To allow the new virDomainUpdateDeviceFlags() API to be universally
used with all drivers, this patch adds an impl to all the current
drivers which support CDROM or Floppy disk media change via the
current virDomainAttachDeviceFlags API
* src/qemu/qemu_driver.c, src/vbox/vbox_tmpl.c,
src/xen/proxy_internal.c, src/xen/xen_driver.c,
src/xen/xend_internal.c: Implement media change via the
virDomainUpdateDeviceFlags API
* src/xen/xen_driver.h, src/xen/xen_hypervisor.c,
src/xen/xen_inotify.c, src/xen/xm_internal.c,
src/xen/xs_internal.c: Stubs for Xen driver entry points
* src/xen/xs_internal.c (xenStoreDomainIntroduced): Don't use -1
as an allocation size upon xenStoreNumOfDomains failure.
(xenStoreDomainReleased): Likewise.
The Xen code for making HVM VT-d PCI passthrough attach and detach
wasn't working properly:
1) In xenDaemonAttachDevice(), we were always trying to reconfigure
a PCI passthrough device, even the first time we added it. This was
because the code in virDomainXMLDevID() was not checking xenstore for
the existence of the device, and always returning 0 (meaning that
the device already existed).
2) In xenDaemonDetachDevice(), we were trying to use "device_destroy"
to detach a PCI device. While you would think that is the right
method to call, it's actually wrong for PCI devices. In particular,
in upstream Xen (and soon in RHEL-5 Xen), device_configure is actually
used to destroy a PCI device.
To fix the attach
problem I add a lookup into xenstore to see if the device we are
trying to attach already exists. To fix the detach problem I change
it so that for PCI detach (only), we use device_configure with the
appropriate sxpr to do the detachment.
* src/xen/xend_internal.c: don't use device_destroy for PCI devices
and fix the other issues.
* src/xen/xs_internal.c src/xen/xs_internal.h: add
xenStoreDomainGetPCIID()
Replace free(virBufferContentAndReset()) with virBufferFreeAndReset().
Update documentation and replace all remaining calls to free() with
calls to VIR_FREE(). Also add missing calls to virBufferFreeAndReset()
and virReportOOMError() in OOM error cases.
The xenstore database sometimes has stale domain IDs which are not
present in the hypervisor anymore. Filter these out to avoid causing
confusion
* src/xen/xs_internal.c: Filter domain IDs against HV's list
* src/xen/xen_hypervisor.h, src/xen/xen_hypervisor.c: Add new
xenHypervisorHasDomain() method for checking ID validity
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>
