Commit Graph

224 Commits

Author SHA1 Message Date
Koichiro Den
8d2da07c81 virtio_ring: add a func argument 'recycle_done' to virtqueue_reset()
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>
2024-12-10 11:22:21 +01:00
Koichiro Den
8d6712c892 virtio_ring: add a func argument 'recycle_done' to virtqueue_resize()
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>
2024-12-10 11:22:21 +01:00
Linus Torvalds
2a50b1e766 virtio: features, fixes, cleanups
A small number of improvements all over the place.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

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
2024-11-27 13:11:58 -08:00
Xuan Zhuo
880ebcbe06 virtio_ring: remove API virtqueue_set_dma_premapped
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>
2024-11-15 18:46:55 -08:00
Xuan Zhuo
3ef66af31f virtio_ring: introduce add api for premapped
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>
2024-11-15 18:46:55 -08:00
Xuan Zhuo
c7e1b422af virtio_ring: perform premapped operations based on per-buffer
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>
2024-11-15 18:46:55 -08:00
Xuan Zhuo
aaa789843a virtio_ring: packed: record extras for indirect buffers
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>
2024-11-15 18:46:54 -08:00
Xuan Zhuo
bc2b4c3401 virtio_ring: split: record extras for indirect buffers
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>
2024-11-15 18:46:54 -08:00
Xuan Zhuo
9f19c08405 virtio_ring: introduce vring_need_unmap_buffer
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>
2024-11-15 18:46:54 -08:00
Wenyu Huang
a49c26f761 virtio: Make vring_new_virtqueue support packed vring
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>
2024-11-12 18:07:24 -05:00
Michael S. Tsirkin
83c334ed52 virtio_ring: tag event_triggered as racy for KCSAN
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>
2024-09-25 07:07:44 -04:00
Jeff Johnson
ab0727f3dd virtio: add missing MODULE_DESCRIPTION() macros
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>
2024-07-09 08:42:41 -04:00
Xuan Zhuo
840b2d39a2 virtio_ring: fix KMSAN error for premapped mode
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>
2024-07-04 11:00:31 -04:00
Xuan Zhuo
f9dac92ba9 virtio_ring: enable premapped mode whatever use_dma_api
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>
2024-05-13 17:07:41 -07:00
Xuan Zhuo
d5c0ed17fe virtio: packed: fix unmap leak for indirect desc table
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: b319940f83 ("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>
2024-03-19 03:19:22 -04:00
Xuan Zhuo
1f475cd572 virtio_ring: fix syncs DMA memory with different direction
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: 8bd2f71054 ("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>
2023-12-04 08:36:25 -05:00
Yuan Yao
1acfe2c122 virtio_ring: fix avail_wrap_counter in virtqueue_add_packed
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: 1ce9e6055f ("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>
2023-09-03 18:10:24 -04:00
Xuan Zhuo
8bd2f71054 virtio_ring: introduce dma sync api for virtqueue
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
b6253b4e21 virtio_ring: introduce dma map api for virtqueue
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
ba3e0c47c0 virtio_ring: introduce virtqueue_reset()
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
ad48d53b5b virtio_ring: separate the logic of reset/enable from virtqueue_resize
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
4d09f24080 virtio_ring: correct the expression of the description of virtqueue_resize()
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
b319940f83 virtio_ring: skip unmap for premapped
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
2df6475907 virtio_ring: introduce virtqueue_dma_dev()
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
d7344a2f71 virtio_ring: support add premapped buf
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>
2023-09-03 18:10:23 -04:00
Xuan Zhuo
8daafe9ebb virtio_ring: introduce virtqueue_set_dma_premapped()
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>
2023-09-03 18:10:22 -04:00
Xuan Zhuo
0e27fa6dde virtio_ring: put mapping error check in vring_map_one_sg
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>
2023-09-03 18:10:22 -04:00
Xuan Zhuo
610c708bf8 virtio_ring: check use_dma_api before unmap desc for indirect
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>
2023-09-03 18:10:22 -04:00
Viktor Prutyanov
af8ececda1 virtio: add VIRTIO_F_NOTIFICATION_DATA feature support
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>
2023-04-21 03:02:35 -04:00
Albert Huang
6c0b057cec virtio_ring: don't update event idx on get_buf
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: 8d622d21d2 ("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>
2023-04-21 03:02:34 -04:00
Feng Liu
4b6ec919b8 virtio_ring: Use const to annotate read-only pointer params
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>
2023-04-21 03:02:30 -04:00
Feng Liu
1adbd6b2fc virtio_ring: Avoid using inline for small functions
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>
2023-04-21 03:02:30 -04:00
Jason Wang
2713ea3c7d virtio_ring: per virtqueue dma device
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>
2023-02-20 19:26:58 -05:00
Shaoqin Huang
b9d978a892 virtio_ring: use helper function is_power_of_2()
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>
2022-12-28 05:28:09 -05:00
Linus Torvalds
27bc50fc90 - 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 R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight 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
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   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.
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Merge tag 'mm-stable-2022-10-08' of 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
  ...
2022-10-10 17:53:04 -07:00
Deming Wang
f7adf38928 virtio_ring: make vring_alloc_queue_packed prettier
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>
2022-10-07 09:32:40 -04:00
Deming Wang
bdeb2f9836 virtio_ring: split: Operators use unified style
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>
2022-10-07 09:32:40 -04:00
Alexander Potapenko
88938359e2 virtio: kmsan: check/unpoison scatterlist in vring_map_one_sg()
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>
2022-10-03 14:03:22 -07:00
Ricardo Cañuelo
5c669c4a4c virtio: kerneldocs fixes and enhancements
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>
2022-08-16 01:40:24 -04:00
Xuan Zhuo
4913e85441 virtio_ring: struct virtqueue introduce reset
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>
2022-08-11 04:06:40 -04:00
Xuan Zhuo
3251063155 virtio: allow to unbreak/break virtqueue individually
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>
2022-08-11 04:06:40 -04:00
Xuan Zhuo
c790e8e181 virtio_ring: introduce virtqueue_resize()
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>
2022-08-11 04:06:40 -04:00
Xuan Zhuo
947f9fcf67 virtio_ring: packed: introduce virtqueue_resize_packed()
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>
2022-08-11 04:06:40 -04:00
Xuan Zhuo
56775e141b virtio_ring: packed: introduce virtqueue_reinit_packed()
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>
2022-08-11 04:06:40 -04:00
Xuan Zhuo
51d649f14a virtio_ring: packed: extract the logic of attach vring
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>
2022-08-11 04:06:39 -04:00
Xuan Zhuo
1a107c87eb virtio_ring: packed: extract the logic of vring init
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>
2022-08-11 04:06:39 -04:00
Xuan Zhuo
ef3167cfd5 virtio_ring: packed: extract the logic of alloc state and extra
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>
2022-08-11 04:06:39 -04:00
Xuan Zhuo
6b60b9c008 virtio_ring: packed: extract the logic of alloc queue
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>
2022-08-11 04:06:39 -04:00
Xuan Zhuo
6356f8bb01 virtio_ring: packed: introduce vring_free_packed
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>
2022-08-11 04:06:39 -04:00
Xuan Zhuo
6fea20e561 virtio_ring: split: introduce virtqueue_resize_split()
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>
2022-08-11 04:06:39 -04:00