kernel/linux.git/drivers/block/virtio_blk.c, branch v5.15.208

virtio-blk: don't keep queue frozen during system suspend

2025-01-09T12:28:40+00:00

[ Upstream commit 7678abee0867e6b7fb89aa40f6e9f575f755fb37 ] Commit 4ce6e2db00de ("virtio-blk: Ensure no requests in virtqueues before deleting vqs.") replaces queue quiesce with queue freeze in virtio-blk's PM callbacks. And the motivation is to drain inflight IOs before suspending. block layer's queue freeze looks very handy, but it is also easy to cause deadlock, such as, any attempt to call into bio_queue_enter() may run into deadlock if the queue is frozen in current context. There are all kinds of ->suspend() called in suspend context, so keeping queue frozen in the whole suspend context isn't one good idea. And Marek reported lockdep warning[1] caused by virtio-blk's freeze queue in virtblk_freeze(). [1] https://lore.kernel.org/linux-block/ca16370e-d646-4eee-b9cc-87277c89c43c@samsung.com/ Given the motivation is to drain in-flight IOs, it can be done by calling freeze & unfreeze, meantime restore to previous behavior by keeping queue quiesced during suspend. Cc: Yi Sun Cc: Michael S. Tsirkin Cc: Jason Wang Cc: Stefan Hajnoczi Cc: virtualization@lists.linux.dev Reported-by: Marek Szyprowski Signed-off-by: Ming Lei Acked-by: Stefan Hajnoczi Link: https://lore.kernel.org/r/20241112125821.1475793-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

virtio-blk: Ensure no requests in virtqueues before deleting vqs.

2024-03-01T12:21:47+00:00

[ Upstream commit 4ce6e2db00de8103a0687fb0f65fd17124a51aaa ] Ensure no remaining requests in virtqueues before resetting vdev and deleting virtqueues. Otherwise these requests will never be completed. It may cause the system to become unresponsive. Function blk_mq_quiesce_queue() can ensure that requests have become in_flight status, but it cannot guarantee that requests have been processed by the device. Virtqueues should never be deleted before all requests become complete status. Function blk_mq_freeze_queue() ensure that all requests in virtqueues become complete status. And no requests can enter in virtqueues. Signed-off-by: Yi Sun Reviewed-by: Stefan Hajnoczi Link: https://lore.kernel.org/r/20240129085250.1550594-1-yi.sun@unisoc.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

virtio-blk: fix implicit overflow on virtio_max_dma_size

2023-11-28T16:56:20+00:00

[ Upstream commit fafb51a67fb883eb2dde352539df939a251851be ] The following codes have an implicit conversion from size_t to u32: (u32)max_size = (size_t)virtio_max_dma_size(vdev); This may lead overflow, Ex (size_t)4G -> (u32)0. Once virtio_max_dma_size() has a larger size than U32_MAX, use U32_MAX instead. Signed-off-by: zhenwei pi Message-Id: <20230904061045.510460-1-pizhenwei@bytedance.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio-blk: modify the value type of num in virtio_queue_rq()

2022-07-12T14:35:11+00:00

commit 0466a39bd0b6c462338f10d18076703d14a552de upstream. This was found by coccicheck: ./drivers/block/virtio_blk.c, 334, 14-17, WARNING Unsigned expression compared with zero num < 0 Reported-by: Zeal Robot Signed-off-by: Ye Guojin Link: https://lore.kernel.org/r/20211117063955.160777-1-ye.guojin@zte.com.cn Signed-off-by: Michael S. Tsirkin Fixes: 02746e26c39e ("virtio-blk: avoid preallocating big SGL for data") Reviewed-by: Stefano Garzarella Reviewed-by: Max Gurtovoy Reviewed-by: Stefan Hajnoczi Signed-off-by: Greg Kroah-Hartman

