Commit Graph

22 Commits

Author SHA1 Message Date
Eli Cohen 23750e39d5 vdpa: Modify get_vq_state() to return error code
Modify get_vq_state() so it returns an error code. In case of hardware
acceleration, the available index may be retrieved from the device, an
operation that can possibly fail.

Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Link: https://lore.kernel.org/r/20200804162048.22587-9-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2020-08-05 19:00:23 -04:00
Eli Cohen aac50c0bd4 net/vdpa: Use struct for set/get vq state
For now VQ state involves 16 bit available index value encoded in u64
variable. In the future it will be extended to contain more fields. Use
struct to contain the state, now containing only a single u16 for the
available index. In the future we can add fields to this struct.

Reviewed-by: Parav Pandit <parav@mellanox.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Link: https://lore.kernel.org/r/20200804162048.22587-8-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 18:39:19 -04:00
Max Gurtovoy a9974489b6 vdpa: remove hard coded virtq num
This will enable vdpa providers to add support for multi queue feature
and publish it to upper layers (vhost and virtio).

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-7-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 18:39:18 -04:00
Jason Wang 25abc060d2 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 <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-5-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 18:39:18 -04:00
Jason Wang 653055b9ac vhost-vdpa: support get/set backend features
This patch makes userspace can get and set backend features to
vhost-vdpa.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-4-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 18:39:18 -04:00
Jason Wang b0bd82bf72 vhost-vdpa: refine ioctl pre-processing
Switch to use 'switch' to make the codes more easier to be extended.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-2-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 18:39:17 -04:00
Zhu Lingshan 4c05433bc6 vDPA: dont change vq irq after DRIVER_OK
IRQ of a vq is not expected to be changed in a DRIVER_OK ~ !DRIVER_OK
period for irq offloading purposes. Place this comment at the side of
bus ops get_vq_irq than in set_status in vhost_vdpa.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20200804102123.69978-1-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:42 -04:00
Zhu Lingshan 2cf1ba9a4d vhost_vdpa: implement IRQ offloading in vhost_vdpa
This patch introduce a set of functions for setup/unsetup
and update irq offloading respectively by register/unregister
and re-register the irq_bypass_producer.

With these functions, this commit can setup/unsetup
irq offloading through setting DRIVER_OK/!DRIVER_OK, and
update irq offloading through SET_VRING_CALL.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200731065533.4144-5-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:42 -04:00
Zhu Lingshan 265a0ad873 vhost: introduce vhost_vring_call
This commit introduces struct vhost_vring_call which replaced
raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue.
Besides eventfd_ctx, it contains a spin lock and an
irq_bypass_producer in its structure.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200731065533.4144-2-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:42 -04:00
Jason Wang 6234f80574 vhost: vdpa: remove per device feature whitelist
We used to have a per device feature whitelist to filter out the
unsupported virtio features. But this seems unnecessary since:

- the main idea behind feature whitelist is to block control vq
  feature until we finalize the control virtqueue API. But the current
  vhost-vDPA uAPI is sufficient to support control virtqueue. For
  device that has hardware control virtqueue, the vDPA device driver
  can just setup the hardware virtqueue and let userspace to use
  hardware virtqueue directly. For device that doesn't have a control
  virtqueue, the vDPA device driver need to use e.g vringh to emulate
  a software control virtqueue.
- we don't do it in virtio-vDPA driver

So remove this limitation.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200720085043.16485-1-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:41 -04:00
Michael S. Tsirkin 0d234007a5 vhost/vdpa: switch to new helpers
For new helpers handling legacy features to be effective,
vhost needs to invoke them. Tie them in.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:40 -04:00
Michael S. Tsirkin 321bd21261 virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORM
Rename the bit to match latest virtio spec.
Add a compat macro to avoid breaking existing userspace.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
2020-08-03 16:11:42 -04:00
Dan Carpenter c09cc2c319 vhost_vdpa: Fix potential underflow in vhost_vdpa_mmap()
The "vma->vm_pgoff" variable is an unsigned long so if it's larger than
INT_MAX then "index" can be negative leading to an underflow.  Fix this
by changing the type of "index" to "unsigned long".

