[pve-devel] [PATCH-SERIES v3 qemu-server/manager/common] add and set x86-64-v2 as default model for new vms and detect best cpumodel

[Thomas Lamprecht]

Am 01/06/2023 um 11:06 schrieb DERUMIER, Alexandre:
>> Maybe the easiest would be to extract the aes flag out of the grid
>> into
>> the non-advanced part?
>>
> Couldn't be easier to keep aes enable by default in a single model
> (even if it's doesn't match the x86-64 spec). and allow user to optin
> disable it.
> The only server where you need to disable aes if for nahelem, and I
> don't think that a lot of users still have this cpu in production.
> (so keeping the aes flag in advanced section make sense).
> Also, user with really old servers, could keep to use kvm64 model,
> where aes is not enabled.


I also think that we should not bend to much for Nehalem, and fwiw if
we go for a v2+aes CPU model (which IMO is one of the easies solutions)
we would only need that for v2, as v3 could always have that enabled by
default FWIWCT?

So:

x86-64-v2
x86-64-v2-aes   (UI default)
x86-64-v3

(and that as real models, not just UI fakery) would work,

But tbh., I'd not be completely against just enabling it for v2 and warning,
or even erroring, if the VM gets created on a host that doesn't supports it
(which might be a good idea for any vX level); as Alexandre is right, a lot of
users needlessly get slower VMs that they could be and production setups with
a 14 year old CPU are just very unlikely, and they simply can disable AES again...