[PATCH] virtinst: use 'host-passthrough' as default 'host' on AArch64

[Liang Yan]

On 4/7/20 9:24 AM, Andrea Bolognani wrote:
> On Tue, 2020-04-07 at 08:01 -0400, Liang Yan wrote:
>> On 4/7/20 3:54 AM, Andrea Bolognani wrote:
>>> These semantics are not architecture dependent and, while the choice
>>> of name is a bit unfortunate considering that QEMU's -cpu host and
>>> virt-install's --cpu host have different meanings, I think they're
>>> completely unambiguous and reasonably documented, and we should not
>>> mess with them.
>>
>> virt-install supports both "host","host-mdoel" and "host-passthrough",
>> "--cpu host" is mapped to "host-model" based on "cli:det_model_b",
>> however if you check the default setup in "cpu"set_defaults", it has
>> different configuration. Btw, it has different setup for different
>> architecture already.  Nova also has different setup for aarch64 in my
>> defense.
>>
>> https://opendev.org/openstack/nova/commit/8bc7b950b7c0a3c80cdd120fe4df97c14848c344
> 
> The default being architecture-dependent, both in virt-install and
> in nova, is fine, but if the user explicitly asks for a certain mode
> it should still get that mode, not a different one.
> 
>> I agree we could document this situation at least. It does block our
>> aarch64 tests while it is ok for x86_64.
> 
> Can't you just use the default? That works on all architectures.
> 

Yes, that is what I suggest our QA people to do. To me, I just thought
if we could setup "--cpu host-model" and "--cpu host-passthrough"
manually, does it mean we can remove "--cpu host"? Of course, I may
misunderstood the meaning of "--cpu host".