According to section 5.3.6.2 (Multiport Device Operation) of the virtio
spec(version 1.2) a control buffer with the event VIRTIO_CONSOLE_RESIZE
is followed by a virtio_console_resize struct containing cols then rows.
The kernel implements this the wrong way around (rows then cols) resulting
in the two values being swapped.
Signed-off-by: Maximilian Immanuel Brandtner <maxbr@linux.ibm.com>
Message-Id: <20250324144300.905535-1-maxbr@linux.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
As per virtio spec the fields cols and rows are specified as little
endian. Although there is no legacy interface requirement that would
state that cols and rows need to be handled as native endian when legacy
interface is used, unlike for the fields of the adjacent struct
virtio_console_control, I decided to err on the side of caution based
on some non-conclusive virtio spec repo archaeology and opt for using
virtio16_to_cpu() much like for virtio_console_control.event. Strictly
by the letter of the spec virtio_le_to_cpu() would have been sufficient.
But when the legacy interface is not used, it boils down to the same.
And when using the legacy interface, the device formatting these as
little endian when the guest is big endian would surprise me more than
it using guest native byte order (which would make it compatible with
the current implementation). Nevertheless somebody trying to implement
the spec following it to the letter could end up forcing little endian
byte order when the legacy interface is in use. So IMHO this ultimately
needs a judgement call by the maintainers.
Fixes: 8345adbf96 ("virtio: console: Accept console size along with resize control message")
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Cc: stable@vger.kernel.org # v2.6.35+
Message-Id: <20250322002954.3129282-1-pasic@linux.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The fix to atomically read the pipe head and tail state when not holding
the pipe mutex has caused a number of headaches due to the size change
of the involved types.
It turns out that we don't have _that_ many places that access these
fields directly and were affected, but we have more than we strictly
should have, because our low-level helper functions have been designed
to have intimate knowledge of how the pipes work.
And as a result, that random noise of direct 'pipe->head' and
'pipe->tail' accesses makes it harder to pinpoint any actual potential
problem spots remaining.
For example, we didn't have a "is the pipe full" helper function, but
instead had a "given these pipe buffer indexes and this pipe size, is
the pipe full". That's because some low-level pipe code does actually
want that much more complicated interface.
But most other places literally just want a "is the pipe full" helper,
and not having it meant that those places ended up being unnecessarily
much too aware of this all.
It would have been much better if only the very core pipe code that
cared had been the one aware of this all.
So let's fix it - better late than never. This just introduces the
trivial wrappers for "is this pipe full or empty" and to get how many
pipe buffers are used, so that instead of writing
if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
the places that literally just want to know if a pipe is full can just
say
if (pipe_is_full(pipe))
instead. The existing trivial cases were converted with a 'sed' script.
This cuts down on the places that access pipe->head and pipe->tail
directly outside of the pipe code (and core splice code) quite a lot.
The splice code in particular still revels in doing the direct low-level
accesses, and the fuse fuse_dev_splice_write() code also seems a bit
unnecessarily eager to go very low-level, but it's at least a bit better
than it used to be.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When compiling a kernel with GCC using `make W=1` with CONFIG_WERROR=y
(which is default nowadays), the build fails:
drivers/char/virtio_console.c:1427:9: note: ‘snprintf’ output between 9 and 27 bytes into a destination of size 16
Indeed, GCC can't see the limits of the variables that are in use.
Fix this by using dev_name() of the newly created device that is
luckily the same as the string used for the DebugFS node name.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Amit Shah <amit@kernel.org>
Link: https://lore.kernel.org/r/20250210095946.4122771-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull virtio fixes from Michael Tsirkin:
"Several small bugfixes all over the place.
Most notably, fixes the vsock allocation with GFP_KERNEL in atomic
context, which has been triggering warnings for lots of testers"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost/scsi: null-ptr-dereference in vhost_scsi_get_req()
vsock/virtio: use GFP_ATOMIC under RCU read lock
virtio_console: fix misc probe bugs
virtio_ring: tag event_triggered as racy for KCSAN
vdpa/octeon_ep: Fix format specifier for pointers in debug messages
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes the following issue discovered by code review:
after vqs have been created, a buggy device can send an interrupt.
A control vq callback will then try to schedule control_work which has
not been initialized yet. Similarly for config interrupt. Further, in
and out vq callbacks invoke find_port_by_vq which attempts to take
ports_lock which also has not been initialized.
To fix, init all locks and work before creating vqs.
