kernel/linux.git/drivers/vhost/vhost.c, branch v5.15.208

vhost: fail early when __vhost_add_used() fails

2025-08-28T14:24:22+00:00

[ Upstream commit b4ba1207d45adaafa2982c035898b36af2d3e518 ] This patch fails vhost_add_used_n() early when __vhost_add_used() fails to make sure used idx is not updated with stale used ring information. Reported-by: Eugenio Pérez Signed-off-by: Jason Wang Message-Id: <20250714084755.11921-2-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang Signed-off-by: Sasha Levin

vhost: Add smp_rmb() in vhost_vq_avail_empty()

2024-04-17T09:15:16+00:00

commit 22e1992cf7b034db5325660e98c41ca5afa5f519 upstream. A smp_rmb() has been missed in vhost_vq_avail_empty(), spotted by Will. Otherwise, it's not ensured the available ring entries pushed by guest can be observed by vhost in time, leading to stale available ring entries fetched by vhost in vhost_get_vq_desc(), as reported by Yihuang Yu on NVidia's grace-hopper (ARM64) platform. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \ -accel kvm -machine virt,gic-version=host -cpu host \ -smp maxcpus=1,cpus=1,sockets=1,clusters=1,cores=1,threads=1 \ -m 4096M,slots=16,maxmem=64G \ -object memory-backend-ram,id=mem0,size=4096M \ : \ -netdev tap,id=vnet0,vhost=true \ -device virtio-net-pci,bus=pcie.8,netdev=vnet0,mac=52:54:00:f1:26:b0 : guest# netperf -H 10.26.1.81 -l 60 -C -c -t UDP_STREAM virtio_net virtio0: output.0:id 100 is not a head! Add the missed smp_rmb() in vhost_vq_avail_empty(). When tx_can_batch() returns true, it means there's still pending tx buffers. Since it might read indices, so it still can bypass the smp_rmb() in vhost_get_vq_desc(). Note that it should be safe until vq->avail_idx is changed by commit 275bf960ac697 ("vhost: better detection of available buffers"). Fixes: 275bf960ac69 ("vhost: better detection of available buffers") Cc: # v4.11+ Reported-by: Yihuang Yu Suggested-by: Will Deacon Signed-off-by: Gavin Shan Acked-by: Jason Wang Message-Id: <20240328002149.1141302-2-gshan@redhat.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella Signed-off-by: Greg Kroah-Hartman

vhost: use kzalloc() instead of kmalloc() followed by memset()

2024-02-23T07:55:00+00:00

commit 4d8df0f5f79f747d75a7d356d9b9ea40a4e4c8a9 upstream. Use kzalloc() to allocate new zeroed out msg node instead of memsetting a node allocated with kmalloc(). Signed-off-by: Prathu Baronia Message-Id: <20230522085019.42914-1-prathubaronia2011@gmail.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella Signed-off-by: Ajay Kaher Signed-off-by: Greg Kroah-Hartman

vhost: Allow null msg.size on VHOST_IOTLB_INVALIDATE

2023-11-08T16:26:36+00:00

commit ca50ec377c2e94b0a9f8735de2856cd0f13beab4 upstream. Commit e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries") Forbade vhost iotlb msg with null size to prevent entries with size = start = 0 and last = ULONG_MAX to end up in the iotlb. Then commit 95932ab2ea07 ("vhost: allow batching hint without size") only applied the check for VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE message types to fix a regression observed with batching hit. Still, the introduction of that check introduced a regression for some users attempting to invalidate the whole ULONG_MAX range by setting the size to 0. This is the case with qemu/smmuv3/vhost integration which does not work anymore. It Looks safe to partially revert the original commit and allow VHOST_IOTLB_INVALIDATE messages with null size. vhost_iotlb_del_range() will compute a correct end iova. Same for vhost_vdpa_iotlb_unmap(). Signed-off-by: Eric Auger Fixes: e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries") Cc: stable@vger.kernel.org # v5.17+ Acked-by: Jason Wang Message-Id: <20230927140544.205088-1-eric.auger@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

vhost: support PACKED when setting-getting vring_base

2023-06-14T09:13:09+00:00

[ Upstream commit 55d8122f5cd62d5aaa225d7167dcd14a44c850b9 ] Use the right structs for PACKED or split vqs when setting and getting the vring base. Fixes: 4c8cf31885f6 ("vhost: introduce vDPA-based backend") Signed-off-by: Shannon Nelson Message-Id: <20230424225031.18947-3-shannon.nelson@amd.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

vhost/net: Clear the pending messages when the backend is removed

2023-02-09T10:26:34+00:00

[ Upstream commit 9526f9a2b762af16be94a72aca5d65c677d28f50 ] When the vhost iotlb is used along with a guest virtual iommu and the guest gets rebooted, some MISS messages may have been recorded just before the reboot and spuriously executed by the virtual iommu after the reboot. As vhost does not have any explicit reset user API, VHOST_NET_SET_BACKEND looks a reasonable point where to clear the pending messages, in case the backend is removed. Export vhost_clear_msg() and call it in vhost_net_set_backend() when fd == -1. Signed-off-by: Eric Auger Suggested-by: Jason Wang Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Message-Id: <20230117151518.44725-3-eric.auger@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

vhost: fix range used in translate_desc()

2023-01-12T10:59:11+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: allow batching hint without size

2022-03-16T13:23:47+00:00

commit 95932ab2ea07b79cdb33121e2f40ccda9e6a73b5 upstream. 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 Signed-off-by: Greg Kroah-Hartman

vhost: fix hung thread due to erroneous iotlb entries

2022-03-16T13:23:36+00:00

[ Upstream commit e2ae38cf3d91837a493cb2093c87700ff3cbe667 ] 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 Signed-off-by: Sasha Levin

vhost: Fix the calculation in vhost_overflow()

2021-08-11T10:44:15+00:00

This fixes the incorrect calculation for integer overflow when the last address of iova range is 0xffffffff. Fixes: ec33d031a14b ("vhost: detect 32 bit integer wrap around") Reported-by: Jason Wang Signed-off-by: Xie Yongji Acked-by: Jason Wang Link: https://lore.kernel.org/r/20210728130756.97-2-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin