Commit Graph

81 Commits

Author SHA1 Message Date
Simon Horman 33bd91fd24 virtio: Add missing documentation for structure fields
Add missing documentation for the vqs_list_lock field of struct virtio_device,
and the validate field of struct virtio_driver.

./scripts/kernel-doc says:

 .../virtio.h:131: warning: Function parameter or member 'vqs_list_lock' not described in 'virtio_device'
 .../virtio.h:192: warning: Function parameter or member 'validate' not described in 'virtio_driver'
 2 warnings as Errors

No functional changes intended.

Signed-off-by: Simon Horman <horms@kernel.org>
Message-Id: <20230510-virtio-kdoc-v3-1-e2681ed7a425@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2023-06-27 10:47:09 -04:00
Feng Liu 4b6ec919b8 virtio_ring: Use const to annotate read-only pointer params
Add const to make the read-only pointer parameters clear, similar to
many existing functions.

To implement this change, the commit also introduces the use of
`container_of_const` to implement `to_vvq`, which ensures the const-ness
of read-only parameters and avoids accidental modification of their
members.

Signed-off-by: Feng Liu <feliu@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Bodong Wang <bodong@nvidia.com>

Message-Id: <20230310053428.3376-4-feliu@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-04-21 03:02:30 -04:00
Christophe JAILLET 48cd6bc5b2 virtio: Reorder fields in 'struct virtqueue'
Group some variables based on their sizes to reduce hole and avoid padding.
On x86_64, this shrinks the size of 'struct virtqueue'
from 72 to 68 bytes.

It saves a few bytes of memory.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Message-Id: <8f3d2e49270a2158717e15008e7ed7228196ba02.1676707807.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Lafreniere <peter@n8pjl.ca>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2023-04-21 03:02:29 -04:00
Greg Kroah-Hartman af3011b663 virtio: move dev_to_virtio() to use container_of_const()
The driver core is changing to pass some pointers as const, so move
dev_to_virtio() to use container_of_const() to handle this change.

dev_to_virtio() now properly keeps the const-ness of the pointer passed
into it, while as before it could be lost.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-12-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-27 13:45:46 +01:00
Ricardo Cañuelo 5c669c4a4c virtio: kerneldocs fixes and enhancements
Fix variable names in some kerneldocs, naming in others.
Add kerneldocs for struct vring_desc and vring_interrupt.

Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Message-Id: <20220810094004.1250-2-ricardo.canuelo@collabora.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2022-08-16 01:40:24 -04:00
Xuan Zhuo 4913e85441 virtio_ring: struct virtqueue introduce reset
Introduce a new member reset to the structure virtqueue to determine
whether the current vq is in the reset state. Subsequent patches will
use it.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-29-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11 04:06:40 -04:00
Xuan Zhuo 3251063155 virtio: allow to unbreak/break virtqueue individually
This patch allows the new introduced
__virtqueue_break()/__virtqueue_unbreak() to break/unbreak the
virtqueue.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-27-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11 04:06:40 -04:00
Xuan Zhuo c790e8e181 virtio_ring: introduce virtqueue_resize()
Introduce virtqueue_resize() to implement the resize of vring.
Based on these, the driver can dynamically adjust the size of the vring.
For example: ethtool -G.

virtqueue_resize() implements resize based on the vq reset function. In
case of failure to allocate a new vring, it will give up resize and use
the original vring.

During this process, if the re-enable reset vq fails, the vq can no
longer be used. Although the probability of this situation is not high.

The parameter recycle is used to recycle the buffer that is no longer
used.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-25-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11 04:06:40 -04:00
Xuan Zhuo da80296183 virtio: record the maximum queue num supported by the device.
virtio-net can display the maximum (supported by hardware) ring size in
ethtool -g eth0.

