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path: root/drivers/virtio/virtio_ring.c
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2024-12-10virtio_ring: add a func argument 'recycle_done' to virtqueue_reset()Koichiro Den
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 <koichiro.den@canonical.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-10virtio_ring: add a func argument 'recycle_done' to virtqueue_resize()Koichiro Den
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: <stable@vger.kernel.org> # v6.11+ Signed-off-by: Koichiro Den <koichiro.den@canonical.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-27Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: "A small number of improvements all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio_vdpa: remove redundant check on desc virtio_fs: store actual queue index in mq_map virtio_fs: add informative log for new tag discovery virtio: Make vring_new_virtqueue support packed vring virtio_pmem: Add freeze/restore callbacks vdpa/mlx5: Fix suboptimal range on iotlb iteration
2024-11-15virtio_ring: remove API virtqueue_set_dma_premappedXuan Zhuo
Now, this API is useless. remove it. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20241112012928.102478-8-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15virtio_ring: introduce add api for premappedXuan Zhuo
Two APIs are introduced to submit premapped per-buffers. int virtqueue_add_inbuf_premapped(struct virtqueue *vq, struct scatterlist *sg, unsigned int num, void *data, void *ctx, gfp_t gfp); int virtqueue_add_outbuf_premapped(struct virtqueue *vq, struct scatterlist *sg, unsigned int num, void *data, gfp_t gfp); Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20241112012928.102478-6-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15virtio_ring: perform premapped operations based on per-bufferXuan Zhuo
The current configuration sets the virtqueue (vq) to premapped mode, implying that all buffers submitted to this queue must be mapped ahead of time. This presents a challenge for the virtnet send queue (sq): the virtnet driver would be required to keep track of dma information for vq size * 17, which can be substantial. However, if the premapped mode were applied on a per-buffer basis, the complexity would be greatly reduced. With AF_XDP enabled, AF_XDP buffers would become premapped, while kernel skb buffers could remain unmapped. And consider that some sgs are not generated by the virtio driver, that may be passed from the block stack. So we can not change the sgs, new APIs are the better way. So we pass the new argument 'premapped' to indicate the buffers submitted to virtio are premapped in advance. Additionally, DMA unmap operations for these buffers will be bypassed. Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20241112012928.102478-5-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15virtio_ring: packed: record extras for indirect buffersXuan Zhuo
The subsequent commit needs to know whether every indirect buffer is premapped or not. So we need to introduce an extra struct for every indirect buffer to record this info. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20241112012928.102478-4-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15virtio_ring: split: record extras for indirect buffersXuan Zhuo
The subsequent commit needs to know whether every indirect buffer is premapped or not. So we need to introduce an extra struct for every indirect buffer to record this info. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20241112012928.102478-3-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15virtio_ring: introduce vring_need_unmap_bufferXuan Zhuo
To make the code readable, introduce vring_need_unmap_buffer() to replace do_unmap. use_dma_api premapped -> vring_need_unmap_buffer() 1. false false false 2. true false true 3. true true false Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20241112012928.102478-2-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-12virtio: Make vring_new_virtqueue support packed vringWenyu Huang
It is used for testing in tools/virtio/vringh_test.c. If vring_new_virtqueue supports packed vring, we can add support for packed vring to vringh and test it. Signed-off-by: Wenyu Huang <huangwenyu1998@gmail.com> Message-Id: <20241013033233.65026-1-huangwenyu1998@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2024-09-25virtio_ring: tag event_triggered as racy for KCSANMichael S. Tsirkin
