On Wed, Feb 16, 2022 at 05:40:44PM +0000, Dr. David Alan Gilbert wrote:
* Thomas Huth (thuth@redhat.com) wrote:
On 16/02/2022 12.01, Dr. David Alan Gilbert wrote:
* Gerd Hoffmann (kraxel@redhat.com) wrote:
Hi,
Given the semantic differences from 'i440fx', changing the default
machine type has effects that are equivalent to breaking command
line syntax compatibility, which is something we've always tried
to avoid.
And if we are fine breaking backward compatibility I'd rather *not* pick
a default, effectively making -M $something mandatory, similar to arm.
Oh, that's probably easy to do; what are other peoples thoughts on
that?
I agree with Gerd. Getting rid of a default machine on x86 is likely better
than silently changing it to q35. But I'd maybe say that this should go
through the deprecation process first?
So just adding something like the following under 'System emulator
machines':
x86 default machine type
------------------------
x86 currently defaults to the very old ```pc``` machine type
which is based on the very old ```i440f``` chipset. This default
will be removed and the user will be required to specify a machine
type explicitly using -M; users are encouraged to switch to the
not quite as old ```q35``` machine types.
(This option is going to take a lot more work switching all the
test cases over; in my world here I'd only changed the tests that broke
on q35, now everything is going to need to specify a type).
....which is still nothing compared to how many users will be impacted
and the docs all over the internet we'll never be able to change, which
give illustrations using qemu command lines without '-M pc'