Re: [PATCH v2 2/6] xen: backends: touch some XenStore nodes only if device...

[Volodymyr Babchuk]

Hi Paul,

Paul Durrant <xadimgnik@gmail.com> writes:

> On 21/11/2023 22:10, Volodymyr Babchuk wrote:
>> was created by QEMU
>> Xen PV devices in QEMU can be created in two ways: either by QEMU
>> itself, if they were passed via command line, or by Xen toolstack. In
>> the latter case, QEMU scans XenStore entries and configures devices
>> accordingly.
>> In the second case we don't want QEMU to write/delete front-end
>> entries for two reasons: it might have no access to those entries if
>> it is running in un-privileged domain and it is just incorrect to
>> overwrite entries already provided by Xen toolstack, because toolstack
>> manages those nodes. For example, it might read backend- or frontend-
>> state to be sure that they are both disconnected and it is safe to
>> destroy a domain.
>> This patch checks presence of xendev->backend to check if Xen PV
>> device is acting as a backend (i.e. it was configured by Xen
>
> Technally *all* XenDevice objects are backends.
>

Yes, you are right of course. I'll rephrase this paragraph in the next
version.

-- 
WBR, Volodymyr