[PATCH v5 06/15] pc-bios/s390-ccw: Split virtio-ccw and generic virtio

[jrossi@linux.ibm.com]

From: Jared Rossi <jrossi@linux.ibm.com>

Separate the CCW specific virtio routines and create generic wrappers for easier
reuse of existing virtio functions with non-CCW devices.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
---
 pc-bios/s390-ccw/Makefile        |   3 +-
 pc-bios/s390-ccw/main.c          |   8 +-
 pc-bios/s390-ccw/netmain.c       |   2 +-
 pc-bios/s390-ccw/s390-ccw.h      |   3 -
 pc-bios/s390-ccw/virtio-blkdev.c |  15 +-
 pc-bios/s390-ccw/virtio-ccw.c    | 241 +++++++++++++++++++++++++++++++
 pc-bios/s390-ccw/virtio-ccw.h    |  24 +++
 pc-bios/s390-ccw/virtio-net.c    |   3 +-
 pc-bios/s390-ccw/virtio-scsi.c   |   8 +-
 pc-bios/s390-ccw/virtio-scsi.h   |   2 +-
 pc-bios/s390-ccw/virtio.c        | 239 +++++-------------------------
 pc-bios/s390-ccw/virtio.h        |   5 +-
 12 files changed, 332 insertions(+), 221 deletions(-)
 create mode 100644 pc-bios/s390-ccw/virtio-ccw.c
 create mode 100644 pc-bios/s390-ccw/virtio-ccw.h

diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
index a0f24c94a8..259cff09db 100644
--- a/pc-bios/s390-ccw/Makefile
+++ b/pc-bios/s390-ccw/Makefile
@@ -34,7 +34,8 @@ QEMU_DGFLAGS = -MMD -MP -MT $@ -MF $(@D)/$(*F).d
 .PHONY : all clean build-all distclean
 
 OBJECTS = start.o main.o bootmap.o jump2ipl.o sclp.o menu.o netmain.o \
-	  virtio.o virtio-net.o virtio-scsi.o virtio-blkdev.o cio.o dasd-ipl.o
+	  virtio.o virtio-net.o virtio-scsi.o virtio-blkdev.o cio.o dasd-ipl.o \
+	  virtio-ccw.o
 
 SLOF_DIR := $(SRC_PATH)/../../roms/SLOF
 
diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 64bde49710..32154c5db8 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -71,6 +71,7 @@ static int is_dev_possibly_bootable(int dev_no, int sch_no)
     bool is_virtio;
     Schib schib;
     int r;
+    VDev *vdev = virtio_get_device();
 
     blk_schid.sch_no = sch_no;
     r = stsch_err(blk_schid, &schib);
@@ -91,7 +92,8 @@ static int is_dev_possibly_bootable(int dev_no, int sch_no)
      * 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);
+    vdev->schid = blk_schid;
+    is_virtio = virtio_is_supported(vdev);
 
     /* No specific devno given, just return whether the device is possibly bootable */
     if (dev_no < 0) {
@@ -256,10 +258,10 @@ static int virtio_setup(void)
         puts("Network boot device detected");
         return 0;
     case VIRTIO_ID_BLOCK:
-        ret = virtio_blk_setup_device(blk_schid);
+        ret = virtio_blk_setup_device(vdev);
         break;
     case VIRTIO_ID_SCSI:
-        ret = virtio_scsi_setup_device(blk_schid);
+        ret = virtio_scsi_setup_device(vdev);
         break;
     default:
         puts("\n! No IPL device available !\n");
diff --git a/pc-bios/s390-ccw/netmain.c b/pc-bios/s390-ccw/netmain.c
index a9521dff41..651cedf6ef 100644
--- a/pc-bios/s390-ccw/netmain.c
+++ b/pc-bios/s390-ccw/netmain.c
@@ -500,7 +500,7 @@ static bool find_net_dev(Schib *schib, int dev_no)
             continue;
         }
         enable_subchannel(net_schid);
-        if (!virtio_is_supported(net_schid)) {
+        if (!virtio_is_supported(virtio_get_device())) {
             continue;
         }
         if (virtio_get_device_type() != VIRTIO_ID_NET) {
diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
index 47ea66bd4d..ccd68ff0a4 100644
--- a/pc-bios/s390-ccw/s390-ccw.h
+++ b/pc-bios/s390-ccw/s390-ccw.h
@@ -66,9 +66,6 @@ void sclp_setup(void);
 void sclp_get_loadparm_ascii(char *loadparm);
 int sclp_read(char *str, size_t count);
 
