On Mon, Dec 13, 2010 at 10:53:07AM +0200, Avi Kivity wrote:
On 12/13/2010 10:49 AM, Gleb Natapov wrote:
On Mon, Dec 13, 2010 at 10:41:25AM +0200, Avi
On 12/13/2010 02:00 AM, Marcelo Tosatti wrote:
On Sat, Dec 11, 2010 at 09:39:30AM +0200, Avi
> 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
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 already have out own mini pci hot-plug controller at io port 0xae00.
The patch just extends its functionality a bit. Logically this
functionality belongs there.
Well, at least it should be documented.
We could also deprecate the old port and use fwcfg for
(try fwcfg, fall back to ae00).
fwcfg designed to be simple for easy use by firmware. It has two port
one for index another for value, so its use is racy in multi-threaded SMP
environment. DSDT code is executed in such environment. There is lock
facility in AML, but why complicate things.
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.
This is even worse. It requires some fixed address to be shared between
DSDT and Seabios (or alternatively Seabios will have to generate this
part of DSDT dynamically).
Could easily be something in the F segment.
Yes, but then we will have two magic values (fwcfg index + address
in F segment) instead of one (address of pci hot-plug controller).