kernel/linux.git/drivers/vhost/vhost.c, branch linux-5.9.y

vhost: add helper to check if a vq has been setup

2020-12-02T07:51:50+00:00

[ Upstream commit 6bcf34224ac1e94103797fd68b9836061762f2b2 ] This adds a helper check if a vq has been setup. The next patches will use this when we move the vhost scsi cmd preallocation from per session to per vq. In the per vq case, we only want to allocate cmds for vqs that have actually been setup and not for all the possible vqs. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/1604986403-4931-2-git-send-email-michael.christie@oracle.com Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Acked-by: Stefan Hajnoczi Signed-off-by: Sasha Levin

vhost: Don't call log_access_ok() when using IOTLB

2020-10-04T07:45:20+00:00

When the IOTLB device is enabled, the log_guest_addr that is passed by userspace to the VHOST_SET_VRING_ADDR ioctl, and which is then written to vq->log_addr, is a GIOVA. All writes to this address are translated by log_user() to writes to an HVA, and then ultimately logged through the corresponding GPAs in log_write_hva(). No logging will ever occur with vq->log_addr in this case. It is thus wrong to pass vq->log_addr and log_guest_addr to log_access_vq() which assumes they are actual GPAs. Introduce a new vq_log_used_access_ok() helper that only checks accesses to the log for the used structure when there isn't an IOTLB device around. Signed-off-by: Greg Kurz Link: https://lore.kernel.org/r/160171933385.284610.10189082586063280867.stgit@bahia.lan Signed-off-by: Michael S. Tsirkin

vhost: Use vhost_get_used_size() in vhost_vring_set_addr()

2020-10-04T07:44:25+00:00

The open-coded computation of the used size doesn't take the event into account when the VIRTIO_RING_F_EVENT_IDX feature is present. Fix that by using vhost_get_used_size(). Fixes: 8ea8cf89e19a ("vhost: support event index") Cc: stable@vger.kernel.org Signed-off-by: Greg Kurz Link: https://lore.kernel.org/r/160171932300.284610.11846106312938909461.stgit@bahia.lan Signed-off-by: Michael S. Tsirkin

vhost: Don't call access_ok() when using IOTLB

2020-10-04T07:43:03+00:00

When the IOTLB device is enabled, the vring addresses we get from userspace are GIOVAs. It is thus wrong to pass them down to access_ok() which only takes HVAs. Access validation is done at prefetch time with IOTLB. Teach vq_access_ok() about that by moving the (vq->iotlb) check from vhost_vq_access_ok() to vq_access_ok(). This prevents vhost_vring_set_addr() to fail when verifying the accesses. No behavior change for vhost_vq_access_ok(). BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1883084 Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") Cc: jasowang@redhat.com CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Greg Kurz Acked-by: Jason Wang Link: https://lore.kernel.org/r/160171931213.284610.2052489816407219136.stgit@bahia.lan Signed-off-by: Michael S. Tsirkin

vhost: fix typo in error message

2020-09-01T22:34:49+00:00

"enable" should be "disable" when the function name is vhost_disable_notify(), which does the disabling work. Signed-off-by: Yunsheng Lin Acked-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2020-08-11T21:34:17+00:00

Pull virtio updates from Michael Tsirkin: - IRQ bypass support for vdpa and IFC - MLX5 vdpa driver - Endianness fixes for virtio drivers - Misc other fixes * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (71 commits) vdpa/mlx5: fix up endian-ness for mtu vdpa: Fix pointer math bug in vdpasim_get_config() vdpa/mlx5: Fix pointer math in mlx5_vdpa_get_config() vdpa/mlx5: fix memory allocation failure checks vdpa/mlx5: Fix uninitialised variable in core/mr.c vdpa_sim: init iommu lock virtio_config: fix up warnings on parisc vdpa/mlx5: Add VDPA driver for supported mlx5 devices vdpa/mlx5: Add shared memory registration code vdpa/mlx5: Add support library for mlx5 VDPA implementation vdpa/mlx5: Add hardware descriptive header file vdpa: Modify get_vq_state() to return error code net/vdpa: Use struct for set/get vq state vdpa: remove hard coded virtq num vdpasim: support batch updating vhost-vdpa: support IOTLB batching hints vhost-vdpa: support get/set backend features vhost: generialize backend features setting/getting vhost-vdpa: refine ioctl pre-processing vDPA: dont change vq irq after DRIVER_OK ...

vhost: generialize backend features setting/getting

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

Move the backend features setting/getting from net.c to vhost.c to be reused by vhost-vdpa. Signed-off-by: Jason Wang Link: https://lore.kernel.org/r/20200804162048.22587-3-eli@mellanox.com Signed-off-by: Michael S. Tsirkin

vhost: introduce vhost_vring_call

2020-08-05T15:08:42+00:00

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 Suggested-by: Jason Wang Link: https://lore.kernel.org/r/20200731065533.4144-2-lingshan.zhu@intel.com Signed-off-by: Michael S. Tsirkin

vhost: Use flex_array_size() helper in copy_from_user()

2020-08-05T15:08:42+00:00

Make use of the flex_array_size() helper to calculate the size of a flexible array member within an enclosing structure. This helper offers defense-in-depth against potential integer overflows, while at the same time makes it explicitly clear that we are dealing with a flexible array member. Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200731130956.GA30525@embeddedor Signed-off-by: Michael S. Tsirkin

vhost: Remove redundant use of read_barrier_depends() barrier

2020-07-21T09:50:36+00:00

Since commit 76ebbe78f739 ("locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()"), there is no need to use smp_read_barrier_depends() outside of the Alpha architecture code. Unfortunately, there is precisely _one_ user in the vhost code, and there isn't an obvious READ_ONCE() access making the barrier redundant. However, on closer inspection (thanks, Jason), it appears that vring synchronisation between the producer and consumer occurs via the 'avail_idx' field, which is followed up by an rmb() in vhost_get_vq_desc(), making the read_barrier_depends() redundant on Alpha. Jason says: | I'm also confused about the barrier here, basically in driver side | we did: | | 1) allocate pages | 2) store pages in indirect->addr | 3) smp_wmb() | 4) increase the avail idx (somehow a tail pointer of vring) | | in vhost we did: | | 1) read avail idx | 2) smp_rmb() | 3) read indirect->addr | 4) read from indirect->addr | | It looks to me even the data dependency barrier is not necessary | since we have rmb() which is sufficient for us to the correct | indirect->addr and driver are not expected to do any writing to | indirect->addr after avail idx is increased Remove the redundant barrier invocation. Acked-by: Michael S. Tsirkin Acked-by: Peter Zijlstra (Intel) Suggested-by: Jason Wang Acked-by: Paul E. McKenney Signed-off-by: Will Deacon