Message-ID: <ad982e975a6160ad110c623c016041311ca15b4f.1726511547.git.mst@redhat.com>
Fixes: 17634ba255 ("virtio: console: Add a new MULTIPORT feature, support for generic ports")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull virtio updates from Michael Tsirkin:
- resume support in vdpa/solidrun
- structure size optimizations in virtio_pci
- new pds_vdpa driver
- immediate initialization mechanism for vdpa/ifcvf
- interrupt bypass for vdpa/mlx5
- multiple worker support for vhost
- viirtio net in Intel F2000X-PL support for vdpa/ifcvf
- fixes, cleanups all over the place
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits)
vhost: Make parameter name match of vhost_get_vq_desc()
vduse: fix NULL pointer dereference
vhost: Allow worker switching while work is queueing
vhost_scsi: add support for worker ioctls
vhost: allow userspace to create workers
vhost: replace single worker pointer with xarray
vhost: add helper to parse userspace vring state/file
vhost: remove vhost_work_queue
vhost_scsi: flush IO vqs then send TMF rsp
vhost_scsi: convert to vhost_vq_work_queue
vhost_scsi: make SCSI cmd completion per vq
vhost_sock: convert to vhost_vq_work_queue
vhost: convert poll work to be vq based
vhost: take worker or vq for flushing
vhost: take worker or vq instead of dev for queueing
vhost, vhost_net: add helper to check if vq has work
vhost: add vhost_worker pointer to vhost_virtqueue
vhost: dynamically allocate vhost_worker
vhost: create worker at end of vhost_dev_set_owner
virtio_bt: call scheduler when we free unused buffs
...
When a virtio console port is initialized, it is registered as an hvc
console using a virtual console number. If a KVM guest is started with
multiple virtio console devices, the same vtermno (or virtual console
number) can be used to allocate different hvc consoles, which leads to
various communication problems later on.
This is also reported in debugfs :
# grep vtermno /sys/kernel/debug/virtio-ports/*
/sys/kernel/debug/virtio-ports/vport1p1:console_vtermno: 1
/sys/kernel/debug/virtio-ports/vport2p1:console_vtermno: 1
/sys/kernel/debug/virtio-ports/vport3p1:console_vtermno: 2
/sys/kernel/debug/virtio-ports/vport4p1:console_vtermno: 3
Replace the next_vtermno global with an ID allocator and start the
allocation at 1 as it is today. Also recycle IDs when a console port
is removed.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20221122134643.376184-1-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull char/misc and other driver updates from Greg KH:
"Here is the big set of char/misc and other small driver subsystem
updates for 5.18-rc1.
Included in here are merges from driver subsystems which contain:
- iio driver updates and new drivers
- fsi driver updates
- fpga driver updates
- habanalabs driver updates and support for new hardware
- soundwire driver updates and new drivers
- phy driver updates and new drivers
- coresight driver updates
- icc driver updates
Individual changes include:
- mei driver updates
- interconnect driver updates
- new PECI driver subsystem added
- vmci driver updates
- lots of tiny misc/char driver updates
All of these have been in linux-next for a while with no reported
problems"
* tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (556 commits)
firmware: google: Properly state IOMEM dependency
kgdbts: fix return value of __setup handler
firmware: sysfb: fix platform-device leak in error path
firmware: stratix10-svc: add missing callback parameter on RSU
arm64: dts: qcom: add non-secure domain property to fastrpc nodes
misc: fastrpc: Add dma handle implementation
misc: fastrpc: Add fdlist implementation
misc: fastrpc: Add helper function to get list and page
misc: fastrpc: Add support to secure memory map
dt-bindings: misc: add fastrpc domain vmid property
misc: fastrpc: check before loading process to the DSP
misc: fastrpc: add secure domain support
dt-bindings: misc: add property to support non-secure DSP
misc: fastrpc: Add support to get DSP capabilities
misc: fastrpc: add support for FASTRPC_IOCTL_MEM_MAP/UNMAP
misc: fastrpc: separate fastrpc device from channel context
dt-bindings: nvmem: brcm,nvram: add basic NVMEM cells
dt-bindings: nvmem: make "reg" property optional
nvmem: brcm_nvram: parse NVRAM content into NVMEM cells
nvmem: dt-bindings: Fix the error of dt-bindings check
...
Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs,
or an initcall_debug log.
Give each of these init and exit functions unique driver-specific
names to eliminate the anonymous names.
Example 1: (System.map)
ffffffff832fc78c t init
ffffffff832fc79e t init
ffffffff832fc8f8 t init
Example 2: (initcall_debug log)
calling init+0x0/0x12 @ 1
initcall init+0x0/0x12 returned 0 after 15 usecs
calling init+0x0/0x60 @ 1
initcall init+0x0/0x60 returned 0 after 2 usecs
calling init+0x0/0x9a @ 1
initcall init+0x0/0x9a returned 0 after 74 usecs
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Amit Shah <amit@kernel.org>
Cc: virtualization@lists.linux-foundation.org
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20220316192010.19001-3-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A common pattern for device reset is currently:
vdev->config->reset(vdev);
.. cleanup ..
reset prevents new interrupts from arriving and waits for interrupt
handlers to finish.
