vhost: fix VHOST_*_OWNER documentation

VHOST_OWNER_SET and VHOST_OWNER_RESET are used in the documentation
instead of VHOST_SET_OWNER and VHOST_RESET_OWNER respectively.

To avoid confusion, let's u

vhost: fix VHOST_*_OWNER documentation

VHOST_OWNER_SET and VHOST_OWNER_RESET are used in the documentation
instead of VHOST_SET_OWNER and VHOST_RESET_OWNER respectively.

To avoid confusion, let's use the right names in the documentation.
No change to the API, only the documentation is involved.

Signed-off-by: Stefano Garzarella <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE

VDPA_GET_VRING_SIZE by mistake uses the already occupied
ioctl # 0x80 and we never noticed - it happens to work
because the direction and size are

vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE

VDPA_GET_VRING_SIZE by mistake uses the already occupied
ioctl # 0x80 and we never noticed - it happens to work
because the direction and size are different, but confuses
tools such as perf which like to look at just the number,
and breaks the extra robustness of the ioctl numbering macros.

To fix, sort the entries and renumber the ioctl - not too late
since it wasn't in any released kernels yet.

Cc: Arnaldo Carvalho de Melo <[email protected]>
Reported-by: Namhyung Kim <[email protected]>
Fixes: 1496c47065f9 ("vhost-vdpa: uapi to support reporting per vq size")
Cc: "Zhu Lingshan" <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Message-Id: <41c1c5489688abe5bfef9f7cf15584e3fb872ac5.1712092759.git.mst@redhat.com>
Reviewed-by: Eugenio Pérez <[email protected]>
Reviewed-by: Zhu Lingshan <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Acked-by: Jason Wang <[email protected]>

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vhost-vdpa: uapi to support reporting per vq size

The size of a virtqueue is a per vq configuration.
This commit introduce a new ioctl uAPI to support this flexibility.

Signed-off-by: Zhu Lingshan

vhost-vdpa: uapi to support reporting per vq size

The size of a virtqueue is a per vq configuration.
This commit introduce a new ioctl uAPI to support this flexibility.

Signed-off-by: Zhu Lingshan <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: uAPI to get dedicated descriptor group id

With _F_DESC_ASID backend feature, the device can now support the
VHOST_VDPA_GET_VRING_DESC_GROUP ioctl, and it may expose the descriptor
table

vhost-vdpa: uAPI to get dedicated descriptor group id

With _F_DESC_ASID backend feature, the device can now support the
VHOST_VDPA_GET_VRING_DESC_GROUP ioctl, and it may expose the descriptor
table (including avail and used ring) in a different group than the
buffers it contains. This new uAPI will fetch the group ID of the
descriptor table.

Signed-off-by: Si-Wei Liu <[email protected]>
Acked-by: Eugenio Pérez <[email protected]>
Acked-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Si-Wei Liu <[email protected]>
Tested-by: Si-Wei Liu <[email protected]>
Tested-by: Lei Yang <[email protected]>

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vhost: Allow worker switching while work is queueing

This patch drops the requirement that we can only switch workers if work
has not been queued by using RCU for the vq based queueing paths and a
m

vhost: Allow worker switching while work is queueing

This patch drops the requirement that we can only switch workers if work
has not been queued by using RCU for the vq based queueing paths and a
mutex for the device wide flush.

We can also use this to support SIGKILL properly in the future where we
should exit almost immediately after getting that signal. With this
patch, when get_signal returns true, we can set the vq->worker to NULL
and do a synchronize_rcu to prevent new work from being queued to the
vhost_task that has been killed.

Signed-off-by: Mike Christie <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost: allow userspace to create workers

For vhost-scsi with 3 vqs or more and a workload that tries to use
them in parallel like:

fio --filename=/dev/sdb --direct=1 --rw=randrw --bs=4k \
--ioengi

vhost: allow userspace to create workers

For vhost-scsi with 3 vqs or more and a workload that tries to use
them in parallel like:

fio --filename=/dev/sdb --direct=1 --rw=randrw --bs=4k \
--ioengine=libaio --iodepth=128 --numjobs=3

the single vhost worker thread will become a bottlneck and we are stuck
at around 500K IOPs no matter how many jobs, virtqueues, and CPUs are
used.

