Commit Graph

36 Commits

Author SHA1 Message Date
Feng Liu 4f0fc22534 virtio_pci: Optimize virtio_pci_device structure size
Improve the size of the virtio_pci_device structure, which is commonly
used to represent a virtio PCI device. A given virtio PCI device can
either of legacy type or modern type, with the
struct virtio_pci_legacy_device occupying 32 bytes and the
struct virtio_pci_modern_device occupying 88 bytes. Make them a union,
thereby save 32 bytes of memory as shown by the pahole tool. This
improvement is particularly beneficial when dealing with numerous
devices, as it helps conserve memory resources.

Before the modification, pahole tool reported the following:
struct virtio_pci_device {
[...]
        struct virtio_pci_legacy_device ldev;            /*   824    32 */
        /* --- cacheline 13 boundary (832 bytes) was 24 bytes ago --- */
        struct virtio_pci_modern_device mdev;            /*   856    88 */

        /* XXX last struct has 4 bytes of padding */
[...]
        /* size: 1056, cachelines: 17, members: 19 */
[...]
};

After the modification, pahole tool reported the following:
struct virtio_pci_device {
[...]
        union {
                struct virtio_pci_legacy_device ldev;    /*   824    32 */
                struct virtio_pci_modern_device mdev;    /*   824    88 */
        };                                               /*   824    88 */
[...]
	/* size: 1024, cachelines: 16, members: 18 */
[...]
};

Signed-off-by: Feng Liu <feliu@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Message-Id: <20230516135446.16266-1-feliu@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2023-06-27 10:47:08 -04:00
Michael S. Tsirkin 9993a4f989 virtio: Revert "virtio: find_vqs() add arg sizes"
This reverts commit a10fba0377145fccefea4dc4dd5915b7ed87e546: the
proposed API isn't supported on all transports but no
effort was made to address this.

It might not be hard to fix if we want to: maybe just
rename size to size_hint and make sure legacy
transports ignore the hint.

But it's not sure what the benefit is in any case, so
let's drop it.

Fixes: a10fba0377 ("virtio: find_vqs() add arg sizes")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220816053602.173815-8-mst@redhat.com>
2022-08-16 01:40:24 -04:00
Michael S. Tsirkin 13aa8c6c37 virtio_pci: Revert "virtio_pci: support the arg sizes of find_vqs()"
This reverts commit cdb44806fca2d0ad29ca644cbf1505433902ee0c: the legacy
path is wrong and in fact can not support the proposed API since for a
legacy device we never communicate the vq size to the hypervisor.

Reported-by: Andres Freund <andres@anarazel.de>
Fixes: cdb44806fc ("virtio_pci: support the arg sizes of find_vqs()")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220816053602.173815-5-mst@redhat.com>
2022-08-16 01:38:29 -04:00
Xuan Zhuo cdb44806fc virtio_pci: support the arg sizes of find_vqs()
Virtio PCI supports new parameter sizes of find_vqs().

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-35-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11 04:06:41 -04:00
Xuan Zhuo a10fba0377 virtio: find_vqs() add arg sizes
find_vqs() adds a new parameter sizes to specify the size of each vq
vring.

NULL as sizes means that all queues in find_vqs() use the maximum size.
A value in the array is 0, which means that the corresponding queue uses
the maximum size.

In the split scenario, the meaning of size is the largest size, because
it may be limited by memory, the virtio core will try a smaller size.
And the size is power of 2.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-34-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11 04:06:40 -04:00
Solomon Tan 3153234097 virtio: Replace unsigned with unsigned int
This patch addresses the checkpatch.pl warning where unsigned int is
preferred over unsigned.

Signed-off-by: Solomon Tan <solomonbstoner@protonmail.ch>
Message-Id: <YlzS49Wo8JMDhKOt@ArchDesktop>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-31 12:45:09 -04:00
Jason Wang eb4cecb453 Revert "virtio_pci: harden MSI-X interrupts"
This reverts commit 9e35276a53. Issue
were reported for the drivers that are using affinity managed IRQ
where manually toggling IRQ status is not expected. And we forget to
enable the interrupts in the restore path as well.

In the future, we will rework on the interrupt hardening.

Fixes: 9e35276a53 ("virtio_pci: harden MSI-X interrupts")
Reported-by: Marc Zyngier <maz@kernel.org>
Reported-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20220323031524.6555-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-28 16:52:59 -04:00
Jason Wang 7b79edfb86 Revert "virtio-pci: harden INTX interrupts"
This reverts commit 080cd7c3ac. Since
the MSI-X interrupts hardening will be reverted in the next patch. We
will rework the interrupt hardening in the future.

