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>
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.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>
- removal of the old dma_alloc_noncoherent interface
- remove unused flags to dma_declare_coherent_memory
- restrict OF DMA configuration to specific physical busses
- use the iommu mailing list for dma-mapping questions and
patches
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Merge tag 'dma-mapping-4.14' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- removal of the old dma_alloc_noncoherent interface
- remove unused flags to dma_declare_coherent_memory
- restrict OF DMA configuration to specific physical busses
- use the iommu mailing list for dma-mapping questions and patches
* tag 'dma-mapping-4.14' of git://git.infradead.org/users/hch/dma-mapping:
dma-coherent: fix dma_declare_coherent_memory() logic error
ARM: imx: mx31moboard: Remove unused 'dma' variable
dma-coherent: remove an unused variable
MAINTAINERS: use the iommu list for the dma-mapping subsystem
dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags
dma-coherent: remove the DMA_MEMORY_INCLUDES_CHILDREN flag
of: restrict DMA configuration
dma-mapping: remove dma_alloc_noncoherent and dma_free_noncoherent
i825xx: switch to switch to dma_alloc_attrs
au1000_eth: switch to dma_alloc_attrs
sgiseeq: switch to dma_alloc_attrs
dma-mapping: reduce dma_mapping_error inline bloat
Here is the big char/misc driver update for 4.14-rc1.
Lots of different stuff in here, it's been an active development cycle
for some reason. Highlights are:
- updated binder driver, this brings binder up to date with what
shipped in the Android O release, plus some more changes that
happened since then that are in the Android development trees.
- coresight updates and fixes
- mux driver file renames to be a bit "nicer"
- intel_th driver updates
- normal set of hyper-v updates and changes
- small fpga subsystem and driver updates
- lots of const code changes all over the driver trees
- extcon driver updates
- fmc driver subsystem upadates
- w1 subsystem minor reworks and new features and drivers added
- spmi driver updates
Plus a smattering of other minor driver updates and fixes.
All of these have been in linux-next with no reported issues for a
while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big char/misc driver update for 4.14-rc1.
Lots of different stuff in here, it's been an active development cycle
for some reason. Highlights are:
- updated binder driver, this brings binder up to date with what
shipped in the Android O release, plus some more changes that
happened since then that are in the Android development trees.
- coresight updates and fixes
- mux driver file renames to be a bit "nicer"
- intel_th driver updates
- normal set of hyper-v updates and changes
- small fpga subsystem and driver updates
- lots of const code changes all over the driver trees
- extcon driver updates
- fmc driver subsystem upadates
- w1 subsystem minor reworks and new features and drivers added
- spmi driver updates
Plus a smattering of other minor driver updates and fixes.
All of these have been in linux-next with no reported issues for a
while"
* tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (244 commits)
ANDROID: binder: don't queue async transactions to thread.
ANDROID: binder: don't enqueue death notifications to thread todo.
ANDROID: binder: Don't BUG_ON(!spin_is_locked()).
ANDROID: binder: Add BINDER_GET_NODE_DEBUG_INFO ioctl
ANDROID: binder: push new transactions to waiting threads.
ANDROID: binder: remove proc waitqueue
android: binder: Add page usage in binder stats
android: binder: fixup crash introduced by moving buffer hdr
drivers: w1: add hwmon temp support for w1_therm
drivers: w1: refactor w1_slave_show to make the temp reading functionality separate
drivers: w1: add hwmon support structures
eeprom: idt_89hpesx: Support both ACPI and OF probing
mcb: Fix an error handling path in 'chameleon_parse_cells()'
MCB: add support for SC31 to mcb-lpc
mux: make device_type const
char: virtio: constify attribute_group structures.
Documentation/ABI: document the nvmem sysfs files
lkdtm: fix spelling mistake: "incremeted" -> "incremented"
perf: cs-etm: Fix ETMv4 CONFIGR entry in perf.data file
nvmem: include linux/err.h from header
...
attribute_group are not supposed to change at runtime. All functions
working with attribute_group provided by <linux/sysfs.h> work with
const attribute_group. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lguest seems to be rather unused these days. It has seen only patches
ensuring it still builds the last two years and its official state is
"Odd Fixes".
Remove it in order to be able to clean up the paravirt code.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: lguest@lists.ozlabs.org
Cc: rusty@rustcorp.com.au
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A bunch of changes to virtio, most affecting virtio net.
ptr_ring batched zeroing - first of batching enhancements
that seems ready.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:
"Fixes, cleanups, performance
A bunch of changes to virtio, most affecting virtio net. Also ptr_ring
batched zeroing - first of batching enhancements that seems ready."