However if - as is common - the handler queues a work request which is
flushed during the cleanup stage, we have code adding buffers / trying
to get buffers while device is reset. Not good.
This was reproduced by running
modprobe virtio_console
modprobe -r virtio_console
in a loop.
Fix this up by calling virtio_break_device + flush before reset.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1786239
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We calculate nr_ports based on the max_nr_ports:
nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
If the device advertises a large max_nr_ports, we will end up with a
integer overflow. Fixing this by validating the max_nr_ports and fail
the probe for invalid max_nr_ports in this case.
Cc: Amit Shah <amit@kernel.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211019070152.8236-3-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Since commit 086d08725d ("remoteproc: create vdev subdevice with
specific dma memory pool"), every remoteproc has a DMA subdevice
("remoteprocX#vdevYbuffer") for each virtio device, which inherits
DMA capabilities from the corresponding platform device. This allowed
to associate different DMA pools with each vdev, and required from
virtio drivers to perform DMA operations with the parent device
(vdev->dev.parent) instead of grandparent (vdev->dev.parent->parent).
virtio_rpmsg_bus was already changed in the same merge cycle with
commit d999b622fc ("rpmsg: virtio: allocate buffer from parent"),
but virtio_console did not. In fact, operations using the grandparent
worked fine while the grandparent was the platform device, but since
commit c774ad0108 ("remoteproc: Fix and restore the parenting
hierarchy for vdev") this was changed, and now the grandparent device
is the remoteproc device without any DMA capabilities.
So, starting v5.8-rc1 the following warning is observed:
[ 2.483925] ------------[ cut here ]------------
[ 2.489148] WARNING: CPU: 3 PID: 101 at kernel/dma/mapping.c:427 0x80e7eee8
[ 2.489152] Modules linked in: virtio_console(+)
[ 2.503737] virtio_rpmsg_bus rpmsg_core
[ 2.508903]
[ 2.528898] <Other modules, stack and call trace here>
[ 2.913043]
[ 2.914907] ---[ end trace 93ac8746beab612c ]---
[ 2.920102] virtio-ports vport1p0: Error allocating inbufs
kernel/dma/mapping.c:427 is:
WARN_ON_ONCE(!dev->coherent_dma_mask);
obviously because the grandparent now is remoteproc dev without any
DMA caps:
[ 3.104943] Parent: remoteproc0#vdev1buffer, grandparent: remoteproc0
Fix this the same way as it was for virtio_rpmsg_bus, using just the
parent device (vdev->dev.parent, "remoteprocX#vdevYbuffer") for DMA
operations.
This also allows now to reserve DMA pools/buffers for rproc serial
via Device Tree.
Fixes: c774ad0108 ("remoteproc: Fix and restore the parenting hierarchy for vdev")
Cc: stable@vger.kernel.org # 5.1+
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Date: Thu, 5 Nov 2020 11:10:24 +0800
Link: https://lore.kernel.org/r/AOKowLclCbOCKxyiJ71WeNyuAAj2q8EUtxrXbyky5E@cp7-web-042.plabs.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The id_table and feature_table pointers in struct virtio_driver are
pointers to const. Mark the corresponding static variables const to
allow the compiler to put them in read-only memory.
Before:
text data bss dec hex filename
25447 713 76 26236 667c drivers/char/virtio_console.o
After:
text data bss dec hex filename
25488 673 76 26237 667d drivers/char/virtio_console.o
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Amit Shah <amit@kernel.org>
Link: https://lore.kernel.org/r/20200701200950.30314-6-rikard.falkeborn@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
And replace the arcane return value convention with a simple bool
where true means success and false means failure.
[AV: braino fix folded in]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200211222941.GA7657@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull pipe rework from David Howells:
"This is my set of preparatory patches for building a general
notification queue on top of pipes. It makes a number of significant
changes:
- It removes the nr_exclusive argument from __wake_up_sync_key() as
this is always 1. This prepares for the next step:
- Adds wake_up_interruptible_sync_poll_locked() so that poll can be
woken up from a function that's holding the poll waitqueue
spinlock.
- Change the pipe buffer ring to be managed in terms of unbounded
head and tail indices rather than bounded index and length. This
means that reading the pipe only needs to modify one index, not
two.
- A selection of helper functions are provided to query the state of
the pipe buffer, plus a couple to apply updates to the pipe
indices.
- The pipe ring is allowed to have kernel-reserved slots. This allows
many notification messages to be spliced in by the kernel without
allowing userspace to pin too many pages if it writes to the same
pipe.
- Advance the head and tail indices inside the pipe waitqueue lock
and use wake_up_interruptible_sync_poll_locked() to poke poll
without having to take the lock twice.
