Re: [Qemu-devel] How do we do user input bitmap properties?

[Andrea Bolognani]

On Fri, 2019-05-24 at 15:24 -0300, Eduardo Habkost wrote:
> On Thu, May 23, 2019 at 10:35:24AM +0200, Andrea Bolognani wrote:
> > [...] the above looks good to
> > me as a general direction, but note that you'll have to implement at
> > the very least the query-cpu-model-expansion QMP command for the
> > introspection to work.
> 
> Why is query-cpu-model-expansion needed?  Isn't
> device-list-properties enough?

Good question.

I'll have to check with Jirka, but from playing with both commands
it looks like the latter returns a superset of what the former does,
so for the purpose of figuring out which vector lengths the QEMU
binary recognizes it should be good enough; I suspect, however, that
query-cpu-model-expansion might be (made to be) smarter and for
example not report vector lengths that the underlying hardware
doesn't support, which would be valuable for the purpose of user
friendly error reporting and allowing applications to decide which
vector lengths to request when creating guests.

I'll try to come back with more than theories soon :)

-- 
Andrea Bolognani / Red Hat / Virtualization