When the subsequent patch implements vring reset, it can judge whether
the ring size passed by the driver is legal based on this.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-2-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11 04:06:38 -04:00
Jason Wang be83f04d25 virtio: allow to unbreak virtqueue
This patch allows the new introduced __virtio_break_device() to
unbreak the virtqueue.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Vineeth Vijayan <vneethv@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220527060120.20964-8-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2022-05-31 12:45:10 -04:00
Michael S. Tsirkin 838d6d3461 virtio: unexport virtio_finalize_features
virtio_finalize_features is only used internally within virtio.
No reason to export it.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2022-03-04 08:33:21 -05:00
Michael S. Tsirkin d9679d0013 virtio: wrap config->reset calls
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>
2022-01-14 18:50:52 -05:00
Michael S. Tsirkin f124034faa Revert "virtio_ring: validate used buffer length"
This reverts commit 939779f515.

Attempts to validate length in the core did not work out: there turn out
to exist multiple broken devices, and in particular legacy devices are
known to be broken in this respect.

We have ideas for handling this better in the next version but for now
let's revert to a known good state to make sure drivers work for people.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-24 18:47:27 -05:00
Jason Wang 939779f515 virtio_ring: validate used buffer length
This patch validate the used buffer length provided by the device
before trying to use it. This is done by record the in buffer length
in a new field in desc_state structure during virtqueue_add(), then we
can fail the virtqueue_get_buf() when we find the device is trying to
give us a used buffer length which is greater than the in buffer
length.

Since some drivers have already done the validation by themselves,
this patch tries to makes the core validation optional. For the driver
that doesn't want the validation, it can set the
suppress_used_validation to be true (which could be overridden by
force_used_validation module parameter). To be more efficient, a
dedicate array is used for storing the validate used length, this
helps to eliminate the cache stress if validation is done by the
driver.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211027022107.14357-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01 05:26:48 -04:00
Parav Pandit 0e566c8f0f virtio: Protect vqs list access
VQs may be accessed to mark the device broken while they are
created/destroyed. Hence protect the access to the vqs list.

Fixes: e2dcdfe95c ("virtio: virtio_break_device() to mark all virtqueues broken.")
Signed-off-by: Parav Pandit <parav@nvidia.com>
Link: https://lore.kernel.org/r/20210721142648.1525924-4-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-08-10 11:50:55 -04:00
Xianting Tian bc22ed2ea1 virtio: remove export for virtio_config_{enable, disable}
virtio_config_enable(), virtio_config_disable() are only used inside
drivers/virtio/virtio.c, so it doesn't need export the symbols.

Signed-off-by: Xianting Tian <xianting_tian@126.com>
Link: https://lore.kernel.org/r/1613838498-8791-1-git-send-email-xianting_tian@126.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2021-03-14 04:37:35 -04:00
David Stevens a0308938ec virtio: add dma-buf support for exported objects
This change adds a new flavor of dma-bufs that can be used by virtio
drivers to share exported objects. A virtio dma-buf can be queried by
virtio drivers to obtain the UUID which identifies the underlying
exported object.

Signed-off-by: David Stevens <stevensd@chromium.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200818071343.3461203-2-stevensd@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2020-08-18 10:01:44 +02:00
Michael S. Tsirkin 15064e7090 virtio: drop vringh.h dependency
Most virtio drivers don't depend on vringh, let's not
pull that dependency, include it directly as needed.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17 06:05:30 -04:00
Halil Pasic f35f54f11f virtio/s390: DMA support for virtio-ccw
Currently virtio-ccw devices do not work if the device has
VIRTIO_F_IOMMU_PLATFORM. In future we do want to support DMA API with
virtio-ccw.

Let us do the plumbing, so the feature VIRTIO_F_IOMMU_PLATFORM works
with virtio-ccw.

Let us also switch from legacy avail/used accessors to the DMA aware
ones (even if it isn't strictly necessary), and remove the legacy
accessors (we were the last users).

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2019-05-12 13:11:36 -04:00
Joerg Roedel e6d6dd6c87 virtio: Introduce virtio_max_dma_size()
This function returns the maximum segment size for a single
dma transaction of a virtio device. The possible limit comes
from the SWIOTLB implementation in the Linux kernel, that
has an upper limit of (currently) 256kb of contiguous
memory it can map. Other DMA-API implementations might also
have limits.

