pc-bios/s390-ccw: Scan through all devices if no boot device specified

If no boot device has been specified (via "bootindex=..."), the s390-ccw
bios scans through all devices to find a bootable device. But so far, it
stops at the very first block device (including virtio-scsi controllers
without attached devices) that it finds, no matter whether it is bootable
or not. That leads to some weird situatation where it is e.g. possible
to boot via:

 qemu-system-s390x -hda /path/to/disk.qcow2

but not if there is e.g. a virtio-scsi controller specified before:

 qemu-system-s390x -device virtio-scsi -hda /path/to/disk.qcow2

While using "bootindex=..." is clearly the preferred way of booting
on s390x, we still can make the life for the users at least a little
bit easier if we look at all available devices to find a bootable one.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1846975
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200806105349.632-7-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
This commit is contained in:
Thomas Huth 2020-07-28 16:29:03 +02:00
parent 605751b5a5
commit 869d0e2f59

View File

@ -182,20 +182,8 @@ static void boot_setup(void)
static void find_boot_device(void)
{
VDev *vdev = virtio_get_device();
int ssid;
bool found;
if (!have_iplb) {
for (ssid = 0; ssid < 0x3; ssid++) {
blk_schid.ssid = ssid;
found = find_subch(-1);
if (found) {
return;
}
}
panic("Could not find a suitable boot device (none specified)\n");
}
switch (iplb.pbt) {
case S390_IPL_TYPE_CCW:
debug_print_int("device no. ", iplb.ccw.devno);
@ -261,14 +249,42 @@ static void ipl_boot_device(void)
}
}
/*
* No boot device has been specified, so we have to scan through the
* channels to find one.
*/
static void probe_boot_device(void)
{
int ssid, sch_no, ret;
for (ssid = 0; ssid < 0x3; ssid++) {
blk_schid.ssid = ssid;
for (sch_no = 0; sch_no < 0x10000; sch_no++) {
ret = is_dev_possibly_bootable(-1, sch_no);
if (ret < 0) {
break;
}
if (ret == true) {
ipl_boot_device(); /* Only returns if unsuccessful */
}
}
}
sclp_print("Could not find a suitable boot device (none specified)\n");
}
int main(void)
{
sclp_setup();
css_setup();
boot_setup();
if (have_iplb) {
find_boot_device();
enable_subchannel(blk_schid);
ipl_boot_device();
} else {
probe_boot_device();
}
panic("Failed to load OS from hard disk\n");
return 0; /* make compiler happy */