Re: [PATCH] i386/acpi: restore device paths for pre-5.1 vms

[Thomas Lamprecht]

On 23.03.21 15:55, Vitaly Cheptsov wrote:
>> 23 марта 2021 г., в 17:48, Michael S. Tsirkin <mst@redhat.com> написал(а):
>>
>> The issue is with people who installed a VM using 5.1 qemu,
>> migrated to 5.2, booted there and set a config on a device
>> e.g. IP on a NIC.
>> They now have a 5.1 machine type but changing uid back
>> like we do will break these VMs.
>>
>> Unlikley to be common but let's at least create a way for these people
>> to used these VMs.
>>
> They can simply set the 5.2 VM version in such a case. I do not want to 
let this legacy hack to be enabled in any modern QEMU VM version, as it 
violates ACPI specification and makes the life more difficult for various other 
software like bootloaders and operating systems.

Yeah here I agree with Vitaly, if they already used 5.2 and made some 
configurations
for those "new" devices they can just keep using 5.2?

If some of the devices got configured on 5.1 and some on 5.2 there's nothing we 
can
do anyway, from a QEMU POV - there the user always need to choose one machine 
version
and fix up the device configured while on the other machine.