Re: [Qemu-devel] [PATCH 23/27] pc: ACPI BIOS: implement memory hotplug interface

[Igor Mammedov]

On Thu, 21 Nov 2013 11:37:01 +0200
"Michael S. Tsirkin" <address@hidden> wrote:

> On Thu, Nov 21, 2013 at 03:38:44AM +0100, Igor Mammedov wrote:
> > - provides static SSDT object for memory hotplug
> > - SSDT template for memory devices and runtime generator
> >   of them in SSDT table.
> > 
> > Signed-off-by: Vasilis Liaskovitis <address@hidden>
> > Signed-off-by: Igor Mammedov <address@hidden>
> > ---
[...]

> > diff --git a/hw/i386/ssdt-misc.dsl b/hw/i386/ssdt-misc.dsl
> > index a4484b8..b0c581e 100644
> > --- a/hw/i386/ssdt-misc.dsl
> > +++ b/hw/i386/ssdt-misc.dsl
> > @@ -116,4 +116,183 @@ DefinitionBlock ("ssdt-misc.aml", "SSDT", 0x01, 
> > "BXPC", "BXSSDTSUSP", 0x1)
> >              }
> >          }
> >      }
> > +
> > +    External(MTFY, MethodObj)
> > +
> > +    Scope(\_SB) {
> > +        Device(MHPD) {
> > +            Name(_HID, EISAID("PNP0C08"))
> > +
> > +            ACPI_EXTRACT_NAME_WORD_CONST ssdt_mctrl_port
> > +            Name(MHPP, 0xFFFF)
> > +
> > +            ACPI_EXTRACT_NAME_DWORD_CONST ssdt_mctrl_nr_slots
> > +            Name(MDNR, 0x12345678)
> > +
> > +            /* Memory hotplug IO registers */
> > +            OperationRegion(HPMR, SystemIO, MHPP, 24)
> > +
> > +            Method(_CRS, 0, Serialized) {
> > +                Name(CRS, ResourceTemplate() {
> > +                    IO(Decode16, 0x00, 0x00, 0x01, 24, IO)
> > +                })
> 
> 
> Declaring name makes us serialize it.
> Can't we use a local variable?
If that works, I'll change it.

But I have a question of my own perhaps to Paolo or Gerd,
Do we really need this _CRS, because if you look at next hunk
_STA should report not present but functioning to avoid windows BSOD.
So there is not guaranties that OSPM would care or even query it
and honor _CRS provided range.


[...]
> > +
> > +            Method(_STA, 0) {
> > +                If (LEqual(MDNR, Zero)) {
> > +                    Return(0x0)
> > +                }
> > +                /* Leave bit 0 cleared to avoid Windows BSOD */
> > +                Return(0xA)
> > +            }
[...]