Some frontend drivers will handle dynamic resizing of PV disks, so set up
the BlockDevOps resize_cb() method during xen_block_realize() to allow
this to be done.
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 should have been removed then xen_disk.c was removed but I missed them.
Fixes: 19f87870ba
xen: remove the legacy 'xen_disk' backend
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190122145132.12571-1-paul.durrant@citrix.com>
[lv: s/stake/stale/ and add "Fixes" tag]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
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>
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>
This patch adds new XenDevice-s: 'xen-disk' and 'xen-cdrom', both derived
from a common 'xen-block' parent type. These will eventually replace the
'xen_disk' (note the underscore rather than hyphen) legacy PV backend but
it is illustrative to build up the implementation incrementally, along with
the XenBus/XenDevice framework. Subsequent patches will therefore add to
these devices' implementation as new features are added to the framework.
After this patch has been applied it is possible to instantiate new
'xen-disk' or 'xen-cdrom' devices with a single 'vdev' parameter, which
accepts values adhering to the Xen VBD naming scheme [1]. For example, a
command-line instantiation of a xen-disk can be done with an argument
similar to the following:
-device xen-disk,vdev=hda
The implementation of the vdev parameter formulates the appropriate VBD
number for use in the PV protocol.
[1] https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
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>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
[Fixed lx -> PRIx64 as suggested by Philippe.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
SystemTap's dtrace(1) produces the following warning when it encounters
"char const" instead of "const char":
Warning: /usr/bin/dtrace:trace-dtrace-root.dtrace:66: syntax error near:
probe flatview_destroy_rcu
Warning: Proceeding as if --no-pyparsing was given.
This is a limitation in current SystemTap releases. I have sent a patch
upstream to accept "char const" since it is valid C:
https://sourceware.org/ml/systemtap/2018-q1/msg00017.html
In QEMU we still wish to avoid warnings in the current SystemTap
release. It's simple enough to replace "char const" with "const char".
I'm not changing the documentation or implementing checks to prevent
this from occurring again in the future. The next release of SystemTap
will hopefully resolve this issue.
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20180201162625.4276-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add trace output for commands, errors, and undefined behavior.
Add guest error log output for undefined behavior.
Report invalid undefined accesses to MMIO.
Annotate unlikely error checks with unlikely.
Signed-off-by: Doug Gale <doug16k@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch allocates an IOThread object for each xen_disk instance and
sets the AIO context appropriately on connect. This allows processing
of I/O to proceed in parallel.
The patch also adds tracepoints into xen_disk to make it possible to
follow the state transtions of an instance in the log.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
With the move of some docs/ to docs/devel/ on ac06724a71,
no references were updated.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
It is hard to analyze trace logs with multiple virtio-blk devices
because none of the trace events include the VirtIODevice *vdev.
This patch adds vdev so it's clear which device a request is associated
with.
I considered using VirtIOBlock *s instead but VirtIODevice *vdev is more
general and may be correlated with generic virtio trace events like
virtio_set_status.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170614092930.11234-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The trace-events for a given source file should generally
always live in the same directory as the source file.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170125161417.31949-3-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/block/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-8-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
