Re: [PATCH v8 0/8] hw/arm/virt: Introduce cpu topology support

["wangyanan (Y)" <wangyanan55@huawei.com>]

Ping... for review of the newly added ACPI patches.

On 2021/10/14 21:21, Yanan Wang wrote:
> Hi,
>
> This is the latest v8 with update in patch #6 and #8. Now only one
> generic reference file for PPTT is added in tests/data/acpi/virt.
> Machiel and Igor, please help to have a look, thanks!
And sorry for the name typo, definitely should be Michael of course.

Thanks,
Yanan
> 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
>
> Series tested locally on Arm64 machines kunpeng920.
> After booting a Linux guest with "-smp 16,sockets=4,cores=4,threads=1,maxcpus=16",
> through lscpu we will see the information about CPU topology like:
> Architecture:        aarch64
> Byte Order:          Little Endian
> CPU(s):              16
> On-line CPU(s) list: 0-15
> Thread(s) per core:  1
> Core(s) per socket:  4
> Socket(s):           4
> NUMA node(s):        1
> Vendor ID:           0x48
> Model:               0
> Stepping:            0x1
> BogoMIPS:            200.00
> NUMA node0 CPU(s):   0-15
>
> and with "-smp 16" we will see:
> Architecture:        aarch64
> Byte Order:          Little Endian
> CPU(s):              16
> On-line CPU(s) list: 0-15
> Thread(s) per core:  1
> Core(s) per socket:  16
> Socket(s):           1
> NUMA node(s):        1
> Vendor ID:           0x48
> Model:               0
> Stepping:            0x1
> BogoMIPS:            200.00
> NUMA node0 CPU(s):   0-15
>
> Changelog:
> 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-wangyanan55@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-wangyanan55@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          |  86 +++++++++++++++++++++++++++++++++++
>   hw/arm/virt-acpi-build.c     |   8 +++-
>   hw/arm/virt.c                |  71 +++++++++++++++++++++++++----
>   include/hw/acpi/aml-build.h  |   7 +++
>   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, 207 insertions(+), 14 deletions(-)
>   create mode 100644 tests/data/acpi/virt/PPTT
>
> --
> 2.19.1
>
> .