<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/virtio, branch v6.6.39</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.39</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.39'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2024-06-12T09:12:49+00:00</updated>
<entry>
<title>virtio: delete vq in vp_find_vqs_msix() when request_irq() fails</title>
<updated>2024-06-12T09:12:49+00:00</updated>
<author>
<name>Jiri Pirko</name>
<email>jiri@nvidia.com</email>
</author>
<published>2024-04-26T15:08:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=04207a9c64e0b16dac842e5b2ecfa53af25bdea7'/>
<id>urn:sha1:04207a9c64e0b16dac842e5b2ecfa53af25bdea7</id>
<content type='text'>
[ Upstream commit 89875151fccdd024d571aa884ea97a0128b968b6 ]

When request_irq() fails, error path calls vp_del_vqs(). There, as vq is
present in the list, free_irq() is called for the same vector. That
causes following splat:

[    0.414355] Trying to free already-free IRQ 27
[    0.414403] WARNING: CPU: 1 PID: 1 at kernel/irq/manage.c:1899 free_irq+0x1a1/0x2d0
[    0.414510] Modules linked in:
[    0.414540] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc4+ #27
[    0.414540] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
[    0.414540] RIP: 0010:free_irq+0x1a1/0x2d0
[    0.414540] Code: 1e 00 48 83 c4 08 48 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 90 8b 74 24 04 48 c7 c7 98 80 6c b1 e8 00 c9 f7 ff 90 &lt;0f&gt; 0b 90 90 48 89 ee 4c 89 ef e8 e0 20 b8 00 49 8b 47 40 48 8b 40
[    0.414540] RSP: 0000:ffffb71480013ae0 EFLAGS: 00010086
[    0.414540] RAX: 0000000000000000 RBX: ffffa099c2722000 RCX: 0000000000000000
[    0.414540] RDX: 0000000000000000 RSI: ffffb71480013998 RDI: 0000000000000001
[    0.414540] RBP: 0000000000000246 R08: 00000000ffffdfff R09: 0000000000000001
[    0.414540] R10: 00000000ffffdfff R11: ffffffffb18729c0 R12: ffffa099c1c91760
[    0.414540] R13: ffffa099c1c916a4 R14: ffffa099c1d2f200 R15: ffffa099c1c91600
[    0.414540] FS:  0000000000000000(0000) GS:ffffa099fec40000(0000) knlGS:0000000000000000
[    0.414540] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.414540] CR2: 0000000000000000 CR3: 0000000008e3e001 CR4: 0000000000370ef0
[    0.414540] Call Trace:
[    0.414540]  &lt;TASK&gt;
[    0.414540]  ? __warn+0x80/0x120
[    0.414540]  ? free_irq+0x1a1/0x2d0
[    0.414540]  ? report_bug+0x164/0x190
[    0.414540]  ? handle_bug+0x3b/0x70
[    0.414540]  ? exc_invalid_op+0x17/0x70
[    0.414540]  ? asm_exc_invalid_op+0x1a/0x20
[    0.414540]  ? free_irq+0x1a1/0x2d0
[    0.414540]  vp_del_vqs+0xc1/0x220
[    0.414540]  vp_find_vqs_msix+0x305/0x470
[    0.414540]  vp_find_vqs+0x3e/0x1a0
[    0.414540]  vp_modern_find_vqs+0x1b/0x70
[    0.414540]  init_vqs+0x387/0x600
[    0.414540]  virtnet_probe+0x50a/0xc80
[    0.414540]  virtio_dev_probe+0x1e0/0x2b0
[    0.414540]  really_probe+0xc0/0x2c0
[    0.414540]  ? __pfx___driver_attach+0x10/0x10
[    0.414540]  __driver_probe_device+0x73/0x120
[    0.414540]  driver_probe_device+0x1f/0xe0
[    0.414540]  __driver_attach+0x88/0x180
[    0.414540]  bus_for_each_dev+0x85/0xd0
[    0.414540]  bus_add_driver+0xec/0x1f0
[    0.414540]  driver_register+0x59/0x100
[    0.414540]  ? __pfx_virtio_net_driver_init+0x10/0x10
[    0.414540]  virtio_net_driver_init+0x90/0xb0
[    0.414540]  do_one_initcall+0x58/0x230
[    0.414540]  kernel_init_freeable+0x1a3/0x2d0
[    0.414540]  ? __pfx_kernel_init+0x10/0x10
[    0.414540]  kernel_init+0x1a/0x1c0
[    0.414540]  ret_from_fork+0x31/0x50
[    0.414540]  ? __pfx_kernel_init+0x10/0x10
[    0.414540]  ret_from_fork_asm+0x1a/0x30
[    0.414540]  &lt;/TASK&gt;

Fix this by calling deleting the current vq when request_irq() fails.

