Here are some IBMers who use their personal addresses when submitting
patches.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Relying on sleep to always return having slept isn't safe as a signal
may have occurred. If signals are constantly incoming the program will
never reach its termination condition. This is believed to be the
mechanism causing time outs for qht-test in Travis.
The glib g_usleep() deals with all of this for us so lets use it instead.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Now we are using "named" snapshots of debian-sid we can rely on the
existing checksum mechanism for detecting changes.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
We are now using Xenial based images on Travis so we should make the
same one available as our qemu:travis docker image.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Travis is slowly catching up. Move to Xenial based images for our
current builds. These are now all proper VMs.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
The Debian Sid repository is not garanteed to be stable, as his
'unstable' name suggest :)
To allow quick testing, packages are pushed various time a day,
which my be annoying when trying to use it for stable development
(which is not recommended, but Sid provides edge packages we use
for testing).
Debian provides repositories snapshots which are suitable for our
use. Pick a recent date that works. When required, update to newer
releases will be easy.
This fixes current issues with this image:
$ make docker-image-debian-sid
[...]
The following packages have unmet dependencies:
build-essential : Depends: dpkg-dev (>= 1.17.11) but it is not going to be installed
git : Depends: perl but it is not going to be installed
Depends: liberror-perl but it is not going to be installed
pkg-config : Depends: libdpkg-perl but it is not going to be installed
texinfo : Depends: perl (>= 5.26.2-6) but it is not going to be installed
Depends: libtext-unidecode-perl but it is not going to be installed
Depends: libxml-libxml-perl but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[AJB: also tweak FROM to a earlier snapshot]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The global defaults request "trusty" and "gcc", so matrix entries do not
need to repeat this.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Travis sometimes fails a build because it produces no console output for
over 10 minutes. If this is due to a genuine hang, it would be useful to
have used verbose test output to see where it failed. If this is just
due to tests being very slow, having verbose output might allow the
build to succeed.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
The Travis container based envs are deprecated:
https://docs.travis-ci.com/user/reference/trusty/
"Container-based infrastructure is currently being deprecated.
Please remove any sudo: false keys in your .travis.yml file
to use the default fully-virtualized Linux infrastructure
instead."
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
One of the matrix entries redefines the script command in order to add
the ${MAKEFLAGS} variable. Ideally ${MAKEFLAGS} would be referenced by
the definition of the ${TEST_CMD} env variable, but this isn't possible
in travis. ${MAKEFLAGS} exists to eliminate duplication of flags in
every "make" command, but this cure causes a worse problem, namely the
reduplication of the "script" command. It is simpler to just insert "-j3"
directly into any "make" command.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Rather than poking homebrew manually we can specify the packages
needed via the homebrew addon. These are only installed on MacOS based
builds.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The configure script & Makefile are already capable of figuring out
which git submodules are required for a given build platform, and
cloning them at the right time.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Matrix entries are defining env variables using two different syntax
styles:
- env: FOO=bar
WIZZ=bang
and
- env:
- FOO=bar
- WIZZ=bang
Switch everything to use the latter style as the more normal indentation
approach.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
The current build matrix is constructed from entries listed under the
environment variable config section, as well as the general purpose
build matrix section. Move everything under the general purpose section
so it is clear at a glance what is in the matrix.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Improve the readability of the travis config by adding two blank lines
between each major section and matrix entry.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
This avoids potential problems with duplicates.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Using the "latest" tag is not a good idea because this changes what
release it points to every 6 months. Together with caching of docker
builds this can cause confusion where CI has cached & built with Fedora
N, while a developer tries to reproduce a CI problem with Fedora N + 1,
or vica-verca.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Fedora 29 is the current newest release, so switch to using that
from the current Fedora 28.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
The 'debian' dockerfile was deprecated in favour of versioned
dockerfiles in July 2017. That is enough time for developers to
be warned about the rename.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The docker file builds and installs software into /usr/local but does
not run ldconfig. As a result QEMU links to libvirglrenderer.so, but
then crashes in "make check" unable to find the library.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Use a stable tag instead of some random commit from mainstream
development, to avoid unexpected build failures.