virtio-blk: avoid preallocating big SGL for data

2022-07-12T14:34:56+00:00

[ Upstream commit 02746e26c39ee473b975e0f68d1295abc92672ed ] No need to pre-allocate a big buffer for the IO SGL anymore. If a device has lots of deep queues, preallocation for the sg list can consume substantial amounts of memory. For HW virtio-blk device, nr_hw_queues can be 64 or 128 and each queue's depth might be 128. This means the resulting preallocation for the data SGLs is big. Switch to runtime allocation for SGL for lists longer than 2 entries. This is the approach used by NVMe drivers so it should be reasonable for virtio block as well. Runtime SGL allocation has always been the case for the legacy I/O path so this is nothing new. The preallocated small SGL depends on SG_CHAIN so if the ARCH doesn't support SG_CHAIN, use only runtime allocation for the SGL. Re-organize the setup of the IO request to fit the new sg chain mechanism. No performance degradation was seen (fio libaio engine with 16 jobs and 128 iodepth): IO size IOPs Rand Read (before/after) IOPs Rand Write (before/after) -------- --------------------------------- ---------------------------------- 512B 318K/316K 329K/325K 4KB 323K/321K 353K/349K 16KB 199K/208K 250K/275K 128KB 36K/36.1K 39.2K/41.7K Signed-off-by: Max Gurtovoy Reviewed-by: Israel Rukshin Link: https://lore.kernel.org/r/20210901131434.31158-1-mgurtovoy@nvidia.com Reviewed-by: Feng Li Reviewed-by: Stefan Hajnoczi Tested-by: Stefan Hajnoczi Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann # kconfig fixups Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_blk: fix the discard_granularity and discard_alignment queue limits

2022-06-09T08:22:53+00:00

[ Upstream commit 62952cc5bccd89b76d710de1d0b43244af0f2903 ] The discard_alignment queue limit is named a bit misleading means the offset into the block device at which the discard granularity starts. On the other hand the discard_sector_alignment from the virtio 1.1 looks similar to what Linux uses as discard granularity (even if not very well described): "discard_sector_alignment can be used by OS when splitting a request based on alignment. " And at least qemu does set it to the discard granularity. So stop setting the discard_alignment and use the virtio discard_sector_alignment to set the discard granularity. Fixes: 1f23816b8eb8 ("virtio_blk: add discard and write zeroes support") Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20220418045314.360785-5-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

virtio-blk: Use blk_validate_block_size() to validate block size

2022-04-08T12:22:48+00:00

commit 57a13a5b8157d9a8606490aaa1b805bafe6c37e1 upstream. The block layer can't support a block size larger than page size yet. And a block size that's too small or not a power of two won't work either. If a misconfigured device presents an invalid block size in configuration space, it will result in the kernel crash something like below: [ 506.154324] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 506.160416] RIP: 0010:create_empty_buffers+0x24/0x100 [ 506.174302] Call Trace: [ 506.174651] create_page_buffers+0x4d/0x60 [ 506.175207] block_read_full_page+0x50/0x380 [ 506.175798] ? __mod_lruvec_page_state+0x60/0xa0 [ 506.176412] ? __add_to_page_cache_locked+0x1b2/0x390 [ 506.177085] ? blkdev_direct_IO+0x4a0/0x4a0 [ 506.177644] ? scan_shadow_nodes+0x30/0x30 [ 506.178206] ? lru_cache_add+0x42/0x60 [ 506.178716] do_read_cache_page+0x695/0x740 [ 506.179278] ? read_part_sector+0xe0/0xe0 [ 506.179821] read_part_sector+0x36/0xe0 [ 506.180337] adfspart_check_ICS+0x32/0x320 [ 506.180890] ? snprintf+0x45/0x70 [ 506.181350] ? read_part_sector+0xe0/0xe0 [ 506.181906] bdev_disk_changed+0x229/0x5c0 [ 506.182483] blkdev_get_whole+0x6d/0x90 [ 506.183013] blkdev_get_by_dev+0x122/0x2d0 [ 506.183562] device_add_disk+0x39e/0x3c0 [ 506.184472] virtblk_probe+0x3f8/0x79b [virtio_blk] [ 506.185461] virtio_dev_probe+0x15e/0x1d0 [virtio] So let's use a block layer helper to validate the block size. Signed-off-by: Xie Yongji Acked-by: Michael S. Tsirkin Link: https://lore.kernel.org/r/20211026144015.188-5-xieyongji@bytedance.com Signed-off-by: Jens Axboe Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

