virtio-pci: Introduce admin virtqueue

Introduce support for the admin virtqueue. By negotiating
VIRTIO_F_ADMIN_VQ feature, driver detects capability and creates one
administration virtqueue. Administration virtqueue implementation in
virtio pci generic layer, enables multiple types of upper layer
drivers such as vfio, net, blk to utilize it.

Signed-off-by: Feng Liu <feliu@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20231219093247.170936-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

virtio_pci: move structure to a header

These are guest/host interfaces, so they belong in the header where e.g.
qemu will know to find them.

Note: we added a new structure as opposed to extending existing one
because someone might be relying on the size of the existing structure
staying unchanged. Add a warning to avoid using sizeof.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

virtio_pci: add check for common cfg size

Some buggy devices, the common cfg size may not match the features.

This patch checks the common cfg size for the
features(VIRTIO_F_NOTIF_CONFIG_DATA, VIRTIO_F_RING_RESET). When the
common cfg size does not match the corresponding feature, we fail the
probe and print error message.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20231019034902.7346-1-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio_pci: add build offset check for the new common cfg items

Add checks to the check_offsets(void) for queue_notify_data and
queue_reset.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20231010031120.81272-5-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio_pci: fix the common cfg map size

The function vp_modern_map_capability() takes the size parameter,
which corresponds to the size of virtio_pci_common_cfg. As a result,
this indicates the size of memory area to map.

Now the size is the size of virtio_pci_common_cfg, but some feature(such
as the _F_RING_RESET) needs the virtio_pci_modern_common_cfg, so this
commit changes the size to the size of virtio_pci_modern_common_cfg.

Cc: stable@vger.kernel.org
Fixes: 0b50cece0b78 ("virtio_pci: introduce helper to get/set queue reset")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Message-Id: <20231010031120.81272-3-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

virtio: allow caller to override device DMA mask in vp_modern

To add a bit of vendor flexibility with various virtio based devices,
allow the caller to specify a different DMA mask. This adds a dma_mask
field to struct virtio_pci_modern_device. If defined by the driver,
this mask will be used in a call to dma_set_mask_and_coherent() instead
of the traditional DMA_BIT_MASK(64). This allows limiting the DMA space
on vendor devices with address limitations.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230519215632.12343-3-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: allow caller to override device id in vp_modern

To add a bit of vendor flexibility with various virtio based devices,
allow the caller to check for a different device id. This adds a function
pointer field to struct virtio_pci_modern_device to specify an override
device id check. If defined by the driver, this function will be called
to check that the PCI device is the vendor's expected device, and will
return the found device id to be stored in mdev->id.device. This allows
vendors with alternative vendor device ids to use this library on their
own device BAR.

Note: A lot of the diff in this is simply indenting the existing code
into an else block.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230519215632.12343-2-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio_pci: introduce helper to get/set queue reset

Introduce new helpers to implement queue reset and get queue reset
status.

https://github.com/oasis-tcs/virtio-spec/issues/124
https://github.com/oasis-tcs/virtio-spec/issues/139

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-31-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: Remove unnecessary variable assignments

In function vp_modern_probe(), "pci_dev" is initialized with the
value of "mdev->pci_dev", so assigning "pci_dev" to "mdev->pci_dev"
is unnecessary since they store the same value.

Signed-off-by: Bo Liu <liubo03@inspur.com>
Message-Id: <20220617055952.5364-1-liubo03@inspur.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

virtio: Fix all occurences of the "the the" typo

There are double "the" in message in file virtio_mmio.c
and virtio_pci_modern_dev.c, fix it.

Signed-off-by: Bo Liu <liubo03@inspur.com>
Message-Id: <20220609031106.2161-1-liubo03@inspur.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: harden vring IRQ

This is a rework on the previous IRQ hardening that is done for
virtio-pci where several drawbacks were found and were reverted:

1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ
that is used by some device such as virtio-blk
2) done only for PCI transport

The vq->broken is re-used in this patch for implementing the IRQ
hardening. The vq->broken is set to true during both initialization
and reset. And the vq->broken is set to false in
virtio_device_ready(). Then vring_interrupt() can check and return
when vq->broken is true. And in this case, switch to return IRQ_NONE
to let the interrupt core aware of such invalid interrupt to prevent
IRQ storm.

The reason of using a per queue variable instead of a per device one
is that we may need it for per queue reset hardening in the future.

Note that the hardening is only done for vring interrupt since the
config interrupt hardening is already done in commit 22b7050a024d7
("virtio: defer config changed notifications"). But the method that is
used by config interrupt can't be reused by the vring interrupt
handler because it uses spinlock to do the synchronization which is
expensive.

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: <20220527060120.20964-9-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

virtio: pci: Fix an error handling path in vp_modern_probe()

If an error occurs after a successful pci_request_selected_regions() call,
it should be undone by a corresponding pci_release_selected_regions() call,
as already done in vp_modern_remove().

Fixes: fd502729fbbf ("virtio-pci: introduce modern device module")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Message-Id: <237109725aad2c3c03d14549f777b1927c84b045.1648977064.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: pci: check bar values read from virtio config space

virtio pci config structures may in future have non-standard bar
values in the bar field. We should anticipate this by skipping any
structures containing such a reserved value.

The bar value should never change: check for harmful modified values
we re-read it from the config space in vp_modern_map_capability().

Also clean up an existing check to consistently use PCI_STD_NUM_BARS.

Signed-off-by: Keir Fraser <keirf@google.com>
Link: https://lore.kernel.org/r/20220323140727.3499235-1-keirf@google.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: fix a typo in function "vp_modern_remove" comments.

Function name "vp_modern_remove" in comments is written to
"vp_modern_probe" incorrectly. Change it.

Signed-off-by: Dapeng Mi <dapeng1.mi@intel.com>
Link: https://lore.kernel.org/r/20211210073546.700783-1-dapeng1.mi@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

virtio-pci library: introduce vp_modern_get_driver_features()

This patch introduce a helper to get driver/guest features from the
device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210602021536.39525-3-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>

virtio_pci_modern: correct sparse tags for notify

When switching virtio_pci_modern to use a helper for mappings we lost an
__iomem tag. Restore it.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 9e3bb9b79a71 ("virtio_pci_modern: introduce helper to map vq notify area")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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>

virito_pci libray: hide vp_modern_map_capability()

No user now and the capability should not be setup
externally. Instead, every access to the capability should be done via
virtio_pci_modern_device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210415073147.19331-6-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>

virtio_pci_modern: hide vp_modern_get_queue_notify_off()

All users (both virtio-pci library and vp_vdpa driver) has been
switched to use vp_modern_map_vq_notify(). So there's no need to
export the low level helper of vp_modern_get_queue_notify_off().

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210415073147.19331-5-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>

virtio_pci_modern: introduce helper to map vq notify area

This patch factors out the logic of vq notify area mapping. Following
patches will switch to use this common helpers for both virtio_pci
library and virtio-pci vDPA driver.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210415073147.19331-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>

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>