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

Glauber Costa
2009-05-17T15:41:58Z

On Sun, May 17, 2009 at 06:21:45PM +0300, Gleb Natapov wrote:
> 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.
I admitedly know almost nothing about windows, but one thing jumped to my eyes:
By looking at the device manager, hidden devices, the "working" cpu seems to be
cpu1, not cpu0. Maybe this is related to this problem?