From cdc1df196d9e1cf5e6f6fe2900637b78d606ee85 Mon Sep 17 00:00:00 2001

From: Thomas Huth <thuth@redhat.com>

Date: Mon, 14 Oct 2019 10:06:45 +0100

Subject: [PATCH 20/21] s390-bios: Use control unit type to find bootable

 devices

RH-Author: Thomas Huth <thuth@redhat.com>

Message-id: <20191014100645.22862-18-thuth@redhat.com>

Patchwork-id: 91790

O-Subject: [RHEL-8.2.0 qemu-kvm PATCH v2 17/17] s390-bios: Use control unit type to find bootable devices

Bugzilla: 1664376

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: David Hildenbrand <david@redhat.com>

RH-Acked-by: Jens Freimann <jfreimann@redhat.com>

From: "Jason J. Herne" <jjherne@linux.ibm.com>

When the user does not specify which device to boot from then we end

up guessing. Instead of simply grabbing the first available device let's

be a little bit smarter and only choose devices that might be bootable

like disk, and not console devices.

Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>

Message-Id: <1554388475-18329-17-git-send-email-jjherne@linux.ibm.com>

[thuth: Added fix for virtio_is_supported() not being called anymore]

Signed-off-by: Thomas Huth <thuth@redhat.com>

(cherry picked from commit 2880469c95e42f8a5b0acbe8c4808255cc6c9e5b)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 pc-bios/s390-ccw/main.c | 45 +++++++++++++++++++++++++++++++++++----------

 1 file changed, 35 insertions(+), 10 deletions(-)

diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c

index 3c449ad..a69c733 100644

--- a/pc-bios/s390-ccw/main.c

+++ b/pc-bios/s390-ccw/main.c

@@ -21,6 +21,7 @@ static char loadparm_str[LOADPARM_LEN + 1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };

 QemuIplParameters qipl;

 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));

 static bool have_iplb;

+static uint16_t cutype;

 LowCore const *lowcore; /* Yes, this *is* a pointer to address 0 */

 #define LOADPARM_PROMPT "PROMPT  "

@@ -58,11 +59,15 @@ unsigned int get_loadparm_index(void)

  * subchannel information block (schib) with the connected subchannel's info.

  * NOTE: The global variable blk_schid is updated to contain the subchannel

  * information.

+ *

+ * If the caller gives dev_no=-1 then the user did not specify a boot device.

+ * In this case we'll just use the first potentially bootable device we find.

  */

 static bool find_subch(int dev_no)

 {

     Schib schib;

     int i, r;

+    bool is_virtio;

     for (i = 0; i < 0x10000; i++) {

         blk_schid.sch_no = i;

@@ -74,16 +79,39 @@ static bool find_subch(int dev_no)

             continue;

         }

-        /* 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;

+        cutype = cu_type(blk_schid);

+

+        /*

+         * Note: we always have to run virtio_is_supported() here to make

+         * sure that the vdev.senseid data gets pre-initialized correctly

+         */

+        is_virtio = virtio_is_supported(blk_schid);

+

+        /* No specific devno given, just return 1st possibly bootable device */

+        if (dev_no < 0) {

+            switch (cutype) {

+            case CU_TYPE_VIRTIO:

+                if (is_virtio) {

+                    /*

+                     * Skip net devices since no IPLB is created and therefore

+                     * no network bootloader has been loaded

+                     */

+                    if (virtio_get_device_type() != VIRTIO_ID_NET) {

+                        return true;

+                    }

+                }

+                continue;

+            case CU_TYPE_DASD_3990:

+            case CU_TYPE_DASD_2107:

+                return true;

+            default:

+                continue;

+            }

         }

-        if ((dev_no < 0) || (schib.pmcw.dev == dev_no)) {

+        /* Caller asked for a specific devno */

+        if (schib.pmcw.dev == dev_no) {

             return true;

         }

     }

@@ -200,15 +228,12 @@ static void virtio_setup(void)

 int main(void)

 {

-    uint16_t cutype;

-

     sclp_setup();

     css_setup();

     boot_setup();

     find_boot_device();

     enable_subchannel(blk_schid);

-    cutype = cu_type(blk_schid);

     switch (cutype) {

     case CU_TYPE_DASD_3990:

     case CU_TYPE_DASD_2107:

-- 

1.8.3.1