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): >> 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(-) >> > > . >