-/* virtio.c */
-bool virtio_is_supported(SubChannelId schid);
-
 /* bootmap.c */
 void zipl_load(void);
 
diff --git a/pc-bios/s390-ccw/virtio-blkdev.c b/pc-bios/s390-ccw/virtio-blkdev.c
index 9cc40e9108..9722b6970f 100644
--- a/pc-bios/s390-ccw/virtio-blkdev.c
+++ b/pc-bios/s390-ccw/virtio-blkdev.c
@@ -12,6 +12,7 @@
 #include "s390-ccw.h"
 #include "virtio.h"
 #include "virtio-scsi.h"
+#include "virtio-ccw.h"
 
 #define VIRTIO_BLK_F_GEOMETRY   (1 << 4)
 #define VIRTIO_BLK_F_BLK_SIZE   (1 << 6)
@@ -229,15 +230,17 @@ uint64_t virtio_get_blocks(void)
     }
 }
 
-int virtio_blk_setup_device(SubChannelId schid)
+int virtio_blk_setup_device(VDev *vdev)
 {
-    VDev *vdev = virtio_get_device();
-
     vdev->guest_features[0] = VIRTIO_BLK_F_GEOMETRY | VIRTIO_BLK_F_BLK_SIZE;
-    vdev->schid = schid;
-    virtio_setup_ccw(vdev);
 
     puts("Using virtio-blk.");
 
