linux-toradex.git/include/uapi/linux/virtio_config.h, branch v5.19-rc3

Add definition of VIRTIO_F_IN_ORDER feature bit

2022-03-28T20:52:58+00:00

This patch adds the definition of VIRTIO_F_IN_ORDER feature bit
in the relevant header file to make it available in QEMU's
linux standard header file virtio_config.h, which is updated using
scripts/update-linux-headers.sh

Signed-off-by: Gautam Dawar 
Link: https://lore.kernel.org/r/20220215053430.24650-1-gdawar@xilinx.com
Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang

virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORM

2020-08-03T20:11:42+00:00

Rename the bit to match latest virtio spec.
Add a compat macro to avoid breaking existing userspace.

Signed-off-by: Michael S. Tsirkin 
Reviewed-by: David Hildenbrand

virtio: support VIRTIO_F_ORDER_PLATFORM

2019-01-24T15:15:42+00:00

This patch introduces the support for VIRTIO_F_ORDER_PLATFORM.
If this feature is negotiated, the driver must use the barriers
suitable for hardware devices. Otherwise, the device and driver
are assumed to be implemented in software, that is they can be
assumed to run on identical CPUs in an SMP configuration. Thus
a weaker form of memory barriers is sufficient to yield better
performance.

It is recommended that an add-in card based PCI device offers
this feature for portability. The device will fail to operate
further or will operate in a slower emulation mode if this
feature is offered but not accepted.

Signed-off-by: Tiwei Bie 
Signed-off-by: Michael S. Tsirkin

virtio: add packed ring types and macros

2018-11-27T06:17:39+00:00

Add types and macros for packed ring.

Signed-off-by: Tiwei Bie 
Signed-off-by: David S. Miller

virtio: update the comments for transport features

2018-06-12T01:59:29+00:00

The existing comments for transport features are outdated.
So update them to address the latest changes in the spec.

Suggested-by: Michael S. Tsirkin 
Signed-off-by: Tiwei Bie 
Reviewed-by: Cornelia Huck 
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Stefan Hajnoczi

virtio_pci: support enabling VFs

2018-06-12T01:59:29+00:00

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 
Signed-off-by: Michael S. Tsirkin

virtio: new feature to detect IOMMU device quirk

2016-08-01T18:44:52+00:00

The interaction between virtio and IOMMUs is messy.

On most systems with virtio, physical addresses match bus addresses,
and it doesn't particularly matter which one we use to program
the device.

On some systems, including Xen and any system with a physical device
that speaks virtio behind a physical IOMMU, we must program the IOMMU
for virtio DMA to work at all.

On other systems, including SPARC and PPC64, virtio-pci devices are
enumerated as though they are behind an IOMMU, but the virtio host
ignores the IOMMU, so we must either pretend that the IOMMU isn't
there or somehow map everything as the identity.

Add a feature bit to detect that quirk: VIRTIO_F_IOMMU_PLATFORM.

Any device with this feature bit set to 0 needs a quirk and has to be
passed physical addresses (as opposed to bus addresses) even though
the device is behind an IOMMU.

Note: it has to be a per-device quirk because for example, there could
be a mix of passed-through and virtual virtio devices. As another
example, some devices could be implemented by an out of process
hypervisor backend (in case of qemu vhost, or vhost-user) and so support
for an IOMMU needs to be coded up separately.

It would be cleanest to handle this in IOMMU core code, but that needs
per-device DMA ops. While we are waiting for that to be implemented, use
a work-around in virtio core.

Note: a "noiommu" feature is a quirk - add a wrapper to make
that clear.

Signed-off-by: Michael S. Tsirkin

virtio: add VIRTIO_CONFIG_S_NEEDS_RESET device status bit

2016-04-07T12:16:41+00:00

The VIRTIO 1.0 specification added the DEVICE_NEEDS_RESET device status
bit in "VIRTIO-98: Add DEVICE_NEEDS_RESET".  This patch defines the
device status bit in the uapi header file so that both the kernel and
userspace applications can use it.

The bit is currently unused by the virtio guest drivers and vhost.
According to the spec "a good implementation will try to recover by
issuing a reset".  This is not attempted here because it requires
auditing the virtio drivers to ensure there are no resource leaks or
crashes if the device needs to be reset mid-operation.

See "2.1 Device Status Field" in the VIRTIO 1.0 specification for
details.

Signed-off-by: Stefan Hajnoczi 
Signed-off-by: Michael S. Tsirkin

virtio: Don't expose legacy config features when VIRTIO_CONFIG_NO_LEGACY defined.

2015-02-11T04:33:16+00:00

The VIRTIO_F_ANY_LAYOUT and VIRTIO_F_NOTIFY_ON_EMPTY features are pre-1.0
only.

Signed-off-by: Rusty Russell 
Acked-by: Michael S. Tsirkin

virtio: make VIRTIO_F_VERSION_1 a transport bit

2014-12-09T10:06:32+00:00

Activate VIRTIO_F_VERSION_1 automatically unless legacy_only
is set.

Signed-off-by: Michael S. Tsirkin