linux/drivers/virtio, branch v6.15

virtgpu: don't reset on shutdown

2025-04-18T14:05:49Z

It looks like GPUs are used after shutdown is invoked. Thus, breaking virtio gpu in the shutdown callback is not a good idea - guest hangs attempting to finish console drawing, with these warnings: [ 20.504464] WARNING: CPU: 0 PID: 568 at drivers/gpu/drm/virtio/virtgpu_vq.c:358 virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu] [ 20.505685] Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables nfnetlink vfat fat intel_rapl_msr intel_rapl_common intel_uncore_frequency_common nfit libnvdimm kvm_intel kvm rapl iTCO_wdt iTCO_vendor_support virtio_gpu virtio_dma_buf pcspkr drm_shmem_helper i2c_i801 drm_kms_helper lpc_ich i2c_smbus virtio_balloon joydev drm fuse xfs libcrc32c ahci libahci crct10dif_pclmul crc32_pclmul crc32c_intel libata virtio_net ghash_clmulni_intel net_failover virtio_blk failover serio_raw dm_mirror dm_region_hash dm_log dm_mod [ 20.511847] CPU: 0 PID: 568 Comm: kworker/0:3 Kdump: loaded Tainted: G W ------- --- 5.14.0-578.6675_1757216455.el9.x86_64 #1 [ 20.513157] Hardware name: Red Hat KVM/RHEL, BIOS edk2-20241117-3.el9 11/17/2024 [ 20.513918] Workqueue: events drm_fb_helper_damage_work [drm_kms_helper] [ 20.514626] RIP: 0010:virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu] [ 20.515332] Code: 00 00 48 85 c0 74 0c 48 8b 78 08 48 89 ee e8 51 50 00 00 65 ff 0d 42 e3 74 3f 0f 85 69 ff ff ff 0f 1f 44 00 00 e9 5f ff ff ff <0f> 0b e9 3f ff ff ff 48 83 3c 24 00 74 0e 49 8b 7f 40 48 85 ff 74 [ 20.517272] RSP: 0018:ff34f0a8c0787ad8 EFLAGS: 00010282 [ 20.517820] RAX: 00000000fffffffb RBX: 0000000000000000 RCX: 0000000000000820 [ 20.518565] RDX: 0000000000000000 RSI: ff34f0a8c0787be0 RDI: ff218bef03a26300 [ 20.519308] RBP: ff218bef03a26300 R08: 0000000000000001 R09: ff218bef07224360 [ 20.520059] R10: 0000000000008dc0 R11: 0000000000000002 R12: ff218bef02630028 [ 20.520806] R13: ff218bef0263fb48 R14: ff218bef00cb8000 R15: ff218bef07224360 [ 20.521555] FS: 0000000000000000(0000) GS:ff218bef7ba00000(0000) knlGS:0000000000000000 [ 20.522397] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 20.522996] CR2: 000055ac4f7871c0 CR3: 000000010b9f2002 CR4: 0000000000771ef0 [ 20.523740] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 20.524477] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 [ 20.525223] PKRU: 55555554 [ 20.525515] Call Trace: [ 20.525777] [ 20.526003] ? show_trace_log_lvl+0x1c4/0x2df [ 20.526464] ? show_trace_log_lvl+0x1c4/0x2df [ 20.526925] ? virtio_gpu_queue_fenced_ctrl_buffer+0x82/0x2c0 [virtio_gpu] [ 20.527643] ? virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu] [ 20.528282] ? __warn+0x7e/0xd0 [ 20.528621] ? virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu] [ 20.529256] ? report_bug+0x100/0x140 [ 20.529643] ? handle_bug+0x3c/0x70 [ 20.530010] ? exc_invalid_op+0x14/0x70 [ 20.530421] ? asm_exc_invalid_op+0x16/0x20 [ 20.530862] ? virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu] [ 20.531506] ? virtio_gpu_queue_ctrl_sgs+0x174/0x290 [virtio_gpu] [ 20.532148] virtio_gpu_queue_fenced_ctrl_buffer+0x82/0x2c0 [virtio_gpu] [ 20.532843] virtio_gpu_primary_plane_update+0x3e2/0x460 [virtio_gpu] [ 20.533520] drm_atomic_helper_commit_planes+0x108/0x320 [drm_kms_helper] [ 20.534233] drm_atomic_helper_commit_tail+0x45/0x80 [drm_kms_helper] [ 20.534914] commit_tail+0xd2/0x130 [drm_kms_helper] [ 20.535446] drm_atomic_helper_commit+0x11b/0x140 [drm_kms_helper] [ 20.536097] drm_atomic_commit+0xa4/0xe0 [drm] [ 20.536588] ? __pfx___drm_printfn_info+0x10/0x10 [drm] [ 20.537162] drm_atomic_helper_dirtyfb+0x192/0x270 [drm_kms_helper] [ 20.537823] drm_fbdev_shmem_helper_fb_dirty+0x43/0xa0 [drm_shmem_helper] [ 20.538536] drm_fb_helper_damage_work+0x87/0x160 [drm_kms_helper] [ 20.539188] process_one_work+0x194/0x380 [ 20.539612] worker_thread+0x2fe/0x410 [ 20.540007] ? __pfx_worker_thread+0x10/0x10 [ 20.540456] kthread+0xdd/0x100 [ 20.540791] ? __pfx_kthread+0x10/0x10 [ 20.541190] ret_from_fork+0x29/0x50 [ 20.541566] [ 20.541802] ---[ end trace 0000000000000000 ]--- It looks like the shutdown is called in the middle of console drawing, so we should either wait for it to finish, or let drm handle the shutdown. This patch implements this second option: Add an option for drivers to bypass the common break+reset handling. As DRM is careful to flush/synchronize outstanding buffers, it looks like GPU can just have a NOP there. Reviewed-by: Eric Auger Tested-by: Eric Auger Fixes: 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()") Cc: Eric Auger Cc: Jocelyn Falempe Signed-off-by: Michael S. Tsirkin Message-Id: <8490dbeb6f79ed039e6c11d121002618972538a3.1744293540.git.mst@redhat.com>