-    return 0;
+    switch (vdev->ipl_type) {
+    case S390_IPL_TYPE_QEMU_SCSI:
+    case S390_IPL_TYPE_CCW:
+        return virtio_ccw_setup(vdev);
+    default:
+        return 1;
+    }
 }
diff --git a/pc-bios/s390-ccw/virtio-ccw.c b/pc-bios/s390-ccw/virtio-ccw.c
new file mode 100644
index 0000000000..ab98da90c3
--- /dev/null
+++ b/pc-bios/s390-ccw/virtio-ccw.c
@@ -0,0 +1,241 @@
+/*
+ * Virtio functionality for CCW devices
+ *
+ * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
+ * Copyright 2025 IBM Corp.
+ *
+ * Author(s): Jared Rossi <jrossi@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include <string.h>
+#include "s390-ccw.h"
+#include "cio.h"
+#include "virtio.h"
+#include "virtio-ccw.h"
+#include "virtio-scsi.h"
+#include "bswap.h"
+#include "helper.h"
+#include "s390-time.h"
+
+/* virtio spec v1.0 para 4.3.3.2 */
+static long kvm_hypercall(unsigned long nr, unsigned long param1,
+                          unsigned long param2, unsigned long param3)
+{
+    register unsigned long r_nr asm("1") = nr;
+    register unsigned long r_param1 asm("2") = param1;
+    register unsigned long r_param2 asm("3") = param2;
+    register unsigned long r_param3 asm("4") = param3;
+    register long retval asm("2");
+
+    asm volatile ("diag %%r2,%%r4,0x500"
+                  : "=d" (retval)
+                  : "d" (r_nr), "0" (r_param1), "r"(r_param2), "d"(r_param3)
+                  : "memory", "cc");
+
+    return retval;
+}
+
+static int run_ccw(VDev *vdev, int cmd, void *ptr, int len, bool sli)
+{
+    Ccw1 ccw = {};
+
+    ccw.cmd_code = cmd;
+    ccw.cda = (long)ptr;
+    ccw.count = len;
+
+    if (sli) {
+        ccw.flags |= CCW_FLAG_SLI;
+    }
+
+    return do_cio(vdev->schid, vdev->senseid.cu_type, ptr2u32(&ccw), CCW_FMT1);
+}
+
+bool virtio_ccw_is_supported(VDev *vdev)
+{
+    memset(&vdev->senseid, 0, sizeof(vdev->senseid));
+
+    /*
+     * Run sense id command.
+     * The size of the senseid data differs between devices (notably,
+     * between virtio devices and dasds), so specify the largest possible
+     * size and suppress the incorrect length indication for smaller sizes.
+     */
+    if (run_ccw(vdev, CCW_CMD_SENSE_ID, &vdev->senseid, sizeof(vdev->senseid),
+                true)) {
+        return false;
+    }
+
+    vdev->dev_type = vdev->senseid.cu_model;
+
+    if (vdev->senseid.cu_type == 0x3832) {
+        switch (vdev->dev_type) {
+        case VIRTIO_ID_BLOCK:
+        case VIRTIO_ID_SCSI:
+        case VIRTIO_ID_NET:
+            return true;
+        default:
+            return false;
+        }
+    }
+    return false;
+}
+
+int drain_irqs_ccw(SubChannelId schid)
+{
+    Irb irb = {};
+    int r = 0;
+
+    while (1) {
+        /* FIXME: make use of TPI, for that enable subchannel and isc */
+        if (tsch(schid, &irb)) {
+            /* Might want to differentiate error codes later on. */
+            if (irb.scsw.cstat) {
+                r = -EIO;
+            } else if (irb.scsw.dstat != 0xc) {
+                r = -EIO;
+            }
+            return r;
+        }
+    }
+}
+
+long virtio_ccw_notify(SubChannelId schid, int vq_idx, long cookie)
+{
+    return kvm_hypercall(KVM_S390_VIRTIO_CCW_NOTIFY, *(u32 *)&schid,
+                         vq_idx, cookie);
+}
+
+int virtio_ccw_run(VDev *vdev, int vqid, VirtioCmd *cmd)
+{
+    VRing *vr = &vdev->vrings[vqid];
+    int i = 0;
+
+    do {
+        vring_send_buf(vr, cmd[i].data, cmd[i].size,
+                       cmd[i].flags | (i ? VRING_HIDDEN_IS_CHAIN : 0));
+    } while (cmd[i++].flags & VRING_DESC_F_NEXT);
+
+    vring_wait_reply();
+    if (drain_irqs()) {
+        return -1;
+    }
+    return 0;
+}
+
+int virtio_ccw_reset(VDev *vdev)
+{
+    return run_ccw(vdev, CCW_CMD_VDEV_RESET, NULL, 0, false);
+}
+
+int virtio_ccw_setup(VDev *vdev)
+{
+    int i, cfg_size = 0;
+    uint8_t status;
+    struct VirtioFeatureDesc {
+        uint32_t features;
+        uint8_t index;
+    } __attribute__((packed)) feats;
+
+    if (!virtio_ccw_is_supported(vdev)) {
+        puts("Virtio unsupported for this device ID");
