[SeaBIOS] Re: [QEMU] [PATCH v5 0/8] Add Qemu to SeaBIOS LCHS interface

[Sam Eiderman]

Well, this patch introduces 3 command line parameters (“lcyls”, “lheads”, “lsecs”)
to “scsi-hd” “ide-hd” and “virtio-pci-blk” so this somehow has something to do with
block.

This patch also adds fw_cfg interface to send these parameters to SeaBIOS.

"scripts/get_maintainer.pl -f hw/nvram/fw_cfg.c” gives

"Philippe Mathieu-Daudé" <[e-mail]> (supporter:Firmware configur...)
Laszlo Ersek <[e-mail]> (reviewer:Firmware configur...)
Gerd Hoffmann <[e-mail]> (reviewer:Firmware configur…)

And this was already Reviewed-by Gerd.

How should I proceed?

Sam
> On 17 Jul 2019, at 22:46, Kevin Wolf <[e-mail]> wrote:
>
> Am 17.07.2019 um 21:03 hat Sam Eiderman geschrieben:
> > Gentle ping.
>
> Through which tree is this supposed to go? I feel this is more firmware
> interface related than block layer stuff.
>
> Kevin
> > > On 8 Jul 2019, at 20:30, Sam Eiderman <[e-mail]> wrote:
> > >
> > > Thanks Gerd,
> > >
> > > Gentle ping on this.
> > >
> > > Sam
> > > > On 1 Jul 2019, at 10:41, Gerd Hoffmann <[e-mail]> wrote:
> > > >
> > > > On Wed, Jun 26, 2019 at 03:39:40PM +0300, Sam Eiderman wrote:
> > > > > v1:
> > > > >
> > > > > Non-standard logical geometries break under QEMU.
> > > > >
> > > > > A virtual disk which contains an operating system which depends on
> > > > > logical geometries (consistent values being reported from BIOS INT13
> > > > > AH=08) will most likely break under QEMU/SeaBIOS if it has non-standard
> > > > > logical geometries - for example 56 SPT (sectors per track).
> > > > > No matter what QEMU will guess - SeaBIOS, for large enough disks - will
> > > > > use LBA translation, which will report 63 SPT instead.
> > > > >
> > > > > In addition we can not enforce SeaBIOS to rely on phyiscal geometries at
> > > > > all. A virtio-blk-pci virtual disk with 255 phyiscal heads can not
> > > > > report more than 16 physical heads when moved to an IDE controller, the
> > > > > ATA spec allows a maximum of 16 heads - this is an artifact of
> > > > > virtualization.
> > > > >
> > > > > By supplying the logical geometies directly we are able to support such
> > > > > "exotic" disks.
> > > > >
> > > > > We will use fw_cfg to do just that.
> > > > >
> > > > > v2:
> > > > >
> > > > > Fix missing parenthesis check in
> > > > >  "hd-geo-test: Add tests for lchs override"
> > > > >
> > > > > v3:
> > > > >
> > > > > * Rename fw_cfg key to "bios-geometry".
> > > > > * Remove "extendible" interface.
> > > > > * Add cpu_to_le32 fix as Laszlo suggested or big endian hosts
> > > > > * Fix last qtest commit - automatic docker tester for some reason does not have qemu-img set
> > > > >
> > > > > v4:
> > > > >
> > > > > * Change fw_cfg interface from mixed textual/binary to textual only
> > > > >
> > > > > v5:
> > > > >
> > > > > * Fix line > 80 chars in tests/hd-geo-test.c
> > > >
> > > > Reviewed-by: Gerd Hoffmann <[e-mail]>
> > > >
> > > > cheers,
> > > > Gerd