To better utilize virtqueues and available CPUs, this patch allows
userspace to create workers and bind them to vqs. You can have N workers
per dev and also share N workers with M vqs on that dev.

This patch adds the interface related code and the next patch will hook
vhost-scsi into it. The patches do not try to hook net and vsock into
the interface because:

1. multiple workers don't seem to help vsock. The problem is that with
only 2 virtqueues we never fully use the existing worker when doing
bidirectional tests. This seems to match vhost-scsi where we don't see
the worker as a bottleneck until 3 virtqueues are used.

2. net already has a way to use multiple workers.

Signed-off-by: Mike Christie <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: uAPI to resume the device

This new ioctl adds support for resuming the device from userspace.

This is required when trying to restore the device in a functioning
state after it's been s

vhost-vdpa: uAPI to resume the device

This new ioctl adds support for resuming the device from userspace.

This is required when trying to restore the device in a functioning
state after it's been suspended. It is already possible to reset a
suspended device, but that means the device must be reconfigured and
all the IOMMU/IOTLB mappings must be recreated. This new operation
allows the device to be resumed without going through a full reset.

This is particularly useful when trying to perform offline migration of
a virtual machine (also known as snapshot/restore) as it allows the VMM
to resume the virtual machine back to a running state after the snapshot
is performed.

Acked-by: Jason Wang <[email protected]>
Signed-off-by: Sebastien Boeuf <[email protected]>
Message-Id: <73b75fb87d25cff59768b4955a81fe7ffe5b4770.1672742878.git.sebastien.boeuf@intel.com>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>

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vhost-vdpa: uAPI to suspend the device

The ioctl adds support for suspending the device from userspace.

This is a must before getting virtqueue indexes (base) for live migration,
since the device c

vhost-vdpa: uAPI to suspend the device

The ioctl adds support for suspending the device from userspace.

This is a must before getting virtqueue indexes (base) for live migration,
since the device could modify them after userland gets them. There are
individual ways to perform that action for some devices
(VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no
way to perform it for any vhost device (and, in particular, vhost-vdpa).

After a successful return of the ioctl call the device must not process
more virtqueue descriptors. The device can answer to read or writes of
config fields as if it were not suspended. In particular, writing to
"queue_enable" with a value of 1 will not make the device start
processing buffers of the virtqueue.

Signed-off-by: Eugenio Pérez <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: introduce uAPI to set group ASID

Follows the vDPA support for associating ASID to a specific virtqueue
group. This patch adds a uAPI to support setting them from userspace.

Signed-off-b

vhost-vdpa: introduce uAPI to set group ASID

Follows the vDPA support for associating ASID to a specific virtqueue
group. This patch adds a uAPI to support setting them from userspace.

Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: Gautam Dawar <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: uAPI to get virtqueue group id

Follows the support for virtqueue group in vDPA. This patches
introduces uAPI to get the virtqueue group ID for a specific virtqueue
in vhost-vdpa.

Signed

vhost-vdpa: uAPI to get virtqueue group id

Follows the support for virtqueue group in vDPA. This patches
introduces uAPI to get the virtqueue group ID for a specific virtqueue
in vhost-vdpa.

Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: Gautam Dawar <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: introduce uAPI to get the number of address spaces

This patch introduces the uAPI for getting the number of address
spaces supported by this vDPA device.

Signed-off-by: Jason Wang <jaso

vhost-vdpa: introduce uAPI to get the number of address spaces

This patch introduces the uAPI for getting the number of address
spaces supported by this vDPA device.

Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: Gautam Dawar <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: introduce uAPI to get the number of virtqueue groups

Follows the vDPA support for multiple address spaces, this patch
introduce uAPI for the userspace to know the number of virtqueue
gro

vhost-vdpa: introduce uAPI to get the number of virtqueue groups

Follows the vDPA support for multiple address spaces, this patch
introduce uAPI for the userspace to know the number of virtqueue
groups supported by the vDPA device.

Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: Gautam Dawar <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost: move the backend feature bits to vhost_types.h

We should store feature bits in vhost_types.h as what has been done
for e.g VHOST_F_LOG_ALL.

Signed-off-by: Jason Wang <[email protected]>
Si

vhost: move the backend feature bits to vhost_types.h

We should store feature bits in vhost_types.h as what has been done
for e.g VHOST_F_LOG_ALL.

Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: Gautam Dawar <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vdpa: support exposing the count of vqs to userspace

- GET_VQS_COUNT: the count of virtqueues that exposed

Signed-off-by: Longpeng <[email protected]>
Link: https://lore.kernel.org/r/20220315032

vdpa: support exposing the count of vqs to userspace

- GET_VQS_COUNT: the count of virtqueues that exposed

Signed-off-by: Longpeng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>
Acked-by: Jason Wang <[email protected]>
Signed-off-by: Longpeng &lt;<a href="mailto:[email protected]" target="_blank">[email protected]</a>&gt;<br>
Reviewed-by: Stefano Garzarella <[email protected]>

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vdpa: support exposing the config size to userspace

- GET_CONFIG_SIZE: return the size of the virtio config space.

The size contains the fields which are conditional on feature
bits.

Acked-by: Jas

vdpa: support exposing the config size to userspace

- GET_CONFIG_SIZE: return the size of the virtio config space.

The size contains the fields which are conditional on feature
bits.

Acked-by: Jason Wang <[email protected]>
Signed-off-by: Longpeng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>

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vhost: vdpa: report iova range

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

vhost: vdpa: report iova range

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost-vdpa: support IOTLB batching hints

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

vhost-vdpa: support IOTLB batching hints

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost_vdpa: Support config interrupt in vdpa

This commit implements config interrupt support in
vhost_vdpa layer.

Signed-off-by: Zhu Lingshan <[email protected]>
Acked-by: Jason Wang <jasowang

vhost_vdpa: Support config interrupt in vdpa

This commit implements config interrupt support in
vhost_vdpa layer.

Signed-off-by: Zhu Lingshan <[email protected]>
Acked-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost: introduce vDPA-based backend

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

vhost: introduce vDPA-based backend

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 <[email protected]>
Signed-off-by: Eugenio Pérez <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost: split structs into a separate header file

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 th

vhost: split structs into a separate header file

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 <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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vhost: fix VHOST_GET_BACKEND_FEATURES ioctl request definition

The _IOC_READ flag fits this ioctl request more because this request
actually only writes to, but doesn't read from userspace.
See NOTE

vhost: fix VHOST_GET_BACKEND_FEATURES ioctl request definition

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 <[email protected]>
Acked-by: Jason Wang <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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vhost: switch to use new message format

We use to have message like:

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

Unfortunately, there will be

vhost: switch to use new message format

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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Revert "vhost: make msg padding explicit"

This reverts commit 93c0d549c4c5a7382ad70de6b86610b7aae57406.

Unfortunately the padding will break 32 bit userspace.
Ouch. Need to add some compat code, re

Revert "vhost: make msg padding explicit"

This reverts commit 93c0d549c4c5a7382ad70de6b86610b7aae57406.

Unfortunately the padding will break 32 bit userspace.
Ouch. Need to add some compat code, revert for now.

Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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vhost: make msg padding explicit

There's a 32 bit hole just after type. It's best to
give it a name, this way compiler is forced to initialize
it with rest of the structure.

Reported-by: Kevin East

vhost: make msg padding explicit

There's a 32 bit hole just after type. It's best to
give it a name, this way compiler is forced to initialize
it with rest of the structure.

Reported-by: Kevin Easton <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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

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

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

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 <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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