[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 4/6] i386: Infrastructure for versioned CPU mode
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH 4/6] i386: Infrastructure for versioned CPU models |
Date: |
Tue, 25 Jun 2019 15:32:16 +0100 |
User-agent: |
Mutt/1.12.0 (2019-05-25) |
* Eduardo Habkost (address@hidden) wrote:
> On Tue, Jun 25, 2019 at 10:32:01AM +0100, Dr. David Alan Gilbert wrote:
> > * Eduardo Habkost (address@hidden) wrote:
> > > Base code for versioned CPU models. This will register a "-4.1"
> > > version of all existing CPU models, and make the unversioned CPU
> > > models be an alias for the -4.1 versions on the pc-*-4.1 machine
> > > types.
> > >
> > > On older machine types, the unversioned CPU models will keep the
> > > old behavior. This way, management software can use old machine
> > > types while resolving aliases if compatibility with older QEMU
> > > versions is required.
> > >
> > > Using "-machine none", the unversioned CPU models will be aliases
> > > to the latest CPU model version.
> > >
> > > Includes a test case to ensure that:
> > > old machine types won't report any alias to versioned CPU models;
> > > "pc-*-4.1" will return aliases to -4.1 CPU models;
> > > and "-machine none" will report aliases to some versioned CPU model.
> > >
> > > Signed-off-by: Eduardo Habkost <address@hidden>
> >
> > What happens when we add the next new CPU model? So say in 4.2 we add
> > a new CPU, does that default to being newcpu-4.2 ?
>
> We can choose between providing old versions of the CPU model
> retroactively ("NewModel-4.1" and "NewModel-4.2"), or providing
> only "NewModel-4.2".
>
> The question is: if we provide only "NewModel-4.2", what should
> be the behavior of "-machine pc-i440fx-4.1 -cpu NewModel"?
Perhaps the existing CPUs and the first instance of a new CPU
we should use something non-numeric, e.g. 'orig' rather than 4.1;
we only go numeric when we cause a divergence.
Dave
> --
> Eduardo
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
Re: [Qemu-devel] [PATCH 4/6] i386: Infrastructure for versioned CPU models, Daniel P . Berrangé, 2019/06/25
Re: [Qemu-devel] [PATCH 4/6] i386: Infrastructure for versioned CPU models, Daniel P . Berrangé, 2019/06/25
[Qemu-devel] [PATCH 5/6] docs: Deprecate CPU model runnability guarantees, Eduardo Habkost, 2019/06/25
[Qemu-devel] [PATCH 6/6] i386: Add Cascadelake-Server-4.1.1 CPU model, Eduardo Habkost, 2019/06/25