On Tue, Feb 11, 2020 at 02:50:29PM -0800, Andy Lutomirski wrote: > On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@xxxxxxxxxx> wrote: > This patch is overcomplicated IMO. Just do the magic incantation in C > from do_nmi or from here: > > /* > * For ease of testing, unmask NMIs right away. Disabled by > * default because IRET is very expensive. > > If you do the latter, you'll need to handle the case where the NMI > came from user mode. > > The ideal solution is do_nmi, I think. > > if (static_cpu_has(X86_BUG_AMD_FORGOT_ABOUT_NMI)) > sev_es_unmask_nmi(); > > Feel free to use X86_FEATURE_SEV_ES instead :) Yeah, I also had that implemented once, but then changed it because I thought that nested NMIs do not necessarily call into do_nmi(), which would cause NMIs to stay blocked forever. I need to read through the NMI entry code again to check if that can really happen. Regards, Joerg
