Re: [Qemu-devel] [PATCH] ppc/kvm: have the "family" CPU alias to point to TYPE_HOST_POWERPC_CPU

[Greg Kurz <groug@kaod.org>]

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On Thu, 6 Jul 2017 17:32:33 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Wed, Jul 05, 2017 at 10:49:52AM +0200, Greg Kurz wrote:
> > When running KVM on POWER, we allow the user to pass "-cpu POWERx" instead
> > of "-cpu host". This is achieved by patching the ppc_cpu_aliases[] array
> > so that "POWERx" points to the CPU class with the same PVR as the host CPU.
> > This causes CPUs to be instantiated from this CPU class instead of the
> > TYPE_HOST_POWERPC_CPU class which is used with "-cpu host". These CPUs thus
> > miss all the KVM specific tuning from kvmppc_host_cpu_class_init().
> > 
> > This currently causes QEMU with "-cpu POWER9" to fail when running KVM on a
> > POWER9 DD1 host:
> > 
> > qemu-system-ppc64: Register sync failed... If you're using kvm-hv.ko, only
> >  "-cpu host" is possible
> > kvm_init_vcpu failed: Invalid argument
> > 
> > Let's have the "POWERx" alias to point to TYPE_HOST_POWERPC_CPU directly,
> > so that "-cpu POWERx" instantiates CPUs from the same class as "-cpu host".
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>  
> 
> Nice.  I had mistakenly thought it already did that.
> 
> I've applied this to ppc-for-2.10.
> 
> Just to make sure I've understood, this obsoletes Laurent's earlier
> patches moving DD1 workarounds about, yes?
> 

Yes it does.

Cheers,

--
Greg

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