kernel/linux.git/drivers/virtio, branch v6.12.80

mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

2026-01-08T09:15:05+00:00

[ Upstream commit 15504b1163007bbfbd9a63460d5c14737c16e96d ] Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

virtio_vdpa: fix misleading return in void function

2025-12-18T12:55:09+00:00

[ Upstream commit e40b6abe0b1247d43bc61942aa7534fca7209e44 ] virtio_vdpa_set_status() is declared as returning void, but it used "return vdpa_set_status()" Since vdpa_set_status() also returns void, the return statement is unnecessary and misleading. Remove it. Fixes: c043b4a8cf3b ("virtio: introduce a vDPA based transport") Signed-off-by: Alok Tiwari Message-Id: <20251001191653.1713923-1-alok.a.tiwari@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

virtio_ring: Fix error reporting in virtqueue_resize

2025-08-01T08:48:39+00:00

[ Upstream commit 45ebc7e6c125ce93d2ddf82cd5bea20121bb0258 ] The virtqueue_resize() function was not correctly propagating error codes from its internal resize helper functions, specifically virtqueue_resize_packet() and virtqueue_resize_split(). If these helpers returned an error, but the subsequent call to virtqueue_enable_after_reset() succeeded, the original error from the resize operation would be masked. Consequently, virtqueue_resize() could incorrectly report success to its caller despite an underlying resize failure. This change restores the original code behavior: if (vdev->config->enable_vq_after_reset(_vq)) return -EBUSY; return err; Fix: commit ad48d53b5b3f ("virtio_ring: separate the logic of reset/enable from virtqueue_resize") Cc: xuanzhuo@linux.alibaba.com Signed-off-by: Laurent Vivier Acked-by: Jason Wang Link: https://patch.msgid.link/20250521092236.661410-2-lvivier@redhat.com Tested-by: Lei Yang Acked-by: Michael S. Tsirkin Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

virtio_ring: Fix data race by tagging event_triggered as racy for KCSAN

2025-05-29T09:01:58+00:00

[ Upstream commit 2e2f925fe737576df2373931c95e1a2b66efdfef ] syzbot reports a data-race when accessing the event_triggered, here is the simplified stack when the issue occurred: ================================================================== BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_enable_cb_delayed write to 0xffff8881025bc452 of 1 bytes by task 3288 on cpu 0: virtqueue_enable_cb_delayed+0x42/0x3c0 drivers/virtio/virtio_ring.c:2653 start_xmit+0x230/0x1310 drivers/net/virtio_net.c:3264 __netdev_start_xmit include/linux/netdevice.h:5151 [inline] netdev_start_xmit include/linux/netdevice.h:5160 [inline] xmit_one net/core/dev.c:3800 [inline] read to 0xffff8881025bc452 of 1 bytes by interrupt on cpu 1: virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:880 [inline] virtqueue_disable_cb+0x92/0x180 drivers/virtio/virtio_ring.c:2566 skb_xmit_done+0x5f/0x140 drivers/net/virtio_net.c:777 vring_interrupt+0x161/0x190 drivers/virtio/virtio_ring.c:2715 __handle_irq_event_percpu+0x95/0x490 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] value changed: 0x01 -> 0x00 ================================================================== When the data race occurs, the function virtqueue_enable_cb_delayed() sets event_triggered to false, and virtqueue_disable_cb_split/packed() reads it as false due to the race condition. Since event_triggered is an unreliable hint used for optimization, this should only cause the driver temporarily suggest that the device not send an interrupt notification when the event index is used. Fix this KCSAN reported data-race issue by explicitly tagging the access as data_racy. Reported-by: syzbot+efe683d57990864b8c8e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67c7761a.050a0220.15b4b9.0018.GAE@google.com/ Signed-off-by: Zhongqiu Han Message-Id: <20250312130412.3516307-1-quic_zhonhan@quicinc.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

virtio_ring: add a func argument 'recycle_done' to virtqueue_reset()

2025-05-22T12:29:38+00:00

[ Upstream commit 8d2da07c813ad333c20eb803e15f8c4541f25350 ] When virtqueue_reset() has actually recycled all unused buffers, additional work may be required in some cases. Relying solely on its return status is fragile, so introduce a new function argument 'recycle_done', which is invoked when it really occurs. Signed-off-by: Koichiro Den Acked-by: Jason Wang Reviewed-by: Xuan Zhuo Signed-off-by: Paolo Abeni Stable-dep-of: 76a771ec4c9a ("virtio_net: ensure netdev_tx_reset_queue is called on bind xsk for tx") Signed-off-by: Sasha Levin

virtio_ring: add a func argument 'recycle_done' to virtqueue_resize()

