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

[Jia He]

Hi Xiongfeng

Sorry, I missed your latter mail, you used a emulated SCI interrupt

---
Cheers,
Justin (Jia He)

On 2019/7/4 11:26, Xiongfeng Wang wrote:
> Hi Justin,
>
> On 2019/7/4 11:00, Jia He wrote:
> > 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?
> Yes, my purpose is to implement the vcpu hotplug in arm64 qemu. So that I can add or remove vcpu
> without shutting down the Guest OS.
>
> Thanks,
> Xiongfeng
>
> > 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):
> > >  ÂÂ ACPI / scan: evaluate _STA for processors declared via ASL Device
> > >  ÂÂÂÂ statement
> > >  ÂÂ arm64: mark all the GICC nodes in MADT as possible cpu
> > >  ÂÂ arm64: Add CPU hotplug support
> > >
> > >   arch/arm64/kernel/acpi.c | 22 ++++++++++++++++++++++
> > >  Â arch/arm64/kernel/setup.c | 19 ++++++++++++++++++-
> > >  Â arch/arm64/kernel/smp.cÂÂ | 11 +++++------
> > >  Â drivers/acpi/scan.cÂÂÂÂÂÂ | 12 ++++++++++++
> > >  Â 4 files changed, 57 insertions(+), 7 deletions(-)
> > .
--