Use the new dma_max_mapping_size() function to determine the
maximum mapping size when DMA-API is in use for virtio.

Cc: stable@vger.kernel.org
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-06 11:19:15 -05:00
Michael S. Tsirkin 24a7e4d207 virtio: add ability to iterate over vqs
For cleanup it's helpful to be able to simply scan all vqs and discard
all data. Add an iterator to do that.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-04-25 20:33:19 +03:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Cornelia Huck 9ea762a5ae virtio: virtio_driver doc
Add comments for the virtio_driver members that were not documented.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-05-09 16:43:22 +03:00
Michael S. Tsirkin 5a08b04f63 virtio: allow extra context per descriptor
Allow extra context per descriptor. To avoid slow down for data path,
this disables use of indirect descriptors for this vq.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-05-02 23:41:43 +03:00
Michael S. Tsirkin 404123c2db virtio: allow drivers to validate features
Some drivers can't support all features in all configurations.  At the
moment we blindly set FEATURES_OK and later FAILED.  Support this better
by adding a callback drivers can use to do some early checks.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-04-07 16:38:59 +03:00
John Fastabend 9fe7bfce8b virtio_net: refactor freeze/restore logic into virtnet reset logic
For XDP we will need to reset the queues to allow for buffer headroom
to be configured. In order to do this we need to essentially run the
freeze()/restore() code path. Unfortunately the locking requirements
between the freeze/restore and reset paths are different however so
we can not simply reuse the code.

This patch refactors the code path and adds a reset helper routine.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 10:05:12 -05:00
Andy Lutomirski 2a2d1382fe virtio: Add improved queue allocation API
This leaves vring_new_virtqueue alone for compatbility, but it
adds two new improved APIs:

vring_create_virtqueue: Creates a virtqueue backed by automatically
allocated coherent memory.  (Some day it this could be extended to
support non-coherent memory, too, if there ends up being a platform
on which it's worthwhile.)

__vring_new_virtqueue: Creates a virtqueue with a manually-specified
layout.  This should allow mic_virtio to work much more cleanly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-02 17:01:57 +02:00
Michael S. Tsirkin 9abbfb486f virtio: drop virtio_device_is_legacy_only
virtio_device_is_legacy_only is now unused, drop
it from core.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15 12:41:14 +09:30
Linus Torvalds 9f3e151299 A balloon enhancement, and a minor race-on-module-unload theoretical
bug which doesn't merit cc: stable.
 
 All the exciting stuff went via MST this cycle.
 
 Thanks,
 Rusty.
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Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell:
 "A balloon enhancement, and a minor race-on-module-unload theoretical
  bug which doesn't merit cc: stable.

  All the exciting stuff went via MST this cycle"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio_balloon: free some memory from balloon on OOM
  virtio_balloon: return the amount of freed memory from leak_balloon()
  virtio_blk: fix race at module removal
  virtio: Fix comment typo 'CONFIG_S_FAILED'
2014-12-17 10:37:56 -08:00
Michael S. Tsirkin d71a6fc6b9 virtio: drop legacy_only driver flag
legacy_only flag is now unused, drop it from core.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 21:42:00 +02:00
Michael S. Tsirkin b6098c3042 virtio: add API to detect legacy devices
transports need to be able to detect legacy-only
devices (ATM balloon only) to use legacy path
to drive them.

Add a core API to do just that.
The implementation just blacklists balloon:
not too pretty, but let's not over-engineer.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 12:06:33 +02:00
Michael S. Tsirkin df1b57fe59 virtio_balloon: add legacy_only flag
We have no plans to support virtio 1.0 in balloon driver.  Add an
explicit flag to mark it legacy only.