Fixes: 0b0f9dc52ed0 ("Revert "virtio_pci: use shared interrupts for virtqueues"")
Signed-off-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Message-Id: &lt;20240426150845.3999481-1-jiri@resnulli.us&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>virtio: reenable config if freezing device failed</title>
<updated>2024-04-03T13:28:36+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>david@redhat.com</email>
</author>
<published>2024-02-13T13:54:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3d26a2d801819bea2d49076a24835e3a34ae1cdd'/>
<id>urn:sha1:3d26a2d801819bea2d49076a24835e3a34ae1cdd</id>
<content type='text'>
[ Upstream commit 310227f42882c52356b523e2f4e11690eebcd2ab ]

Currently, we don't reenable the config if freezing the device failed.

For example, virtio-mem currently doesn't support suspend+resume, and
trying to freeze the device will always fail. Afterwards, the device
will no longer respond to resize requests, because it won't get notified
about config changes.

Let's fix this by re-enabling the config if freezing fails.

Fixes: 22b7050a024d ("virtio: defer config changed notifications")
Cc: &lt;stable@kernel.org&gt;
Cc: "Michael S. Tsirkin" &lt;mst@redhat.com&gt;
Cc: Jason Wang &lt;jasowang@redhat.com&gt;
Cc: Xuan Zhuo &lt;xuanzhuo@linux.alibaba.com&gt;
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Message-Id: &lt;20240213135425.795001-1-david@redhat.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>virtio: packed: fix unmap leak for indirect desc table</title>
<updated>2024-03-26T22:20:11+00:00</updated>
<author>
<name>Xuan Zhuo</name>
<email>xuanzhuo@linux.alibaba.com</email>
</author>
<published>2024-02-23T07:18:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e142169aca5546ae6619c39a575cda8105362100'/>
<id>urn:sha1:e142169aca5546ae6619c39a575cda8105362100</id>
<content type='text'>
[ Upstream commit d5c0ed17fea60cca9bc3bf1278b49ba79242bbcd ]

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-&gt;do_unmap)) {
                curr = id;
                for (i = 0; i &lt; state-&gt;num; i++) {
                        vring_unmap_extra_packed(vq,
                                                 &amp;vq-&gt;packed.desc_extra[curr]);
                        curr = vq-&gt;packed.desc_extra[curr].next;
                }
  }

So the indirect desc table is not unmapped. This causes the unmap leak.

So here, we check vq-&gt;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 &lt;xuanzhuo@linux.alibaba.com&gt;
Message-Id: &lt;20240223071833.26095-1-xuanzhuo@linux.alibaba.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>virtio_ring: fix syncs DMA memory with different direction</title>
<updated>2024-01-05T14:19:41+00:00</updated>
<author>
<name>Xuan Zhuo</name>
<email>xuanzhuo@linux.alibaba.com</email>
</author>
<published>2023-12-01T03:33:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=28d6cde17f219133a68d530b575e8725fe17a90f'/>
<id>urn:sha1:28d6cde17f219133a68d530b575e8725fe17a90f</id>
<content type='text'>
[ Upstream commit 1f475cd572ea77ae6474a17e693a96bca927efe9 ]

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 &lt;0f&gt; 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]  &lt;IRQ&gt;
[    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]  &lt;/IRQ&gt;

