linux-toradex.git/include/uapi/linux/vhost.h, branch v5.10-rc3

vhost: vdpa: report iova range

2020-10-23T15:55:28+00:00

This patch introduces a new ioctl for vhost-vdpa device that can
report the iova range by the device.

For device that implements get_iova_range() method, we fetch it from
the vDPA device. If device doesn't implement get_iova_range() but
depends on platform IOMMU, we will query via DOMAIN_ATTR_GEOMETRY,
otherwise [0, ULLONG_MAX] is assumed.

For safety, this patch also rules out the map request which is not in
the valid range.

Signed-off-by: Jason Wang 
Link: https://lore.kernel.org/r/20201023090043.14430-3-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin

vhost-vdpa: support IOTLB batching hints

2020-08-05T22:39:18+00:00

This patches extend the vhost IOTLB API to accept batch updating hints
form userspace. When userspace wants update the device IOTLB in a
batch, it may do:

1) Write vhost_iotlb_msg with VHOST_IOTLB_BATCH_BEGIN flag
2) Perform a batch of IOTLB updating via VHOST_IOTLB_UPDATE/INVALIDATE
3) Write vhost_iotlb_msg with VHOST_IOTLB_BATCH_END flag

Vhost-vdpa may decide to batch the IOMMU/IOTLB updating in step 3 when
vDPA device support set_map() ops. This is useful for the vDPA device
that want to know all the mappings to tweak their own DMA translation
logic.

For vDPA device that doesn't require set_map(), no behavior changes.

This capability is advertised via VHOST_BACKEND_F_IOTLB_BATCH capability.

Signed-off-by: Jason Wang 
Link: https://lore.kernel.org/r/20200804162048.22587-5-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin

vhost_vdpa: Support config interrupt in vdpa

2020-06-06T20:26:27+00:00

This commit implements config interrupt support in
vhost_vdpa layer.

Signed-off-by: Zhu Lingshan 
Acked-by: Jason Wang 
Link: https://lore.kernel.org/r/1591352835-22441-4-git-send-email-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin

vhost: introduce vDPA-based backend

2020-04-02T14:41:40+00:00

This patch introduces a vDPA-based vhost backend. This backend is
built on top of the same interface defined in virtio-vDPA and provides
a generic vhost interface for userspace to accelerate the virtio
devices in guest.

This backend is implemented as a vDPA device driver on top of the same
ops used in virtio-vDPA. It will create char device entry named
vhost-vdpa-$index for userspace to use. Userspace can use vhost ioctls
on top of this char device to setup the backend.

Vhost ioctls are extended to make it type agnostic and behave like a
virtio device, this help to eliminate type specific API like what
vhost_net/scsi/vsock did:

- VHOST_VDPA_GET_DEVICE_ID: get the virtio device ID which is defined
  by virtio specification to differ from different type of devices
- VHOST_VDPA_GET_VRING_NUM: get the maximum size of virtqueue
  supported by the vDPA device
- VHSOT_VDPA_SET/GET_STATUS: set and get virtio status of vDPA device
- VHOST_VDPA_SET/GET_CONFIG: access virtio config space
- VHOST_VDPA_SET_VRING_ENABLE: enable a specific virtqueue

For memory mapping, IOTLB API is mandated for vhost-vDPA which means
userspace drivers are required to use
VHOST_IOTLB_UPDATE/VHOST_IOTLB_INVALIDATE to add or remove mapping for
a specific userspace memory region.

The vhost-vDPA API is designed to be type agnostic, but it allows net
device only in current stage. Due to the lacking of control virtqueue
support, some features were filter out by vhost-vdpa.

We will enable more features and devices in the near future.

Signed-off-by: Tiwei Bie 
Signed-off-by: Eugenio Pérez 
Signed-off-by: Jason Wang 
Link: https://lore.kernel.org/r/20200326140125.19794-8-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin

vhost: split structs into a separate header file

2018-12-19T23:23:49+00:00

vhost structs are shared by vhost-kernel and vhost-user.  Split them
into a separate file to ease copying them into programs that implement
either the server or the client side of vhost-user.

Signed-off-by: Paolo Bonzini 
Signed-off-by: Michael S. Tsirkin

vhost: fix VHOST_GET_BACKEND_FEATURES ioctl request definition

2018-09-04T04:23:24+00:00

The _IOC_READ flag fits this ioctl request more because this request
actually only writes to, but doesn't read from userspace.
See NOTEs in include/uapi/asm-generic/ioctl.h for more information.

Fixes: 429711aec282 ("vhost: switch to use new message format")
Signed-off-by: Gleb Fotengauer-Malinovskiy 
Acked-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

vhost: switch to use new message format

2018-08-06T17:41:04+00:00

We use to have message like:

struct vhost_msg {
	int type;
	union {
		struct vhost_iotlb_msg iotlb;
		__u8 padding[64];
	};
};

Unfortunately, there will be a hole of 32bit in 64bit machine because
of the alignment. This leads a different formats between 32bit API and
64bit API. What's more it will break 32bit program running on 64bit
machine.

So fixing this by introducing a new message type with an explicit
32bit reserved field after type like:

struct vhost_msg_v2 {
	__u32 type;
	__u32 reserved;
	union {
		struct vhost_iotlb_msg iotlb;
		__u8 padding[64];
	};
};

We will have a consistent ABI after switching to use this. To enable
this capability, introduce a new ioctl (VHOST_SET_BAKCEND_FEATURE) for
userspace to enable this feature (VHOST_BACKEND_F_IOTLB_V2).

Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API")
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller

License cleanup: add SPDX license identifier to uapi header files with no license

2017-11-02T10:19:54+00:00

Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

vhost: remove unused feature bit

2016-12-15T22:13:38+00:00

Signed-off-by: Jason Wang 
Signed-off-by: Michael S. Tsirkin

vhost: new device IOTLB API

2016-08-02T13:53:54+00:00

This patch tries to implement an device IOTLB for vhost. This could be
used with userspace(qemu) implementation of DMA remapping
to emulate an IOMMU for the guest.

The idea is simple, cache the translation in a software device IOTLB
(which is implemented as an interval tree) in vhost and use vhost_net
file descriptor for reporting IOTLB miss and IOTLB
update/invalidation. When vhost meets an IOTLB miss, the fault
address, size and access can be read from the file. After userspace
finishes the translation, it writes the translated address to the
vhost_net file to update the device IOTLB.

When device IOTLB is enabled by setting VIRTIO_F_IOMMU_PLATFORM all vq
addresses set by ioctl are treated as iova instead of virtual address and
the accessing can only be done through IOTLB instead of direct userspace
memory access. Before each round or vq processing, all vq metadata is
prefetched in device IOTLB to make sure no translation fault happens
during vq processing.

In most cases, virtqueues are contiguous even in virtual address space.
The IOTLB translation for virtqueue itself may make it a little
slower. We might add fast path cache on top of this patch.

Signed-off-by: Jason Wang 
[mst: use virtio feature bit: VHOST_F_DEVICE_IOTLB -> VIRTIO_F_IOMMU_PLATFORM ]
[mst: fix build warnings ]
Signed-off-by: Michael S. Tsirkin 
[ weiyj.lk: missing unlock on error ]
Signed-off-by: Wei Yongjun