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 <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Marco Elver <elver@google.com>
2024-07-09virtio: add missing MODULE_DESCRIPTION() macrosJeff Johnson
With ARCH=sh, make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/virtio/virtio.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/virtio/virtio_ring.o Add the missing invocations of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Message-Id: <20240702-md-sh-drivers-virtio-v1-1-cf7325ab6ccc@quicinc.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-04virtio_ring: fix KMSAN error for premapped modeXuan Zhuo
Add kmsan for virtqueue_dma_map_single_attrs to fix: BUG: KMSAN: uninit-value in receive_buf+0x45ca/0x6990 receive_buf+0x45ca/0x6990 virtnet_poll+0x17e0/0x3130 net_rx_action+0x832/0x26e0 handle_softirqs+0x330/0x10f0 [...] Uninit was created at: __alloc_pages_noprof+0x62a/0xe60 alloc_pages_noprof+0x392/0x830 skb_page_frag_refill+0x21a/0x5c0 virtnet_rq_alloc+0x50/0x1500 try_fill_recv+0x372/0x54c0 virtnet_open+0x210/0xbe0 __dev_open+0x56e/0x920 __dev_change_flags+0x39c/0x2000 dev_change_flags+0xaa/0x200 do_setlink+0x197a/0x7420 rtnl_setlink+0x77c/0x860 [...] Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Tested-by: Alexander Potapenko <glider@google.com> Message-Id: <20240606111345.93600-1-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x Acked-by: Jason Wang <jasowang@redhat.com>
2024-05-13virtio_ring: enable premapped mode whatever use_dma_apiXuan Zhuo
Now, we have virtio DMA APIs, the driver can be the premapped mode whatever the virtio core uses dma api or not. So remove the limit of checking use_dma_api from virtqueue_set_dma_premapped(). Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20240511031404.30903-2-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-19virtio: packed: fix unmap leak for indirect desc tableXuan Zhuo
When use_dma_api and premapped are true, then the do_unmap is false. Because the do_unmap is false, vring_unmap_extra_packed is not called by detach_buf_packed. if (unlikely(vq->do_unmap)) { curr = id; for (i = 0; i < state->num; i++) { vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); curr = vq->packed.desc_extra[curr].next; } } So the indirect desc table is not unmapped. This causes the unmap leak. So here, we check vq->use_dma_api instead. Synchronously, dma info is updated based on use_dma_api judgment This bug does not occur, because no driver use the premapped with indirect. Fixes: b319940f83c2 ("virtio_ring: skip unmap for premapped") Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20240223071833.26095-1-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-12-04virtio_ring: fix syncs DMA memory with different directionXuan Zhuo
Now the APIs virtqueue_dma_sync_single_range_for_{cpu,device} ignore the parameter 'dir', that is a mistake. [ 6.101666] ------------[ cut here ]------------ [ 6.102079] DMA-API: virtio-pci 0000:00:04.0: device driver syncs DMA memory with different direction [device address=0x00000000ae010000] [size=32752 bytes] [mapped with DMA_FROM_DEVICE] [synced with DMA_BIDIRECTIONAL] [ 6.103630] WARNING: CPU: 6 PID: 0 at kernel/dma/debug.c:1125 check_sync+0x53e/0x6c0 [ 6.107420] CPU: 6 PID: 0 Comm: swapper/6 Tainted: G E 6.6.0+ #290 [ 6.108030] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 6.108936] RIP: 0010:check_sync+0x53e/0x6c0 [ 6.109289] Code: 24 10 e8 f5 d9 74 00 4c 8b 4c 24 10 4c 8b 44 24 18 48 8b 4c 24 20 48 89 c6 41 56 4c 89 ea 48 c7 c7 b0 f1 50 82 e8 32 fc f3 ff <0f> 0b 48 c7 c7 48 4b 4a 82 e8 74 d9 fc ff 8b 73 4c 48 8d 7b 50 31 [ 6.110750] RSP: 0018:ffffc90000180cd8 EFLAGS: 00010092 [ 6.111178] RAX: 00000000000000ce RBX: ffff888100aa5900 RCX: 0000000000000000 [ 6.111744] RDX: 0000000000000104 RSI: ffffffff824c3208 RDI: 00000000ffffffff [ 6.112316] RBP: ffffc90000180d40 R08: 0000000000000000 R09: 00000000fffeffff [ 6.112893] R10: ffffc90000180b98 R11: ffffffff82f63308 R12: ffffffff83d5af00 [ 6.113460] R13: ffff888100998200 R14: ffffffff824a4b5f R15: 0000000000000286 [ 6.114027] FS: 0000000000000000(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000 [ 6.114665] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.115128] CR2: 00007f10f1e03030 CR3: 0000000108272004 CR4: 0000000000770ee0 [ 6.115701] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6.116272] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6.116842] PKRU: 55555554 [ 6.117069] Call Trace: [ 6.117275] <IRQ> [ 6.117452] ? __warn+0x84/0x140 [ 