Re: [Xen-devel] [PATCH] xen/arm64: Avoid sending SGI when kicking secondary cpus with spin_table

[Julien Grall <julien.grall@xxxxxxxxxx>]

Hi Chen,

Subject: I think you can drop the "_" in spin_table.

On 07/04/15 08:33, Chen Baozi wrote:
> From: Chen Baozi <baozich@xxxxxxxxx>
> 
> On arm64, either firmware or xen's smp_up_cpu gate uses WFE on secondary
> cpus to stand-by when booting. Thus, using SEV is enough for the boot
> cpu to kick other secondaries. Further more, the current implementation
> of cpu_up_send_sgi would pass a NULL cpumask pointer to send_SGI, which
> then lead a data fault on GICv3 send_SGI implementation.

I'm not familiar with spin table on ARM64, so I will let Ian answer
about it.

Aside that, the GICv3 implementation looks buggy to me.
The GIC code provides two helpers which lead to pass NULL to the
callback send_SGI:
        - send_SGI_self: AFAICT nobody is using it
        - send_SGI_allbutself: Only used by the smp boot code


I think the former can be dropped or modify to send_SGI_one.

For the later, I can't find why we need to send an SGI on ARM too. Ian,
Stefano, any idea?

Regards.

-- 
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel