Re: [Qemu-devel] [PATCH v2 0/8] Add system_powerdown support on ARM for ACPI and DT

[Wei Huang]

On 10/29/2015 09:27 AM, Shannon Zhao wrote:
> ACPI SPEC 5.0 defines GPIO-signaled ACPI Events for Hardware-reduced
> platforms(like ARM). It uses GPIO pin to trigger an event to the guest.
> For QEMU, here we add PL061 GPIO controller and use PIN 3 for
> system_powerdown, reserving PIN 0, 1, 2 for PCI hotplug, CPU hotplug and
> memory hotplug.
> 
> This patchset adds system_powerdown support on ARM through both ACPI and
> DT ways. It adds a GPIO controller(here is PL061) in machine virt and
> uses GPIO-singled event for ACPI while gpio-keys for DT. It can be
> fetched from [1] and has been tested for the guests starting by ACPI or
> DT while guests use systemd or acpid.
> 
> a) ACPI way. Since Graeme send a patchset to make ACPI on ARM64 support
> amba device[2], it could use PL061 directly without modification to its
> kernel driver code. In addition, we should use ACPI to start VM,
> referring to below script. QEMU_EFI.fd can be fetched from [3]. 

Hi Shannon,

Thanks for re-sending it. This is a desired feature because we don't
want to rely on tricks (such as guest-agent) for external VM power
management. I have tested V1 recently by back-porting to my in-house
kernel; it worked well.

I will help review this new version.

Thanks,
-Wei

> 
>     qemu-system-aarch64 \
>     -smp 1 -m 1024 -M virt \
>     -cpu cortex-a57 -nographic \
>     -monitor telnet::4444,server,nowait \
>     -bios QEMU_EFI.fd \
>     -kernel Image \
>     -initrd guestfs.cpio.gz \
>     -append "rdinit=/sbin/init console=ttyAMA0 mem=512M root=/dev/ram 
> earlycon=pl011,0x9000000 rw acpi=force"
> 
> b) DT way. Start vm as usual.
> 
>     qemu-system-aarch64 \
>     -smp 1 -m 1024 -M virt \
>     -cpu cortex-a57 -nographic \
>     -monitor telnet::4444,server,nowait \
>     -kernel Image \
>     -initrd guestfs.cpio.gz \
>     -append "rdinit=/sbin/init console=ttyAMA0 mem=512M root=/dev/ram 
> earlycon=pl011,0x9000000 rw"
> 
> Guest internal setup:
> If your guest FS uses systemd, you should check file
> /lib/udev/rules.d/70-power-switch.rules and add the following line in it
> if it doesn't exist.
> 
> SUBSYSTEM=="input", KERNEL=="event*", SUBSYSTEMS=="platform",
> ATTRS{keys}=="116", TAG+="power-switch"
> 
> If your guest FS uses acpid, you should check it has
> /etc/acpi/powerbtn.sh and /etc/acpi/events/powerbtn. Refer to [4] for
> the setup of acpid.
> 
> Thanks,
> Shannon
> 
> [1] 
> https://git.linaro.org/people/shannon.zhao/qemu.git/shortlog/refs/heads/PowerButton_v2
> [2] https://lkml.org/lkml/2015/9/30/392
> [3] http://people.linaro.org/~shannon.zhao/ACPI_ARM/QEMU_EFI.fd
> [4] https://wiki.linaro.org/LEG/Engineering/Kernel/ACPI/GPIOPowerButton
> 
> Changes since v1:
> * rewrite GPIO Connection Descriptor (Michael)
> 
> Shannon Zhao (8):
>   hw/arm/virt: Add a GPIO controller
>   hw/arm/virt-acpi-build: Add GPIO controller in ACPI DSDT table
>   hw/arm/virt-acpi-build: Add power button device in ACPI DSDT table
>   hw/acpi/aml-build: Add GPIO Connection Descriptor
>   hw/acpi/aml-build: Add a wrapper for GPIO Interrupt Connection
>   hw/arm/virt-acpi-build: Add _E03 for Power Button
>   hw/arm/virt: Add QEMU powerdown notifier and hook it to GPIO Pin 3
>   hw/arm/virt: Add gpio-keys node for Poweroff using DT
> 
>  hw/acpi/aml-build.c         | 79 
> +++++++++++++++++++++++++++++++++++++++++++++
>  hw/arm/virt-acpi-build.c    | 45 ++++++++++++++++++++++++++
>  hw/arm/virt.c               | 60 ++++++++++++++++++++++++++++++++++
>  include/hw/acpi/aml-build.h | 26 +++++++++++++++
>  include/hw/arm/virt.h       |  1 +
>  5 files changed, 211 insertions(+)
>