Fixes: ddd89d0a05 ("vhost_vdpa: support doorbell mapping via mmap")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200610085852.GB5439@mwanda
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-22 12:34:21 -04:00
Linus Torvalds 09102704c6 virtio: features, fixes
virtio-mem
 doorbell mapping for vdpa
 config interrupt support in ifc
 fixes all over the place
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:

 - virtio-mem: paravirtualized memory hotplug

 - support doorbell mapping for vdpa

 - config interrupt support in ifc

 - fixes all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (40 commits)
  vhost/test: fix up after API change
  virtio_mem: convert device block size into 64bit
  virtio-mem: drop unnecessary initialization
  ifcvf: implement config interrupt in IFCVF
  vhost: replace -1 with VHOST_FILE_UNBIND in ioctls
  vhost_vdpa: Support config interrupt in vdpa
  ifcvf: ignore continuous setting same status value
  virtio-mem: Don't rely on implicit compiler padding for requests
  virtio-mem: Try to unplug the complete online memory block first
  virtio-mem: Use -ETXTBSY as error code if the device is busy
  virtio-mem: Unplug subblocks right-to-left
  virtio-mem: Drop manual check for already present memory
  virtio-mem: Add parent resource for all added "System RAM"
  virtio-mem: Better retry handling
  virtio-mem: Offline and remove completely unplugged memory blocks
  mm/memory_hotplug: Introduce offline_and_remove_memory()
  virtio-mem: Allow to offline partially unplugged memory blocks
  mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE
  virtio-mem: Paravirtualized memory hotunplug part 2
  virtio-mem: Paravirtualized memory hotunplug part 1
  ...
2020-06-10 13:42:09 -07:00
Michel Lespinasse d8ed45c5dc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Zhu Lingshan 776f395004 vhost_vdpa: Support config interrupt in vdpa
This commit implements config interrupt support in
vhost_vdpa layer.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/1591352835-22441-4-git-send-email-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-06 16:26:27 -04:00
Michael S. Tsirkin 4b4e4867d9 vhost_vdpa: disable doorbell mapping for !MMU
There could be ways to support doorbell mapping with !MMU, but things
like pgprot_noncached are not universally supported.
Fixable, but just disable this for now.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04 15:36:51 -04:00
Jason Wang ddd89d0a05 vhost_vdpa: support doorbell mapping via mmap
Currently the doorbell is relayed via eventfd which may have
significant overhead because of the cost of vmexits or syscall. This
patch introduces mmap() based doorbell mapping which can eliminate the
overhead caused by vmexit or syscall.

To ease the userspace modeling of the doorbell layout (usually
virtio-pci), this patch starts from a doorbell per page
model. Vhost-vdpa only support the hardware doorbell that sit at the
boundary of a page and does not share the page with other registers.

Doorbell of each virtqueue must be mapped separately, pgoff is the
index of the virtqueue. This allows userspace to map a subset of the
doorbell which may be useful for the implementation of software
assisted virtqueue (control vq) in the future.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200529080303.15449-5-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04 15:36:51 -04:00
Jason Wang 01fcb1cbc8 vhost: allow device that does not depend on vhost worker
vDPA device currently relays the eventfd via vhost worker. This is
inefficient due the latency of wakeup and scheduling, so this patch
tries to introduce a use_worker attribute for the vhost device. When
use_worker is not set with vhost_dev_init(), vhost won't try to
allocate a worker thread and the vhost_poll will be processed directly
in the wakeup function.

This help for vDPA since it reduces the latency caused by vhost worker.

In my testing, it saves 0.2 ms in pings between VMs on a mutual host.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200529080303.15449-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04 15:36:51 -04:00
Jason Yan e373f3d78d vhost: remove set but not used variable 'status'
Fix the following gcc warning:
drivers/vhost/vdpa.c:299:5: warning: variable 'status' set but not used [-Wunused-but-set-variable]
  u8 status;
     ^~~~~~

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200402065106.20108-1-yanaijie@huawei.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-16 18:31:03 -04:00
Gustavo A. R. Silva aa21c2e73e vhost: vdpa: remove unnecessary null check
container_of is never null, so this null check is
unnecessary.

Addresses-Coverity-ID: 1492006 ("Logically dead code")
Fixes: 20453a45fb06 ("vhost: introduce vDPA-based backend")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200330235040.GA9997@embeddedor
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2020-04-16 18:31:02 -04:00
Tiwei Bie 4c8cf31885 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 <tiwei.bie@intel.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200326140125.19794-8-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-02 10:41:40 -04:00