the drivers
explicitly and the additional refs added by the Xen subdrivers were
removed properly. After the commit this additional refs result in a
virConnectPtr leak (including a leak of the hypercall file handle;
that's how I noticed this problem), because now the drivers are only
close if and only if the ref-count drops to zero, but this cannot
happen anymore, because the additional refs from the Xen subdrivers
would only be removed if the drivers get closed, but that doesn't
happen because the ref-count cannot drop to zero.
The fix for this problem is simple: remove the
virConnectRef/virUnrefConnect calls from the Xen subdrivers (see
attached patch). Maybe someone could explain why the Xen Inotify and
Xen Store driver do this extra ref-counting, but none of the other Xen
subdrivers. It seems unnecessary to me and can be removed without
problems.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
