Support booting from 9pfs

[patmaddox]

Example config:

disk0_type="virtio-9p"
disk0_name="devroot=/vm/p9-test/p9-root"
disk0_dev="9p"

It also requires 9pfs root /boot/loader.conf to have:

virtio_p9fs_load="YES"

[metalefty]

Sounds good.

[dch]

🚢 LGTM! I noticed that bhyveload(8) can't handle
-e virtio_p9fs_load="YES" yet, so this is as good as we
can get. I'll see if we can teach bhyveload to do that for
future FreeBSD releases to be able to boot without any
local modifications in the 9pfs share directory.

[metalefty]

Testing...

[metalefty]

LGTM.

I prepared FreeBSD rootfs in the following way:

zfs create -o mountpoint=/p9fs zroot/p9fs
zfs create zroot/p9fs/instance
cd /p9fs/instance1
curl https://download.freebsd.org/releases/amd64/amd64/15.0-RELEASE/base.txz | tar xf -
curl https://download.freebsd.org/releases/amd64/amd64/15.0-RELEASE/kernel.txz | tar xf -
zfs snapshot zroot/p9fs/instance1@init
echo 'virtio_p9fs_load="YES"' >> /p9fs/instance1/boot/loader.conf

Created a VM with the following config. It boots successfully.

loader="bhyveload"
cpu=1
memory=512M
network0_type="virtio-net"
network0_switch="public"
#disk0_type="virtio-blk"
#disk0_name="disk0.img"
uuid="1921a12a-f501-11f0-9c0f-00f0cbfed980"
network0_mac="58:9c:fc:03:77:7c"

disk0_type="virtio-9p"
disk0_name="instance1=/p9fs/instance1"
disk0_dev="9p"

@michael-o Thoughts?

[michael-o]

Interesting case, no objections.