[SeaBIOS] seabios: acpi: add _RMV control method for PCI devices
Avi Kivity
avi at redhat.com
Mon Dec 13 09:41:25 CET 2010
On 12/13/2010 02:00 AM, Marcelo Tosatti wrote:
> On Sat, Dec 11, 2010 at 09:39:30AM +0200, Avi Kivity wrote:
> > On 12/08/2010 07:08 PM, Marcelo Tosatti wrote:
> > >Use _RMV method to indicate whether device can be removed.
> > >
> > >Data is retrieved from QEMU via I/O port 0xae0c.
> > >
> >
> > Where did this port come from?
>
> Its the next available address after "PCI EJ base", used
> for QEMU<->ACPI hotplug communication.
>
> > What's the protocol?
>
> ACPI reads the 32-bit field indicating the return value of the _RMV
> method (which is used by Windows to decide removability). 1-bit per
> slot.
>
> More ports have to be registered if more buses are added.
>
> > Maybe we should do this via fw_cfg.
>
> I don't see a need for it? (yes, it might be possible, but i'm not
> familiar enough with AML).
To avoid adding tons of undocumented I/O ports, and to allow
discoverability (what happens with a new seabios on old qemu)?
We could do this in two ways: by adding a fwcfg client to the DSDT, or
by copying the information to system memory, and referencing system
memory from the DSDT.
--
error compiling committee.c: too many arguments to function
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