This fixes:
CC virglrenderer.lo
virglrenderer.c: In function 'virgl_has_gl_colorspace':
virglrenderer.c:208:11: error: implicit declaration of function 'virgl_has_egl_khr_gl_colorspace' [-Werror=implicit-function-declaration]
virgl_has_egl_khr_gl_colorspace(egl_info));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
virglrenderer.c:208:43: error: 'egl_info' undeclared (first use in this function)
virgl_has_egl_khr_gl_colorspace(egl_info));
^~~~~~~~
virglrenderer.c:208:43: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors
As of this commit 'git virglrenderer-0.7.0' is the last stable tag.
(virglrenderer commit breaking: fb4f7577f7ef)
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Hyper-V .feat_names are, unlike hardware features, commented out and it is
not obvious why we do that. Document the current status quo.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20181221141604.16935-1-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Some downstream distributions of QEMU set host-phys-bits=on by
default. This worked very well for most use cases, because
phys-bits really didn't have huge consequences. The only
difference was on the CPUID data seen by guests, and on the
handling of reserved bits.
This changed in KVM commit 855feb673640 ("KVM: MMU: Add 5 level
EPT & Shadow page table support"). Now choosing a large
phys-bits value for a VM has bigger impact: it will make KVM use
5-level EPT even when it's not really necessary. This means
using the host phys-bits value may not be the best choice.
Management software could address this problem by manually
configuring phys-bits depending on the size of the VM and the
amount of MMIO address space required for hotplug. But this is
not trivial to implement.
However, there's another workaround that would work for most
cases: keep using the host phys-bits value, but only if it's
smaller than 48. This patch makes this possible by introducing a
new "-cpu" option: "host-phys-bits-limit". Management software
or users can make sure they will always use 4-level EPT using:
"host-phys-bits=on,host-phys-bits-limit=48".
This behavior is still not enabled by default because QEMU
doesn't enable host-phys-bits=on by default. But users,
management software, or downstream distributions may choose to
change their defaults using the new option.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20181211192527.13254-1-ehabkost@redhat.com>
[ehabkost: removed test code while some issues are addressed]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
MPX support is being phased out by Intel; GCC has dropped it, Linux
is also going to do that. Even though KVM will have special code
to support MPX after the kernel proper stops enabling it in XCR0,
we probably also want to deprecate that in a few years. As a start,
do not enable it by default for any named CPU model starting with
the 4.0 machine types; this include Skylake, Icelake and Cascadelake.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20181220121100.21554-1-pbonzini@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The missing functionality was added ~3 years ago with the Linux commit
46896c73c1a4 ("KVM: svm: add support for RDTSCP")
so reenable RDTSCP support on those CPU models.
Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support
(the real hardware doesn't have it. K8 got RDTSCP support with the NPT
models, i.e., models >= 0x40).
Document the host's minimum required kernel version, while at it.
Signed-off-by: Borislav Petkov <bp@suse.de>
Message-ID: <20181212200803.GG6653@zn.tnic>
[ehabkost: moved compat properties code to pc.c]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
It was found that QMP users of QEMU (e.g. libvirt) may need
HV_CPUID_ENLIGHTMENT_INFO.EAX/HV_CPUID_NESTED_FEATURES.EAX information. In
particular, 'hv_tlbflush' and 'hv_evmcs' enlightenments are only exposed in
HV_CPUID_ENLIGHTMENT_INFO.EAX.
HV_CPUID_NESTED_FEATURES.EAX is exposed for two reasons: convenience
(we don't need to export it from hyperv_handle_properties() and as
future-proof for Enlightened MSR-Bitmap, PV EPT invalidation and
direct virtual flush features.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20181126135958.20956-1-vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
It is possible for an io_poll callback to be concurrently executed along
with an aio_set_fd_handlers. This can cause all sorts of problems, like
a NULL callback or a bad opaque pointer.
This changes set_fd_handlers so that it no longer modify existing handlers
entries and instead, always insert those after having proper initialisation.
