kernel/linux.git/drivers/vhost/vhost.c, branch linux-6.0.y

vhost: fix range used in translate_desc()

2023-01-12T11:00:34+00:00

[ Upstream commit 98047313cdb46828093894d0ac8b1183b8b317f9 ] vhost_iotlb_itree_first() requires `start` and `last` parameters to search for a mapping that overlaps the range. In translate_desc() we cyclically call vhost_iotlb_itree_first(), incrementing `addr` by the amount already translated, so rightly we move the `start` parameter passed to vhost_iotlb_itree_first(), but we should hold the `last` parameter constant. Let's fix it by saving the `last` parameter value before incrementing `addr` in the loop. Fixes: a9709d6874d5 ("vhost: convert pre sorted vhost memory array to interval tree") Acked-by: Jason Wang Signed-off-by: Stefano Garzarella Message-Id: <20221109102503.18816-3-sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

vhost: rename vhost_work_dev_flush

2022-05-31T16:45:10+00:00

This patch renames vhost_work_dev_flush to just vhost_dev_flush to relfect that it flushes everything on the device and that drivers don't know/care that polls are based on vhost_works. Drivers just flush the entire device and polls, and works for vhost-scsi management TMFs and IO net virtqueues, etc all are flushed. Signed-off-by: Mike Christie Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Message-Id: <20220517180850.198915-9-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: flush dev once during vhost_dev_stop

2022-05-31T16:45:10+00:00

When vhost_work_dev_flush returns all work queued at that time will have completed. There is then no need to flush after every vhost_poll_stop call, and we can move the flush call to after the loop that stops the pollers. Signed-off-by: Mike Christie Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Message-Id: <20220517180850.198915-3-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: get rid of vhost_poll_flush() wrapper

2022-05-31T16:45:10+00:00

vhost_poll_flush() is a simple wrapper around vhost_work_dev_flush(). It gives wrong impression that we are doing some work over vhost_poll, while in fact it flushes vhost_poll->dev. It only complicate understanding of the code and leads to mistakes like flushing the same vhost_dev several times in a row. Just remove vhost_poll_flush() and call vhost_work_dev_flush() directly. Signed-off-by: Andrey Ryabinin [merge vhost_poll_flush removal from Stefano Garzarella] Signed-off-by: Mike Christie Reviewed-by: Chaitanya Kulkarni Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Message-Id: <20220517180850.198915-2-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost-vdpa: support ASID based IOTLB API

2022-05-31T16:44:32+00:00

This patch extends the vhost-vdpa to support ASID based IOTLB API. The vhost-vdpa device will allocated multiple IOTLBs for vDPA device that supports multiple address spaces. The IOTLBs and vDPA device memory mappings is determined and maintained through ASID. Note that we still don't support vDPA device with more than one address spaces that depends on platform IOMMU. This work will be done by moving the IOMMU logic from vhost-vDPA to vDPA device driver. Signed-off-by: Jason Wang Signed-off-by: Gautam Dawar Message-Id: <20220330180436.24644-16-gdawar@xilinx.com> Signed-off-by: Michael S. Tsirkin Includes fixup: vhost-vdpa: Fix some error handling path in vhost_vdpa_process_iotlb_msg() In the error paths introduced by the original patch, a mutex may be left locked. Add the correct goto instead of a direct return. Signed-off-by: Christophe JAILLET Message-Id: <89ef0ae4c26ac3cfa440c71e97e392dcb328ac1b.1653227924.git.christophe.jaillet@wanadoo.fr> Acked-by: Jason Wang Signed-off-by: Michael S. Tsirkin

vhost: support ASID in IOTLB API

2022-05-31T16:44:29+00:00

This patches allows userspace to send ASID based IOTLB message to vhost. This idea is to use the reserved u32 field in the existing V2 IOTLB message. Vhost device should advertise this capability via VHOST_BACKEND_F_IOTLB_ASID backend feature. Signed-off-by: Jason Wang Signed-off-by: Gautam Dawar Message-Id: <20220330180436.24644-10-gdawar@xilinx.com> Signed-off-by: Michael S. Tsirkin

vhost: cache avail index in vhost_enable_notify()

2022-03-28T20:52:57+00:00

In vhost_enable_notify() we enable the notifications and we read the avail index to check if new buffers have become available in the meantime. We are not caching the avail index, so when the device will call vhost_get_vq_desc(), it will find the old value in the cache and it will read the avail index again. It would be better to refresh the cache every time we read avail index, so let's change vhost_enable_notify() caching the value in `avail_idx` and compare it with `last_avail_idx` to check if there are new buffers available. We don't expect a significant performance boost because the above path is not very common, indeed vhost_enable_notify() is often called with unlikely(), expecting that avail index has not been updated. We ran virtio-test/vhost-test and noticed minimal improvement as expected. To stress the patch more, we modified vhost_test.ko to call vhost_enable_notify()/vhost_disable_notify() on every cycle when calling vhost_get_vq_desc(); in this case we observed a more evident improvement, with a reduction of the test execution time of about 3.7%. Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20220121153108.187291-1-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi

vhost: allow batching hint without size

2022-03-10T13:12:04+00:00

Commit e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries") tries to reject the IOTLB message whose size is zero. But the size is not necessarily meaningful, one example is the batching hint, so the commit breaks that. Fixing this be reject zero size message only if the message is used to update/invalidate the IOTLB. Fixes: e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries") Reported-by: Eli Cohen Cc: Anirudh Rayabharam Signed-off-by: Jason Wang Link: https://lore.kernel.org/r/20220310075211.4801-1-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin Tested-by: Eli Cohen

vhost: remove avail_event arg from vhost_update_avail_event()

2022-03-06T11:06:50+00:00

In vhost_update_avail_event() we never used the `avail_event` argument, since its introduction in commit 2723feaa8ec6 ("vhost: set log when updating used flags or avail event"). Let's remove it to clean up the code. Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20220113141134.186773-1-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin

vhost: fix hung thread due to erroneous iotlb entries

2022-03-06T11:05:45+00:00

In vhost_iotlb_add_range_ctx(), range size can overflow to 0 when start is 0 and last is ULONG_MAX. One instance where it can happen is when userspace sends an IOTLB message with iova=size=uaddr=0 (vhost_process_iotlb_msg). So, an entry with size = 0, start = 0, last = ULONG_MAX ends up in the iotlb. Next time a packet is sent, iotlb_access_ok() loops indefinitely due to that erroneous entry. Call Trace: iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Reported by syzbot at: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 To fix this, do two things: 1. Return -EINVAL in vhost_chr_write_iter() when userspace asks to map a range with size 0. 2. Fix vhost_iotlb_add_range_ctx() to handle the range [0, ULONG_MAX] by splitting it into two entries. Fixes: 0bbe30668d89e ("vhost: factor out IOTLB") Reported-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com Tested-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com Signed-off-by: Anirudh Rayabharam Link: https://lore.kernel.org/r/20220305095525.5145-1-mail@anirudhrb.com Signed-off-by: Michael S. Tsirkin