linux/drivers/vdpa
Xie Yongji c8a6153b6c vduse: Introduce VDUSE - vDPA Device in Userspace
This VDUSE driver enables implementing software-emulated vDPA
devices in userspace. The vDPA device is created by
ioctl(VDUSE_CREATE_DEV) on /dev/vduse/control. Then a char device
interface (/dev/vduse/$NAME) is exported to userspace for device
emulation.

In order to make the device emulation more secure, the device's
control path is handled in kernel. A message mechnism is introduced
to forward some dataplane related control messages to userspace.

And in the data path, the DMA buffer will be mapped into userspace
address space through different ways depending on the vDPA bus to
which the vDPA device is attached. In virtio-vdpa case, the MMU-based
software IOTLB is used to achieve that. And in vhost-vdpa case, the
DMA buffer is reside in a userspace memory region which can be shared
to the VDUSE userspace processs via transferring the shmfd.

For more details on VDUSE design and usage, please see the follow-on
Documentation commit.

NB(mst): when merging this with
b542e383d8 ("eventfd: Make signal recursion protection a task bit")
replace eventfd_signal_count with eventfd_signal_allowed,
and drop the previous
("eventfd: Export eventfd_wake_count to modules").

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210831103634.33-13-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-06 07:20:58 -04:00
..
ifcvf vdpa: Support transferring virtual addressing during DMA mapping 2021-09-06 07:20:57 -04:00
mlx5 vdpa: Support transferring virtual addressing during DMA mapping 2021-09-06 07:20:57 -04:00
vdpa_sim vdpa: Support transferring virtual addressing during DMA mapping 2021-09-06 07:20:57 -04:00
vdpa_user vduse: Introduce VDUSE - vDPA Device in Userspace 2021-09-06 07:20:58 -04:00
virtio_pci vdpa: Support transferring virtual addressing during DMA mapping 2021-09-06 07:20:57 -04:00
Kconfig vduse: Introduce VDUSE - vDPA Device in Userspace 2021-09-06 07:20:58 -04:00
Makefile vduse: Introduce VDUSE - vDPA Device in Userspace 2021-09-06 07:20:58 -04:00
vdpa.c vdpa: Support transferring virtual addressing during DMA mapping 2021-09-06 07:20:57 -04:00