+        return -ENODEV;
+    }
+    /* device ID has been established now */
+
+    vdev->config.blk.blk_size = 0; /* mark "illegal" - setup started... */
+    vdev->guessed_disk_nature = VIRTIO_GDN_NONE;
+
+    virtio_reset(vdev);
+
+    status = VIRTIO_CONFIG_S_ACKNOWLEDGE;
+    if (run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false)) {
+        puts("Could not write ACKNOWLEDGE status to host");
+        return -EIO;
+    }
+
+    switch (vdev->dev_type) {
+    case VIRTIO_ID_NET:
+        vdev->nr_vqs = 2;
+        vdev->cmd_vr_idx = 0;
+        cfg_size = sizeof(vdev->config.net);
+        break;
+    case VIRTIO_ID_BLOCK:
+        vdev->nr_vqs = 1;
+        vdev->cmd_vr_idx = 0;
+        cfg_size = sizeof(vdev->config.blk);
+        break;
+    case VIRTIO_ID_SCSI:
+        vdev->nr_vqs = 3;
+        vdev->cmd_vr_idx = VR_REQUEST;
+        cfg_size = sizeof(vdev->config.scsi);
+        break;
+    default:
+        puts("Unsupported virtio device");
+        return -ENODEV;
+    }
+
+    status |= VIRTIO_CONFIG_S_DRIVER;
+    if (run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false)) {
+        puts("Could not write DRIVER status to host");
+        return -EIO;
+    }
+
+    /* Feature negotiation */
+    for (i = 0; i < ARRAY_SIZE(vdev->guest_features); i++) {
+        feats.features = 0;
+        feats.index = i;
+        if (run_ccw(vdev, CCW_CMD_READ_FEAT, &feats, sizeof(feats), false)) {
+            puts("Could not get features bits");
+            return -EIO;
+        }
+
+        vdev->guest_features[i] &= bswap32(feats.features);
+        feats.features = bswap32(vdev->guest_features[i]);
+        if (run_ccw(vdev, CCW_CMD_WRITE_FEAT, &feats, sizeof(feats), false)) {
+            puts("Could not set features bits");
+            return -EIO;
+        }
+    }
+
+    if (run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size, false)) {
+        puts("Could not get virtio device configuration");
+        return -EIO;
+    }
+
+    for (i = 0; i < vdev->nr_vqs; i++) {
+        VqInfo info = {
+            .queue = (unsigned long long) virtio_get_ring_area(i),
+            .align = KVM_S390_VIRTIO_RING_ALIGN,
+            .index = i,
+            .num = 0,
+        };
+        VqConfig config = {
+            .index = i,
+            .num = 0,
+        };
+
+        if (run_ccw(vdev, CCW_CMD_READ_VQ_CONF, &config, sizeof(config),
+                false)) {
+            puts("Could not get virtio device VQ config");
+            return -EIO;
+        }
+        info.num = config.num;
+        vring_init(&vdev->vrings[i], &info);
+        if (run_ccw(vdev, CCW_CMD_SET_VQ, &info, sizeof(info), false)) {
+            puts("Cannot set VQ info");
+            return -EIO;
+        }
+    }
+
+    status |= VIRTIO_CONFIG_S_DRIVER_OK;
+    if (run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false)) {
+        puts("Could not write DRIVER_OK status to host");
+        return -EIO;
+    }
+
+    return 0;
+}
diff --git a/pc-bios/s390-ccw/virtio-ccw.h b/pc-bios/s390-ccw/virtio-ccw.h
new file mode 100644
index 0000000000..a506767eaa
--- /dev/null
+++ b/pc-bios/s390-ccw/virtio-ccw.h
@@ -0,0 +1,24 @@
+/*
+ * Virtio definitions for CCW devices
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Jared Rossi <jrossi@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef VIRTIO_CCW_H
+#define VIRTIO_CCW_H
+
+/* main.c */
+extern SubChannelId blk_schid;
+
+/* virtio-ccw.c */
+int drain_irqs_ccw(SubChannelId schid);
+bool virtio_ccw_is_supported(VDev *vdev);
+int virtio_ccw_run(VDev *vdev, int vqid, VirtioCmd *cmd);
+long virtio_ccw_notify(SubChannelId schid, int vq_idx, long cookie);
+int virtio_ccw_setup(VDev *vdev);
+int virtio_ccw_reset(VDev *vdev);
+
+#endif
diff --git a/pc-bios/s390-ccw/virtio-net.c b/pc-bios/s390-ccw/virtio-net.c
index 7eb0850069..f58f7ffc55 100644
--- a/pc-bios/s390-ccw/virtio-net.c
+++ b/pc-bios/s390-ccw/virtio-net.c
@@ -19,6 +19,7 @@
 #include <ethernet.h>
 #include "s390-ccw.h"
 #include "virtio.h"
+#include "virtio-ccw.h"
 #include "s390-time.h"
 #include "helper.h"
 
