Re: [Qemu-devel] [PATCH v2 1/3] KVM: Add new -cpu best

[Andreas Färber]

Am 26.06.2012 18:39, schrieb Alexander Graf:
> During discussions on whether to make -cpu host the default in SLE, I found

s/make -cpu host the default/support/?

> myself disagreeing to the thought, because it potentially opens a big can
> of worms for potential bugs. But if I already am so opposed to it for SLE, how
> can it possibly be reasonable to default to -cpu host in upstream QEMU? And
> what would a sane default look like?
> 
> So I had this idea of looping through all available CPU definitions. We can
> pretty well tell if our host is able to execute any of them by checking the
> respective flags and seeing if our host has all features the CPU definition
> requires. With that, we can create a -cpu type that would fall back to the
> "best known CPU definition" that our host can fulfill. On my Phenom II
> system for example, that would be -cpu phenom.
> 
> With this approach we can test and verify that CPU types actually work at
> any random user setup, because we can always verify that all the -cpu types
> we ship actually work. And we only default to some clever mechanism that
> chooses from one of these.
> 
> Signed-off-by: Alexander Graf <address@hidden>

Despite the long commit message a cover letter would've been nice. ;)

Anything that operates on x86_def_t will obviously need to be refactored
when we agree on the course for x86 CPU subclasses.
But no objection to getting it done some way that works today.

Andreas

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