Re: [PATCH for-9.0] docs/about: Mark the iaspc machine type as deprecated

[Philippe Mathieu-Daudé]

Hi Igor,

On 26/3/24 14:08, Thomas Huth wrote:
> s/iaspc/isapc/ in the subject
>
> On 26/03/2024 13.51, Igor Mammedov wrote:
> > ISAPC machine was introduced 25 years ago and it's a lot of time since
> > such machine was around with real ISA only PC hardware practically 
> > defunct.
> > Also it's slowly bit-rots (for example: I was able to boot RHEL6 on 
> > RHEL9 host
> > in only TCG mode, while in KVM mode it hung in the middle of boot)

I'm quite opposed to this patch. QEMU models various very-old /
defunct hardware. I'm pretty sure Bernhard and myself are OK to
keep maintaining it, besides we are working in separating it from
the i440fx+piix machine. Also, this machine is particularly
interesting for my single-binary experiments.

Where I agree is we should stop reporting "KVM on ISA/PC machine"
as supported.

Regards,

Phil.

> > Rather than spending time on fixing 'the oldest' no longer tested 
> > machine type,
> > deprecate it so we can clean up QEMU code from legacy fixups and 
> > hopefully
> > make it easier to follow.
> >
> > Folks who have to use ancient guest that requires ISAPC can still
> > use older QEMU to play with it.
> >
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >   docs/about/deprecated.rst | 7 +++++++
> >   hw/i386/pc_piix.c         | 1 +
> >   2 files changed, 8 insertions(+)
> >
> > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
> > index 7b548519b5..5708296991 100644
> > --- a/docs/about/deprecated.rst
> > +++ b/docs/about/deprecated.rst
> > @@ -226,6 +226,13 @@ These old machine types are quite neglected 
> > nowadays and thus might have
> >   various pitfalls with regards to live migration. Use a newer machine 
> > type
> >   instead.
> > +``isapc`` (since 9.0)
> > +'''''''''''''''''''''''''''''''''''''''''''''''''''''
> > +
> > +These old machine type are quite neglected nowadays and thus might have
>
> "This old machine type is ..." ?
>
> > +various pitfalls with regards to live migration. Use a newer machine 
> > type
> > +instead.
>
> I doubt that isapc could ever be used reliably for live migration, since 
> it's an unversioned machine type, so I think it would be better to not 
> mention live migration here.
>
>   Thomas