This will be used by follow-up patches.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09 12:06:32 +02:00
Michael S. Tsirkin b3bb62d119 virtio: add legacy feature table support
virtio-blk has some legacy feature bits that modern drivers
must not negotiate, but are needed for old legacy hosts
(that e.g. don't support virtio-scsi).
Allow a separate legacy feature table for such cases.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 12:05:26 +02:00
Cornelia Huck 8906265215 virtio: allow transports to get avail/used addresses
For virtio-1, we can theoretically have a more complex virtqueue
layout with avail and used buffers not on a contiguous memory area
with the descriptor table. For now, it's fine for a transport driver
to stay with the old layout: It needs, however, a way to access
the locations of the avail/used rings so it can register them with
the host.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09 12:05:25 +02:00
Michael S. Tsirkin d025477368 virtio: add support for 64 bit features.
Change u32 to u64, and use BIT_ULL and 1ULL everywhere.

Note: transports are unchanged, and only set low 32 bit.
This guarantees that no transport sets e.g. VERSION_1
by mistake without proper support.

Based on patch by Rusty.

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: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 12:05:24 +02:00
Michael S. Tsirkin e16e12be34 virtio: use u32, not bitmap for features
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>
2014-12-09 12:05:23 +02:00
Paul Bolle cbd7f8d682 virtio: Fix comment typo 'CONFIG_S_FAILED'
Without the VIRTIO_ prefix CONFIG_S_FAILED looks like a Kconfig macro.
So use that prefix here too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11 17:09:57 +10:30
Michael S. Tsirkin 22b7050a02 virtio: defer config changed notifications
Defer config changed notifications that arrive during
probe/scan/freeze/restore.

This will allow drivers to set DRIVER_OK earlier, without worrying about
racing with config change interrupts.

This change will also benefit old hypervisors (before 2009)
that send interrupts without checking DRIVER_OK: previously,
the callback could race with driver-specific initialization.

This will also help simplify drivers.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cosmetic changes)
2014-10-15 10:24:56 +10:30
Michael S. Tsirkin c6716bae52 virtio-pci: move freeze/restore to virtio core
This is in preparation to extending config changed event handling
in core.
Wrapping these in an API also seems to make for a cleaner code.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:24:55 +10:30
Michael S. Tsirkin 016c98c6fe virtio: unify config_changed handling
Replace duplicated code in all transports with a single wrapper in
virtio.c.

The only functional change is in virtio_mmio.c: if a buggy device sends
us an interrupt before driver is set, we previously returned IRQ_NONE,
now we return IRQ_HANDLED.

As this must not happen in practice, this does not look like a big deal.

See also commit 3fff0179e3
	virtio-pci: do not oops on config change if driver not loaded.
for the original motivation behind the driver check.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:24:54 +10:30
Rusty Russell e2dcdfe95c virtio: virtio_break_device() to mark all virtqueues broken.
Good for post-apocalyptic scenarios, like S/390 hotplug.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-28 11:34:13 +09:30
Heinz Graalfs b3b32c9413 virtio_ring: add new function virtqueue_is_broken()
Add new function virtqueue_is_broken(). Callers of virtqueue_get_buf()
should check for a broken queue.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-10-29 11:28:17 +10:30
Heinz Graalfs 5b1bf7cb67 virtio_ring: let virtqueue_{kick()/notify()} return a bool
virtqueue_{kick()/notify()} should exploit the new host notification API.
If the notify call returned with a negative value the host kick failed
(e.g. a kick triggered after a device was hot-unplugged). In this case
the virtqueue is set to 'broken' and false is returned, otherwise true.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-10-29 11:28:12 +10:30
Linus Torvalds 496322bc91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "This is a re-do of the net-next pull request for the current merge
  window.  The only difference from the one I made the other day is that
  this has Eliezer's interface renames and the timeout handling changes
  made based upon your feedback, as well as a few bug fixes that have
  trickeled in.

  Highlights:

   1) Low latency device polling, eliminating the cost of interrupt
      handling and context switches.  Allows direct polling of a network
      device from socket operations, such as recvmsg() and poll().

      Currently ixgbe, mlx4, and bnx2x support this feature.

      Full high level description, performance numbers, and design in
      commit 0a4db187a9 ("Merge branch 'll_poll'")

      From Eliezer Tamir.