Tested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Remy Noel <remy.noel@blade-group.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20181220152030.28035-3-remy.noel@blade-group.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Cleaning the events will cause aio_epoll_update to unregister the fd.
Otherwise, the fd is kept registered until it is destroyed.
Signed-off-by: Remy Noel <remy.noel@blade-group.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20181220152030.28035-2-remy.noel@blade-group.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The xen-block dataplane currently allocates memory to hold the data for
each request as that request is used, and frees it afterwards. Because
it requires page-aligned blocks, this interacts poorly with non-page-
aligned allocations and balloons the heap.
Instead, allocate the maximum possible buffer size required for the
protocol, which is BLKIF_MAX_SEGMENTS_PER_REQUEST (currently 11) pages
when the request structure is created, and keep that buffer until it is
destroyed. Since the requests are re-used via a free list, this should
actually improve memory usage.
Signed-off-by: Tim Smith <tim.smith@citrix.com>
Re-based and commit comment adjusted.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
If the I/O ring is full, the guest cannot send any more requests
until some responses are sent. Only sending all available responses
just before checking for new work does not leave much time for the
guest to supply new work, so this will cause stalls if the ring gets
full. Also, not completing reads as soon as possible adds latency
to the guest.
To alleviate that, complete IO requests as soon as they come back.
xen_block_send_response() already returns a value indicating whether
a notify should be sent, which is all the batching we need.
Signed-off-by: Tim Smith <tim.smith@citrix.com>
Re-based and commit comment adjusted.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
When I/O consists of many small requests, performance is improved by
batching them together in a single io_submit() call. When there are
relatively few requests, the extra overhead is not worth it. This
introduces a check to start batching I/O requests via blk_io_plug()/
blk_io_unplug() in an amount proportional to the number which were
already in flight at the time we started reading the ring.
Signed-off-by: Tim Smith <tim.smith@citrix.com>
Re-based and commit comment adjusted.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
xend have been replaced by libxenlight (libxl) for many Xen releases
now.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
It is broken since Xen 4.9 [1] and it will not build in Xen 4.12. Also,
it is not built by default since QEMU 2.6.
[1] https://lists.xenproject.org/archives/html/xen-devel/2018-09/msg00313.html
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
This backend has now been replaced by the 'xen-qdisk' XenDevice.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
I have made many significant contributions to the Xen code in QEMU,
particularly the recent patches introducing a new PV device framework.
I intend to make further significant contributions, porting other PV back-
ends to the new framework with the intent of eventually removing the
legacy code. It therefore seems reasonable that I become a maintainer of
the Xen code.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch adds create and destroy function for XenBlockDevice-s so that
they can be created automatically when the Xen toolstack instantiates a new
PV backend via xenstore. When the XenBlockDevice is created this way it is
also necessary to create a 'drive' which matches the configuration that the
Xen toolstack has written into xenstore. This is done by formulating the
parameters necessary for each 'blockdev' layer of the drive and then using
qmp_blockdev_add() to create the layers. Also, for compatibility with the
legacy 'xen_disk' implementation, an iothread is automatically created for
the new XenBlockDevice. This, like the driver layers, will be destroyed
after the XenBlockDevice is unrealized.
The legacy backend scan for 'qdisk' is removed by this patch, which makes
the 'xen_disk' code is redundant. The code will be removed by a subsequent
patch.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
...that maintains compatibility with existing Xen toolstacks.
Xen toolstacks instantiate PV backends by simply writing information into
xenstore and expecting a backend implementation to be watching for this.
This patch adds a new 'xen-backend' module to allow individual XenDevice
implementations to register create and destroy functions. The creator
will be called when a tool-stack instantiates a new backend in this way,
and the destructor will then be called after the resulting XenDevice
object is unrealized.
To support this it is also necessary to add new watchers into the XenBus
implementation to handle enumeration of new backends and also destruction
of XenDevice-s when the toolstack sets the backend 'online' key to 0.
NOTE: This patch only adds the framework. A subsequent patch will add a
creator function for xen-block devices.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
...and wire in the dataplane.
