No description
Find a file
Angus Chen 71491c54ea virtio_pci: don't try to use intxif pin is zero
The background is that we use dpu in cloud computing,the arch is x86,80
cores. We will have a lots of virtio devices,like 512 or more.
When we probe about 200 virtio_blk devices,it will fail and
the stack is printed as follows:

[25338.485128] virtio-pci 0000:b3:00.0: virtio_pci: leaving for legacy driver
[25338.496174] genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)
[25338.503822] CPU: 20 PID: 5431 Comm: kworker/20:0 Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-305.30.1.el8.x86_64
[25338.516403] Hardware name: Inspur NF5280M5/YZMB-00882-10E, BIOS 4.1.21 08/25/2021
[25338.523881] Workqueue: events work_for_cpu_fn
[25338.528235] Call Trace:
[25338.530687]  dump_stack+0x5c/0x80
[25338.534000]  __setup_irq.cold.53+0x7c/0xd3
[25338.538098]  request_threaded_irq+0xf5/0x160
[25338.542371]  vp_find_vqs+0xc7/0x190
[25338.545866]  init_vq+0x17c/0x2e0 [virtio_blk]
[25338.550223]  ? ncpus_cmp_func+0x10/0x10
[25338.554061]  virtblk_probe+0xe6/0x8a0 [virtio_blk]
[25338.558846]  virtio_dev_probe+0x158/0x1f0
[25338.562861]  really_probe+0x255/0x4a0
[25338.566524]  ? __driver_attach_async_helper+0x90/0x90
[25338.571567]  driver_probe_device+0x49/0xc0
[25338.575660]  bus_for_each_drv+0x79/0xc0
[25338.579499]  __device_attach+0xdc/0x160
[25338.583337]  bus_probe_device+0x9d/0xb0
[25338.587167]  device_add+0x418/0x780
[25338.590654]  register_virtio_device+0x9e/0xe0
[25338.595011]  virtio_pci_probe+0xb3/0x140
[25338.598941]  local_pci_probe+0x41/0x90
[25338.602689]  work_for_cpu_fn+0x16/0x20
[25338.606443]  process_one_work+0x1a7/0x360
[25338.610456]  ? create_worker+0x1a0/0x1a0
[25338.614381]  worker_thread+0x1cf/0x390
[25338.618132]  ? create_worker+0x1a0/0x1a0
[25338.622051]  kthread+0x116/0x130
[25338.625283]  ? kthread_flush_work_fn+0x10/0x10
[25338.629731]  ret_from_fork+0x1f/0x40
[25338.633395] virtio_blk: probe of virtio418 failed with error -16

The log :
"genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)"
was printed because of the irq 0 is used by timer exclusive,and when
vp_find_vqs call vp_find_vqs_msix and returns false twice (for
whatever reason), then it will call vp_find_vqs_intx as a fallback.
Because vp_dev->pci_dev->irq is zero, we request irq 0 with
flag IRQF_SHARED, and get a backtrace like above.

According to PCI spec about "Interrupt Pin" Register (Offset 3Dh):
"The Interrupt Pin register is a read-only register that identifies the
 legacy interrupt Message(s) the Function uses. Valid values are 01h, 02h,
 03h, and 04h that map to legacy interrupt Messages for INTA,
 INTB, INTC, and INTD respectively. A value of 00h indicates that the
 Function uses no legacy interrupt Message(s)."

So if vp_dev->pci_dev->pin is zero, we should not request legacy
interrupt.

Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220930000915.548-1-angus.chen@jaguarmicro.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-07 20:00:44 -04:00
arch Misc fixes: 2022-10-02 09:41:27 -07:00
block
certs
crypto
Documentation dt-bindings: i2c: st,stm32-i2c: Document wakeup-source property 2022-10-02 00:34:28 +02:00
drivers virtio_pci: don't try to use intxif pin is zero 2022-10-07 20:00:44 -04:00
fs
include vDPA: allow userspace to query features of a vDPA device 2022-10-07 20:00:42 -04:00
init
io_uring
ipc
kernel Misc fixes: 2022-10-02 09:41:27 -07:00
lib
LICENSES
mm One MAINTAINERS update, two MM fixes, both cc:stable 2022-10-01 09:13:29 -07:00
net
samples
scripts
security
sound
tools
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS One MAINTAINERS update, two MM fixes, both cc:stable 2022-10-01 09:13:29 -07:00
Makefile Linux 6.0 2022-10-02 14:09:07 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.