Implement suspend operation for vduse devices, so vhost-vdpa will offer
that backend feature and userspace can effectively suspend the device.

This is a must before get virtqueue indexes (base) for live migration,
since the device could modify them after userland gets them.

This patch does not implement resume, so VMM resets the whole device
to recover from a live migration failure.  Resume optimization can be
implemented on top of these patches, as other vDPA devices have done in
the past.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260707123344.244575-3-eperezma@redhat.com>

Add the VDUSE_F_QUEUE_READY feature flag. This allows the kernel module
to explicitly signal userspace when a specific virtqueue has been
enabled.

In scenarios like Live Migration of VirtIO net devices, the dataplane
starts after the control virtqueue allowing QEMU to apply configuration
in the destination device.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260707122502.239022-5-eperezma@redhat.com>

Add an ioctl to allow VDUSE instances to set the VDUSE features
supported by the userland VDUSE instance.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260707122502.239022-4-eperezma@redhat.com>

Add an ioctl to allow VDUSE instances to query the available features
supported by the kernel module.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260707122502.239022-3-eperezma@redhat.com>

The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warnings:

vduse.h:305:1: error: padding struct size to alignment boundary with 4 bytes [-Werror=padded]
vduse.h:374:1: error: padding struct size to alignment boundary with 4 bytes [-Werror=padded]

Change the amount of padding in these two structures to align them to
64 bit words and avoid those problems. Since the v1 vduse_iotlb_entry
already has an inconsistent size, do not attempt to reuse the structure
but rather list the members indiviudally, with a fixed amount of
padding.

Fixes: 079212f6877e ("vduse: add vq group asid support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260202224835.559538-1-arnd@kernel.org>

Add support for assigning Address Space Identifiers (ASIDs) to each VQ
group.  This enables mapping each group into a distinct memory space.

The vq group to ASID association is protected by a rwlock now.  But the
mutex domain_lock keeps protecting the domains of all ASIDs, as some
operations like the one related with the bounce buffer size still
requires to lock all the ASIDs.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260119143306.1818855-12-eperezma@redhat.com>

This allows separate the different virtqueues in groups that shares the
same address space.  Asking the VDUSE device for the groups of the vq at
the beginning as they're needed for the DMA API.

Allocating 3 vq groups as net is the device that need the most groups:
* Dataplane (guest passthrough)
* CVQ
* Shadowed vrings.

Future versions of the series can include dynamic allocation of the
groups array so VDUSE can declare more groups.

Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260119143306.1818855-4-eperezma@redhat.com>

This allows the kernel to detect whether the userspace VDUSE device
supports the VQ group and ASID features.  VDUSE devices that don't set
the V1 API will not receive the new messages, and vdpa device will be
created with only one vq group and asid.

The next patches implement the new feature incrementally, only enabling
the VDUSE device to set the V1 API version by the end of the series.

Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260119143306.1818855-3-eperezma@redhat.com>

Fix a spelling mistake in vduse.h: "regsion" → "region" in the
documentation for struct vduse_iova_info.

No functional change.
Signed-off-by: Ashwini Sahu <ashwini@wisig.com>
Message-Id: <20250908095645.610336-1-ashwini@wisig.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Dual-license the vduse kernel header file to dual
GPL-2.0 OR BSD-3-Clause license to make it possible
to ship it with DPDK (under BSD-3-Clause) for older
distros.

Signed-off-by: Yongji Xie <xieyongji@bytedance.com>
Message-Id: <20241119074238.38299-1-xieyongji@bytedance.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>