|
 |
1be5c7 |
From 8433b2ba40d0618c7086da87685e1c51b6da3b11 Mon Sep 17 00:00:00 2001
|
|
|
1be5c7 |
From: Thomas Huth <thuth@redhat.com>
|
|
|
1be5c7 |
Date: Fri, 8 Jul 2022 12:29:50 +0200
|
|
|
1be5c7 |
Subject: [PATCH 30/37] pc-bios/s390-ccw/bootmap: Improve the guessing logic in
|
|
|
1be5c7 |
zipl_load_vblk()
|
|
|
1be5c7 |
|
|
|
1be5c7 |
RH-Author: Thomas Huth <thuth@redhat.com>
|
|
|
1be5c7 |
RH-MergeRequest: 198: pc-bios/s390-ccw: Fix boot from disks with 4k sectors that do not have the typical DASD geometry
|
|
|
1be5c7 |
RH-Commit: [2/9] db1d2e7929352bec0e1a5d4cf3fb385bbe02304b
|
|
|
1be5c7 |
RH-Bugzilla: 2098076
|
|
|
1be5c7 |
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
1be5c7 |
RH-Acked-by: David Hildenbrand <david@redhat.com>
|
|
|
1be5c7 |
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
|
|
|
1be5c7 |
|
|
|
1be5c7 |
Bugzilla: http://bugzilla.redhat.com/2098076
|
|
|
1be5c7 |
|
|
|
1be5c7 |
commit 422865f6672ee1482b98d18321b55c1ecfb06c82
|
|
|
1be5c7 |
Author: Thomas Huth <thuth@redhat.com>
|
|
|
1be5c7 |
Date: Mon Jul 4 13:18:54 2022 +0200
|
|
|
1be5c7 |
|
|
|
1be5c7 |
pc-bios/s390-ccw/bootmap: Improve the guessing logic in zipl_load_vblk()
|
|
|
1be5c7 |
|
|
|
1be5c7 |
The logic of trying an final ISO or ECKD boot on virtio-block devices is
|
|
|
1be5c7 |
very weird: Since the geometry hardly ever matches in virtio_disk_is_scsi(),
|
|
|
1be5c7 |
virtio_blk_setup_device() always sets a "guessed" disk geometry via
|
|
|
1be5c7 |
virtio_assume_scsi() (which is certainly also wrong in a lot of cases).
|
|
|
1be5c7 |
|
|
|
1be5c7 |
zipl_load_vblk() then sees that there's been a "virtio_guessed_disk_nature"
|
|
|
1be5c7 |
and tries to fix up the geometry again via virtio_assume_iso9660() before
|
|
|
1be5c7 |
always trying to do ipl_iso_el_torito(). That's a very brain-twisting
|
|
|
1be5c7 |
way of attempting to boot from ISO images, which won't work anymore after
|
|
|
1be5c7 |
the following patches that will clean up the virtio_assume_scsi() mess
|
|
|
1be5c7 |
(and thus get rid of the "virtio_guessed_disk_nature" here).
|
|
|
1be5c7 |
|
|
|
1be5c7 |
Let's try a better approach instead: ISO files always have a magic
|
|
|
1be5c7 |
string "CD001" at offset 0x8001 (see e.g. the ECMA-119 specification)
|
|
|
1be5c7 |
which we can use to decide whether we should try to boot in ISO 9660
|
|
|
1be5c7 |
mode (which we should also try if we see a sector size of 2048).
|
|
|
1be5c7 |
|
|
|
1be5c7 |
And if we were not able to boot in ISO mode here, the final boot attempt
|
|
|
1be5c7 |
before panicking is to boot in ECKD mode. Since this is our last boot
|
|
|
1be5c7 |
attempt anyway, simply always assume the ECKD geometry here (if the sector
|
|
|
1be5c7 |
size was not 4096 yet), so that we also do not depend on the guessed disk
|
|
|
1be5c7 |
geometry from virtio_blk_setup_device() here anymore.
