Messages in this thread | | | Date | Fri, 5 Apr 2013 15:36:06 -0400 (EDT) | From | Nicolas Pitre <> | Subject | Re: [PATCH v6 4/4] xen/arm: introduce xen_early_init, use PSCI on xen |
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On Fri, 5 Apr 2013, Stefano Stabellini wrote:
> This is what happens: > > - No Xen > Xen is not running on the platform and a Xen hypervisor node is not > available on device tree. > Everything keeps working seamlessly, this patch doesn't change anything. > > - we are running on Xen > Xen is running on the platform, we are running as a guest on Xen and an > hypervisor node is available on device tree. > Let's also assume that there aren't any "arm,cci" compatible nodes on > device tree because Xen wouldn't export this kind of information to any > guests right now. Therefore PSCI should be used to boot secondary cpus. > Because the versatile express machine sets smp_init to > vexpress_smp_init_ops, vexpress_smp_init_ops will be called. > vexpress_smp_init_ops sets smp_ops to vexpress_smp_ops, that *break* > Xen.
OK I see.
> With this patch, xen_smp_init will be called instead of > vexpress_smp_init_ops, and smp_ops will be set to psci_smp_ops, > therefore *unbreaking* Xen.
However that breaks MCPM.
> In fact what makes this patch really necessary is smp_init together with > the MCPM series.
Yes.
> Do you agree with me?
On the Xen issue, yes.
Nicolas
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