Fixes: 080cd7c3ac ("virtio-pci: harden INTX interrupts")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20220323031524.6555-1-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-28 16:52:59 -04:00
Jason Wang 080cd7c3ac virtio-pci: harden INTX interrupts
This patch tries to make sure the virtio interrupt handler for INTX
won't be called after a reset and before virtio_device_ready(). We
can't use IRQF_NO_AUTOEN since we're using shared interrupt
(IRQF_SHARED). So this patch tracks the INTX enabling status in a new
intx_soft_enabled variable and toggle it during in
vp_disable/enable_vectors(). The INTX interrupt handler will check
intx_soft_enabled before processing the actual interrupt.

Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211019070152.8236-6-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01 05:26:48 -04:00
Jason Wang 9e35276a53 virtio_pci: harden MSI-X interrupts
We used to synchronize pending MSI-X irq handlers via
synchronize_irq(), this may not work for the untrusted device which
may keep sending interrupts after reset which may lead unexpected
results. Similarly, we should not enable MSI-X interrupt until the
device is ready. So this patch fixes those two issues by:

1) switching to use disable_irq() to prevent the virtio interrupt
   handlers to be called after the device is reset.
2) using IRQF_NO_AUTOEN and enable the MSI-X irq during .ready()

This can make sure the virtio interrupt handler won't be called before
virtio_device_ready() and after reset.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211019070152.8236-5-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01 05:26:48 -04:00
Wu Zongyong d89c8169bd virtio-pci: introduce legacy device module
Split common codes from virtio-pci-legacy so vDPA driver can reuse it
later.

Signed-off-by: Wu Zongyong <wuzongyong@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/71605acde5e97fcb2760a6973e406279fb1bbd33.1635493219.git.wuzongyong@linux.alibaba.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01 04:30:34 -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 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
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
Caleb Raitto 19e226e8cc virtio: Make vp_set_vq_affinity() take a mask.
Make vp_set_vq_affinity() take a cpumask instead of taking a single CPU.

If there are fewer queues than cores, queue affinity should be able to
map to multiple cores.

Link: https://patchwork.ozlabs.org/patch/948149/
Suggested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Caleb Raitto <caraitto@google.com>
Acked-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:02:18 -07:00
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 0b0f9dc52e Revert "virtio_pci: use shared interrupts for virtqueues"
This reverts commit 07ec51480b.

Conflicts:
	drivers/virtio/virtio_pci_common.c

Unfortunately the idea does not work with threadirqs
as more than 32 queues can then map to a single interrupts.

Further, 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 00:28:57 +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 07ec51480b virtio_pci: use shared interrupts for virtqueues
This lets IRQ layer handle dispatching IRQs to separate handlers for the
case where we don't have per-VQ MSI-X vectors, and allows us to greatly
simplify the code based on the assumption that we always have interrupt
vector 0 (legacy INTx or config interrupt for MSI-X) available, and
any other interrupt is request/freed throught the VQ, even if the
actual interrupt line might be shared in some cases.

This allows removing a great deal of variables keeping track of the
interrupt state in struct virtio_pci_device, as we can now simply walk the
list of VQs and deal with per-VQ interrupt handlers there, and only treat
vector 0 special.

Additionally clean up the VQ allocation code to properly unwind on error
instead of having a single global cleanup label, which is error prone,
and in this case also leads to more code.

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
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
Christoph Hellwig fa3a327935 virtio_pci: use pci_alloc_irq_vectors
This avoids the separate allocation for the msix_entries structures, and
instead allows us to use pci_irq_vector to find a given IRQ vector.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-12-16 00:12:47 +02:00
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
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 46506da5f3 virtio_pci: add an option to disable legacy driver
Useful for testing device virtio 1 compatibility.
Based on patch by Rusty - couldn't resist putting
that flying car joke in there!

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21 16:28:59 +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
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
Michael S. Tsirkin ff31d2e285 virtio_pci: move probe/remove code to common
Most of initialization is device-independent.
Let's move it to common.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21 16:28:51 +10:30
Michael S. Tsirkin 945399a8c7 virtio_pci: device-specific release callback
It turns out we need to add device-specific code
in release callback. Move it to virtio_pci_legacy.c.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-06 16:35:36 +02:00
Michael S. Tsirkin 9a4253db0c virtio_pci: move probe to common file
It turns out this make everything easier.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-14 15:10:30 +02:00
Michael S. Tsirkin de2b48d581 virtio_pci_common.h: drop VIRTIO_PCI_NO_LEGACY
Legacy drivers use virtio_pci_common.h too, we should not
define VIRTIO_PCI_NO_LEGACY there.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-11 20:04:39 +02:00
Michael S. Tsirkin 5f4c976089 virtio_pci: rename virtio_pci -> virtio_pci_common
kbuild does not seem to like it when we name source
files same as the module.
Let's rename virtio_pci -> virtio_pci_common,
and get rid of #include-ing c files.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09 21:42:05 +02:00