On Tue, Nov 29, 2016 at 02:16:49PM +0100, Borislav Petkov wrote: > On Mon, Nov 21, 2016 at 05:06:54PM +0100, Borislav Petkov wrote: > > IOW, what's the worst thing that can happen if we did this below? > > > > We basically get rid of the detection and switch the timer to broadcast > > mode immediately on the halting CPU. > > > > amd_e400_idle() is behind an "if (cpu_has_bug(c, X86_BUG_AMD_APIC_C1E))" > > check so it will run on the affected CPUs only... > > > > Thoughts? > > Actually, here's a better version. The E400 detection works only after > ACPI has been enabled so we piggyback the end of acpi_init(). > > We don't need the MSR read now - we do > > if (static_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) > > on the idle path which is as fast as it gets. > > Any complaints about this before I go and test it everywhere? > > It builds and boots in my guest here ok, not that it means a whole lot. > > The good news is, I have collected a fleet of boxes which all have that > erratum so testing should be pretty reliable. Something that doesn't > happen everytime!
+1 one test server over here.. will check ;-) jirka
