On 03/03/2016 20:06, Richard Henderson wrote: > On 03/03/2016 02:08 AM, Paolo Bonzini wrote: >>> Do you want LOG_UNIMP or LOG_GUEST_ERROR? >> >> I would actually use LOG_IN_ASM. As you noticed, guests sometimes use >> illegal opcodes; another example is Xen's hypercall interface. >> >> On 03/03/2016 07:57, Hervé Poussineau wrote: >>> This patch is not quiet on some operating systems: >>> OS/2: >>> ILLOPC: 000172e1: 0f a6 >>> >>> Windows XP: >>> ILLOPC: 00020d1a: c4 c4 >>> >>> And very verbose in Windows 3.11, Windows 9x: >>> ILLOPC: 000ffb17: 63 >>> ILLOPC: 000ffb17: 63 >>> >>> Is it normal? >> >> Yes, it is. As usual, Raymond Chen explains what's going on: >> >> https://blogs.msdn.microsoft.com/oldnewthing/20041215-00/?p=37003 > > Wow. That's... interesting. > > I think maybe I'll re-do the patch to distinguish between those opcodes > that are completely unrecognized (which is what I was expecting to find) > and those that raise #UD due to cpu state (e.g. this arpl in vm86 mode).
Good idea. UD2 should not warn too, and also VEX prefixes outside 64-bit mode. Any thoughts about patch 7? Paolo
