Am 15.08.2013 17:30, schrieb Alexander Graf: > > On 15.08.2013, at 17:11, Andreas Färber wrote: > >> Am 15.08.2013 15:12, schrieb Anthony Liguori: >>> Everyone is talking past each other and no one is addressing the real >>> problem. There are two distinct issues here: >>> >>> 1) We have two ABIs that cannot be changed unless there's a very good >>> reason to. Alexey's original patch breaks both. The guest ABI >>> cannot change given a fixed command line. >>> >>> IOW, the exposed PVR value for -cpu POWER7 cannot change across >>> versions of QEMU or when running on different hardware. This breaks >>> live migration and save/resume. >>> >>> We also cannot break the command line interface. If the last version >>> of QEMU supported -cpu POWER7_v2.1, then we must continue to support >>> that. >> >> 1a) How should -cpu 0xDEADBEEF or -cpu DEADBEEF behave. >> >> I expect it to error out as before >> rather than applying the same fuzz/mask that -cpu host might. > > I actually think it'd make sense to apply the same fuzz/mask, don't you think?
I think "-cpu host" has the semantics of give-me-what-the-host-has. But -cpu 0xDEADBEEF is asking for PVR DEADBEEF and having it silently return a guest-visible DEADBEBE is going to be undesired. We could of course report our closest match on stderr for the user to decide. Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
