Re: [PATCH v2 4/6] xen_pvdev: Do not assume Dom0 when creating a directory

[Volodymyr Babchuk]

Hi David,

David Woodhouse <dwmw2@infradead.org> writes:

> On 23 November 2023 12:17:57 GMT, Volodymyr Babchuk 
> <Volodymyr_Babchuk@epam.com> wrote:
>>
>>Hi David,
>>
>>David Woodhouse <dwmw2@infradead.org> writes:
>>> Which PV backends do you care about? We already have net, block and console 
>>> converted.
>>
>>Well, this is all what we need, actually. Even console only will be
>>sufficient, as we are using QEMU to provide virtio-pci backends, so both
>>storage and networking should be provided by virtio. Are you proposing
>>to just drop this patch at all? I believe we can live without it, yes.
>
> Yeah, I think you can drop anything that's only needed for the legacy 
> backends. I'm tempted to make a separate config option to compile those out.

Yep, we need this. Because without the patch ("xen_pvdev: Do not assume
Dom0 when creating a directory") I can't run QEMU in the driver domain:

root@spider-domd:~# qemu-system-aarch64  -machine xenpv -m 128M
xen be core: xs_mkdir device-model/0/backends/vkbd: failed
xen be core: xs_mkdir device-model/0/backends/vkbd: failed
xen be core: xs_mkdir device-model/0/backends/9pfs: failed
xen be core: xs_mkdir device-model/0/backends/9pfs: failed

So yeah, we need something like CONFIG_XEN_LEGACY_BACKENDS option if we
don't want to fix xenstore_mkdir()

-- 
WBR, Volodymyr