Re: virtio-pci in qemu-system-arm is broken in 8.2

[Peter Maydell]

On Thu, 21 Dec 2023 at 11:51, Michael Tokarev <mjt@tls.msk.ru> wrote:
>
> It looks like virtio-pci is entirely broke in qemu-system-arm, at least in tcg
> mode running on x86.  The guest (current linux system) just does not detect
> any virtio-pci devices at all.
>
> When 8.1 is booting, the following messages are displayed (debian initramfs):
>
> Loading, please wait...
> Starting systemd-udevd version 255-1
> [    6.455941] virtio-pci 0000:00:01.0: enabling device (0100 -> 0103)
> [    6.929155] virtio-pci 0000:00:02.0: enabling device (0100 -> 0103)
> [    7.764652] virtio_blk virtio1: 2/0/0 default/read/poll queues
> [    7.783216] virtio_blk virtio1: [vda] 2097026 512-byte logical blocks 
> (1.07 GB/1024 MiB)
> [    8.636453] virtio_net virtio0 enp0s1: renamed from eth0
>
> But when 8.2 is booting, it ends up at:
>
> Loading, please wait...
> Starting systemd-udevd version 255-1
> ..and nothing.  here it waits for the root fs to appear, and drops into the 
> shell
>
> git bisect points at this commit:
>
> commit b8f7959f28c4f36496bc0a694fa28bf5078152c5
> Author: Peter Maydell <peter.maydell@linaro.org>
> Date:   Mon Jul 24 18:43:33 2023 +0100
>
>      target/arm: Do all "ARM_FEATURE_X implies Y" checks in post_init
>
> Reverting this commit on top of 8.2.0 (or current qemu master)
> makes things works again.

My local test setup with virtio-pci devices on arm (an old
wheezy image) works fine even with this commit.

Can you provide a complete repro case including full command
line and all image files needed to run it, please?

thanks
-- PMM