6.117727] ? check_sync+0x53e/0x6c0 [ 6.118034] ? __report_bug+0xea/0x100 [ 6.118353] ? check_sync+0x53e/0x6c0 [ 6.118653] ? report_bug+0x41/0xc0 [ 6.118944] ? handle_bug+0x3c/0x70 [ 6.119237] ? exc_invalid_op+0x18/0x70 [ 6.119551] ? asm_exc_invalid_op+0x1a/0x20 [ 6.119900] ? check_sync+0x53e/0x6c0 [ 6.120199] ? check_sync+0x53e/0x6c0 [ 6.120499] debug_dma_sync_single_for_cpu+0x5c/0x70 [ 6.120906] ? dma_sync_single_for_cpu+0xb7/0x100 [ 6.121291] virtnet_rq_unmap+0x158/0x170 [virtio_net] [ 6.121716] virtnet_receive+0x196/0x220 [virtio_net] [ 6.122135] virtnet_poll+0x48/0x1b0 [virtio_net] [ 6.122524] __napi_poll+0x29/0x1b0 [ 6.123083] net_rx_action+0x282/0x360 [ 6.123612] __do_softirq+0xf3/0x2fb [ 6.124138] __irq_exit_rcu+0x8e/0xf0 [ 6.124663] common_interrupt+0xbc/0xe0 [ 6.125202] </IRQ> We need to enable CONFIG_DMA_API_DEBUG and work with need sync mode(such as swiotlb) to reproduce this warn. Fixes: 8bd2f71054bd ("virtio_ring: introduce dma sync api for virtqueue") Reported-by: "Ning, Hongyu" <hongyu.ning@linux.intel.com> Closes: https://lore.kernel.org/all/f37cb55a-6fc8-4e21-8789-46d468325eea@linux.intel.com/ Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20231201033303.25141-1-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Parav Pandit <parav@nvidia.com> Acked-by: Jason Wang <jasowang@redhat.com> Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
2023-09-03virtio_ring: fix avail_wrap_counter in virtqueue_add_packedYuan Yao
In current packed virtqueue implementation, the avail_wrap_counter won't flip, in the case when the driver supplies a descriptor chain with a length equals to the queue size; total_sg == vq->packed.vring.num. Let’s assume the following situation: vq->packed.vring.num=4 vq->packed.next_avail_idx: 1 vq->packed.avail_wrap_counter: 0 Then the driver adds a descriptor chain containing 4 descriptors. We expect the following result with avail_wrap_counter flipped: vq->packed.next_avail_idx: 1 vq->packed.avail_wrap_counter: 1 But, the current implementation gives the following result: vq->packed.next_avail_idx: 1 vq->packed.avail_wrap_counter: 0 To reproduce the bug, you can set a packed queue size as small as possible, so that the driver is more likely to provide a descriptor chain with a length equal to the packed queue size. For example, in qemu run following commands: sudo qemu-system-x86_64 \ -enable-kvm \ -nographic \ -kernel "path/to/kernel_image" \ -m 1G \ -drive file="path/to/rootfs",if=none,id=disk \ -device virtio-blk,drive=disk \ -drive file="path/to/disk_image",if=none,id=rwdisk \ -device virtio-blk,drive=rwdisk,packed=on,queue-size=4,\ indirect_desc=off \ -append "console=ttyS0 root=/dev/vda rw init=/bin/bash" Inside the VM, create a directory and mount the rwdisk device on it. The rwdisk will hang and mount operation will not complete. This commit fixes the wrap counter error by flipping the packed.avail_wrap_counter, when start of descriptor chain equals to the end of descriptor chain (head == i). Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Signed-off-by: Yuan Yao <yuanyaogoog@chromium.org> Message-Id: <20230808051110.3492693-1-yuanyaogoog@chromium.org> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: introduce dma sync api for virtqueueXuan Zhuo
These API has been introduced: * virtqueue_dma_need_sync * virtqueue_dma_sync_single_range_for_cpu * virtqueue_dma_sync_single_range_for_device These APIs can be used together with the premapped mechanism to sync the DMA address. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20230810123057.43407-12-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: introduce dma map api for virtqueueXuan Zhuo
Added virtqueue_dma_map_api* to map DMA addresses for virtual memory in advance. The purpose is to keep memory mapped across multiple add/get buf operations. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20230810123057.43407-11-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: introduce virtqueue_reset()Xuan Zhuo
Introduce virtqueue_reset() to release all buffer inside vq. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-10-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: separate the logic of reset/enable from virtqueue_resizeXuan Zhuo
The subsequent reset function will reuse these logic. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-9-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: correct the expression of the description of virtqueue_resize()Xuan Zhuo