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" &lt;hongyu.ning@linux.intel.com&gt;
Closes: https://lore.kernel.org/all/f37cb55a-6fc8-4e21-8789-46d468325eea@linux.intel.com/
Suggested-by: Jason Wang &lt;jasowang@redhat.com&gt;
Signed-off-by: Xuan Zhuo &lt;xuanzhuo@linux.alibaba.com&gt;
Message-Id: &lt;20231201033303.25141-1-xuanzhuo@linux.alibaba.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Reviewed-by: Parav Pandit &lt;parav@nvidia.com&gt;
Acked-by: Jason Wang &lt;jasowang@redhat.com&gt;
Tested-by: Hongyu Ning &lt;hongyu.ning@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>virtio_pci: fix the common cfg map size</title>
<updated>2023-10-18T15:30:12+00:00</updated>
<author>
<name>Xuan Zhuo</name>
<email>xuanzhuo@linux.alibaba.com</email>
</author>
<published>2023-10-10T03:11:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=061b39fdfe7fd98946e67637213bcbb10a318cca'/>
<id>urn:sha1:061b39fdfe7fd98946e67637213bcbb10a318cca</id>
<content type='text'>
The function vp_modern_map_capability() takes the size parameter,
which corresponds to the size of virtio_pci_common_cfg. As a result,
this indicates the size of memory area to map.

Now the size is the size of virtio_pci_common_cfg, but some feature(such
as the _F_RING_RESET) needs the virtio_pci_modern_common_cfg, so this
commit changes the size to the size of virtio_pci_modern_common_cfg.

Cc: stable@vger.kernel.org
Fixes: 0b50cece0b78 ("virtio_pci: introduce helper to get/set queue reset")
Signed-off-by: Xuan Zhuo &lt;xuanzhuo@linux.alibaba.com&gt;
Message-Id: &lt;20231010031120.81272-3-xuanzhuo@linux.alibaba.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Acked-by: Jason Wang &lt;jasowang@redhat.com&gt;
</content>
</entry>
<entry>
<title>virtio_balloon: Fix endless deflation and inflation on arm64</title>
<updated>2023-10-18T15:29:35+00:00</updated>
<author>
<name>Gavin Shan</name>
<email>gshan@redhat.com</email>
</author>
<published>2023-08-31T01:10:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=07622bd415639e9709579f400afd19e7e9866e5e'/>
<id>urn:sha1:07622bd415639e9709579f400afd19e7e9866e5e</id>
<content type='text'>
The deflation request to the target, which isn't unaligned to the
guest page size causes endless deflation and inflation actions. For
example, we receive the flooding QMP events for the changes on memory
balloon's size after a deflation request to the unaligned target is
sent for the ARM64 guest, where we have 64KB base page size.

  /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64      \
  -accel kvm -machine virt,gic-version=host -cpu host          \
  -smp maxcpus=8,cpus=8,sockets=2,clusters=2,cores=2,threads=1 \
  -m 1024M,slots=16,maxmem=64G                                 \
  -object memory-backend-ram,id=mem0,size=512M                 \
  -object memory-backend-ram,id=mem1,size=512M                 \
  -numa node,nodeid=0,memdev=mem0,cpus=0-3                     \
  -numa node,nodeid=1,memdev=mem1,cpus=4-7                     \
    :                                                          \
  -device virtio-balloon-pci,id=balloon0,bus=pcie.10

  { "execute" : "balloon", "arguments": { "value" : 1073672192 } }
  {"return": {}}
  {"timestamp": {"seconds": 1693272173, "microseconds": 88667},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272174, "microseconds": 89704},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272175, "microseconds": 90819},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272176, "microseconds": 91961},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272177, "microseconds": 93040},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}}
  {"timestamp": {"seconds": 1693272178, "microseconds": 94117},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}}
  {"timestamp": {"seconds": 1693272179, "microseconds": 95337},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272180, "microseconds": 96615},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}}
  {"timestamp": {"seconds": 1693272181, "microseconds": 97626},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272182, "microseconds": 98693},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}}
  {"timestamp": {"seconds": 1693272183, "microseconds": 99698},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272184, "microseconds": 100727},  \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272185, "microseconds": 90430},   \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  {"timestamp": {"seconds": 1693272186, "microseconds": 102999},  \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}}
     :
  &lt;The similar QMP events repeat&gt;

Fix it by aligning the target up to the guest page size, 64KB in this
specific case. With this applied, no flooding QMP events are observed
and the memory balloon's size can be stablizied to 0x3ffe0000 soon
after the deflation request is sent.