This patch adds the remaining code to make the xen-block XenDevice
functional. The parameters that a block frontend expects to find are
populated in the backend xenstore area, and the 'ring-ref' and
'event-channel' values specified in the frontend xenstore area are
mapped/bound and used to set up the dataplane.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This is a purely cosmetic patch that purges remaining use of 'blk' and
'ioreq' in local function names, and then makes sure all functions are
prefixed with 'xen_block_'.
No functional change.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This is a purely cosmetic patch that purges the name 'ioreq' from struct,
variable and field names. (This name has been problematic for a long time
as 'ioreq' is the name used for generic I/O requests coming from Xen).
The patch replaces 'struct ioreq' with a new 'XenBlockRequest' type and
'ioreq' field/variable names with 'request', and then does necessary
fix-up to adhere to coding style.
Function names are not modified by this patch. They will be dealt with in
a subsequent patch.
No functional change.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This is a purely cosmetic patch that substitutes the old 'struct XenBlkDev'
name with 'XenBlockDataPlane' and 'blkdev' field/variable names with
'dataplane', and then does necessary fix-up to adhere to coding style.
No functional change.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch adds the transformations necessary to get dataplane/xen-block.c
to build against the new XenBus/XenDevice framework. MAINTAINERS is also
updated due to the introduction of dataplane/xen-block.h.
NOTE: Existing data structure names are retained for the moment. These will
be modified by subsequent patches. A typedef for XenBlockDataPlane
has been added to the header (based on the old struct XenBlkDev name
for the moment) so that the old names don't need to leak out of the
dataplane code.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Not all of the code duplicated from xen_disk.c is required as the basis for
the new dataplane implementation so this patch removes extraneous code,
along with the legacy #includes and calls to the legacy xen_pv_printf()
function. Error messages are changed to be reported using error_report().
NOTE: The code is still not yet built. Further transformations will be
required to make it correctly interface to the new XenBus/XenDevice
framework. They will be delivered in a subsequent patch.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
The new xen-block XenDevice implementation requires the same core
dataplane as the legacy xen_disk implementation it will eventually replace.
This patch therefore copies the legacy xen_disk.c source module into a new
dataplane/xen-block.c source module as the basis for the new dataplane and
adjusts the MAINTAINERS file accordingly.
NOTE: The duplicated code is not yet built. It is simply put into place by
this patch (just fixing style violations) such that the
modifications that will need to be made to the code are not
conflated with code movement, thus making review harder.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
The legacy PV backend infrastructure provides functions to bind, unbind
and send notifications to event channnels. Similar functionality will be
required by XenDevice implementations so this patch adds the necessary
support.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Patch squashed with:
Patch "xen: add event channel interface for XenDevice-s" makes use of
the type xenevtchn_port_or_error_t, but this isn't avaiable before Xen
4.7. Also the function xen_device_bind_event_channel assign the return
value of xenevtchn_bind_interdomain to channel->local_port but check the
result for error with xendev->local_port.
Fix by:
- removing local_port from struct XenDevice as it isn't use anywere.
- adding a compatibility typedef for xenevtchn_port_or_error_t for Xen
4.6 and earlier.
As extra, replace the type of XenEventChannel->local_port by
evtchn_port_t.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
The legacy PV backend infrastructure provides functions to map, unmap and
copy pages granted by frontends. Similar functionality will be required
by XenDevice implementations so this patch adds the necessary support.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
A Xen PV frontend communicates its state to the PV backend by writing to
the 'state' key in the frontend area in xenstore. It is therefore
necessary for a XenDevice implementation to be notified whenever the
value of this key changes.
This patch adds code to do this as follows:
- an 'fd handler' is registered on the libxenstore handle which will be
triggered whenever a 'watch' event occurs
- primitives are added to xen-bus-helper to add or remove watch events
- a list of Notifier objects is added to XenBus to provide a mechanism
to call the appropriate 'watch handler' when its associated event
occurs
The xen-block implementation is extended with a 'frontend_changed' method,
which calls as-yet stub 'connect' and 'disconnect' functions when the
relevant frontend state transitions occur. A subsequent patch will supply
a full implementation for these functions.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Joel Stanley