[Qemu-devel] [PATCH v4 13/15] s390-bios: Use control unit type to determine boot method

[Jason J. Herne]

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 <address@hidden>
---
 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 d3a161c..57a1013 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 5189c0f..f3542cb 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 4cd09eb..e660c7a 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);
 }
 
-- 
2.7.4