git: kernel - Fix KVM implosion by enabling the IOAPIC

Matthew Dillon dillon at
Fri Aug 28 18:36:09 PDT 2020

commit f0ee34376aa227bbd17f5ccbc846ac30c6177693
Author: Matthew Dillon <dillon at>
Date:   Fri Aug 28 18:32:43 2020 -0700

    kernel - Fix KVM implosion by enabling the IOAPIC
    * We were disabling the IOAPIC universally when running under a VM,
      because older VMs sometimes broke when it was enabled.
      However, this can actually implode the virtual machine by causing
      interrupt routing to go haywire.
      Add a case statement and always enable the IOAPIC on bare hardware
      and KVM guests.
    * Change the default to also enable the IOAPIC on all other VMs.
      Cases can be added for specific disablement if necessary.
    * Fixes Google Cloud Environment booting.

Summary of changes:
 sys/platform/pc64/x86_64/machdep.c | 112 ++++++++++++++++++++-----------------
 1 file changed, 62 insertions(+), 50 deletions(-)

DragonFly BSD source repository

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