|
|
|
1be5c7 |
|
|
|
1be5c7 |
Message-Id: <20220704111903.62400-4-thuth@redhat.com>
|
|
|
1be5c7 |
Signed-off-by: Thomas Huth <thuth@redhat.com>
|
|
|
1be5c7 |
|
|
|
1be5c7 |
Signed-off-by: Thomas Huth <thuth@redhat.com>
|
|
|
1be5c7 |
---
|
|
|
1be5c7 |
pc-bios/s390-ccw/bootmap.c | 27 +++++++++++++++++++++++----
|
|
|
1be5c7 |
1 file changed, 23 insertions(+), 4 deletions(-)
|
|
|
1be5c7 |
|
|
|
1be5c7 |
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
|
|
|
1be5c7 |
index 56411ab3b6..994e59c0b0 100644
|
|
|
1be5c7 |
--- a/pc-bios/s390-ccw/bootmap.c
|
|
|
1be5c7 |
+++ b/pc-bios/s390-ccw/bootmap.c
|
|
|
1be5c7 |
@@ -780,18 +780,37 @@ static void ipl_iso_el_torito(void)
|
|
|
1be5c7 |
}
|
|
|
1be5c7 |
}
|
|
|
1be5c7 |
|
|
|
1be5c7 |
+/**
|
|
|
1be5c7 |
+ * Detect whether we're trying to boot from an .ISO image.
|
|
|
1be5c7 |
+ * These always have a signature string "CD001" at offset 0x8001.
|
|
|
1be5c7 |
+ */
|
|
|
1be5c7 |
+static bool has_iso_signature(void)
|
|
|
1be5c7 |
+{
|
|
|
1be5c7 |
+ int blksize = virtio_get_block_size();
|
|
|
1be5c7 |
+
|
|
|
1be5c7 |
+ if (!blksize || virtio_read(0x8000 / blksize, sec)) {
|
|
|
1be5c7 |
+ return false;
|
|
|
1be5c7 |
+ }
|
|
|
1be5c7 |
+
|
|
|
1be5c7 |
+ return !memcmp("CD001", &sec[1], 5);
|
|
|
1be5c7 |
+}
|
|
|
1be5c7 |
+
|
|
|
1be5c7 |
/***********************************************************************
|
|
|
1be5c7 |
* Bus specific IPL sequences
|
|
|
1be5c7 |
*/
|
|
|
1be5c7 |
|
|
|
1be5c7 |
static void zipl_load_vblk(void)
|
|
|
1be5c7 |
{
|
|
|
1be5c7 |
- if (virtio_guessed_disk_nature()) {
|
|
|
1be5c7 |
- virtio_assume_iso9660();
|
|
|
1be5c7 |
+ int blksize = virtio_get_block_size();
|
|
|
1be5c7 |
+
|
|
|
1be5c7 |
+ if (blksize == VIRTIO_ISO_BLOCK_SIZE || has_iso_signature()) {
|
|
|
1be5c7 |
+ if (blksize != VIRTIO_ISO_BLOCK_SIZE) {
|
|
|
1be5c7 |
+ virtio_assume_iso9660();
|
|
|
1be5c7 |
+ }
|
|
|
1be5c7 |
+ ipl_iso_el_torito();
|
|
|
1be5c7 |
}
|
|
|
1be5c7 |
- ipl_iso_el_torito();
|
|
|
1be5c7 |
|
|
|
1be5c7 |
- if (virtio_guessed_disk_nature()) {
|
|
|
1be5c7 |
+ if (blksize != VIRTIO_DASD_DEFAULT_BLOCK_SIZE) {
|
|
|
1be5c7 |
sclp_print("Using guessed DASD geometry.\n");
|
|
|
1be5c7 |
virtio_assume_eckd();
|
|
|
1be5c7 |
}
|
|
|
1be5c7 |
--
|
|
|
1be5c7 |
2.35.3
|
|
|
1be5c7 |
|