Add missing comment for number of virtqueue.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20201112064005.349268-2-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Modify get_vq_state() so it returns an error code. In case of hardware
acceleration, the available index may be retrieved from the device, an
operation that can possibly fail.
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Link: https://lore.kernel.org/r/20200804162048.22587-9-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
For now VQ state involves 16 bit available index value encoded in u64
variable. In the future it will be extended to contain more fields. Use
struct to contain the state, now containing only a single u16 for the
available index. In the future we can add fields to this struct.
Reviewed-by: Parav Pandit <parav@mellanox.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Link: https://lore.kernel.org/r/20200804162048.22587-8-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This will enable vdpa providers to add support for multi queue feature
and publish it to upper layers (vhost and virtio).
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-7-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
IRQ of a vq is not expected to be changed in a DRIVER_OK ~ !DRIVER_OK
period for irq offloading purposes. Place this comment at the side of
bus ops get_vq_irq than in set_status in vhost_vdpa.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20200804102123.69978-1-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit adds a new function get_vq_irq() in struct
vdpa_config_ops, which will return the irq number of a
virtqueue.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200731065533.4144-4-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Some legacy guests just assume features are 0 after reset.
We detect that config space is accessed before features are
set and set features to 0 automatically.
Note: some legacy guests might not even access config space, if this is
reported in the field we might need to catch a kick to handle these.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch introduces a new method in the vdpa_config_ops which
reports the physical address and the size of the doorbell for a
specific virtqueue.
This will be used by the future patches that maps doorbell to
userspace.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200529080303.15449-4-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
get_vq_align returns u16 now, but that's not enough for
systems/devices with 64K pages. All callers assign it to
a u32 variable anyway, so let's just change the return
value type to u32.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vDPA device is a device that uses a datapath which complies with the
virtio specifications with vendor specific control path. vDPA devices
can be both physically located on the hardware or emulated by
software. vDPA hardware devices are usually implemented through PCIE
with the following types:
- PF (Physical Function) - A single Physical Function
- VF (Virtual Function) - Device that supports single root I/O
virtualization (SR-IOV). Its Virtual Function (VF) represents a
virtualized instance of the device that can be assigned to different
partitions
- ADI (Assignable Device Interface) and its equivalents - With
technologies such as Intel Scalable IOV, a virtual device (VDEV)
composed by host OS utilizing one or more ADIs. Or its equivalent
like SF (Sub function) from Mellanox.
>From a driver's perspective, depends on how and where the DMA
translation is done, vDPA devices are split into two types:
- Platform specific DMA translation - From the driver's perspective,
the device can be used on a platform where device access to data in
memory is limited and/or translated. An example is a PCIE vDPA whose
DMA request was tagged via a bus (e.g PCIE) specific way. DMA
translation and protection are done at PCIE bus IOMMU level.
- Device specific DMA translation - The device implements DMA
isolation and protection through its own logic. An example is a vDPA
device which uses on-chip IOMMU.
To hide the differences and complexity of the above types for a vDPA
device/IOMMU options and in order to present a generic virtio device
to the upper layer, a device agnostic framework is required.
This patch introduces a software vDPA bus which abstracts the
common attributes of vDPA device, vDPA bus driver and the
communication method (vdpa_config_ops) between the vDPA device
abstraction and the vDPA bus driver. This allows multiple types of
drivers to be used for vDPA device like the virtio_vdpa and vhost_vdpa
driver to operate on the bus and allow vDPA device could be used by
either kernel virtio driver or userspace vhost drivers as:
virtio drivers vhost drivers
| |
[virtio bus] [vhost uAPI]
| |
virtio device vhost device
virtio_vdpa drv vhost_vdpa drv
\ /
[vDPA bus]
|
vDPA device
hardware drv
|
[hardware bus]
|
vDPA hardware
With the abstraction of vDPA bus and vDPA bus operations, the
difference and complexity of the under layer hardware is hidden from
upper layer. The vDPA bus drivers on top can use a unified
vdpa_config_ops to control different types of vDPA device.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200326140125.19794-6-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Parav Pandit