[PATCH v3 0/6] KVM: arm64: Enable ring-based dirty memory tracking

[Gavin Shan <gshan@redhat.com>]

This series enables the ring-based dirty memory tracking for ARM64.
The feature has been available and enabled on x86 for a while. It
is beneficial when the number of dirty pages is small in a checkpointing
system or live migration scenario. More details can be found from
fb04a1eddb1a ("KVM: X86: Implement ring-based dirty memory tracking").

The generic part has been comprehensive, meaning there isn't too much
work, needed to extend it to ARM64.

  PATCH[1]   introduces KVM_REQ_RING_SOFT_FULL for x86
  PATCH[2]   moves declaration of kvm_cpu_dirty_log_size()
  PATCH[3]   enables the feature on ARM64
  PATCH[4-6] improves kvm/selftests/dirty_log_test

v2: https://lore.kernel.org/lkml/YyiV%2Fl7O23aw5aaO@xz-m1.local/T/
v1: https://lore.kernel.org/lkml/20220819005601.198436-1-gshan@redhat.com

Testing
=======
(1) kvm/selftests/dirty_log_test
(2) Live migration by QEMU

Changelog
=========
v3:
  * Check KVM_REQ_RING_SOFT_RULL inside kvm_request_pending()  (Peter)
  * Move declaration of kvm_cpu_dirty_log_size()               (test-robot)
v2:
  * Introduce KVM_REQ_RING_SOFT_FULL                           (Marc)
  * Changelog improvement                                      (Marc)
  * Fix dirty_log_test without knowing host page size          (Drew)

Gavin Shan (6):
  KVM: x86: Introduce KVM_REQ_RING_SOFT_FULL
  KVM: x86: Move declaration of kvm_cpu_dirty_log_size() to
    kvm_dirty_ring.h
  KVM: arm64: Enable ring-based dirty memory tracking
  KVM: selftests: Use host page size to map ring buffer in
    dirty_log_test
  KVM: selftests: Clear dirty ring states between two modes in
    dirty_log_test
  KVM: selftests: Automate choosing dirty ring size in dirty_log_test

 Documentation/virt/kvm/api.rst               |  2 +-
 arch/arm64/include/uapi/asm/kvm.h            |  1 +
 arch/arm64/kvm/Kconfig                       |  1 +
 arch/arm64/kvm/arm.c                         |  8 +++
 arch/x86/include/asm/kvm_host.h              |  2 -
 arch/x86/kvm/mmu/mmu.c                       |  2 +
 arch/x86/kvm/x86.c                           | 19 +++----
 include/linux/kvm_dirty_ring.h               |  1 +
 include/linux/kvm_host.h                     |  1 +
 tools/testing/selftests/kvm/dirty_log_test.c | 53 ++++++++++++++------
 tools/testing/selftests/kvm/lib/kvm_util.c   |  2 +-
 virt/kvm/dirty_ring.c                        |  4 ++
 12 files changed, 69 insertions(+), 27 deletions(-)

-- 
2.23.0