On Thu, Jan 12, 2012 at 05:44:26PM +1100, Benjamin Herrenschmidt wrote: > On Tue, 2012-01-10 at 04:11 +0100, Alexander Graf wrote: > > This is what book3s does: > > > > case EMULATE_FAIL: > > printk(KERN_CRIT "%s: emulation at %lx failed > > (%08x)\n", > > __func__, kvmppc_get_pc(vcpu), > > kvmppc_get_last_inst(vcpu)); > > kvmppc_core_queue_program(vcpu, flags); > > r = RESUME_GUEST; > > > > which also doesn't throttle the printk, but I think injecting a > > program fault into the guest is the most sensible thing to do if we > > don't know what the instruction is supposed to do. Best case we get an > > oops inside the guest telling us what broke :). > > You can also fallback to a slow path that reads the guest TLB, > translates then reads the instruction. Of course you have to be careful > as such a manual translate + read + execute needs to be somewhat > synchronized with a possible TLB invalidation :-) That's how we should deal with a failure to read the instruction due to it being execute-only (once we add the ability to fix up a fault on a booke KVM instruction fetch) -- but the above code is dealing with the case where we read the instruction successfully, but don't have an emulation handler for it. -Scott -- 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
