On Tue, Aug 26, 2025 at 01:27:03PM +0200, Eugenio Pérez wrote: > When used by vhost-vDPA bus driver for VM, the control virtqueue > should be shadowed via userspace VMM (QEMU) instead of being assigned > directly to Guest. This is because QEMU needs to know the device state > in order to start and stop device correctly (e.g for Live Migration). > > This requies to isolate the memory mapping for control virtqueue > presented by vhost-vDPA to prevent guest from accessing it directly. > > This series add support to multiple address spaces in VDUSE device > allowing selective virtqueue isolation through address space IDs (ASID).
There hasn't been a new version of this yet, has there? > The VDUSE device needs to report: > * Number of virtqueue groups > * Association of each vq group with each virtqueue > * Number of address spaces supported. > > Then, the vDPA driver can modify the ASID assigned to each VQ group to > isolate the memory AS. This aligns VDUSE with gq}vdpa_sim and nvidia > mlx5 devices which already support ASID. > > This helps to isolate the environments for the virtqueues that will not > be assigned directly. E.g in the case of virtio-net, the control > virtqueue will not be assigned directly to guest. > > This series depends on the series that reworks the virtio mapping API: > https://lore.kernel.org/all/20250821064641.5025-1-jasow...@redhat.com/ > > Also, to be able to test this patch, the user needs to manually revert > 56e71885b034 ("vduse: Temporarily fail if control queue feature requested"). > > PATCH v1: > * Fix: Remove BIT_ULL(VIRTIO_S_*), as _S_ is already the bit (Maxime) > * Using vduse_vq_group_int directly instead of an empty struct in union > virtio_map. > > RFC v3: > * Increase VDUSE_MAX_VQ_GROUPS to 0xffff (Jason). It was set to a lower > value to reduce memory consumption, but vqs are already limited to > that value and userspace VDUSE is able to allocate that many vqs. Also, > it's > a dynamic array now. Same with ASID. > * Move the valid vq groups range check to vduse_validate_config. > * Embed vduse_iotlb_entry into vduse_iotlb_entry_v2. > * Use of array_index_nospec in VDUSE device ioctls. > * Move the umem mutex to asid struct so there is no contention between > ASIDs. > * Remove the descs vq group capability as it will not be used and we can > add it on top. > * Do not ask for vq groups in number of vq groups < 2. > * Remove TODO about merging VDUSE_IOTLB_GET_FD ioctl with > VDUSE_IOTLB_GET_INFO. > > RFC v2: > * Cache group information in kernel, as we need to provide the vq map > tokens properly. > * Add descs vq group to optimize SVQ forwarding and support indirect > descriptors out of the box. > * Make iotlb entry the last one of vduse_iotlb_entry_v2 so the first > part of the struct is the same. > * Fixes detected testing with OVS+VDUSE. > > Eugenio Pérez (6): > vduse: add v1 API definition > vduse: add vq group support > vduse: return internal vq group struct as map token > vduse: create vduse_as to make it an array > vduse: add vq group asid support > vduse: bump version number > > drivers/vdpa/vdpa_user/vduse_dev.c | 385 ++++++++++++++++++++++------- > include/linux/virtio.h | 6 +- > include/uapi/linux/vduse.h | 73 +++++- > 3 files changed, 373 insertions(+), 91 deletions(-) > > -- > 2.51.0
