File 0096-s390-bios-Use-control-unit-type-to-.patch of Package qemu.20748

From: "Jason J. Herne" <jjherne@linux.ibm.com>
Date: Thu, 4 Apr 2019 10:34:32 -0400
Subject: s390-bios: Use control unit type to determine boot method

The boot method is different depending on which device type we are
booting from. Let's examine the control unit type to determine if we're
a virtio device. We'll eventually add a case to check for a real dasd device
here as well.

Since we have to call enable_subchannel() in main now, might as well
remove that call from virtio.c : run_ccw(). This requires adding some
additional enable_subchannel calls to not break calls to
virtio_is_supported().

Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1554388475-18329-14-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit 3668cb7ce864ee9351d5d20a1ec6b427cd0b3be4)
[LY: BSC#1145379 JIRA-SLE-6132]
Signed-off-by: Liang Yan <lyan@suse.com>
---
 pc-bios/s390-ccw/main.c    | 16 ++++++++++++++--
 pc-bios/s390-ccw/netmain.c |  1 +
 pc-bios/s390-ccw/virtio.c  |  1 -
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index d3a161c68546bfc4b4b5d232c719..57a10138c65dd87b5f585912145b 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -76,6 +76,7 @@ static bool find_subch(int dev_no)
         /* Skip net devices since no IPLB is created and therefore no
          * network bootloader has been loaded
          */
+        enable_subchannel(blk_schid);
         if (virtio_is_supported(blk_schid) &&
             virtio_get_device_type() == VIRTIO_ID_NET && dev_no < 0) {
             continue;
@@ -198,13 +199,24 @@ static void virtio_setup(void)
 
 int main(void)
 {
+    uint16_t cutype;
+
     sclp_setup();
     css_setup();
     boot_setup();
     find_boot_device();
+    enable_subchannel(blk_schid);
 
-    virtio_setup();
-    zipl_load(); /* no return */
+    cutype = cu_type(blk_schid);
+    switch (cutype) {
+    case CU_TYPE_VIRTIO:
+        virtio_setup();
+        zipl_load(); /* no return */
+        break;
+    default:
+        print_int("Attempting to boot from unexpected device type", cutype);
+        panic("");
+    }
 
     panic("Failed to load OS from hard disk\n");
     return 0; /* make compiler happy */
diff --git a/pc-bios/s390-ccw/netmain.c b/pc-bios/s390-ccw/netmain.c
index 5189c0fc39e5eaeff975345a7742..f3542cb2cf118d96248a728a48a8 100644
--- a/pc-bios/s390-ccw/netmain.c
+++ b/pc-bios/s390-ccw/netmain.c
@@ -476,6 +476,7 @@ static bool find_net_dev(Schib *schib, int dev_no)
         if (!schib->pmcw.dnv) {
             continue;
         }
+        enable_subchannel(net_schid);
         if (!virtio_is_supported(net_schid)) {
             continue;
         }
diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index 35278eaee13d1a1f6f36ea3da003..fb40ca982853a8d7ac5afd2f403c 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -102,7 +102,6 @@ static int run_ccw(VDev *vdev, int cmd, void *ptr, int len, bool sli)
         ccw.flags |= CCW_FLAG_SLI;
     }
 
-    enable_subchannel(vdev->schid);
     return do_cio(vdev->schid, vdev->senseid.cu_type, ptr2u32(&ccw), CCW_FMT1);
 }