Re: [PATCH] Set bit 1 in disabled processor's _STA

Gleb Natapov
2009-05-17T15:21:46Z

On Sun, May 17, 2009 at 12:06:22PM -0300, Glauber Costa wrote:
> On Sun, May 17, 2009 at 05:30:06PM +0300, Gleb Natapov wrote:
> > On Sun, May 17, 2009 at 10:27:41AM -0300, Glauber Costa wrote:
> > > On Sun, May 17, 2009 at 11:23:47AM +0300, Gleb Natapov wrote:
> > > > On Fri, May 15, 2009 at 08:14:43AM -0400, Glauber Costa wrote:
> > > > > This patch sets bits 1 in disabled processor's _STA.
> > > > > According to the ACPI spec, this bit means:
> > > > > "Set if the device is enabled and decoding its resources."
> > > > >
> > > > > Without it, Windows 2008 device manager shows the processors
> > > > > as malfunctioning hardware.
> > > > >
> > > > If you uncheck "show hidden devices" option in View menu of the
> > > > device manager you should see only enabled CPUs (bit 2 of _STA).
> > > Yes, that is what happens. But then, by checking "show hidden devices",
> > > the disabled processor appears, but are listed as malfunctioning.
> > >
> > > Because of this, SVVP tests break without this patch.
> > >
> > What kind of error?
> Message 4/15/2009 4:07:04.635 AM Checking Intel Processor
> Error 4/15/2009 4:07:04.635 AM ERROR: Device (QEMU Virtual CPU version 0.9.1)
> is not currently enabled, or has some problem
> File: Line: 0
> Error Type: BOOL
> Error Code: 0x1
> Error Text: Error 0x00000001
>
> Alternatively, if you go to the device manager, and "Show hidden processors",
> you'll see the processors appear, but marked with a "!". Clicking into details,
> there is a message saying that the device is malfunctioning.
>
> >
> > > > This patch breaks resume from hibernate on windows 2008/vista.
> > > Oh god... do you have any idea why?
> > >
> > > which bits should we set for everything to work?
> > Bit 1 should not be set :) What I think is happening windows finds more
> > CPUs on resume then it had before hibernate.
>
> It does not make sense to me at first. resume should not be a much different
> use case than plain boot. If it does the right thing on bootup, why would it
> mess up in case of resume?
I wish I had an answer to this. It may be a bug. On boot windows calculates
number of processors from madt tables, but on resume it does the same
by executing _STA method of each defined CPU.

--
Gleb.