On 21/10/16 10:05, Auger Eric wrote: > Hi Marc, > > On 21/10/2016 10:45, Marc Zyngier wrote: >> +Robert >> >> On 21/10/16 08:01, Auger Eric wrote: >>> Hi, >>> >>> I am not able to boot 4.9-rc1 as a guest on Cavium ThunderX (dt and acpi >>> mode). Bisecting the guest shows that the problem shows up at >>> >>> 91ef84428a86b75a52e15c6fe4f56b446ba75f93 >>> irqchip/gic-v3: Reset BPR during initialization >>> >>> If I remove the write to the ICC_BPR1_EL1 register on guest, the VM boots. >> >> That's very odd. A ICC_BPR1_EL1 access when HCR_EL2.IMO is set only >> affects ICH_VMCR_EL2.VBPR1. It is not trapped, since we don't set >> ICH_HCR_EL2.TALL1. It is a very boring sysreg! >> >> So from a pure architectural point of view, I don't see how this can >> fail. I've just run the same configuration on my Freescale board (GICv3 >> as well), and can't see any issue at all. >> >>> Investigating KVM code ... >> >> What is the failure syndrome? Do you see it crashing? Locking up? What >> is the PC at that stage? > No guest crash. the guest just locks up. No traces output. But you're able to kill the guest, right, and the CPU is not going to lalaland. We should be able to put a breakpoint on this instruction using qemu + GDB, and step it to find out what's happening. Or even execute the instruction in isolation with a bunch of printks in the guest. M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
