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aea60a13b9
Using fw_cfg, supply logical CHS values directly from QEMU to the BIOS. 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 report - SeaBIOS, for large enough disks - will use LBA translation, which will report 63 SPT instead. In addition we cannot force SeaBIOS to rely on physical geometries at all. A virtio-blk-pci virtual disk with 255 phyiscal heads cannot report more than 16 physical heads when moved to an IDE controller, since the ATA spec allows a maximum of 16 heads - this is an artifact of virtualization. By supplying the logical geometries directly we are able to support such "exotic" disks. We serialize this information in a similar way to the "bootorder" interface. The new fw_cfg entry is "bios-geometry". Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com> Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Sam Eiderman <shmuel.eiderman@oracle.com> Signed-off-by: Sam Eiderman <sameid@google.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> |
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| .. | ||
| authz | ||
| block | ||
| chardev | ||
| crypto | ||
| disas | ||
| exec | ||
| fpu | ||
| hw | ||
| io | ||
| libdecnumber | ||
| migration | ||
| monitor | ||
| net | ||
| qapi | ||
| qemu | ||
| qom | ||
| scsi | ||
| standard-headers | ||
| sysemu | ||
| ui | ||
| user | ||
| elf.h | ||
| glib-compat.h | ||
| qemu-common.h | ||
| qemu-io.h | ||
| trace-tcg.h | ||