kernel/linux.git/drivers/vhost/vhost.c, branch v5.10.257

vhost: fail early when __vhost_add_used() fails

2025-08-28T14:22:44+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()

2024-05-02T14:23:35+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()

2024-02-23T07:42:22+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: support PACKED when setting-getting vring_base

2023-06-14T09:09:57+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

2023-02-15T16:22:11+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()

2023-01-14T09:16:46+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: Fix the calculation in vhost_overflow()

2021-08-26T12:35:42+00:00

[ Upstream commit f7ad318ea0ad58ebe0e595e59aed270bb643b29b ] 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 Signed-off-by: Sasha Levin

vhost: Fix vhost_vq_reset()

2021-04-07T13:00:05+00:00

[ Upstream commit beb691e69f4dec7bfe8b81b509848acfd1f0dbf9 ] vhost_reset_is_le() is vhost_init_is_le(), and in the case of cross-endian legacy, vhost_init_is_le() depends on vq->user_be. vq->user_be is set by vhost_disable_cross_endian(). But in vhost_vq_reset(), we have: vhost_reset_is_le(vq); vhost_disable_cross_endian(vq); And so user_be is used before being set. To fix that, reverse the lines order as there is no other dependency between them. Signed-off-by: Laurent Vivier Link: https://lore.kernel.org/r/20210312140913.788592-1-lvivier@redhat.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

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

2020-11-15T22:30:54+00:00

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

vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call

2020-10-21T14:48:10+00:00

This commit removed unnecessary spin_locks in vhost_vring_call and related operations. Because we manipulate irq offloading contents in vhost_vdpa ioctl code path which is already protected by dev mutex and vq mutex. Signed-off-by: Zhu Lingshan Link: https://lore.kernel.org/r/20200909065234.3313-1-lingshan.zhu@intel.com Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang