qemu-kvm/SOURCES/kvm-pc-bios-s390-ccw-virtio-blkdev-Simplify-fix-virtio_i.patch

From f09f2f12133073d6ccab3b2bd95717d435adc442 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Fri, 8 Jul 2022 12:29:50 +0200
Subject: [PATCH 31/37] pc-bios/s390-ccw/virtio-blkdev: Simplify/fix
 virtio_ipl_disk_is_valid()

RH-Author: Thomas Huth <thuth@redhat.com>
RH-MergeRequest: 198: pc-bios/s390-ccw: Fix boot from disks with 4k sectors that do not have the typical DASD geometry
RH-Commit: [3/9] ca0b836a417ce5bbd26e489551f573d6b2fc9e94
RH-Bugzilla: 2098076
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

Bugzilla: http://bugzilla.redhat.com/2098076

commit bbf615f7b707f009ef8e757d170902ad33b90644
Author: Thomas Huth <thuth@redhat.com>
Date:   Mon Jul 4 13:18:55 2022 +0200

    pc-bios/s390-ccw/virtio-blkdev: Simplify/fix virtio_ipl_disk_is_valid()

    The s390-ccw bios fails to boot if the boot disk is a virtio-blk
    disk with a sector size of 4096. For example:

     dasdfmt -b 4096 -d cdl -y -p -M quick /dev/dasdX
     fdasd -a /dev/dasdX
     install a guest onto /dev/dasdX1 using virtio-blk
     qemu-system-s390x -nographic -hda /dev/dasdX1

    The bios then bails out with:

     ! Cannot read block 0 !

    Looking at virtio_ipl_disk_is_valid() and especially the function
    virtio_disk_is_scsi(), it does not really make sense that we expect
    only such a limited disk geometry (like a block size of 512) for
    our boot disks. Let's relax the check and allow everything that
    remotely looks like a sane disk.

    Message-Id: <20220704111903.62400-5-thuth@redhat.com>
    Reviewed-by: Eric Farman <farman@linux.ibm.com>
    Signed-off-by: Thomas Huth <thuth@redhat.com>

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 pc-bios/s390-ccw/virtio-blkdev.c | 41 ++++++--------------------------
 pc-bios/s390-ccw/virtio.h        |  2 --
 2 files changed, 7 insertions(+), 36 deletions(-)

diff --git a/pc-bios/s390-ccw/virtio-blkdev.c b/pc-bios/s390-ccw/virtio-blkdev.c
index 6483307630..7e13155589 100644
--- a/pc-bios/s390-ccw/virtio-blkdev.c
+++ b/pc-bios/s390-ccw/virtio-blkdev.c
@@ -166,46 +166,19 @@ void virtio_assume_eckd(void)
         virtio_eckd_sectors_for_block_size(vdev->config.blk.blk_size);
 }
 
-bool virtio_disk_is_scsi(void)
-{
-    VDev *vdev = virtio_get_device();
-
-    if (vdev->guessed_disk_nature == VIRTIO_GDN_SCSI) {
-        return true;
-    }
-    switch (vdev->senseid.cu_model) {
-    case VIRTIO_ID_BLOCK:
-        return (vdev->config.blk.geometry.heads == 255)
-            && (vdev->config.blk.geometry.sectors == 63)
-            && (virtio_get_block_size()  == VIRTIO_SCSI_BLOCK_SIZE);
-    case VIRTIO_ID_SCSI:
-        return true;
-    }
-    return false;
-}
-
-bool virtio_disk_is_eckd(void)
+bool virtio_ipl_disk_is_valid(void)
 {
+    int blksize = virtio_get_block_size();
     VDev *vdev = virtio_get_device();
-    const int block_size = virtio_get_block_size();
 
-    if (vdev->guessed_disk_nature == VIRTIO_GDN_DASD) {
+    if (vdev->guessed_disk_nature == VIRTIO_GDN_SCSI ||
+        vdev->guessed_disk_nature == VIRTIO_GDN_DASD) {
         return true;
     }
-    switch (vdev->senseid.cu_model) {
-    case VIRTIO_ID_BLOCK:
-        return (vdev->config.blk.geometry.heads == 15)
-            && (vdev->config.blk.geometry.sectors ==
-                virtio_eckd_sectors_for_block_size(block_size));
-    case VIRTIO_ID_SCSI:
-        return false;
-    }
-    return false;
-}
 
-bool virtio_ipl_disk_is_valid(void)
-{
-    return virtio_disk_is_scsi() || virtio_disk_is_eckd();
+    return (vdev->senseid.cu_model == VIRTIO_ID_BLOCK ||
+            vdev->senseid.cu_model == VIRTIO_ID_SCSI) &&
+           blksize >= 512 && blksize <= 4096;
 }
 
 int virtio_get_block_size(void)
diff --git a/pc-bios/s390-ccw/virtio.h b/pc-bios/s390-ccw/virtio.h
index 9e410bde6f..241730effe 100644
--- a/pc-bios/s390-ccw/virtio.h
+++ b/pc-bios/s390-ccw/virtio.h
@@ -186,8 +186,6 @@ void virtio_assume_scsi(void);
 void virtio_assume_eckd(void);
 void virtio_assume_iso9660(void);
 
-extern bool virtio_disk_is_scsi(void);
-extern bool virtio_disk_is_eckd(void);
 extern bool virtio_ipl_disk_is_valid(void);
 extern int virtio_get_block_size(void);
 extern uint8_t virtio_get_heads(void);
-- 
2.35.3