Re: [Qemu-devel] [PATCH 0/4] add ACPI Embedded Controller

[Anthony Liguori <anthony@codemonkey.ws>]

li guang <lig.fnst@cn.fujitsu.com> writes:

> 在 2013-05-24五的 14:45 +0300，Michael S. Tsirkin写道：
>> On Wed, May 22, 2013 at 11:46:33AM +0800, liguang wrote:
>> > These patches try to add ACPI Embedded Controller (EC),
>> > refer-to:
>> > ACPI SPEC v5 chapter 5 
>> > "ACPI Embedded Controller Interface Specification"
>> > 
>> > EC is a standard ACPI device, it plays flexible roles,
>> > e.g. 
>> > power controller, it can control power sequence for
>> > platform to enter or leave system state(0,1,3,4,5),
>> > it can controller CPU fan by the temperature of sensor.
>> > event carrier, it can pass events between platform
>> > and OS, so OS can execute _Qxx method which defined
>> > by yourself.
>> > 
>> > So, I want to deliver CPU online/offline event between
>> > OS and QEMU for CPU hotplug feature, then we will don't
>> > need to "echo 1 > /sys/devices/system/cpu/cpu1/online"
>> > again after 'cpu-add'.
>> > 
>> > patches for online/offline event handler of QEUM and 
>> > linux kernel are writing, and will send once finished.
>> > 
>> > since EC is a common device, so I send pathes separately.
>> 
>> Do any non-linux guests support this device?
>> 
>
> In fact, any OSes support ACPI will support this device.
> so, windows will.

When you say "any OSes supporting ACPI" I think what you really mean is
that we can provide bytecode that interacts with the embedded
controller.

There is not explicit driver in Linux or Windows AFAIK.

I still don't get the point of this.  We can make ACPI hotplug work
without introducing a new device like this.

Regards,

Anthony Liguori