On 09.06.25 16:47, Albert Esteve wrote:
Add SHMEM_MAP/UNMAP requests to vhost-user to
handle VIRTIO Shared Memory mappings.
This request allows backends to dynamically map
fds into a VIRTIO Shared Memory Region indentified
by its `shmid`. The map is performed by calling
`memory_region_init_ram_from_fd` and adding the
new region as a subregion of the shmem container
MR. Then, the fd memory is advertised to the
driver as a base addres + offset, so it can be
s/addres/address/
read/written (depending on the mmap flags
requested) while it is valid.
The backend can unmap the memory range
in a given VIRTIO Shared Memory Region (again,
identified by its `shmid`), to free it.
Upon receiving this message, the front-end
must delete the MR as a subregion of
the shmem container region and free its
resources.
Note that commit all these operations need
to be delayed to after we respond the request
to the backend to avoid deadlocks.
The device model needs to create VirtSharedMemory
instances for the VirtIO Shared Memory Regions
and add them to the `VirtIODevice` instance.
Just a general comment: you can use more characters per line in the
patch desription.
--
Cheers,
David / dhildenb