2024-12-19T17:12:59+00:00

commit 8d6712c892019b9b9dc5c7039edd3c9d770b510b upstream. When virtqueue_resize() has actually recycled all unused buffers, additional work may be required in some cases. Relying solely on its return status is fragile, so introduce a new function argument 'recycle_done', which is invoked when the recycle really occurs. Cc: # v6.11+ Signed-off-by: Koichiro Den Acked-by: Jason Wang Reviewed-by: Xuan Zhuo Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

virtio_pci: Fix admin vq cleanup by using correct info pointer

2024-11-06T09:40:07+00:00

vp_modern_avq_cleanup() and vp_del_vqs() clean up admin vq resources by virtio_pci_vq_info pointer. The info pointer of admin vq is stored in vp_dev->admin_vq.info instead of vp_dev->vqs[]. Using the info pointer from vp_dev->vqs[] for admin vq causes a kernel NULL pointer dereference bug. In vp_modern_avq_cleanup() and vp_del_vqs(), get the info pointer from vp_dev->admin_vq.info for admin vq to clean up the resources. Also make info ptr as argument of vp_del_vq() to be symmetric with vp_setup_vq(). vp_reset calls vp_modern_avq_cleanup, and causes the Call Trace: ================================================================== BUG: kernel NULL pointer dereference, address:0000000000000000 ... CPU: 49 UID: 0 PID: 4439 Comm: modprobe Not tainted 6.11.0-rc5 #1 RIP: 0010:vp_reset+0x57/0x90 [virtio_pci] Call Trace: ... ? vp_reset+0x57/0x90 [virtio_pci] ? vp_reset+0x38/0x90 [virtio_pci] virtio_reset_device+0x1d/0x30 remove_vq_common+0x1c/0x1a0 [virtio_net] virtnet_remove+0xa1/0xc0 [virtio_net] virtio_dev_remove+0x46/0xa0 ... virtio_pci_driver_exit+0x14/0x810 [virtio_pci] ================================================================== Fixes: 4c3b54af907e ("virtio_pci_modern: use completion instead of busy loop to wait on admin cmd result") Signed-off-by: Feng Liu Signed-off-by: Jiri Pirko Reviewed-by: Parav Pandit Message-Id: <20241024135406.81388-1-feliu@nvidia.com> Signed-off-by: Michael S. Tsirkin

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

2024-10-07T18:33:26+00:00

Pull virtio fixes from Michael Tsirkin: "Several small bugfixes all over the place. Most notably, fixes the vsock allocation with GFP_KERNEL in atomic context, which has been triggering warnings for lots of testers" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost/scsi: null-ptr-dereference in vhost_scsi_get_req() vsock/virtio: use GFP_ATOMIC under RCU read lock virtio_console: fix misc probe bugs virtio_ring: tag event_triggered as racy for KCSAN vdpa/octeon_ep: Fix format specifier for pointers in debug messages

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

2024-09-26T15:43:17+00:00

Pull virtio updates from Michael Tsirkin: "Several new features here: - virtio-balloon supports new stats - vdpa supports setting mac address - vdpa/mlx5 suspend/resume as well as MKEY ops are now faster - virtio_fs supports new sysfs entries for queue info - virtio/vsock performance has been improved And fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (34 commits) vsock/virtio: avoid queuing packets when intermediate queue is empty vsock/virtio: refactor virtio_transport_send_pkt_work fw_cfg: Constify struct kobj_type vdpa/mlx5: Postpone MR deletion vdpa/mlx5: Introduce init/destroy for MR resources vdpa/mlx5: Rename mr_mtx -> lock vdpa/mlx5: Extract mr members in own resource struct vdpa/mlx5: Rename function vdpa/mlx5: Delete direct MKEYs in parallel vdpa/mlx5: Create direct MKEYs in parallel MAINTAINERS: add virtio-vsock driver in the VIRTIO CORE section virtio_fs: add sysfs entries for queue information virtio_fs: introduce virtio_fs_put_locked helper vdpa: Remove unused declarations vdpa/mlx5: Parallelize VQ suspend/resume for CVQ MQ command vdpa/mlx5: Small improvement for change_num_qps() vdpa/mlx5: Keep notifiers during suspend but ignore vdpa/mlx5: Parallelize device resume vdpa/mlx5: Parallelize device suspend vdpa/mlx5: Use async API for vq modify commands ...

virtio_ring: tag event_triggered as racy for KCSAN

2024-09-25T11:07:44+00:00

Setting event_triggered from the interrupt handler is fundamentally racy. There are races of 2 types: 1. vq processing can read false value while interrupt triggered and set it to true. result will be a bit of extra work when disabling cbs, no big deal. 1. vq processing can set false value then interrupt immediately sets true value since interrupt then triggers a callback which will process buffers, this is also not an issue. However, looks like KCSAN can not figure all this out, and warns about the race between the write and the read. Tag the access data_racy for now. We should probably look at ways to make this more straight-forwardly correct. Message-ID: <6bdd771a4fb7625a9227971b3cf4745c34c31a32.1726153334.git.mst@redhat.com> Reported-by: syzbot+8a02104389c2e0ef5049@syzkaller.appspotmail.com Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Acked-by: Marco Elver