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authorLev Kujawski <lkujaw@member.fsf.org>2022-07-07 20:40:45 +0000
committerKevin Wolf <kwolf@redhat.com>2022-08-02 11:21:56 +0200
commitfd8a68ad6823d33bedeba20a22857867a1c3890e (patch)
treeb7747836a0c83d0e9575ca2ce58b48621c81a069 /hw/block
parent630179b7f7d147ee0f7d396e71775b60a16f46a1 (diff)
hw/block/hd-geometry: Do not override specified bios-chs-trans
For small disk images (<4 GiB), QEMU and SeaBIOS default to the LARGE/ECHS disk translation method, but it is not uncommon for other BIOS software to use LBA in these cases as well. Some operating system boot loaders (e.g., NT 4) do not handle LARGE translations outside of fixed configurations. See, e.g., Q154052: "When starting an x86 based computer, Ntdetect.com retrieves and stores Interrupt 13 information. . . If the disk controller is using a 32 sector/64 head translation scheme, this boundary will be 1 GB. If the controller uses 63 sector/255 head translation [AUTHOR: i.e., LBA], the limit will be 4 GB." To accommodate these situations, hd_geometry_guess() now follows the disk translation specified by the user even when the ATA disk geometry is guessed. hd_geometry_guess(): * Only set the disk translation when translation is AUTO. * Show the soon-to-be active translation (*ptrans) in the trace rather than what was guessed. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/56 Buglink: https://bugs.launchpad.net/qemu/+bug/1745312 Signed-off-by: Lev Kujawski <lkujaw@member.fsf.org> Message-Id: <20220707204045.999544-1-lkujaw@member.fsf.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/block')
-rw-r--r--hw/block/hd-geometry.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/hw/block/hd-geometry.c b/hw/block/hd-geometry.c
index 112094358e..dae13ab14d 100644
--- a/hw/block/hd-geometry.c
+++ b/hw/block/hd-geometry.c
@@ -150,7 +150,12 @@ void hd_geometry_guess(BlockBackend *blk,
translation = BIOS_ATA_TRANSLATION_NONE;
}
if (ptrans) {
- *ptrans = translation;
+ if (*ptrans == BIOS_ATA_TRANSLATION_AUTO) {
+ *ptrans = translation;
+ } else {
+ /* Defer to the translation specified by the user. */
+ translation = *ptrans;
+ }
}
trace_hd_geometry_guess(blk, *pcyls, *pheads, *psecs, translation);
}