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"). For PATCH[v9 3/7], Peter's ack-by is kept since the recent changes don't fundamentally break what he agreed. However, it would be nice for Peter to double confirm. v9: https://lore.kernel.org/kvmarm/20221108041039.111145-1-gshan@xxxxxxxxxx/T/ v8: https://lore.kernel.org/kvmarm/e7196fb5-1e65-3a5b-ba88-1d98264110e3@xxxxxxxxxx/T/#t v7: https://lore.kernel.org/kvmarm/20221031003621.164306-1-gshan@xxxxxxxxxx/ v6: https://lore.kernel.org/kvmarm/20221011061447.131531-1-gshan@xxxxxxxxxx/ v5: https://lore.kernel.org/all/20221005004154.83502-1-gshan@xxxxxxxxxx/ v4: https://lore.kernel.org/kvmarm/20220927005439.21130-1-gshan@xxxxxxxxxx/ v3: https://lore.kernel.org/r/20220922003214.276736-1-gshan@xxxxxxxxxx v2: https://lore.kernel.org/lkml/YyiV%2Fl7O23aw5aaO@xz-m1.local/T/ v1: https://lore.kernel.org/lkml/20220819005601.198436-1-gshan@xxxxxxxxxx Testing ======= (1) kvm/selftests/dirty_log_test (2) Live migration by QEMU (partially) Changelog ========= v10: * Replace CONFIG_HAVE_DIRTY_RING_WITH_BITMAP with CONFIG_NEED_DIRTY_RING_WITH_BITMAP, improve the comments about the option, and reserve cap->flags for future needs to disable KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP in PATCH[v10 3/7] (Sean) v9: * Improved documentation in PATCH[v9 3/7] (Marc/Peter) * Add helper to check if we have any memslot and lockdep assert is added to kvm_use_dirty_bitmap() in PATCH[v9 3/7] (Sean/Oliver) * Drop the helper to return dist->save_its_tables_in_progress and move kvm_arch_allow_write_without_running_vcpu() to vgic-its.c in PATCH[v9 4/7] (Marc) v8: * Pick review-by and ack-by (Peter/Sean) * Drop chunk of code to clear KVM_REQ_DIRTY_RING_SOFT_FULL in kvm_dirty_ring_reset(). Add comments to say the event will be cleared by the VCPU thread next time when it enters the guest. All other changes related to kvm_dirty_ring_reset() are dropped in PATCH[v8 1/7]. (Sean/Peter/Marc) * Drop PATCH[v7 3/7] since it has been merged (Marc/Oliver) * Document the order of DIRTY_RING_{ACQ_REL, WITH_BITMAP}, add check to ensure no memslots are created when DIRTY_RING_WITH_BITMAP is enabled, and add weak function kvm_arch_allow_write_without_running_vcpu() in PATCH[v8 3/7] (Oliver) * Only keep ourself out of non-running-vcpu radar when vgic/its tables are being saved in PATCH[v8 4/7] (Marc/Sean) v7: * Cut down #ifdef, avoid using 'container_of()', move the dirty-ring check after KVM_REQ_VM_DEAD, add comments for kvm_dirty_ring_check_request(), use tab character for KVM event definitions in kvm_host.h in PATCH[v7 01] (Sean) * Add PATCH[v7 03] to recheck if the capability has been advertised prior to enable RING/RING_ACEL_REL (Sean) * Improve the description about capability RING_WITH_BITMAP, rename kvm_dirty_ring_exclusive() to kvm_use_dirty_bitmap() in PATCH[v7 04/09] (Peter/Oliver/Sean) * Add PATCH[v7 05/09] to improve no-running-vcpu report (Marc/Sean) * Improve commit messages (Sean/Oliver) v6: * Add CONFIG_HAVE_KVM_DIRTY_RING_WITH_BITMAP, for arm64 to advertise KVM_CAP_DIRTY_RING_WITH_BITMAP in PATCH[v6 3/8] (Oliver/Peter) * Add helper kvm_dirty_ring_exclusive() to check if traditional bitmap-based dirty log tracking is exclusive to dirty-ring in PATCH[v6 3/8] (Peter) * Enable KVM_CAP_DIRTY_RING_WITH_BITMAP in PATCH[v6 5/8] (Gavin) v5: * Drop empty stub kvm_dirty_ring_check_request() (Marc/Peter) * Add PATCH[v5 3/7] to allow using bitmap, indicated by KVM_CAP_DIRTY_LOG_RING_ALLOW_BITMAP (Marc/Peter) v4: * Commit log improvement (Marc) * Add helper kvm_dirty_ring_check_request() (Marc) * Drop ifdef for kvm_cpu_dirty_log_size() (Marc) 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 (7): KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h KVM: Support dirty ring in conjunction with bitmap 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 | 36 ++++++++--- .../virt/kvm/devices/arm-vgic-its.rst | 5 +- arch/arm64/include/uapi/asm/kvm.h | 1 + arch/arm64/kvm/Kconfig | 2 + arch/arm64/kvm/arm.c | 3 + arch/arm64/kvm/vgic/vgic-its.c | 20 ++++++ arch/x86/include/asm/kvm_host.h | 2 - arch/x86/kvm/x86.c | 15 ++--- include/kvm/arm_vgic.h | 1 + include/linux/kvm_dirty_ring.h | 20 +++--- include/linux/kvm_host.h | 10 +-- include/uapi/linux/kvm.h | 1 + tools/testing/selftests/kvm/dirty_log_test.c | 53 +++++++++++---- tools/testing/selftests/kvm/lib/kvm_util.c | 2 +- virt/kvm/Kconfig | 6 ++ virt/kvm/dirty_ring.c | 46 ++++++++++++- virt/kvm/kvm_main.c | 64 +++++++++++++++---- 17 files changed, 227 insertions(+), 60 deletions(-) -- 2.23.0