On Wed, 3 Jan 2018, Guillaume Tucker wrote: > On 03/01/18 09:48, Thomas Gleixner wrote: > > > Well, it turns out this is not exactly a conflict as there's a > > > subtle difference between the qemu devices in lab-mhart and in > > > lab-collabora. The ones in lab-collabora are configured to use > > > KVM, and it looks like the ones in lab-mhart aren't. > > > > > > So this job with KVM enabled passes in lab-collabora: > > > > > > https://lava.collabora.co.uk/scheduler/job/1032358 > > > > > > but it fails if I tell LAVA (qemu) to disable KVM: > > > > > > https://lava.collabora.co.uk/scheduler/job/1032359 > > > > > > with the same panic as in lab-mhart. It seems like it's failing > > > to return from an interrupt: > > > > > > http://lava.streamtester.net/scheduler/job/87308 > > > > > > [ 2.678828] ? native_iret+0x7/0x7 > > > [ 2.679208] WARNING: can't dereference iret registers at > > > 00000000ffc66068 > > > for ip page_fault+0x11/0x60 > > > > > > This triggered an automated bisection on kernelci.org, please see > > > the results below. > > > > > > I may run another bisection with this config enabled earlier in > > > the history to track down the actual change in the code that > > > introduced the issue, let me know if it's worth doing. > > > > No, because before that commit not all pieces are in place. > > > > Can you please try the failing kernel with pti=off on the command line? > > It does boot with pti=off (and KVM disabled): > > https://lava.collabora.co.uk/scheduler/job/1032387 So it's a qemu issue. Added qemu folks on Cc. > > I'll start a test instance here as well. Thanks, tglx