@@ -54,7 +55,7 @@ int virtio_net_init(void *mac_addr)
     rx_last_idx = 0;
 
     vdev->guest_features[0] = VIRTIO_NET_F_MAC_BIT;
-    virtio_setup_ccw(vdev);
+    virtio_ccw_setup(vdev);
 
     if (!(vdev->guest_features[0] & VIRTIO_NET_F_MAC_BIT)) {
         puts("virtio-net device does not support the MAC address feature");
diff --git a/pc-bios/s390-ccw/virtio-scsi.c b/pc-bios/s390-ccw/virtio-scsi.c
index 71db75ce7b..9ea00c6fe6 100644
--- a/pc-bios/s390-ccw/virtio-scsi.c
+++ b/pc-bios/s390-ccw/virtio-scsi.c
@@ -15,6 +15,7 @@
 #include "virtio.h"
 #include "scsi.h"
 #include "virtio-scsi.h"
+#include "virtio-ccw.h"
 #include "s390-time.h"
 #include "helper.h"
 
@@ -476,12 +477,9 @@ static int virtio_scsi_setup(VDev *vdev)
     return 0;
 }
 
-int virtio_scsi_setup_device(SubChannelId schid)
+int virtio_scsi_setup_device(VDev *vdev)
 {
-    VDev *vdev = virtio_get_device();
-
-    vdev->schid = schid;
-    virtio_setup_ccw(vdev);
+    virtio_ccw_setup(vdev);
 
     if (vdev->config.scsi.sense_size != VIRTIO_SCSI_SENSE_SIZE) {
         puts("Config: sense size mismatch");
diff --git a/pc-bios/s390-ccw/virtio-scsi.h b/pc-bios/s390-ccw/virtio-scsi.h
index c5612e16a2..070f24b7e5 100644
--- a/pc-bios/s390-ccw/virtio-scsi.h
+++ b/pc-bios/s390-ccw/virtio-scsi.h
@@ -69,6 +69,6 @@ static inline bool virtio_scsi_response_ok(const VirtioScsiCmdResp *r)
 
 int virtio_scsi_read_many(VDev *vdev,
                           unsigned long sector, void *load_addr, int sec_num);
-int virtio_scsi_setup_device(SubChannelId schid);
+int virtio_scsi_setup_device(VDev *vdev);
 
 #endif /* VIRTIO_SCSI_H */
diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index 5dd407d5c9..956b34ff33 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -2,6 +2,9 @@
  * Virtio driver bits
  *
  * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
+ * Copyright 2025 IBM Corp.
+ *
+ * Author(s): Jared Rossi <jrossi@linux.ibm.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or (at
  * your option) any later version. See the COPYING file in the top-level
@@ -13,6 +16,7 @@
 #include "cio.h"
 #include "virtio.h"
 #include "virtio-scsi.h"
+#include "virtio-ccw.h"
 #include "bswap.h"
 #include "helper.h"
 #include "s390-time.h"
@@ -44,28 +48,9 @@ VirtioDevType virtio_get_device_type(void)
     return vdev.dev_type;
 }
 
-/* virtio spec v1.0 para 4.3.3.2 */
-static long kvm_hypercall(unsigned long nr, unsigned long param1,
-                          unsigned long param2, unsigned long param3)
+char *virtio_get_ring_area(int ring_num)
 {
-    register unsigned long r_nr asm("1") = nr;
-    register unsigned long r_param1 asm("2") = param1;
-    register unsigned long r_param2 asm("3") = param2;
-    register unsigned long r_param3 asm("4") = param3;
-    register long retval asm("2");
-
-    asm volatile ("diag %%r2,%%r4,0x500"
-                  : "=d" (retval)
-                  : "d" (r_nr), "0" (r_param1), "r"(r_param2), "d"(r_param3)
-                  : "memory", "cc");
-
-    return retval;
-}
-
-static long virtio_notify(SubChannelId schid, int vq_idx, long cookie)
-{
-    return kvm_hypercall(KVM_S390_VIRTIO_CCW_NOTIFY, *(u32 *)&schid,
-                         vq_idx, cookie);
+    return ring_area + ring_num * VIRTIO_RING_SIZE;
 }
 
 /***********************************************
@@ -74,39 +59,27 @@ static long virtio_notify(SubChannelId schid, int vq_idx, long cookie)
 
 int drain_irqs(void)
 {
-    Irb irb = {};
-    int r = 0;
-
-    while (1) {
-        /* FIXME: make use of TPI, for that enable subchannel and isc */
-        if (tsch(vdev.schid, &irb)) {
-            /* Might want to differentiate error codes later on. */
-            if (irb.scsw.cstat) {
-                r = -EIO;
-            } else if (irb.scsw.dstat != 0xc) {
-                r = -EIO;
-            }
-            return r;
-        }
+    switch (vdev.ipl_type) {
+    case S390_IPL_TYPE_QEMU_SCSI:
+    case S390_IPL_TYPE_CCW:
+        return drain_irqs_ccw(vdev.schid);
+    default:
+        return 0;
     }
 }
 
