On 3/20/20 6:17 AM, Joerg Roedel wrote: > On Thu, Mar 19, 2020 at 08:35:59AM -0700, Andy Lutomirski wrote: >> 1. Just put the NMI unmask in do_nmi(). The kernel *already* knows >> how to handle running do_nmi() with NMIs unmasked. This is much, much >> simpler than your code. > Okay, attached is the updated patch which implements this approach. I > tested it in an SEV-ES guest with 'perf top' running for a little more > than 30 minutes and all looked good. I also removed the dead code from > the patch. FWIW, perf plus the x86 selftests run in a big loop was my best way of stressing the NMI path when we mucked with it for PTI. The selftests make sure to hit some of the more rare entry/exit paths.
