Re: RE: [PATCH 1/2] Vcpu hotplug: Move ACPI processor from \_PR to \_SB

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 12/02/2010 02:57, "Jiang, Yunhong" <yunhong.jiang@intel.com> wrote:

> However, according to ACPI spec, the _PR is for ACPI1.0 compatible. We have no
> idea which OS is ACPI 1.0 OS. As HeQing found ACPI 1.0 bugs in Win2K, so we
> assume W2K is ACPI 1.0. We test shows W2K guest is ok with the _SB definition
> in our testing. Maybe Win98/WinMe is ACPI 1.0, but we have no image for these
> OS. But yes, that's a main issue for _SB method and we need more consideration
> here.
> 
> In fact, we have internal argue to choose _PR or _SB method before Jinsong's
> initial patch sent out. Later _PR method is chosen because of the ACPI 1.0
> compatible benifit, and kernel 30 version is ok. (IIRC, .32 kernel is not
> released at that time).

Well, that's tricky. 2.6.32 is supposed to be a long-term maintained kernel,
so presumably there will be a 2.6.32.x along in the not-too-far future which
fixes this Linux bug? I feel we're a bit close to the wire to make this
change now.

I'd be a bit more comfortable if we had the cover of lots of other modern
systems putting their processor objects under \_SB, but actually I've never
seen one. Then again I haven't been looking at high-end systems supporting
CPU hotplug and the like.

 -- Keir