[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] About hotplug multifunction

From: Michael S. Tsirkin
Subject: Re: [Qemu-devel] About hotplug multifunction
Date: Sun, 11 Sep 2011 12:23:57 +0300
User-agent: Mutt/1.5.21 (2010-09-15)

On Fri, Sep 09, 2011 at 03:34:26PM -0300, Marcelo Tosatti wrote:
> > > something I noted when readin our acpi code:
> > > we currently pass eject request for function 0 only:
> > >                Name (_ADR, nr##0000)
> > > We either need a device per function there (acpi 1.0),
> > > send eject request for them all, or use ffff
> > > as function number (newer acpi, not sure which version).
> > > Need to see which guests (windows,linux) can handle which form.
> > 
> > I'd guess we need to change that to ffff.
> No need, only make sure function 0 is there and all other functions
> should be removed automatically by the guest on eject notification.

Hmm, the ACPI spec explicitly says:

High word = Device #, Low word = Function #.
(e.g., device 3, function 2 is 0x00030002). To refer
to all the functions on a device #, use a function
number of FFFF).

> ACPI PCI hotplug is based on slots, not on functions. It does not
> support addition/removal of individual functions.

Interesting. Is this just based on general logic,
reading of the linux driver or the ACPI spec?

The ACPI spec itself seems pretty vague. All tables
list devices, where each device has an _ADR entry,
which is built up of PCI device # and function #.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]