On 2/26/2018 10:37 AM, Morton, Eric wrote: > Thomas, > > Yazen dug out PLAT-21393 as sounding like this issue. I haven't had a chance > to digest it.
Yes, internally to AMD, that was the bug that tracked the issue I was referring to. Thanks, Tom > > Eric > > On 2/26/18, 10:31 AM, "Borislav Petkov" <b...@alien8.de> wrote: > > On Mon, Feb 26, 2018 at 10:14:10AM -0600, Tom Lendacky wrote: > > On 2/24/2018 2:59 AM, Thomas Gleixner wrote: > > > On Sat, 24 Feb 2018, Paul Menzel wrote: > > >> Am 23.02.2018 um 20:09 schrieb Borislav Petkov: > > >>> On Fri, Feb 23, 2018 at 07:18:34PM +0100, Thomas Gleixner wrote: > > >>>> Borislav is seeing similar issues on larger AMD machines. The > interrupt > > >>>> seems to come from BIOS/microcode during bringup of secondary CPUs > and we > > >>>> have no idea why. > > >>> > > >>> Paul, can you boot 4.14 and grep your dmesg for something like: > > >>> > > >>> [ 0.000000] spurious 8259A interrupt: IRQ7. > > > >>> ? > > >> > > >> No, I do not see that. Please find the logs attached. > > > > > > From your 4.14 log: > > > > > > Feb 19 09:48:06.843173 kodi kernel: CPU 0 irqstacks, hard=e9b0a000 > soft=e9b0c000 > > > Feb 19 09:48:06.843216 kodi kernel: spurious 8259A interrupt: IRQ7. > > > > I think I remember seeing something like this previously and it turned > out > > to be a BIOS bug. All the AP's were enabled to work with the legacy > 8259 > > interrupt controller. In an SMP system, only one processor in the > system > > should be configured to handle legacy 8259 interrupts (ExtINT delivery > > mode - see Intel's SDM, Volume 3, section 10.5.1, Delivery Mode). Once > > the BIOS was fixed, the spurious interrupt message went away. > > > > I believe at some point during UEFI, the APs were exposed to an ExtINT > > interrupt. Since they were configured to handle ExtINT delivery mode > and > > interrupts were not yet enabled, the interrupt was left pending. When > the > > APs were started by the OS and interrupts were enabled, the interrupt > > triggered. Since the original pending interrupt was handled by the BSP, > > there was no longer an interrupt actually pending, so the 8259 responds > > with IRQ 7 when queried by the OS. This occurred for each AP. > > Interesting - is this something that can happen on Zen too? > > Because I have such reports too. > > -- > Regards/Gruss, > Boris. > > Good mailing practices for 400: avoid top-posting and trim the reply. > >