[Qemu-devel] [PULL 12/19] s390-bios: Refactor virtio to run channel programs via cio

[Cornelia Huck <cohuck@redhat.com>]

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

Now that we have a Channel I/O library let's modify virtio boot code to
make use of it for running channel programs.

Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1554388475-18329-13-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 pc-bios/s390-ccw/virtio.c | 57 +++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 30 deletions(-)

diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index aa9da7253fb2..35278eaee13d 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -14,6 +14,7 @@
 #include "virtio.h"
 #include "virtio-scsi.h"
 #include "bswap.h"
+#include "helper.h"
 
 #define VRING_WAIT_REPLY_TIMEOUT 30
 
@@ -89,33 +90,20 @@ int drain_irqs(SubChannelId schid)
     }
 }
 
-static int run_ccw(VDev *vdev, int cmd, void *ptr, int len)
+static int run_ccw(VDev *vdev, int cmd, void *ptr, int len, bool sli)
 {
     Ccw1 ccw = {};
-    CmdOrb orb = {};
-    int r;
-
-    enable_subchannel(vdev->schid);
-
-    /* start subchannel command */
-    orb.fmt = 1;
-    orb.cpa = (u32)(long)&ccw;
-    orb.lpm = 0x80;
 
     ccw.cmd_code = cmd;
     ccw.cda = (long)ptr;
     ccw.count = len;
 
-    r = ssch(vdev->schid, &orb);
-    /*
-     * XXX Wait until device is done processing the CCW. For now we can
-     *     assume that a simple tsch will have finished the CCW processing,
-     *     but the architecture allows for asynchronous operation
-     */
-    if (!r) {
-        r = drain_irqs(vdev->schid);
+    if (sli) {
+        ccw.flags |= CCW_FLAG_SLI;
     }
-    return r;
+
+    enable_subchannel(vdev->schid);
+    return do_cio(vdev->schid, vdev->senseid.cu_type, ptr2u32(&ccw), CCW_FMT1);
 }
 
 static void vring_init(VRing *vr, VqInfo *info)
@@ -257,7 +245,7 @@ void virtio_setup_ccw(VDev *vdev)
     vdev->config.blk.blk_size = 0; /* mark "illegal" - setup started... */
     vdev->guessed_disk_nature = VIRTIO_GDN_NONE;
 
-    run_ccw(vdev, CCW_CMD_VDEV_RESET, NULL, 0);
+    run_ccw(vdev, CCW_CMD_VDEV_RESET, NULL, 0, false);
 
     switch (vdev->senseid.cu_model) {
     case VIRTIO_ID_NET:
@@ -278,18 +266,19 @@ void virtio_setup_ccw(VDev *vdev)
     default:
         panic("Unsupported virtio device\n");
     }
-    IPL_assert(run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size) == 0,
-               "Could not get block device configuration");
+    IPL_assert(
+        run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size, false) == 0,
+       "Could not get block device configuration");
 
     /* Feature negotiation */
     for (i = 0; i < ARRAY_SIZE(vdev->guest_features); i++) {
         feats.features = 0;
         feats.index = i;
-        rc = run_ccw(vdev, CCW_CMD_READ_FEAT, &feats, sizeof(feats));
+        rc = run_ccw(vdev, CCW_CMD_READ_FEAT, &feats, sizeof(feats), false);
         IPL_assert(rc == 0, "Could not get features bits");
         vdev->guest_features[i] &= bswap32(feats.features);
         feats.features = bswap32(vdev->guest_features[i]);
-        rc = run_ccw(vdev, CCW_CMD_WRITE_FEAT, &feats, sizeof(feats));
+        rc = run_ccw(vdev, CCW_CMD_WRITE_FEAT, &feats, sizeof(feats), false);
         IPL_assert(rc == 0, "Could not set features bits");
     }
 
@@ -306,16 +295,17 @@ void virtio_setup_ccw(VDev *vdev)
         };
 
         IPL_assert(
-            run_ccw(vdev, CCW_CMD_READ_VQ_CONF, &config, sizeof(config)) == 0,
+            run_ccw(vdev, CCW_CMD_READ_VQ_CONF, &config, sizeof(config), false) == 0,
             "Could not get block device VQ configuration");
         info.num = config.num;
         vring_init(&vdev->vrings[i], &info);
         vdev->vrings[i].schid = vdev->schid;
-        IPL_assert(run_ccw(vdev, CCW_CMD_SET_VQ, &info, sizeof(info)) == 0,
-                   "Cannot set VQ info");
+        IPL_assert(
+            run_ccw(vdev, CCW_CMD_SET_VQ, &info, sizeof(info), false) == 0,
+            "Cannot set VQ info");
     }
     IPL_assert(
-        run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status)) == 0,
+        run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false) == 0,
         "Could not write status to host");
 }
 
@@ -323,8 +313,15 @@ bool virtio_is_supported(SubChannelId schid)
 {
     vdev.schid = schid;
     memset(&vdev.senseid, 0, sizeof(vdev.senseid));
-    /* run sense id command */
-    if (run_ccw(&vdev, CCW_CMD_SENSE_ID, &vdev.senseid, 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;
     }
     if (vdev.senseid.cu_type == 0x3832) {
-- 
2.17.2