Re: [Xen-devel] [PATCH] tools/firmware: remove "_PS0/3" Method

["Hao, Xudong" <xudong.hao@xxxxxxxxx>]

> -----Original Message-----
> From: Ian Campbell [mailto:Ian.Campbell@xxxxxxxxxx]
> Sent: Friday, December 02, 2011 4:48 PM
> To: Hao, Xudong
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Tian, Kevin; Keir Fraser; Shan, Haitao
> Subject: Re: [Xen-devel] [PATCH] tools/firmware: remove "_PS0/3" Method
> 
> On Fri, 2011-12-02 at 08:38 +0000, Hao, Xudong wrote:
> > tools/firmware: remove "_PS0/3" Method
> >
> > Do not expose the ACPI power management "_PS0/3" Method to guest
> > firmware. According to section 3.4 of the APCI specification 4.0, PCI
> > device control the device power through its own specification but not
> > through APCI.
> >
> > Qemu pushes "_PS0/3" to guest will cause a mess between ACPI PM and
> > PCI PM as a result of incorrect ACPI table shipped with the guest
> > BIOS, it may cause a failure of PCI device PM state transition(from
> > PCI_UNKNOWN to PCI_D0).
> 
> How have you tested this and with which guest OSes? Was there a specific
> failure which you observed?
> 
I tested it with SLES11 SP2 guest, where the assigned Kawela VF device can't 
transit state to D0.

> Is this a different fix for the issue fixed by Linux upstream  changeset
> 47e9037ac166 "PCI hotplug: acpiphp: set current_state to D0 in
> register_slot"?

I look at this patch, the acpiphp module set current_state to D0 as your patch. 
However, apciphp is used for PCI device hotplug. 
SELS11 SP2 build acpiphp as a module, my case is static assigning VF to guest 
when guest are creating, loading acpiphp module will workaround this failure, 
but the device static assignment should not be depend on hotplug mechanism.

> 
> Ian.
> 
> >
> > Signed-off-by: Xudong Hao <xudong.hao@xxxxxxxxx>
> > Signed-off-by: Haitao Shan <haitao.shan@xxxxxxxxx>
> >
> > diff -r df7cec2c6c03 tools/firmware/hvmloader/acpi/mk_dsdt.c
> > --- a/tools/firmware/hvmloader/acpi/mk_dsdt.c       Tue Nov 29 13:30:39
> 2011 -0500
> > +++ b/tools/firmware/hvmloader/acpi/mk_dsdt.c       Wed Nov 30 15:08:20
> 2011 +0800
> > @@ -323,8 +323,6 @@
> >       * the ACPI event:
> >       *  _EJ0: eject a device
> >       *  _STA: return a device's status, e.g. enabled or removed
> > -     * Other methods are optional:
> > -     *  _PS0/3: put them here for debug purpose
> >       *
> >       * Eject button would generate a general-purpose event, then the
> >       * control method for this event uses Notify() to inform OSPM which
> @@ -344,13 +342,6 @@
> >              stmt("Name", "_ADR, 0x%08x", ((slot & ~7) << 13) | (slot &
> 7));
> >              /* _SUN == dev */
> >              stmt("Name", "_SUN, 0x%08x", slot >> 3);
> > -            push_block("Method", "_PS0, 0");
> > -            stmt("Store", "0x%02x, \\_GPE.DPT1", slot);
> > -            stmt("Store", "0x80, \\_GPE.DPT2");
> > -            pop_block();
> > -            push_block("Method", "_PS3, 0");
> > -            stmt("Store", "0x%02x, \\_GPE.DPT1", slot);
> > -            stmt("Store", "0x83, \\_GPE.DPT2");
> >              pop_block();
> >              push_block("Method", "_EJ0, 1");
> >              stmt("Store", "0x%02x, \\_GPE.DPT1", slot)
> >
> >
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
> 

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