Commit Graph

47 Commits

Author SHA1 Message Date
Michael S. Tsirkin 0f8a0b0b09 virtio_pci_modern: __force cast the notify mapping
When switching virtio_pci_modern to use a helper for mappings we lost an
__iomem tag. We should restore it.

However, virtio_pci_modern is playing tricks by hiding an iomem pointer
in a regular vq->priv pointer. Which is okay as long as it's
all contained within a single file, but we need to __force cast
the value otherwise we'll get sparse warnings.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 7dca6c0ea9 ("virtio-pci library: switch to use vp_modern_map_vq_notify()")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-05-04 04:19:58 -04:00
Jason Wang 9e311bcad7 virtio-pci library: report resource address
Sometimes it might be useful to report the capability physical
address. One example is to report the physical address of the doorbell
in order to be mapped by userspace.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210415073147.19331-7-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-05-03 04:55:52 -04:00
Jason Wang 7dca6c0ea9 virtio-pci library: switch to use vp_modern_map_vq_notify()
This patch switch to use vp_modern_map_notify() for virtio-pci
library.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210415073147.19331-3-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
2021-05-03 04:55:51 -04:00
Jason Wang fd502729fb virtio-pci: introduce modern device module
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-17-jasowang@redhat.com

Including a bugfix:

virtio: don't prompt CONFIG_VIRTIO_PCI_MODERN

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: 86b87c9d858b6 ("virtio-pci: introduce modern device module")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210223061905.422659-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang 8000a6b602 virito-pci-modern: rename map_capability() to vp_modern_map_capability()
To ease the split, map_capability() was renamed to
vp_modern_map_capability(). While at it, add the comments for the
arguments and switch to use virtio_pci_modern_device as the first
parameter.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-16-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang 1bfd84134c virtio-pci-modern: introduce helper to get notification offset
This patch introduces help to get notification offset of modern device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-15-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang 6e52fc446d virtio-pci-modern: introduce helper for getting queue nums
This patch introduces helper for getting queue num of modern device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-14-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang 75658afbab virtio-pci-modern: introduce helper for setting/geting queue size
This patch introduces helper for setting/getting queue size for modern
device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-13-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang dc2e648198 virtio-pci-modern: introduce helper to set/get queue_enable
This patch introduces a helper to set/get queue_enable for modern device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-12-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang e1b0fa2e38 virtio-pci-modern: introduce vp_modern_queue_address()
This patch introduce a helper to set virtqueue address for modern address.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-11-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00
Jason Wang 3fbda9c1a6 virtio-pci-modern: introduce vp_modern_set_queue_vector()
This patch introduces a helper to set virtqueue MSI vector.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-10-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang ed2a73dbab virtio-pci-modern: introduce vp_modern_generation()
This patch introduces vp_modern_generation() to get device generation.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-9-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang 0b0177089c virtio-pci-modern: introduce helpers for setting and getting features
This patch introduces helpers for setting and getting features.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-8-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang e3669129fd virtio-pci-modern: introduce helpers for setting and getting status
This patch introduces helpers to allow set and get device status.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-7-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang 1a5c85f165 virtio-pci-modern: introduce helper to set config vector
This patch introduces vp_modern_config_vector() for setting config
vector.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-6-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang 3249037088 virtio-pci-modern: introduce vp_modern_remove()
This patch introduces vp_modern_remove() doing device resources
cleanup to make it can be used.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-5-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang 117a9de282 virtio-pci-modern: factor out modern device initialization logic
This patch factors out the modern device initialization logic into a
helper. Note that it still depends on the caller to enable pci device
which allows the caller to use e.g devres.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-4-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang b5d5809450 virtio-pci: split out modern device
This patch splits out the virtio-pci modern device only attributes
into another structure. While at it, a dedicated probe method for
modern only attributes is introduced. This may help for split the
logic into a dedicated module.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-3-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Jason Wang 64f2087aaa virtio-pci: do not access iomem via struct virtio_pci_device directly
Instead of accessing iomem via struct virito_pci_device directly,
tweak to call the io accessors through the iomem structure. This will
ease the splitting of modern virtio device logic.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:57 -05:00
Sebastien Boeuf 0dd4ff93f4 virtio: Implement get_shm_region for PCI transport
On PCI the shm regions are found using capability entries;
find a region by searching for the capability.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: kbuild test robot <lkp@intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 10:05:58 +02:00
Krzysztof Kozlowski fe0580ac5c virtio: pci: constify ioreadX() iomem argument (as in generic implementation)
The ioreadX() helpers have inconsistent interface.  On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200709072837.5869-5-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14 19:56:57 -07:00
Liao Pingfang 46af9adefd virtio_pci_modern: Fix the comment of virtio_pci_find_capability()
Fix the comment of virtio_pci_find_capability() by adding missing comment
for the last parameter: bars.

