On 14.12.2012, at 22:42, Scott Wood wrote: > On 12/14/2012 06:35:12 AM, Alexander Graf wrote: >> On 14.12.2012, at 03:12, Scott Wood wrote: >> > If we access a register via the QEMU memory inspection commands (e.g. >> > "xp") rather than from guest code, we won't have a CPU context. >> > Gracefully fail to access the register in that case, rather than >> > crashing. >> Can't we set cpu_single_env in the debug memory access case? I'm not sure >> this is the only device with that problem, and by always having >> cpu_single_env available we would completely get rid of the whole bug >> category. > > So, how would we go about doing this? cpu_single_env is declared as > thread-local storage. Even if there's some way to deliberately inspect a > different thread's local storage, I don't see how you'd get it to work > automatically without changing all those drivers (and are there really that > many that care about the CPU?) -- and we might break other places that > already check whether cpu_single_env is NULL. > > FWIW, hw/pc.c does pretty much the same thing as this patch in > cpu_get_current_apic().
Ok, convinced :). Patch applied to ppc-next. Thanks ;) Alex