Modify the "useless" to a more accurate "unused". Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-8-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: skip unmap for premappedXuan Zhuo
Now we add a case where we skip dma unmap, the vq->premapped is true. We can't just rely on use_dma_api to determine whether to skip the dma operation. For convenience, I introduced the "do_unmap". By default, it is the same as use_dma_api. If the driver is configured with premapped, then do_unmap is false. So as long as do_unmap is false, for addr of desc, we should skip dma unmap operation. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20230810123057.43407-7-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: introduce virtqueue_dma_dev()Xuan Zhuo
Added virtqueue_dma_dev() to get DMA device for virtio. Then the caller can do dma operation in advance. The purpose is to keep memory mapped across multiple add/get buf operations. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-6-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: support add premapped bufXuan Zhuo
If the vq is the premapped mode, use the sg_dma_address() directly. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20230810123057.43407-5-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: introduce virtqueue_set_dma_premapped()Xuan Zhuo
This helper allows the driver change the dma mode to premapped mode. Under the premapped mode, the virtio core do not do dma mapping internally. This just work when the use_dma_api is true. If the use_dma_api is false, the dma options is not through the DMA APIs, that is not the standard way of the linux kernel. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20230810123057.43407-4-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: put mapping error check in vring_map_one_sgXuan Zhuo
This patch put the dma addr error check in vring_map_one_sg(). The benefits of doing this: 1. reduce one judgment of vq->use_dma_api. 2. make vring_map_one_sg more simple, without calling vring_mapping_error to check the return value. simplifies subsequent code Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-3-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-09-03virtio_ring: check use_dma_api before unmap desc for indirectXuan Zhuo
Inside detach_buf_split(), if use_dma_api is false, vring_unmap_one_split_indirect will be called many times, but actually nothing is done. So this patch check use_dma_api firstly. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-2-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-04-21virtio: add VIRTIO_F_NOTIFICATION_DATA feature supportViktor Prutyanov
According to VirtIO spec v1.2, VIRTIO_F_NOTIFICATION_DATA feature indicates that the driver passes extra data along with the queue notifications. In a split queue case, the extra data is 16-bit available index. In a packed queue case, the extra data is 1-bit wrap counter and 15-bit available index. Add support for this feature for MMIO, channel I/O and modern PCI transports. Signed-off-by: Viktor Prutyanov <viktor@daynix.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20230413081855.36643-2-alvaro.karsz@solid-run.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-04-21virtio_ring: don't update event idx on get_bufAlbert Huang
In virtio_net, if we disable napi_tx, when we trigger a tx interrupt, the vq->event_triggered will be set to true. It is then never reset until we explicitly call virtqueue_enable_cb_delayed or virtqueue_enable_cb_prepare. If we disable the napi_tx, virtqueue_enable_cb* will only be called when the tx ring is getting relatively empty. Since event_triggered is true, VRING_AVAIL_F_NO_INTERRUPT or VRING_PACKED_EVENT_FLAG_DISABLE will not be set. As a result we update vring_used_event(&vq->split.vring) or vq->packed.vring.driver->off_wrap every time we call virtqueue_get_buf_ctx. This causes more interrupts. To summarize: 1) event_triggered was set to true in vring_interrupt() 2) after this nothing will happen in virtqueue_disable_cb() so VRING_AVAIL_F_NO_INTERRUPT is not set in avail_flags_shadow 3) virtqueue_get_buf_ctx_split() will still think the cb is enabled and then it will publish a new event index To fix: update VRING_AVAIL_F_NO_INTERRUPT or VRING_PACKED_EVENT_FLAG_DISABLE in the vq when we call virtqueue_disable_cb even when event_triggered is true. Tested with iperf: iperf3 tcp stream: vm1 -----------------> vm2 vm2 just receives tcp data stream from vm1, and sends acks to vm1, there are many tx interrupts in vm2. with the patch