Fixes: 59a5b0f7bf ("virtio-pci: alloc only resources actually used.")
Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Link: https://lore.kernel.org/r/1596455545-43556-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2020-08-05 11:08:42 -04:00
Matej Genci e7c8cc35a6 virtio: add VIRTIO_RING_NO_LEGACY
Add macro to disable legacy vring functions.

Signed-off-by: Matej Genci <matej.genci@nutanix.com>
Link: https://lore.kernel.org/r/20190911124942.243713-1-matej.genci@nutanix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-02 02:45:13 -04:00
Thomas Gleixner f33f5fe256 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 78
Based on 1 normalized pattern(s):

  this work is licensed under the terms of the gnu gpl version 2 or
  later see the copying file in the top level directory

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 6 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/20190520075210.858783702@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:37:51 +02:00
Tiwei Bie cfecc2918d virtio_pci: support enabling VFs
There is a new feature bit allocated in virtio spec to
support SR-IOV (Single Root I/O Virtualization):

https://github.com/oasis-tcs/virtio-spec/issues/11

This patch enables the support for this feature bit in
virtio driver.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-06-12 04:59:29 +03:00
Michael S. Tsirkin f94682dde5 virtio: add context flag to find vqs
Allows maintaining extra context per vq.  For ease of use, passing in
NULL is legal and disables the feature for all vqs.

Includes fixes by Christian for s390, acked by Cornelia.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-05-02 23:41:43 +03:00
Michael S. Tsirkin 0a9b3f47da Revert "virtio_pci: remove struct virtio_pci_vq_info"
This reverts commit 5c34d002dc.

Conflicts:
	drivers/virtio/virtio_pci_common.c

The cleanup seems to be one of the changes that broke
hybernation for some users. We are still not sure why
but revert helps.

This reverts the cleanup changes but keeps the affinity support.

Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-04-11 00:29:59 +03:00
Michael S. Tsirkin 2008c1544c Revert "virtio_pci: don't duplicate the msix_enable flag in struct pci_dev"
This reverts commit 53a020c661.

The cleanup seems to be one of the changes that broke
hybernation for some users. We are still not sure why
but revert helps.

Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-04-11 00:28:41 +03:00
Christoph Hellwig bbaba47956 virtio: provide a method to get the IRQ affinity mask for a virtqueue
This basically passed up the pci_irq_get_affinity information through
virtio through an optional get_vq_affinity method.  It is only implemented
by the PCI backend for now, and only when we use per-virtqueue IRQs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-27 20:54:05 +02:00
Christoph Hellwig fb5e31d970 virtio: allow drivers to request IRQ affinity when creating VQs
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>
2017-02-27 20:54:04 +02:00
Christoph Hellwig 53a020c661 virtio_pci: don't duplicate the msix_enable flag in struct pci_dev
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-27 20:54:03 +02:00
Christoph Hellwig 5c34d002dc virtio_pci: remove struct virtio_pci_vq_info
We don't really need struct virtio_pci_vq_info, as most field in there
are redundant:

 - the vq backpointer is not strictly neede to start with
 - the entry in the vqs list is not needed - the generic virtqueue already
   has list, we only need to check if it has a callback to get the same
   semantics
 - we can use a simple array to look up the MSI-X vec if needed.
 - That simple array now also duoble serves to replace the per_vq_vectors
   flag

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-27 20:54:03 +02:00
Gonglei 61bd405f4e virtio_pci_modern: fix complaint by sparse
drivers/virtio/virtio_pci_modern.c:66:40: warning: incorrect type in argument 2 (different base types)
drivers/virtio/virtio_pci_modern.c:66:40:    expected unsigned int [noderef] [usertype] <asn:2>*addr
drivers/virtio/virtio_pci_modern.c:66:40:    got restricted __le32 [noderef] [usertype] <asn:2>*lo
drivers/virtio/virtio_pci_modern.c:67:33: warning: incorrect type in argument 2 (different base types)
drivers/virtio/virtio_pci_modern.c:67:33:    expected unsigned int [noderef] [usertype] <asn:2>*addr
drivers/virtio/virtio_pci_modern.c:67:33:    got restricted __le32 [noderef] [usertype] <asn:2>*hi
drivers/virtio/virtio_pci_modern.c:150:32: warning: incorrect type in argument 2 (different base types)
drivers/virtio/virtio_pci_modern.c:150:32:    expected unsigned int [noderef] [usertype] <asn:2>*addr
drivers/virtio/virtio_pci_modern.c:150:32:    got restricted __le32 [noderef] <asn:2>*<noident>
drivers/virtio/virtio_pci_modern.c:151:39: warning: incorrect type in argument 1 (different base types)
drivers/virtio/virtio_pci_modern.c:151:39:    expected unsigned int [noderef] [usertype] <asn:2>*addr
drivers/virtio/virtio_pci_modern.c:151:39:    got restricted __le32 [noderef] <asn:2>*<noident>
drivers/virtio/virtio_pci_modern.c:152:32: warning: incorrect type in argument 2 (different base types)
drivers/virtio/virtio_pci_modern.c:152:32:    expected unsigned int [noderef] [usertype] <asn:2>*addr

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-12-15 06:39:46 +02:00
Michael S. Tsirkin 05dbcb4307 virtio: virtio 1.0 cs04 spec compliance for reset
The spec says: after writing 0 to device_status, the driver MUST wait
for a read of device_status to return 0 before reinitializing the
device.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2016-04-07 15:16:39 +03:00
Andy Lutomirski 7a5589b240 virtio_pci: Use the DMA API if enabled
This switches to vring_create_virtqueue, simplifying the driver and
adding DMA API support.

