From: Andreas Bauer <andreas.bauer.nexus@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: 9pnet_virtio missing dependency
Date: Fri, 10 Sep 2021 19:14:07 +0700 [thread overview]
Message-ID: <YTtMD6Zm0FeXIR7m@ws2> (raw)
Dear all,
While compiling a minimal qemu kernel 5.14.2 with 9p root fs, I encountered a
problem with the 9pnet_virtio code:
| [ 0.553249] 9pnet: Installing 9P2000 support
[...]
| [ 0.561547] 9pnet: -- v9fs_mount (1):
| [ 0.562156] 9pnet_virtio: no channels available for device /dev/root
9p_virtio_create() is called and the list of channels in this loop
| list_for_each_entry(chan, &virtio_chan_list, chan_list) {
turns out to be empty. After instrumenting the code with a few more
debug outputs, it turns out p9_virtio_probe() is not called. I am
not familiar enough with the code flow to see exactly where the
problem lies.
I think all relevant kernel options are enabled:
| $ cat .config | grep -Ei '9P|VIRTIO' | grep -v "^#" | sort
| CONFIG_9P_FS_POSIX_ACL=y
| CONFIG_9P_FS_SECURITY=y
| CONFIG_9P_FS=y
| CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS=y
| CONFIG_BLK_MQ_VIRTIO=y
| CONFIG_HW_RANDOM_VIRTIO=y
| CONFIG_NET_9P_DEBUG=y
| CONFIG_NET_9P_VIRTIO=y
| CONFIG_NET_9P=y
| CONFIG_VIRTIO_BLK=y
| CONFIG_VIRTIO_CONSOLE=y
| CONFIG_VIRTIO_FS=y
| CONFIG_VIRTIO_INPUT=y
| CONFIG_VIRTIO_MEM=y
| CONFIG_VIRTIO_MENU=y
| CONFIG_VIRTIO_NET=y
| CONFIG_VIRTIO_PCI_LEGACY=y
| CONFIG_VIRTIO_PCI_LIB=y
| CONFIG_VIRTIO_PCI=y
| CONFIG_VIRTIO=y
It seems that there is a dependecy on some other kernel code that is neither
documented nor instrumented in config-logic.
When I compile a distribution kernel (i.e. almost everything compiled in)
with "localyesconfig" the 9p root fs is found and mounted properly.
What code is missing?
Thanks,
Andreas
reply other threads:[~2021-09-10 12:14 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YTtMD6Zm0FeXIR7m@ws2 \
--to=andreas.bauer.nexus@gmail.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.