virtio-blk: Don't use MAX_DISCARD_SEGMENTS if max_discard_seg is zero

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

[ Upstream commit dacc73ed0b88f1a787ec20385f42ca9dd9eddcd0 ] Currently the value of max_discard_segment will be set to MAX_DISCARD_SEGMENTS (256) with no basis in hardware if device set 0 to max_discard_seg in configuration space. It's incorrect since the device might not be able to handle such large descriptors. To fix it, let's follow max_segments restrictions in this case. Fixes: 1f23816b8eb8 ("virtio_blk: add discard and write zeroes support") Signed-off-by: Xie Yongji Link: https://lore.kernel.org/r/20220304100058.116-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

Revert "virtio-blk: Add validation for block size in config space"

2021-10-13T12:35:36+00:00

It turns out that access to config space before completing the feature negotiation is broken for big endian guests at least with QEMU hosts up to 6.1 inclusive. This affects any device that accesses config space in the validate callback: at the moment that is virtio-net with VIRTIO_NET_F_MTU but since 82e89ea077b9 ("virtio-blk: Add validation for block size in config space") that also started affecting virtio-blk with VIRTIO_BLK_F_BLK_SIZE. Further, unlike VIRTIO_NET_F_MTU which is off by default on QEMU, VIRTIO_BLK_F_BLK_SIZE is on by default, which resulted in lots of people not being able to boot VMs on BE. The spec is very clear that what we are doing is legal so QEMU needs to be fixed, but given it's been broken for so many years and no one noticed, we need to give QEMU a bit more time before applying this. Further, this patch is incomplete (does not check blk size is a power of two) and it duplicates the logic from nbd. Revert for now, and we'll reapply a cleaner logic in the next release. Cc: stable@vger.kernel.org Fixes: 82e89ea077b9 ("virtio-blk: Add validation for block size in config space") Cc: Xie Yongji Signed-off-by: Michael S. Tsirkin

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

2021-09-11T21:48:42+00:00

Pull virtio updates from Michael Tsirkin: - vduse driver ("vDPA Device in Userspace") supporting emulated virtio block devices - virtio-vsock support for end of record with SEQPACKET - vdpa: mac and mq support for ifcvf and mlx5 - vdpa: management netlink for ifcvf - virtio-i2c, gpio dt bindings - misc fixes and cleanups * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (39 commits) Documentation: Add documentation for VDUSE vduse: Introduce VDUSE - vDPA Device in Userspace vduse: Implement an MMU-based software IOTLB vdpa: Support transferring virtual addressing during DMA mapping vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() vhost-iotlb: Add an opaque pointer for vhost IOTLB vhost-vdpa: Handle the failure of vdpa_reset() vdpa: Add reset callback in vdpa_config_ops vdpa: Fix some coding style issues file: Export receive_fd() to modules eventfd: Export eventfd_wake_count to modules iova: Export alloc_iova_fast() and free_iova_fast() virtio-blk: remove unneeded "likely" statements virtio-balloon: Use virtio_find_vqs() helper vdpa: Make use of PFN_PHYS/PFN_UP/PFN_DOWN helper macro vsock_test: update message bounds test for MSG_EOR af_vsock: rename variables in receive loop virtio/vsock: support MSG_EOR bit processing vhost/vsock: support MSG_EOR bit processing ...