[Qemu-arm] [RFC v3 0/4] vITS Reset

[Eric Auger <eric.auger@redhat.com>]

At the moment the ITS is not properly reset. On System reset or
reboot, previous ITS register values and caches are left
unchanged. Some of the registers might point to some guest RAM
tables which are not valid anymore. This leads to state
inconsistencies that are detected by the kernel save/restore
code. And eventually this may cause qemu abort.

This series adds vITS reset modality:
- the 2 first patches bring a minimalist reset through individual
  register writes. However, with kernel versions < 4.15, this reset
  is not complete (vITS caches are not voided).
- With kernel versions >= 4.15 we can rely on a new ITS KVM device
  reset IOTCL. The last 2 patches introduce the full reset.

Patches 1-2 have all kernel dependencies resolved.
Patches 3-4' dependencies were pulled for v4.15-rc0 but as the tag is
not set, the kernel header update still is partial.

Best Regards

Eric

The series is available at:
https://github.com/eauger/qemu/tree/2.11.0-rc2-its-reset-v3

History:
v2 -> v3:
- don't call post_load on reset (no iidr check anymore)

v1 -> v2:
- Clarify why abort should be removed for save. Leave abort
  for restore.
- Adopt the same reset infra as vgic
- introduce "hw/intc/arm_gicv3_its: Implement a minimalist reset"
  which perform individual register writes. This is sufficient to
  fix the issues without ioctl


Eric Auger (4):
  hw/intc/arm_gicv3_its: Don't call post_load on reset
  hw/intc/arm_gicv3_its: Implement a minimalist reset
  linux-headers: Partial header update for ITS reset
  hw/intc/arm_gicv3_its: Implement full reset

 hw/intc/arm_gicv3_its_common.c |  2 --
 hw/intc/arm_gicv3_its_kvm.c    | 52 ++++++++++++++++++++++++++++++++++++++----
 linux-headers/asm-arm/kvm.h    |  1 +
 linux-headers/asm-arm64/kvm.h  |  1 +
 4 files changed, 50 insertions(+), 6 deletions(-)

-- 
2.5.5