- Rearrange pipe_write() to preallocate the buffer it is going to
write into and then drop the spinlock. This allows kernel
notifications to then be added the ring whilst it is filling the
buffer it allocated. The read side is stalled because the pipe
mutex is still held.
- Don't wake up readers on a pipe if there was already data in it
when we added more.
- Don't wake up writers on a pipe if the ring wasn't full before we
removed a buffer"
* tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
pipe: Remove sync on wake_ups
pipe: Increase the writer-wakeup threshold to reduce context-switch count
pipe: Check for ring full inside of the spinlock in pipe_write()
pipe: Remove redundant wakeup from pipe_write()
pipe: Rearrange sequence in pipe_write() to preallocate slot
pipe: Conditionalise wakeup in pipe_read()
pipe: Advance tail pointer inside of wait spinlock in pipe_read()
pipe: Allow pipes to have kernel-reserved slots
pipe: Use head and tail pointers for the ring, not cursor and length
Add wake_up_interruptible_sync_poll_locked()
Remove the nr_exclusive argument from __wake_up_sync_key()
pipe: Reduce #inclusion of pipe_fs_i.h
When we hot unplug a virtserialport and then try to hot plug again,
it fails:
(qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait
(qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\
chardev=serial0,id=serial0,name=serial0
(qemu) device_del serial0
(qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\
chardev=serial0,id=serial0,name=serial0
kernel error:
virtio-ports vport2p2: Error allocating inbufs
qemu error:
virtio-serial-bus: Guest failure in adding port 2 for device \
virtio-serial0.0
This happens because buffers for the in_vq are allocated when the port is
added but are not released when the port is unplugged.
They are only released when virtconsole is removed (see a7a69ec0d8)
To avoid the problem and to be symmetric, we could allocate all the buffers
in init_vqs() as they are released in remove_vqs(), but it sounds like
a waste of memory.
Rather than that, this patch changes add_port() logic to ignore ENOSPC
error in fill_queue(), which means queue has already been filled.
Fixes: a7a69ec0d8 ("virtio_console: free buffers after reset")
Cc: mst@redhat.com
Cc: stable@vger.kernel.org
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Convert pipes to use head and tail pointers for the buffer ring rather than
pointer and length as the latter requires two atomic ops to update (or a
combined op) whereas the former only requires one.
(1) The head pointer is the point at which production occurs and points to
the slot in which the next buffer will be placed. This is equivalent
to pipe->curbuf + pipe->nrbufs.
The head pointer belongs to the write-side.
(2) The tail pointer is the point at which consumption occurs. It points
to the next slot to be consumed. This is equivalent to pipe->curbuf.
The tail pointer belongs to the read-side.
(3) head and tail are allowed to run to UINT_MAX and wrap naturally. They
are only masked off when the array is being accessed, e.g.:
pipe->bufs[head & mask]
This means that it is not necessary to have a dead slot in the ring as
head == tail isn't ambiguous.
(4) The ring is empty if "head == tail".
A helper, pipe_empty(), is provided for this.
(5) The occupancy of the ring is "head - tail".
A helper, pipe_occupancy(), is provided for this.
(6) The number of free slots in the ring is "pipe->ring_size - occupancy".
A helper, pipe_space_for_user() is provided to indicate how many slots
userspace may use.
(7) The ring is full if "head - tail >= pipe->ring_size".
A helper, pipe_full(), is provided for this.
Signed-off-by: David Howells <dhowells@redhat.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For regular serial ports we do not initialize value of vtermno
variable. A garbage value is assigned for non console ports.
The value can be observed as a random integer with [1].
[1] vim /sys/kernel/debug/virtio-ports/vport*p*
This patch initialize the value of vtermno for console serial
ports to '1' and regular serial ports are initiaized to '0'.
Reported-by: siliu@redhat.com
Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplifies the code and is more conventional to what's used in the rest
of the kernel for debugfs ops.
Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Reviewed-by: Amit Shah <amit@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When out of memory and we can't add ctrl vq buffers,
probe fails. Unfortunately the error handling is
out of spec: it calls del_vqs without bothering
to reset the device first.
To fix, call the full cleanup function in this case.
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We now cleanup all VQs on device removal - no need
to handle the control VQ specially.
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Console driver is out of spec. The spec says:
A driver MUST NOT decrement the available idx on a live
virtqueue (ie. there is no way to “unexpose” buffers).
and it does exactly that by trying to detach unused buffers
without doing a device reset first.
Defer detaching the buffers until device unplug.
Of course this means we might get an interrupt for
a vq without an attached port now. Handle that by
discarding the consumed buffer.
Reported-by: Tiwei Bie <tiwei.bie@intel.com>
Fixes: b3258ff1d6 ("virtio: Decrement avail idx on buffer detach")
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
an allocated buffer doesn't need to be tied to a vq -
only vq->vdev is ever used. Pass the function the
just what it needs - the vdev.
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
