> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Sent: Saturday, December 11, 2021 3:00 AM > > Jason, > > On Fri, Dec 10 2021 at 08:39, Jason Gunthorpe wrote: > > > On Fri, Dec 10, 2021 at 07:29:01AM +0000, Tian, Kevin wrote: > >> > 5) It's not possible for the kernel to reliably detect whether it is > >> > running on bare metal or not. Yes we talked about heuristics, but > >> > that's something I really want to avoid. > >> > >> How would the hypercall mechanism avoid such heuristics? > > > > It is clever, we don't have an vIOMMU that supplies vIR today, so by > > definition all guests are excluded and only bare metal works. > > Dammit. Now you spilled the beans. :) > Unfortunately we do have that today. Qemu supports IR for both AMD and Intel vIOMMU. Thanks Kevin