applied there are just a few tx interrupts. v2->v3: -update the interrupt disable flag even with the event_triggered is set, -instead of checking whether event_triggered is set in -virtqueue_get_buf_ctx_{packed/split}, will cause the drivers which have -not called virtqueue_{enable/disable}_cb to miss notifications. v3->v4: -remove change for -"if (vq->packed.event_flags_shadow != VRING_PACKED_EVENT_FLAG_DISABLE)" -in virtqueue_disable_cb_packed Fixes: 8d622d21d248 ("virtio: fix up virtio_disable_cb") Signed-off-by: Albert Huang <huangjie.albert@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230329102300.61000-1-huangjie.albert@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-04-21virtio_ring: Use const to annotate read-only pointer paramsFeng Liu
Add const to make the read-only pointer parameters clear, similar to many existing functions. To implement this change, the commit also introduces the use of `container_of_const` to implement `to_vvq`, which ensures the const-ness of read-only parameters and avoids accidental modification of their members. Signed-off-by: Feng Liu <feliu@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Parav Pandit <parav@nvidia.com> Reviewed-by: Gavin Li <gavinl@nvidia.com> Reviewed-by: Bodong Wang <bodong@nvidia.com> Message-Id: <20230310053428.3376-4-feliu@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-04-21virtio_ring: Avoid using inline for small functionsFeng Liu
According to kernel coding style [1], defining inline functions is not necessary and beneficial for simple functions. Hence clean up the code by removing the inline keyword. It is verified with GCC 12.2.0, the generated code with/without inline is same. Additionally tested with pktgen and iperf, and verified the result, the pps test results are the same in the cases of with/without inline. Iperf and pps of pktgen for virtio-net didn't change before and after the change. [1] https://www.kernel.org/doc/html/v6.2-rc3/process/coding-style.html#the-inline-disease Signed-off-by: Feng Liu <feliu@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Parav Pandit <parav@nvidia.com> Reviewed-by: Gavin Li <gavinl@nvidia.com> Reviewed-by: Bodong Wang <bodong@nvidia.com> Reviewed-by: David Edmondson <david.edmondson@oracle.com> Message-Id: <20230310053428.3376-3-feliu@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-02-20virtio_ring: per virtqueue dma deviceJason Wang
This patch introduces a per virtqueue dma device. This will be used for virtio devices whose virtqueue are backed by different underlayer devices. One example is the vDPA that where the control virtqueue could be implemented through software mediation. Some of the work are actually done before since the helper like vring_dma_device(). This work left are: - Let vring_dma_device() return the per virtqueue dma device instead of the vdev's parent. - Allow passing a dma_device when creating the virtqueue through a new helper, old vring creation helper will keep using vdev's parent. Reviewed-by: Eli Cohen <elic@nvidia.com> Tested-by: Eli Cohen <elic@nvidia.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230119061525.75068-2-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-12-28virtio_ring: use helper function is_power_of_2()Shaoqin Huang
Use helper function is_power_of_2() to check if num is power of two. Minor readability improvement. Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com> Message-Id: <20221021062734.228881-3-shaoqin.huang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-07virtio_ring: make vring_alloc_queue_packed prettierDeming Wang
Add some spaces to vring_alloc_queue(make it look prettier). Signed-off-by: Deming Wang <wangdeming@inspur.com> Message-Id: <20220926183306.4535-1-wangdeming@inspur.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-07virtio_ring: split: Operators use unified styleDeming Wang
The operators of vring_alloc_queue_split should use the unified style.Add space for the '|' ,make it be looked more pretty. Signed-off-by: Deming Wang <wangdeming@inspur.com> Message-Id: <20220926022202.1516-1-wangdeming@inspur.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-03virtio: kmsan: check/unpoison scatterlist in vring_map_one_sg()Alexander Potapenko
If vring doesn't use the DMA API, KMSAN is unable to tell whether the memory is initialized by hardware. Explicitly call kmsan_handle_dma() from vring_map_one_sg() in this case to prevent false positives. Link: https://lkml.kernel.org/r/20220915150417.722975-23-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-16virtio: kerneldocs fixes and enhancementsRicardo Cañuelo