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

2025-04-14T13:51:31Z

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

virtio_pci: Use self group type for cap commands

2025-04-14T13:51:31Z

Section 2.12.1.2 of v1.4 of the VirtIO spec states: The device and driver capabilities commands are currently defined for self group type. 1. VIRTIO_ADMIN_CMD_CAP_ID_LIST_QUERY 2. VIRTIO_ADMIN_CMD_DEVICE_CAP_GET 3. VIRTIO_ADMIN_CMD_DRIVER_CAP_SET Fixes: bfcad518605d ("virtio: Manage device and driver capabilities via the admin commands") Signed-off-by: Daniel Jurgens Reviewed-by: Parav Pandit Message-Id: <20250304161442.90700-1-danielj@nvidia.com> Signed-off-by: Michael S. Tsirkin

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

2025-04-02T01:52:54Z

Pull virtio updates from Michael Tsirkin: "A small number of improvements all over the place: - shutdown has been reworked to reset devices - virtio fs is now allowed in vduse - vhost-scsi memory use has been reduced - cleanups, fixes all over the place A couple more fixes are being tested and will be merged after rc1" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost-scsi: Reduce response iov mem use vhost-scsi: Allocate iov_iter used for unaligned copies when needed vhost-scsi: Stop duplicating se_cmd fields vhost-scsi: Dynamically allocate scatterlists vhost-scsi: Return queue full for page alloc failures during copy vhost-scsi: Add better resource allocation failure handling vhost-scsi: Allocate T10 PI structs only when enabled vhost-scsi: Reduce mem use by moving upages to per queue vduse: add virtio_fs to allowed dev id sound/virtio: Fix cancel_sync warnings on uninitialized work_structs vdpa/mlx5: Fix oversized null mkey longer than 32bit vdpa/mlx5: Fix mlx5_vdpa_get_config() endianness on big-endian machines vhost-scsi: Fix handling of multiple calls to vhost_scsi_set_endpoint tools: virtio/linux/module.h add MODULE_DESCRIPTION() define. tools: virtio/linux/compiler.h: Add data_race() define. tools/virtio: Add DMA_MAPPING_ERROR and sg_dma_len api define for virtio test virtio: break and reset virtio devices on device_shutdown()

virtio: break and reset virtio devices on device_shutdown()