  { "execute" : "balloon", "arguments": { "value" : 1073672192 } }
  {"return": {}}
  {"timestamp": {"seconds": 1693273328, "microseconds": 793075},  \
   "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}}
  { "execute" : "query-balloon" }
  {"return": {"actual": 1073610752}}

Cc: stable@vger.kernel.org
Signed-off-by: Gavin Shan &lt;gshan@redhat.com&gt;
Tested-by: Zhenyu Zhang &lt;zhenyzha@redhat.com&gt;
Message-Id: &lt;20230831011007.1032822-1-gshan@redhat.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
</content>
</entry>
<entry>
<title>virtio-mmio: fix memory leak of vm_dev</title>
<updated>2023-10-18T15:29:09+00:00</updated>
<author>
<name>Maximilian Heyne</name>
<email>mheyne@amazon.de</email>
</author>
<published>2023-09-11T09:03:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=fab7f259227b8f70aa6d54e1de1a1f5f4729041c'/>
<id>urn:sha1:fab7f259227b8f70aa6d54e1de1a1f5f4729041c</id>
<content type='text'>
With the recent removal of vm_dev from devres its memory is only freed
via the callback virtio_mmio_release_dev. However, this only takes
effect after device_add is called by register_virtio_device. Until then
it's an unmanaged resource and must be explicitly freed on error exit.

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Cc: stable@vger.kernel.org
Fixes: 55c91fedd03d ("virtio-mmio: don't break lifecycle of vm_dev")
Signed-off-by: Maximilian Heyne &lt;mheyne@amazon.de&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Tested-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reviewed-by: Xuan Zhuo &lt;xuanzhuo@linux.alibaba.com&gt;

Message-Id: &lt;20230911090328.40538-1-mheyne@amazon.de&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Reviewed-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
</content>
</entry>
<entry>
<title>virtio_ring: fix avail_wrap_counter in virtqueue_add_packed</title>
<updated>2023-09-03T22:10:24+00:00</updated>
<author>
<name>Yuan Yao</name>
<email>yuanyaogoog@chromium.org</email>
</author>
<published>2023-08-08T05:10:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1acfe2c1225899eab5ab724c91b7e1eb2881b9ab'/>
<id>urn:sha1:1acfe2c1225899eab5ab724c91b7e1eb2881b9ab</id>
<content type='text'>
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-&gt;packed.vring.num.

Let’s assume the following situation:
vq-&gt;packed.vring.num=4
vq-&gt;packed.next_avail_idx: 1
vq-&gt;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-&gt;packed.next_avail_idx: 1
vq-&gt;packed.avail_wrap_counter: 1

But, the current implementation gives the following result:
vq-&gt;packed.next_avail_idx: 1
vq-&gt;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 &lt;yuanyaogoog@chromium.org&gt;
Message-Id: &lt;20230808051110.3492693-1-yuanyaogoog@chromium.org&gt;
Acked-by: Jason Wang &lt;jasowang@redhat.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
</content>
</entry>
<entry>
<title>virtio_vdpa: build affinity masks conditionally</title>
<updated>2023-09-03T22:10:24+00:00</updated>
<author>
<name>Jason Wang</name>
<email>jasowang@redhat.com</email>
</author>
<published>2023-08-11T09:15:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ae15aceaa98ad9499763923f7890e345d9f46b60'/>
<id>urn:sha1:ae15aceaa98ad9499763923f7890e345d9f46b60</id>
<content type='text'>
We try to build affinity mask via create_affinity_masks()
unconditionally which may lead several issues:

- the affinity mask is not used for parent without affinity support
  (only VDUSE support the affinity now)
- the logic of create_affinity_masks() might not work for devices
  other than block. For example it's not rare in the networking device
  where the number of queues could exceed the number of CPUs. Such
  case breaks the current affinity logic which is based on
  group_cpus_evenly() who assumes the number of CPUs are not less than
  the number of groups. This can trigger a warning[1]:

	if (ret &gt;= 0)
		WARN_ON(nr_present + nr_others &lt; numgrps);

Fixing this by only build the affinity masks only when

- Driver passes affinity descriptor, driver like virtio-blk can make
  sure to limit the number of queues when it exceeds the number of CPUs
- Parent support affinity setting config ops

This help to avoid the warning. More optimizations could be done on
top.

