Re: [Qemu-devel] [PATCH for 2.5? 1/1] DSDT: add floppy-related objects

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 14 Dec 2015 18:38:03 +0300
Roman Kagan <rkagan@virtuozzo.com> wrote:

> On Mon, Dec 14, 2015 at 04:05:03PM +0100, Igor Mammedov wrote:
> > On Mon, 14 Dec 2015 11:22:39 +0300
> > "Denis V. Lunev" <den@openvz.org> wrote:
> > 
> > > From: Roman Kagan <rkagan@virtuozzo.com>
> > > 
> > > On x86-based systems Linux determines the presence and the type of
> > > floppy drives via a query of a CMOS field.  So does SeaBIOS when
> > > populating the return data for int 0x13 function 0x08.
> > > 
> > > Windows doesn't; instead, it requests this information from BIOS
> > > via int 0x13/0x08 or through ACPI objects _FDE (Floppy Drive
> > > Enumerate) and _FDI (Floppy Drive Information).  On UEFI systems
> > > only ACPI-based detection is supported.
> > > 
> > > QEMU used not to provide those objects in its DSDT; as a result
> > > floppy drives were invisible to Windows on UEFI/OVMF.
> > > 
> > > This patch implements those objects in ASL, making the ACPI
> > > interpreter query the CMOS field and populate the objects.  The
> > > data values used for _FDI (which, per ACPI spec, is supposed to be
> > > equivalent to BIOS int 0x13/0x08) are taken from SeaBIOS.
> > We are in process of removing static DSDT (ASL template) and
> > replacing it with dynamically generated one.
> > So please do not add new ASL to it, instead of it
> > please redo patch using AML API and it would be better if you
> > do it on top of following series:
> >  "[PATCH 00/74] pc: acpi: convert DSDT to AML API and drop ASL
> > templates support"
> >  http://qemu.patchew.org/series/%3C1449704528-289297-1-git-send-email-imammedo@redhat.com%3E
> 
> Yes we do know about this effort.  However we thought of this patch
> as a bugfix rather than a new feature so we did it against the
> current tree, to make it easy both to merge in the master and to
> backport to the branches so that the distros could pick it up in
> their packages.
> 
> Do I get you right that we should better direct this patch to
> qemu-stable, and cook up a new one on top of your series for master?
You can do just single patch for both trees without dependency on above
series, just put new AML into SSDT as described in comments.

> 
> Roman.