   2) With the routing cache removed, ip_check_mc_rcu() gets exercised
      more than ever before in the case where we have lots of multicast
      addresses.  Use a hash table instead of a simple linked list, from
      Eric Dumazet.

   3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
      Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
      Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

   4) Support reporting the TUN device persist flag to userspace, from
      Pavel Emelyanov.

   5) Allow controlling network device VF link state using netlink, from
      Rony Efraim.

   6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

   7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
      Daniel Borkmann and Eric Dumazet.

   8) Allow controlling of TCP quickack behavior on a per-route basis,
      from Cong Wang.

   9) Several bug fixes and improvements to vxlan from Stephen
      Hemminger, Pravin B Shelar, and Mike Rapoport.  In particular,
      support receiving on multiple UDP ports.

  10) Major cleanups, particular in the area of debugging and cookie
      lifetime handline, to the SCTP protocol code.  From Daniel
      Borkmann.

  11) Allow packets to cross network namespaces when traversing tunnel
      devices.  From Nicolas Dichtel.

  12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
      manner akin to how we monitor real network traffic via ptype_all.
      From Daniel Borkmann.

  13) Several bug fixes and improvements for the new alx device driver,
      from Johannes Berg.

  14) Fix scalability issues in the netem packet scheduler's time queue,
      by using an rbtree.  From Eric Dumazet.

  15) Several bug fixes in TCP loss recovery handling, from Yuchung
      Cheng.

  16) Add support for GSO segmentation of MPLS packets, from Simon
      Horman.

  17) Make network notifiers have a real data type for the opaque
      pointer that's passed into them.  Use this to properly handle
      network device flag changes in arp_netdev_event().  From Jiri
      Pirko and Timo Teräs.

  18) Convert several drivers over to module_pci_driver(), from Peter
      Huewe.

  19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
      O(1) calculation instead.  From Eric Dumazet.

  20) Support setting of explicit tunnel peer addresses in ipv6, just
      like ipv4.  From Nicolas Dichtel.

  21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

  22) Prevent a single high rate flow from overruning an individual cpu
      during RX packet processing via selective flow shedding.  From
      Willem de Bruijn.

  23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
      Dumazet.

  24) Don't just drop GSO packets which are above the TBF scheduler's
      burst limit, chop them up so they are in-bounds instead.  Also
      from Eric Dumazet.

  25) VLAN offloads are missed when configured on top of a bridge, fix
      from Vlad Yasevich.

  26) Support IPV6 in ping sockets.  From Lorenzo Colitti.

  27) Receive flow steering targets should be updated at poll() time
      too, from David Majnemer.

  28) Fix several corner case regressions in PMTU/redirect handling due
      to the routing cache removal, from Timo Teräs.

  29) We have to be mindful of ipv4 mapped ipv6 sockets in
      upd_v6_push_pending_frames().  From Hannes Frederic Sowa.

  30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
  drivers/net: caif: fix wrong rtnl_is_locked() usage
  drivers/net: enic: release rtnl_lock on error-path
  vhost-net: fix use-after-free in vhost_net_flush
  net: mv643xx_eth: do not use port number as platform device id
  net: sctp: confirm route during forward progress
  virtio_net: fix race in RX VQ processing
  virtio: support unlocked queue poll
  net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
  Documentation: Fix references to defunct linux-net@vger.kernel.org
  net/fs: change busy poll time accounting
  net: rename low latency sockets functions to busy poll
  bridge: fix some kernel warning in multicast timer
  sfc: Fix memory leak when discarding scattered packets
  sit: fix tunnel update via netlink
  dt:net:stmmac: Add dt specific phy reset callback support.
  dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
  dt:net:stmmac: Allocate platform data only if its NULL.
  net:stmmac: fix memleak in the open method
  ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
  net: ipv6: fix wrong ping_v6_sendmsg return value
  ...
2013-07-09 18:24:39 -07:00
Michael S. Tsirkin cc229884d3 virtio: support unlocked queue poll
This adds a way to check ring empty state after enable_cb outside any
locks. Will be used by virtio_net.

