| Message ID | 20230509022122.20888-1-gshan@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | hw/arm/virt: Support dirty ring | expand |
Hi Paolo, On 5/9/23 12:21 PM, Gavin Shan wrote: > This series intends to support dirty ring for live migration for arm64. The > dirty ring use discrete buffer to track dirty pages. For arm64, the speciality > is to use backup bitmap to track dirty pages when there is no-running-vcpu > context. It's known that the backup bitmap needs to be synchronized when > KVM device "kvm-arm-gicv3" or "arm-its-kvm" has been enabled. The backup > bitmap is collected in the last stage of migration. The policy here is to > always enable the backup bitmap extension. The overhead to synchronize the > backup bitmap in the last stage of migration, when those two devices aren't > used, is introduced. However, the overhead should be very small and acceptable. > The benefit is to support future cases where those two devices are used without > modifying the code. > > PATCH[1] add migration last stage indicator > PATCH[2] synchronize the backup bitmap in the last stage of migration > PATCH[3] add helper kvm_dirty_ring_init() to enable dirty ring > PATCH[4] enable dirty ring for arm64 > > v2: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg01342.html > v1: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg00434.html > RFCv1: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg00171.html > > Testing > ======= > (1) kvm-unit-tests/its-pending-migration and kvm-unit-tests/its-migration with > dirty ring or normal dirty page tracking mechanism. All test cases passed. > > QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm \ > ./its-pending-migration > > QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm \ > ./its-migration > > QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm,dirty-ring-size=65536 \ > ./its-pending-migration > > QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm,dirty-ring-size=65536 \ > ./its-migration > > (2) Combinations of migration, post-copy migration, e1000e and virtio-net > devices. All test cases passed. > > -netdev tap,id=net0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown \ > -device e1000e,bus=pcie.5,netdev=net0,mac=52:54:00:f1:26:a0 > > -netdev tap,id=vnet0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown \ > -device virtio-net-pci,bus=pcie.6,netdev=vnet0,mac=52:54:00:f1:26:b0 > > Changelog > ========= > v3: > * Rebase for QEMU v8.1.0 (Gavin) > v2: > * Drop PATCH[v1 1/6] to synchronize linux-headers (Gavin) > * More restrictive comments about struct MemoryListener::log_sync_global (PeterX) > * Always enable the backup bitmap extension (PeterM) > v1: > * Combine two patches into one PATCH[v1 2/6] for the last stage indicator (PeterX) > * Drop the secondary bitmap and use the original one directly (Juan) > * Avoid "goto out" in helper kvm_dirty_ring_init() (Juan) > > Gavin Shan (4): > migration: Add last stage indicator to global dirty log > kvm: Synchronize the backup bitmap in the last stage > kvm: Add helper kvm_dirty_ring_init() > kvm: Enable dirty ring for arm64 > > accel/kvm/kvm-all.c | 108 ++++++++++++++++++++++++++++----------- > include/exec/memory.h | 7 ++- > include/sysemu/kvm_int.h | 1 + > migration/dirtyrate.c | 4 +- > migration/ram.c | 20 ++++---- > softmmu/memory.c | 10 ++-- > 6 files changed, 101 insertions(+), 49 deletions(-) > Could you please help to take a look and queue this series for QEMU v8.1 if it looks good? Peter Maydell has the suggestion [1] to merge the v2 series to QEMU v8.1. there is no difference between v2 and v3 except the fixed rebase conflicts in v3. [1] https://lists.nongnu.org/archive/html/qemu-arm/2023-03/msg00551.html Thanks, Gavin
This series intends to support dirty ring for live migration for arm64. The dirty ring use discrete buffer to track dirty pages. For arm64, the speciality is to use backup bitmap to track dirty pages when there is no-running-vcpu context. It's known that the backup bitmap needs to be synchronized when KVM device "kvm-arm-gicv3" or "arm-its-kvm" has been enabled. The backup bitmap is collected in the last stage of migration. The policy here is to always enable the backup bitmap extension. The overhead to synchronize the backup bitmap in the last stage of migration, when those two devices aren't used, is introduced. However, the overhead should be very small and acceptable. The benefit is to support future cases where those two devices are used without modifying the code. PATCH[1] add migration last stage indicator PATCH[2] synchronize the backup bitmap in the last stage of migration PATCH[3] add helper kvm_dirty_ring_init() to enable dirty ring PATCH[4] enable dirty ring for arm64 v2: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg01342.html v1: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg00434.html RFCv1: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg00171.html Testing ======= (1) kvm-unit-tests/its-pending-migration and kvm-unit-tests/its-migration with dirty ring or normal dirty page tracking mechanism. All test cases passed. QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm \ ./its-pending-migration QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm \ ./its-migration QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm,dirty-ring-size=65536 \ ./its-pending-migration QEMU=./qemu.main/build/qemu-system-aarch64 ACCEL=kvm,dirty-ring-size=65536 \ ./its-migration (2) Combinations of migration, post-copy migration, e1000e and virtio-net devices. All test cases passed. -netdev tap,id=net0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown \ -device e1000e,bus=pcie.5,netdev=net0,mac=52:54:00:f1:26:a0 -netdev tap,id=vnet0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown \ -device virtio-net-pci,bus=pcie.6,netdev=vnet0,mac=52:54:00:f1:26:b0 Changelog ========= v3: * Rebase for QEMU v8.1.0 (Gavin) v2: * Drop PATCH[v1 1/6] to synchronize linux-headers (Gavin) * More restrictive comments about struct MemoryListener::log_sync_global (PeterX) * Always enable the backup bitmap extension (PeterM) v1: * Combine two patches into one PATCH[v1 2/6] for the last stage indicator (PeterX) * Drop the secondary bitmap and use the original one directly (Juan) * Avoid "goto out" in helper kvm_dirty_ring_init() (Juan) Gavin Shan (4): migration: Add last stage indicator to global dirty log kvm: Synchronize the backup bitmap in the last stage kvm: Add helper kvm_dirty_ring_init() kvm: Enable dirty ring for arm64 accel/kvm/kvm-all.c | 108 ++++++++++++++++++++++++++++----------- include/exec/memory.h | 7 ++- include/sysemu/kvm_int.h | 1 + migration/dirtyrate.c | 4 +- migration/ram.c | 20 ++++---- softmmu/memory.c | 10 ++-- 6 files changed, 101 insertions(+), 49 deletions(-)