Re: [PATCH RFC 0/3] Support CPU hotplug for ARM64

[Jia He]

Hi Xiongfeng

It is a little bit awkful that I am also investigating acpi based cpu hotplug 
issue silimar with

your idea. My question is your purpose to implement the vcpu hotplug in arm64 qemu?

Thanks for the ellaboration

---
Cheers,
Justin (Jia He)

On 2019/6/28 19:13, Xiongfeng Wang wrote:
> This patchset mark all the GICC node in MADT as possible CPUs even though it
> is disabled. But only those enabled GICC node are marked as present CPUs.
> So that kernel will initialize some CPU related data structure in advance before
> the CPU is actually hot added into the system. This patchset also implement
> 'acpi_(un)map_cpu()' and 'arch_(un)register_cpu()' for ARM64. These functions are
> needed to enable CPU hotplug.
>
> To support CPU hotplug, we need to add all the possible GICC node in MADT
> including those CPUs that are not present but may be hot added later. Those
> CPUs are marked as disabled in GICC nodes.
>
> Xiongfeng Wang (3):
>    ACPI / scan: evaluate _STA for processors declared via ASL Device
>      statement
>    arm64: mark all the GICC nodes in MADT as possible cpu
>    arm64: Add CPU hotplug support
>
>   arch/arm64/kernel/acpi.c  | 22 ++++++++++++++++++++++
>   arch/arm64/kernel/setup.c | 19 ++++++++++++++++++-
>   arch/arm64/kernel/smp.c   | 11 +++++------
>   drivers/acpi/scan.c       | 12 ++++++++++++
>   4 files changed, 57 insertions(+), 7 deletions(-)