Note: there's room for more optimization: caller is likely to have a
memory barrier already, which means we might be able to get rid of a
barrier here.  Deferring this optimization until we do some
benchmarking.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-09 12:45:37 -07:00
Rusty Russell b3087e48ce virtio: remove virtqueue_add_buf().
All users changed to virtqueue_add_sg() or virtqueue_add_outbuf/inbuf.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-20 12:16:01 +09:30
Linus Torvalds 736a2dd257 Lots of virtio work which wasn't quite ready for last merge window. Plus
I dived into lguest again, reworking the pagetable code so we can move
 the switcher page: our fixmaps sometimes take more than 2MB now...
 
 Cheers,
 Rusty.
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Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio & lguest updates from Rusty Russell:
 "Lots of virtio work which wasn't quite ready for last merge window.

  Plus I dived into lguest again, reworking the pagetable code so we can
  move the switcher page: our fixmaps sometimes take more than 2MB now..."

Ugh.  Annoying conflicts with the tcm_vhost -> vhost_scsi rename.
Hopefully correctly resolved.

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits)
  caif_virtio: Remove bouncing email addresses
  lguest: improve code readability in lg_cpu_start.
  virtio-net: fill only rx queues which are being used
  lguest: map Switcher below fixmap.
  lguest: cache last cpu we ran on.
  lguest: map Switcher text whenever we allocate a new pagetable.
  lguest: don't share Switcher PTE pages between guests.
  lguest: expost switcher_pages array (as lg_switcher_pages).
  lguest: extract shadow PTE walking / allocating.
  lguest: make check_gpte et. al return bool.
  lguest: assume Switcher text is a single page.
  lguest: rename switcher_page to switcher_pages.
  lguest: remove RESERVE_MEM constant.
  lguest: check vaddr not pgd for Switcher protection.
  lguest: prepare to make SWITCHER_ADDR a variable.
  virtio: console: replace EMFILE with EBUSY for already-open port
  virtio-scsi: reset virtqueue affinity when doing cpu hotplug
  virtio-scsi: introduce multiqueue support
  virtio-scsi: push vq lock/unlock into virtscsi_vq_done
  virtio-scsi: pass struct virtio_scsi to virtqueue completion function
  ...
2013-05-02 14:14:04 -07:00
Rusty Russell 9d0ca6ed6f virtio: remove obsolete virtqueue_get_queue_index()
You can access it directly now, since 3.8: v3.7-rc1-13-g06ca287
'virtio: move queue_index and num_free fields into core struct
virtqueue.'

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-22 10:23:34 -04:00
Rusty Russell 282edb3649 virtio_ring: virtqueue_add_outbuf / virtqueue_add_inbuf.
These are specialized versions of virtqueue_add_buf(), which cover
over 80% of cases and are far clearer.

In particular, the scatterlists passed to these functions don't have
to be clean (ie. we ignore end markers).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-20 15:44:52 +10:30
Rusty Russell 13816c768d virtio_ring: virtqueue_add_sgs, to add multiple sgs.
virtio_scsi can really use this, to avoid the current hack of copying
the whole sg array.  Some other things get slightly neater, too.

This causes a slowdown in virtqueue_add_buf(), which is implemented as
a wrapper.  This is addressed in the next patches.

for i in `seq 50`; do /usr/bin/time -f 'Wall time:%e' ./vringh_test --indirect --eventidx --parallel --fast-vringh; done 2>&1 | stats --trim-outliers:

Before:
	Using CPUS 0 and 3
	Guest: notified 0, pinged 39009-39063(39062)
	Host: notified 39009-39063(39062), pinged 0
	Wall time:1.700000-1.950000(1.723542)

After:
	Using CPUS 0 and 3
	Guest: notified 0, pinged 39062-39063(39063)
	Host: notified 39062-39063(39063), pinged 0
	Wall time:1.760000-2.220000(1.789167)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:43:29 +10:30