This fixes virtio-pci on platforms and busses that have IOMMUs.  This
will break the experimental QEMU Q35 IOMMU support until QEMU is
fixed.  In exchange, it fixes physical virtio hardware as well as
virtio-pci running under Xen.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-02 17:01:58 +02:00
Ladi Prosek 4e94ebdd06 virtio-pci: read the right virtio_pci_notify_cap field
Looks like a copy-paste bug. The value is used as an optimization and a
wrong value probably isn't causing any serious damage. Found when
porting this code to Windows.

Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-02 17:01:49 +02:00
Stefan Hajnoczi f7ad26ff95 virtio: make find_vqs() checkpatch.pl-friendly
checkpatch.pl wants arrays of strings declared as follows:

  static const char * const names[] = { "vq-1", "vq-2", "vq-3" };

Currently the find_vqs() function takes a const char *names[] argument
so passing checkpatch.pl's const char * const names[] results in a
compiler error due to losing the second const.

This patch adjusts the find_vqs() prototype and updates all virtio
transports.  This makes it possible for virtio_balloon.c, virtio_input.c,
virtgpu_kms.c, and virtio_rpmsg_bus.c to use the checkpatch.pl-friendly
type.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
2016-01-12 20:47:06 +02:00
Gerd Hoffmann 59a5b0f7bf virtio-pci: alloc only resources actually used.
Move resource allocation from common code to legacy and modern code.
Only request resources actually used, i.e. bar0 in legacy mode and
the bar(s) specified by capabilities in modern mode.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-24 08:15:09 +02:00
Michael S. Tsirkin f71d8286c1 virtio_pci: support non-legacy balloon devices
virtio_device_is_legacy_only is always false now,
drop the test from virtio pci.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15 12:41:13 +09:30
Michael S. Tsirkin a8557d32fe virtio_pci_modern: switch to type-safe io accessors
As Rusty noted, we were accessing queue_enable with an incorrect width.
Switch to type-safe accessors so we don't make this mistake again in the
future.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-01 14:43:34 +10:30
Michael S. Tsirkin c5d4c2c9ce virtio_pci_modern: type-safe io accessors
The spec is very clear on this:

4.1.3.1 Driver Requirements: PCI Device Layout

The driver MUST access each field using the “natural” access method,
i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit
fields and 8-bit accesses for 8-bit fields.

Add type-safe wrappers to prevent access with incorrect width.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-01 14:37:15 +10:30
Rusty Russell 7abb568dbb virtio_pci: use 16-bit accessor for queue_enable.
Since PCI is little endian, 8-bit access might work, but the spec section
is very clear on this:

  4.1.3.1 Driver Requirements: PCI Device Layout

  The driver MUST access each field using the “natural” access method,
  i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit
  fields and 8-bit accesses for 8-bit fields.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2015-02-11 15:03:16 +10:30
Michael S. Tsirkin 76545f066d virtio_pci_modern: drop an unused function
release function in modern driver is unused:
it's a left-over from when each driver had
to have its own release.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-21 16:29:01 +10:30
Michael S. Tsirkin d3f5f06560 virtio_pci_modern: support devices with no config
Virtio 1.0 spec lists device config as optional.
Set get/set callbacks to NULL. Drivers can check that
and fail gracefully.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21 16:28:55 +10:30
Michael S. Tsirkin 3909213cfd virtio_pci_modern: reduce number of mappings
We don't know the # of VQs that drivers are going to use so it's hard to
predict how much memory we'll need to map. However, the relevant
capability does give us an upper limit.
If that's below a page, we can reduce the number of required
mappings by mapping it all once ahead of the time.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21 16:28:55 +10:30
Rusty Russell 89461c4a12 virtio_pci: macros for PCI layout offsets
QEMU wants it, so why not?  Trust, but verify.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-21 16:28:54 +10:30
Michael S. Tsirkin 1fcf0512c9 virtio_pci: modern driver
Lightly tested against qemu.

One thing *not* implemented here is separate mappings
for descriptor/avail/used rings. That's nice to have,
will be done later after we have core support.

This also exposes the PCI layout to userspace, and
adds macros for PCI layout offsets:

QEMU wants it, so why not?  Trust, but verify.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-21 16:28:53 +10:30