-static int run_ccw(VDev *vdev, int cmd, void *ptr, int len, bool sli)
+int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd)
 {
-    Ccw1 ccw = {};
-
-    ccw.cmd_code = cmd;
-    ccw.cda = (long)ptr;
-    ccw.count = len;
-
-    if (sli) {
-        ccw.flags |= CCW_FLAG_SLI;
+    switch (vdev->ipl_type) {
+    case S390_IPL_TYPE_QEMU_SCSI:
+    case S390_IPL_TYPE_CCW:
+        return virtio_ccw_run(vdev, vqid, cmd);
+    default:
+        return -1;
     }
-
-    return do_cio(vdev->schid, vdev->senseid.cu_type, ptr2u32(&ccw), CCW_FMT1);
 }
 
-static void vring_init(VRing *vr, VqInfo *info)
+void vring_init(VRing *vr, VqInfo *info)
 {
     void *p = (void *) info->queue;
 
@@ -134,7 +107,15 @@ static void vring_init(VRing *vr, VqInfo *info)
 
 bool vring_notify(VRing *vr)
 {
-    vr->cookie = virtio_notify(vdev.schid, vr->id, vr->cookie);
+    switch (vdev.ipl_type) {
+    case S390_IPL_TYPE_QEMU_SCSI:
+    case S390_IPL_TYPE_CCW:
+        vr->cookie = virtio_ccw_notify(vdev.schid, vr->id, vr->cookie);
+        break;
+    default:
+        return 1;
+    }
+
     return vr->cookie >= 0;
 }
 
@@ -200,164 +181,24 @@ int vring_wait_reply(void)
     return 1;
 }
 
-int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd)
-{
-    VRing *vr = &vdev->vrings[vqid];
-    int i = 0;
-
-    do {
-        vring_send_buf(vr, cmd[i].data, cmd[i].size,
-                       cmd[i].flags | (i ? VRING_HIDDEN_IS_CHAIN : 0));
-    } while (cmd[i++].flags & VRING_DESC_F_NEXT);
-
-    vring_wait_reply();
-    if (drain_irqs()) {
-        return -1;
-    }
-    return 0;
-}
-
 int virtio_reset(VDev *vdev)
 {
-    return run_ccw(vdev, CCW_CMD_VDEV_RESET, NULL, 0, false);
-}
-
-int virtio_setup_ccw(VDev *vdev)
-{
-    int i, cfg_size = 0;
-    uint8_t status;
-    struct VirtioFeatureDesc {
-        uint32_t features;
-        uint8_t index;
-    } __attribute__((packed)) feats;
-
-    if (!virtio_is_supported(vdev->schid)) {
-        puts("Virtio unsupported for this device ID");
-        return -ENODEV;
-    }
-    /* device ID has been established now */
-
-    vdev->config.blk.blk_size = 0; /* mark "illegal" - setup started... */
-    vdev->guessed_disk_nature = VIRTIO_GDN_NONE;
-
-    virtio_reset(vdev);
-
-    status = VIRTIO_CONFIG_S_ACKNOWLEDGE;
-    if (run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false)) {
-        puts("Could not write ACKNOWLEDGE status to host");
-        return -EIO;
-    }
-
-    switch (vdev->dev_type) {
-    case VIRTIO_ID_NET:
-        vdev->nr_vqs = 2;
-        vdev->cmd_vr_idx = 0;
-        cfg_size = sizeof(vdev->config.net);
-        break;
-    case VIRTIO_ID_BLOCK:
-        vdev->nr_vqs = 1;
-        vdev->cmd_vr_idx = 0;
-        cfg_size = sizeof(vdev->config.blk);
-        break;
-    case VIRTIO_ID_SCSI:
-        vdev->nr_vqs = 3;
-        vdev->cmd_vr_idx = VR_REQUEST;
-        cfg_size = sizeof(vdev->config.scsi);
-        break;
+    switch (vdev->ipl_type) {
+    case S390_IPL_TYPE_QEMU_SCSI:
+    case S390_IPL_TYPE_CCW:
+        return virtio_ccw_reset(vdev);
     default:
-        puts("Unsupported virtio device");
-        return -ENODEV;
-    }
-
-    status |= VIRTIO_CONFIG_S_DRIVER;
-    if (run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false)) {
-        puts("Could not write DRIVER status to host");
-        return -EIO;
-    }
-
-    /* Feature negotiation */
-    for (i = 0; i < ARRAY_SIZE(vdev->guest_features); i++) {
-        feats.features = 0;
-        feats.index = i;
-        if (run_ccw(vdev, CCW_CMD_READ_FEAT, &feats, sizeof(feats), false)) {
-            puts("Could not get features bits");
-            return -EIO;
-        }
-
-        vdev->guest_features[i] &= bswap32(feats.features);
-        feats.features = bswap32(vdev->guest_features[i]);
-        if (run_ccw(vdev, CCW_CMD_WRITE_FEAT, &feats, sizeof(feats), false)) {
-            puts("Could not set features bits");
-            return -EIO;
-        }
-    }
-
-    if (run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size, false)) {
-        puts("Could not get virtio device configuration");
-        return -EIO;
-    }
-
-    for (i = 0; i < vdev->nr_vqs; i++) {
-        VqInfo info = {
-            .queue = (unsigned long long) ring_area + (i * VIRTIO_RING_SIZE),
-            .align = KVM_S390_VIRTIO_RING_ALIGN,
-            .index = i,
-            .num = 0,
-        };
-        VqConfig config = {
-            .index = i,
-            .num = 0,
-        };
-
-        if (run_ccw(vdev, CCW_CMD_READ_VQ_CONF, &config, sizeof(config),
-                false)) {
-            puts("Could not get virtio device VQ config");
-            return -EIO;
-        }
-        info.num = config.num;
-        vring_init(&vdev->vrings[i], &info);
-        if (run_ccw(vdev, CCW_CMD_SET_VQ, &info, sizeof(info), false)) {
-            puts("Cannot set VQ info");
-            return -EIO;
-        }
-    }
-
-    status |= VIRTIO_CONFIG_S_DRIVER_OK;
-    if (run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false)) {
-        puts("Could not write DRIVER_OK status to host");
-        return -EIO;
+        return -1;
     }
-
-    return 0;
 }
 
