This intends to support HMP/QMP "nmi" command. When it's issued, the
SError interrupt is injected to the guest. The guest is expected to
crash with it. The behavior is similar to x86: NMI is injected to
guest as error indication. The guest possiblly crashes and reboots
with the injected NMI. Note that the functionality is currently
supported on "virt" machine and {"host", "max"} CPU models only.

PATCH[1/2] allows to inject SError interrupt, which will be used by
the subsequent patch. PATH[2/2] injects SError interrupt when "nmi"
command is issued. With that, the guest is expected to crash and
possiblly reboot.

Testing
=======
Start linux 5.5 guest with "virt"+"host", or "virt"+"max". The
guest crashes and reboot if "/proc/sys/core/panic" had been configured
properly, after "nmi" command is issued. The following error message
is given on "virt"+"cortext-a72": "Error: NMI injection not supported"

Changelog
=========
v2:
   * Redesigned to fully exploit SError interrupt

Gavin Shan (2):
  target/arm: Allow to inject SError interrupt
  target/arm: Support NMI injection

 hw/arm/virt.c          | 18 +++++++++++++
 target/arm/cpu-qom.h   |  1 +
 target/arm/cpu.c       | 59 ++++++++++++++++++++++++++++++++++++++++++
 target/arm/cpu.h       | 12 ++++++---
 target/arm/cpu64.c     | 25 +++++++++++++++---
 target/arm/helper.c    |  4 +++
 target/arm/internals.h |  8 ++++++
 7 files changed, 120 insertions(+), 7 deletions(-)

-- 
2.23.0