
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" <philmd@redhat.com> (supporter:Firmware configur...) Laszlo Ersek <lersek@redhat.com> (reviewer:Firmware configur...) Gerd Hoffmann <kraxel@redhat.com> (reviewer:Firmware configur…) And this was already Reviewed-by Gerd. How should I proceed? Sam
On 17 Jul 2019, at 22:46, Kevin Wolf <kwolf@redhat.com> 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 <shmuel.eiderman@oracle.com> wrote:
Thanks Gerd,
Gentle ping on this.
Sam
On 1 Jul 2019, at 10:41, Gerd Hoffmann <kraxel@redhat.com> 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 <kraxel@redhat.com>
cheers, Gerd