-bool virtio_is_supported(SubChannelId schid)
+bool virtio_is_supported(VDev *vdev)
 {
-    vdev.schid = schid;
-    memset(&vdev.senseid, 0, sizeof(vdev.senseid));
-
-    /*
-     * Run sense id command.
-     * The size of the senseid data differs between devices (notably,
-     * between virtio devices and dasds), so specify the largest possible
-     * size and suppress the incorrect length indication for smaller sizes.
-     */
-    if (run_ccw(&vdev, CCW_CMD_SENSE_ID, &vdev.senseid, sizeof(vdev.senseid),
-                true)) {
+    switch (vdev->ipl_type) {
+    case S390_IPL_TYPE_QEMU_SCSI:
+    case S390_IPL_TYPE_CCW:
+        return virtio_ccw_is_supported(vdev);
+    default:
         return false;
     }
-
-    vdev.dev_type = vdev.senseid.cu_model;
-
-    if (vdev.senseid.cu_type == 0x3832) {
-        switch (vdev.dev_type) {
-        case VIRTIO_ID_BLOCK:
-        case VIRTIO_ID_SCSI:
-        case VIRTIO_ID_NET:
-            return true;
-        default:
-            return false;
-        }
-    }
-    return false;
 }
diff --git a/pc-bios/s390-ccw/virtio.h b/pc-bios/s390-ccw/virtio.h
index 39b507b221..c3cb5a6ee3 100644
--- a/pc-bios/s390-ccw/virtio.h
+++ b/pc-bios/s390-ccw/virtio.h
@@ -108,6 +108,7 @@ struct VRing {
 };
 typedef struct VRing VRing;
 
+char *virtio_get_ring_area(int ring_num);
 
 /***********************************************
  *               Virtio block                  *
@@ -269,6 +270,8 @@ struct VirtioCmd {
 };
 typedef struct VirtioCmd VirtioCmd;
 
+void vring_init(VRing *vr, VqInfo *info);
+bool virtio_is_supported(VDev *vdev);
 bool vring_notify(VRing *vr);
 int drain_irqs(void);
 void vring_send_buf(VRing *vr, void *p, int len, int flags);
@@ -283,7 +286,7 @@ int virtio_net_init(void *mac_addr);
 void virtio_net_deinit(void);
 
 /* virtio-blkdev.c */
-int virtio_blk_setup_device(SubChannelId schid);
+int virtio_blk_setup_device(VDev *vdev);
 int virtio_read(unsigned long sector, void *load_addr);
 unsigned long virtio_load_direct(unsigned long rec_list1, unsigned long rec_list2,
                                  void *load_addr);
-- 
2.52.0