[1]
[  682.146655] WARNING: CPU: 6 PID: 1550 at lib/group_cpus.c:400 group_cpus_evenly+0x1aa/0x1c0
[  682.146668] CPU: 6 PID: 1550 Comm: vdpa Not tainted 6.5.0-rc5jason+ #79
[  682.146671] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[  682.146673] RIP: 0010:group_cpus_evenly+0x1aa/0x1c0
[  682.146676] Code: 4c 89 e0 5b 5d 41 5c 41 5d 41 5e c3 cc cc cc cc e8 1b c4 74 ff 48 89 ef e8 13 ac 98 ff 4c 89 e7 45 31 e4 e8 08 ac 98 ff eb c2 &lt;0f&gt; 0b eb b6 e8 fd 05 c3 00 45 31 e4 eb e5 cc cc cc cc cc cc cc cc
[  682.146679] RSP: 0018:ffffc9000215f498 EFLAGS: 00010293
[  682.146682] RAX: 000000000001f1e0 RBX: 0000000000000041 RCX: 0000000000000000
[  682.146684] RDX: ffff888109922058 RSI: 0000000000000041 RDI: 0000000000000030
[  682.146686] RBP: ffff888109922058 R08: ffffc9000215f498 R09: ffffc9000215f4a0
[  682.146687] R10: 00000000000198d0 R11: 0000000000000030 R12: ffff888107e02800
[  682.146689] R13: 0000000000000030 R14: 0000000000000030 R15: 0000000000000041
[  682.146692] FS:  00007fef52315740(0000) GS:ffff888237380000(0000) knlGS:0000000000000000
[  682.146695] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  682.146696] CR2: 00007fef52509000 CR3: 0000000110dbc004 CR4: 0000000000370ee0
[  682.146698] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  682.146700] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  682.146701] Call Trace:
[  682.146703]  &lt;TASK&gt;
[  682.146705]  ? __warn+0x7b/0x130
[  682.146709]  ? group_cpus_evenly+0x1aa/0x1c0
[  682.146712]  ? report_bug+0x1c8/0x1e0
[  682.146717]  ? handle_bug+0x3c/0x70
[  682.146721]  ? exc_invalid_op+0x14/0x70
[  682.146723]  ? asm_exc_invalid_op+0x16/0x20
[  682.146727]  ? group_cpus_evenly+0x1aa/0x1c0
[  682.146729]  ? group_cpus_evenly+0x15c/0x1c0
[  682.146731]  create_affinity_masks+0xaf/0x1a0
[  682.146735]  virtio_vdpa_find_vqs+0x83/0x1d0
[  682.146738]  ? __pfx_default_calc_sets+0x10/0x10
[  682.146742]  virtnet_find_vqs+0x1f0/0x370
[  682.146747]  virtnet_probe+0x501/0xcd0
[  682.146749]  ? vp_modern_get_status+0x12/0x20
[  682.146751]  ? get_cap_addr.isra.0+0x10/0xc0
[  682.146754]  virtio_dev_probe+0x1af/0x260
[  682.146759]  really_probe+0x1a5/0x410

Fixes: 3dad56823b53 ("virtio-vdpa: Support interrupt affinity spreading mechanism")
Signed-off-by: Jason Wang &lt;jasowang@redhat.com&gt;
Message-Id: &lt;20230811091539.1359865-1-jasowang@redhat.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
</content>
</entry>
<entry>
<title>virtio_ring: introduce dma sync api for virtqueue</title>
<updated>2023-09-03T22:10:23+00:00</updated>
<author>
<name>Xuan Zhuo</name>
<email>xuanzhuo@linux.alibaba.com</email>
</author>
<published>2023-08-10T12:30:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8bd2f71054bd0bc997833e9825143672eb7e2801'/>
<id>urn:sha1:8bd2f71054bd0bc997833e9825143672eb7e2801</id>
<content type='text'>
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 &lt;xuanzhuo@linux.alibaba.com&gt;
Message-Id: &lt;20230810123057.43407-12-xuanzhuo@linux.alibaba.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
</content>
</entry>
</feed>