Fix variable names in some kerneldocs, naming in others. Add kerneldocs for struct vring_desc and vring_interrupt. Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com> Message-Id: <20220810094004.1250-2-ricardo.canuelo@collabora.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2022-08-11virtio_ring: struct virtqueue introduce resetXuan Zhuo
Introduce a new member reset to the structure virtqueue to determine whether the current vq is in the reset state. Subsequent patches will use it. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-29-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio: allow to unbreak/break virtqueue individuallyXuan Zhuo
This patch allows the new introduced __virtqueue_break()/__virtqueue_unbreak() to break/unbreak the virtqueue. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-27-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: introduce virtqueue_resize()Xuan Zhuo
Introduce virtqueue_resize() to implement the resize of vring. Based on these, the driver can dynamically adjust the size of the vring. For example: ethtool -G. virtqueue_resize() implements resize based on the vq reset function. In case of failure to allocate a new vring, it will give up resize and use the original vring. During this process, if the re-enable reset vq fails, the vq can no longer be used. Although the probability of this situation is not high. The parameter recycle is used to recycle the buffer that is no longer used. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-25-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: introduce virtqueue_resize_packed()Xuan Zhuo
virtio ring packed supports resize. Only after the new vring is successfully allocated based on the new num, we will release the old vring. In any case, an error is returned, indicating that the vring still points to the old vring. In the case of an error, re-initialize(by virtqueue_reinit_packed()) the virtqueue to ensure that the vring can be used. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-24-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: introduce virtqueue_reinit_packed()Xuan Zhuo
Introduce a function to initialize vq without allocating new ring, desc_state, desc_extra. Subsequent patches will call this function after reset vq to reinitialize vq. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-23-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: extract the logic of attach vringXuan Zhuo
Separate the logic of attach vring, the subsequent patch will call it separately. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-22-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: extract the logic of vring initXuan Zhuo
Separate the logic of initializing vring, and subsequent patches will call it separately. This function completes the variable initialization of packed vring. It together with the logic of atatch constitutes the initialization of vring. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-21-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: extract the logic of alloc state and extraXuan Zhuo
Separate the logic for alloc desc_state and desc_extra, which will be called separately by subsequent patches. Use struct vring_packed to pass desc_state, desc_extra. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-20-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: extract the logic of alloc queueXuan Zhuo
Separate the logic of packed to create vring queue. This feature is required for subsequent virtuqueue reset vring. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-19-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: packed: introduce vring_free_packedXuan Zhuo
Free the structure struct vring_vritqueue_packed. Subsequent patches require it. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-18-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio_ring: split: introduce virtqueue_resize_split()Xuan Zhuo
virtio ring split supports resize. Only after the new vring is successfully allocated based on the new num, we will release the old vring. In any case, an error is returned, indicating that the vring still points to the old vring. In the case of an error, re-initialize(virtqueue_reinit_split()) the virtqueue to ensure that the vring can be used. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-17-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>