Hi, This is the latest v9 series which supports exposing vCPU topology to the guest for Arm virt machines.
Description of this series: Once the view of an accurate virtual cpu topology is provided to guest, with a well-designed vCPU pinning to the pCPU we may get a huge benefit, e.g., the scheduling performance improvement. See Dario Faggioli's research and the related performance tests in [1] for reference. This patch series introduces cpu topology support for Arm platform. Both cpu-map in DT and ACPI PPTT table are introduced to store the topology information. And we only describe the topology information to 6.2 and newer virt machines, considering compatibility. [1] https://kvmforum2020.sched.com/event/eE1y/virtual-topology-for-virtual-machines -friend-or-foe-dario-faggioli-suse Changelog: v8->v9: - add Eric's R-bs, thanks! - address Eric's suggestions to update some function comments and commit msg (patch #5) - make build_processor_hierarchy_node static as it's only used by build_pptt (patch #4) - retested. - v8: https://lore.kernel.org/qemu-devel/20211014132206.19220-1-wangyana...@huawei.com/ v7->v8: - rebased on top of master (commit e5b2333f24) - only add one generic expected file for PPTT instead of four, which works fine enough for now (patch #6 and #8 updated) - v7: https://lore.kernel.org/qemu-devel/20211007030746.10420-1-wangyana...@huawei.com/ v6->v7: - rebased on top of master (commit ca61fa4b80) - use newly introduced acpi_table_begin/acpi_table_end APIs to build PPTT (patch #5 updated) - add reference files for PPTT to fix broken bios-table-test for Aarch64 virt machine (patch #6-#8 added) - v6: https://lore.kernel.org/qemu-devel/20210824122016.144364-1-wangyana...@huawei.com/ Andrew Jones (2): hw/arm/virt: Add cpu-map to device tree hw/acpi/aml-build: Add PPTT table Yanan Wang (6): hw/arm/virt: Only describe cpu topology since virt-6.2 device_tree: Add qemu_fdt_add_path hw/acpi/aml-build: Add Processor hierarchy node structure tests/data/acpi/virt: Add an empty expected file for PPTT hw/arm/virt-acpi-build: Generate PPTT table tests/data/acpi/virt: Update the empty expected file for PPTT hw/acpi/aml-build.c | 89 +++++++++++++++++++++++++++++++++++ hw/arm/virt-acpi-build.c | 8 +++- hw/arm/virt.c | 71 ++++++++++++++++++++++++---- include/hw/acpi/aml-build.h | 3 ++ include/hw/arm/virt.h | 4 +- include/sysemu/device_tree.h | 1 + softmmu/device_tree.c | 44 ++++++++++++++++- tests/data/acpi/virt/PPTT | Bin 0 -> 76 bytes 8 files changed, 206 insertions(+), 14 deletions(-) create mode 100644 tests/data/acpi/virt/PPTT -- 2.19.1
