Hi all, just to document this publicly here:
I've started to play with the new Raspberry Pi 4 last weekend. It finally has a standard GICv2 (yeah, so modern...) and therefore supports virtualization properly. I got Jailhouse basically running on Raspbian using their 4.19 kernel in 32-bit mode (64-bit is not ready with that yet). However, this is not yet ready for release.
The primary blocker is missing CPU hotplug support in that kernel and the old-style firmware. That firmware only puts the secondary A72 cores into spinning mode after boot and allows the kernel to pick them up via some mailbox messages (commonly accessible registers in the Broadcom interrupt controller). There is no PSCI. Reminds me a bit of the AM57xx. I've hacked in simplistic CPU shutdown into that state, but that may not be upstreamable. And that hack lacked support on the Jailhouse side, thus CPU onlining didn't work anymore.
The other issue was getting Jailhouse to boot in the constrained virtual address space of that configuration. We should resolve that for all ARMv7 boards for the next-but-one release by adopting the ARMv8 boot concept (hyp mode activation during arch_entry).
But the perspective still positive because, if we overcome the blocker, we will gain a broadly available, fairly powerful and nicely affordable ARMv8 target.
Jan -- Siemens AG, Corporate Technology, CT RDA IOT SES-DE Corporate Competence Center Embedded Linux -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jailhouse-dev/15f92023-1caa-389f-fe97-9a41eaaeb103%40siemens.com. For more options, visit https://groups.google.com/d/optout.
