On 28/02/2019 08:49, Marc Zyngier wrote: > On Thu, 28 Feb 2019 08:16:05 +0000, > Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > Hi both, > >> >> On Wed, Feb 27, 2019 at 04:36:39PM -0800, Daniel Verkamp wrote: >>> Hello, >>> >>> In my testing of crosvm[1] with Linux 4.4.175, I am observing failures >>> on a 'kevin' Chromebook (RK3399) device - the guest kernel does not >>> even get to the point of printing its first messages, and the host >>> seems to be spinning at 100% CPU in KVM_RUN. >>> >>> I narrowed this down to the 4.4 stable backport of "arm64: KVM: Skip >>> MMIO insn after emulation" - with this patch reverted, I can boot the >>> guest kernel as normal again. >>> >>> Unfortunately, I am unable to easily test with a newer upstream kernel >>> (this board is using the Chrome OS kernel with many additional patches >>> applied on top of 4.4), so I'm not sure if this issue was introduced >>> in the mainline commit or only in the stable branch. Is it possible >>> that this patch has other dependencies that were missed in the >>> backport? It looks like it was part of a larger series, but only this >>> patch got pulled for 4.4 stable. > > Thanks for reporting this. I'll have a look ASAP. > >> It looks like this got pulled in by Sasha's bot which is why it was >> applied. >> >> I have no objection to reverting this if it is causing problems, unless >> someone here really thinks it needs to remain in the tree? > > Can we hold on a tiny bit so that I can verify we haven't regressed > crosvm all the way into mainline? > > Daniel, is there any chance you could test with kvmtool as well on > your setup? You can easily compile it as a static binary and run it > from ChromeOS with: > > lkvm-static run -c 1 -p "earlycon=uart,mmio,0x3f8" -l Image > > which should start a UP guest and drop you to a shell. In the > meantime, I'm starting to build crosvm on my kevin running mainline. OK, that wasn't a fun experience. Some build instructions for the mere mortals (aka non-ChromeOS people) would be nice (and a mention that crosvm cannot yet deal with GICv3-only systems...) Anyway, I've got enough of it working that I can boot a trivial Debian guest on kevin running 5.0-rc7, so I'm pretty confident that mainline is OK. I'll move back to 4.4, and try to understand what happens there. Thanks, M. -- Jazz is not dead. It just smells funny...
