On Wed, Jun 07, 2017 at 03:06:55PM +0100, Marc Zyngier wrote:
If that is so fundamentally broken that this is the only benefit, I guess we might as well use some old-style SMP ops.
Broken, for sure. Which is why I'm asking about the benefits of running non-secure on something that has evidently been very badly integrated, and for which non-secure is at best an afterthought.
Now, if someone could try and run guests on this turd and report whether this works correctly or not, that'd be an interesting data point. Because in the absence of a TEE running on the secure side, virtualization is basically the only thing you gain from running on the non-secure side.
I just tried running Xen on it, with an adjustment similar to what Chen-Yu made in the kernel.
It fails at boot, and stops with: (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER4 (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER8 (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER12 (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER16 (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER20 (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER24 (XEN) d0v0: vGICD: unhandled word write 0xffffffff to ICACTIVER0
It looks like it won't be easy to support. I guess we could just go for smp_ops, and if someone really cares one day about it, we'll always have the option to support it then.
Maxime