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
s390/virtio: change maintainership
tools/virtio: fix spelling mistake: "wakeus" -> "wakeups"
virtio_net: tidy a couple debug statements
ptr_ring: support testing different batching sizes
ringtest: support test specific parameters
ptr_ring: batch ring zeroing
virtio: virtio_driver doc
virtio_net: don't reset twice on XDP on/off
virtio_net: fix support for small rings
virtio_net: reduce alignment for buffers
virtio_net: rework mergeable buffer handling
virtio_net: allow specifying context for rx
virtio: allow extra context per descriptor
tools/virtio: fix build breakage
virtio: add context flag to find vqs
virtio: wrap find_vqs
ringtest: fix an assert statement
Here is the big set of new char/misc driver drivers and features for
4.12-rc1.
There's lots of new drivers added this time around, new firmware drivers
from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and
a bunch of other driver updates. Nothing major, except if you happen to
have the hardware for these drivers, and then you will be happy :)
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big set of new char/misc driver drivers and features for
4.12-rc1.
There's lots of new drivers added this time around, new firmware
drivers from Google, more auxdisplay drivers, extcon drivers, fpga
drivers, and a bunch of other driver updates. Nothing major, except if
you happen to have the hardware for these drivers, and then you will
be happy :)
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits)
firmware: google memconsole: Fix return value check in platform_memconsole_init()
firmware: Google VPD: Fix return value check in vpd_platform_init()
goldfish_pipe: fix build warning about using too much stack.
goldfish_pipe: An implementation of more parallel pipe
fpga fr br: update supported version numbers
fpga: region: release FPGA region reference in error path
fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe()
mei: drop the TODO from samples
firmware: Google VPD sysfs driver
firmware: Google VPD: import lib_vpd source files
misc: lkdtm: Add volatile to intentional NULL pointer reference
eeprom: idt_89hpesx: Add OF device ID table
misc: ds1682: Add OF device ID table
misc: tsl2550: Add OF device ID table
w1: Remove unneeded use of assert() and remove w1_log.h
w1: Use kernel common min() implementation
uio_mf624: Align memory regions to page size and set correct offsets
uio_mf624: Refactor memory info initialization
uio: Allow handling of non page-aligned memory regions
hangcheck-timer: Fix typo in comment
...
We are going to add more parameters to find_vqs, let's wrap the call so
we don't need to tweak all drivers every time.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We try to disable callbacks on c_ivq even without multiport
even though that vq is not initialized in this configuration.
Fixes: c743d09dbd ("virtio: console: Disable callbacks for virtqueues at start of S4 freeze")
Suggested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
To enable eventual removal of pr_warning
This makes pr_warn use consistent for drivers/char
Prior to this patch, there were 1 use of pr_warning and
40 uses of pr_warn in drivers/char
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Amit Shah <amit@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
put_chars() stuffs the buffer it gets into an sg, but that buffer may be
on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it
manifested as printks getting turned into NUL bytes).
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Add a struct irq_affinity pointer to the find_vqs methods, which if set
is used to tell the PCI layer to create the MSI-X vectors for our I/O
virtqueues with the proper affinity from the start. Compared to after
the fact affinity hints this gives us an instantly working setup and
allows to allocate the irq descritors node-local and avoid interconnect
traffic. Last but not least this will allow blk-mq queues are created
based on the interrupt affinity for storage drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Using control_work instead of config_work as the 3rd argument to
container_of results in an invalid portdev pointer. Indeed, the work
structure is initialized as below:
INIT_WORK(&portdev->config_work, &config_work_handler);
It leads to a crash when portdev->vdev is dereferenced later. This
bug
is triggered when the guest uses a virtio-console without multiport
feature and receives a config_changed virtio interrupt.
Signed-off-by: G. Campana <gcampana@quarkslab.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
struct ports_device includes a config field including the whole
virtio_console_config, but only max_nr_ports in there is ever updated or
used. The rest is unused and in fact does not even mirror the
device config. Drop everything except max_nr_ports,
saving some memory.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Commit c6017e793b ("virtio: console: add locks around buffer removal
in port unplug path") added locking around the freeing of buffers in the
vq. However, when free_buf() is called with can_sleep = true and rproc
is enabled, it calls dma_free_coherent() directly, requiring interrupts
to be enabled. Currently a WARNING is triggered due to the spin locking
around free_buf, with a call stack like this:
WARNING: CPU: 3 PID: 121 at ./include/linux/dma-mapping.h:433
free_buf+0x1a8/0x288
Call Trace:
[<8040c538>] show_stack+0x74/0xc0
[<80757240>] dump_stack+0xd0/0x110
[<80430d98>] __warn+0xfc/0x130
[<80430ee0>] warn_slowpath_null+0x2c/0x3c
[<807e7c6c>] free_buf+0x1a8/0x288
[<807ea590>] remove_port_data+0x50/0xac
[<807ea6a0>] unplug_port+0xb4/0x1bc
[<807ea858>] virtcons_remove+0xb0/0xfc
[<807b6734>] virtio_dev_remove+0x58/0xc0
[<807f918c>] __device_release_driver+0xac/0x134
[<807f924c>] device_release_driver+0x38/0x50
[<807f7edc>] bus_remove_device+0xfc/0x130
[<807f4b74>] device_del+0x17c/0x21c
[<807f4c38>] device_unregister+0x24/0x38
[<807b6b50>] unregister_virtio_device+0x28/0x44
Fix this by restructuring the loops to allow the locks to only be taken
where it is necessary to protect the vqs, and release it while the
buffer is being freed.
Fixes: c6017e793b ("virtio: console: add locks around buffer removal in port unplug path")
Cc: stable@vger.kernel.org
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:
-include $(srctree)/include/linux/kconfig.h
This commit removes explicit includes except the following:
* arch/s390/include/asm/facilities_src.h
* tools/testing/radix-tree/linux/kernel.h
These two are used for host programs.
Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio_console uses a small DMA buffer for control requests. Move
that buffer into heap memory.
Doing virtio DMA on the stack is normally okay on non-DMA-API virtio
systems (which is currently most of them), but it breaks completely
if the stack is virtually mapped.
Tested by typing both directions using picocom aimed at /dev/hvc0.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
My static checker complains that this sprintf() can overflow but really
it can't. Just silence the warning by using snprintf().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the normal return values for bool functions
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
when multiport is off, virtio console invokes config access from irq
context, config access is blocking on s390.
Fix this up by scheduling work from config irq - similar to what we do
for multiport configs.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
when multiport is off, we don't initialize config work,
but we then cancel uninitialized control_work on freeze.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/console needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CHECK drivers/char/virtio_console.c
drivers/char/virtio_console.c:687:36: warning: incorrect type in
argument 1 (different address spaces)
drivers/char/virtio_console.c:687:36: expected void [noderef]
<asn:1>*to
drivers/char/virtio_console.c:687:36: got char *out_buf
drivers/char/virtio_console.c:790:35: warning: incorrect type in
argument 2 (different address spaces)
drivers/char/virtio_console.c:790:35: expected char *out_buf
drivers/char/virtio_console.c:790:35: got char [noderef]
<asn:1>*ubuf
fill_readbuf is reused with both kernel and userspace pointers,
depending on value of to_user flag.
Tag address parameter as __user, and cast to/from regular pointer type
when we know it's safe.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits. Just change it to a u32 for now.
Based on patch by Rusty.
Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Commit f5866db6 (virtio_console: enable VQs early) tried to make
sure that DRIVER_OK was set when virtio_console started using its
virtqueues. Doing this in add_port(), however, means that we try
to set DRIVER_OK again when when a port is dynamically added after
the probe function is done.
Let's move virtio_device_ready() to the probe function just before
trying to use the virtqueues instead. This is fine as nothing can
fail inbetween.
Reported-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after resume returns, virtio console violated this
rule by adding inbufs, which causes the VQ to be used directly within
restore.
To fix, call virtio_device_ready before using VQs.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after probe returns, virtio console violated this
rule by adding inbufs, which causes the VQ to be used directly within
probe.
To fix, call virtio_device_ready before using VQs.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Fix checkpatch warning:
WARNING: debugfs_remove_recursive(NULL) is safe this check is probably not required
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: virtualization@lists.linux-foundation.org
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
While we are at it, don't do kmap() under kmap_atomic(), *especially*
for a page we'd allocated with GFP_KERNEL. It's spelled "page_address",
and had that been more than that, we'd have a real trouble - kmap_high()
can block, and doing that while holding kmap_atomic() is a Bad Idea(tm).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If virtqueue_get_buf() returns with a NULL pointer it should be verified
if the virtqueue is broken, in order to avoid loop calling cpu_relax().
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This lets the transport do endian conversion if necessary, and insulates
the drivers from the difference.
Most drivers can use the simple helpers virtio_cread() and virtio_cwrite().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