2025-02-24T19:29:26Z

Hongyu reported a hang on kexec in a VM. QEMU reported invalid memory accesses during the hang. Invalid read at addr 0x102877002, size 2, region '(null)', reason: rejected Invalid write at addr 0x102877A44, size 2, region '(null)', reason: rejected ... It was traced down to virtio-console. Kexec works fine if virtio-console is not in use. The issue is that virtio-console continues to write to the MMIO even after underlying virtio-pci device is reset. Additionally, Eric noticed that IOMMUs are reset before devices, if devices are not reset on shutdown they continue to poke at guest memory and get errors from the IOMMU. Some devices get wedged then. The problem can be solved by breaking all virtio devices on virtio bus shutdown, then resetting them. Reported-by: Eric Auger Reported-by: Hongyu Ning Message-ID: Tested-by: Eric Auger Acked-by: Jason Wang Signed-off-by: Michael S. Tsirkin

virtio: mem: Switch to use hrtimer_setup()

2025-02-18T10:19:07Z

hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Acked-by: Zack Rusin Link: https://lore.kernel.org/all/4a911503d16684592b59a16d8ade97e42df64a54.1738746904.git.namcao@linutronix.de

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

2025-01-27T23:26:06Z

Pull virtio updates from Michael Tsirkin: "A small number of improvements all over the place: - vdpa/octeon support for multiple interrupts - virtio-pci support for error recovery - vp_vdpa support for notification with data - vhost/net fix to set num_buffers for spec compliance - virtio-mem now works with kdump on s390 And small cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (23 commits) virtio_blk: Add support for transport error recovery virtio_pci: Add support for PCIe Function Level Reset vhost/net: Set num_buffers for virtio 1.0 vdpa/octeon_ep: read vendor-specific PCI capability virtio-pci: define type and header for PCI vendor data vdpa/octeon_ep: handle device config change events vdpa/octeon_ep: enable support for multiple interrupts per device vdpa: solidrun: Replace deprecated PCI functions s390/kdump: virtio-mem kdump support (CONFIG_PROC_VMCORE_DEVICE_RAM) virtio-mem: support CONFIG_PROC_VMCORE_DEVICE_RAM virtio-mem: remember usable region size virtio-mem: mark device ready before registering callbacks in kdump mode fs/proc/vmcore: introduce PROC_VMCORE_DEVICE_RAM to detect device RAM ranges in 2nd kernel fs/proc/vmcore: factor out freeing a list of vmcore ranges fs/proc/vmcore: factor out allocating a vmcore range and adding it to a list fs/proc/vmcore: move vmcore definitions out of kcore.h fs/proc/vmcore: prefix all pr_* with "vmcore:" fs/proc/vmcore: disallow vmcore modifications while the vmcore is open fs/proc/vmcore: replace vmcoredd_mutex by vmcore_mutex fs/proc/vmcore: convert vmcore_cb_lock into vmcore_mutex ...

virtio_pci: Add support for PCIe Function Level Reset

2025-01-27T14:39:26Z

Implement support for Function Level Reset (FLR) in virtio_pci devices. This change adds reset_prepare and reset_done callbacks, allowing drivers to properly handle FLR operations. Without this patch, performing and recovering from an FLR is not possible for virtio_pci devices. This implementation ensures proper FLR handling and recovery for both physical and virtual functions. The device reset can be triggered in case of error or manually via sysfs: echo 1 > /sys/bus/pci/devices/$PCI_ADDR/reset Signed-off-by: Israel Rukshin Reviewed-by: Max Gurtovoy Message-Id: <1732690652-3065-2-git-send-email-israelr@nvidia.com> Signed-off-by: Michael S. Tsirkin

virtio-mem: support CONFIG_PROC_VMCORE_DEVICE_RAM

2025-01-27T14:39:25Z

Let's implement the get_device_ram() vmcore callback, so architectures that select NEED_PROC_VMCORE_NEED_DEVICE_RAM, like s390 soon, can include that memory in a crash dump. Merge ranges, and process ranges that might contain a mixture of plugged and unplugged, to reduce the total number of ranges. Signed-off-by: David Hildenbrand Message-Id: <20241204125444.1734652-12-david@redhat.com> Signed-off-by: Michael S. Tsirkin

virtio-mem: remember usable region size

2025-01-27T14:39:25Z

Let's remember the usable region size, which will be helpful in kdump mode next. Signed-off-by: David Hildenbrand Message-Id: <20241204125444.1734652-11-david@redhat.com> Signed-off-by: Michael S. Tsirkin