s390x/3270: 3270 data stream handling

This introduces the input and output handlers for 3270 device, setting
up the data tunnel among guest kernel, qemu and the 3270 client.

After the client connected and TN3270 handshake done, signal the not-ready
to ready status by an unsolicited device-end interrupt, and then the 3270
data stream could be handled correctly between the channel and socket.
Multiple commands generated by "Reset" key on x3270 are not supported now,
just simply terminate the connection.

Signed-off-by: Jing Liu <liujbjl@linux.vnet.ibm.com>
Signed-off-by: Yang Chen <bjcyang@linux.vnet.ibm.com>
Reviewed-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

2 files changed, 78 insertions, 0 deletions

diff --git a/hw/s390x/3270-ccw.c b/hw/s390x/3270-ccw.c
index 47b9e89..a7a5b41 100644
--- a/hw/s390x/3270-ccw.c
+++ b/hw/s390x/3270-ccw.c
@@ -17,6 +17,80 @@
 #include "hw/s390x/css-bridge.h"
 #include "hw/s390x/3270-ccw.h"
 
+/* Handle READ ccw commands from guest */
+static int handle_payload_3270_read(EmulatedCcw3270Device *dev, CCW1 *ccw)
+{
+    EmulatedCcw3270Class *ck = EMULATED_CCW_3270_GET_CLASS(dev);
+    CcwDevice *ccw_dev = CCW_DEVICE(dev);
+    int len;
+
+    if (!ccw->cda) {
+        return -EFAULT;
+    }
+
+    len = ck->read_payload_3270(dev, ccw->cda, ccw->count);
+    ccw_dev->sch->curr_status.scsw.count = ccw->count - len;
+
+    return 0;
+}
+
+/* Handle WRITE ccw commands to write data to client */
+static int handle_payload_3270_write(EmulatedCcw3270Device *dev, CCW1 *ccw)
+{
+    EmulatedCcw3270Class *ck = EMULATED_CCW_3270_GET_CLASS(dev);
+    CcwDevice *ccw_dev = CCW_DEVICE(dev);
+    int len;
+
+    if (!ccw->cda) {
+        return -EFAULT;
+    }
+
+    len = ck->write_payload_3270(dev, ccw->cmd_code, ccw->cda, ccw->count);
+
+    if (len <= 0) {
+        return -EIO;
+    }
+
+    ccw_dev->sch->curr_status.scsw.count = ccw->count - len;
+    return 0;
+}
+
+static int emulated_ccw_3270_cb(SubchDev *sch, CCW1 ccw)
+{
+    int rc = 0;
+    EmulatedCcw3270Device *dev = sch->driver_data;
+
+    switch (ccw.cmd_code) {
+    case TC_WRITESF:
+    case TC_WRITE:
+    case TC_EWRITE:
+    case TC_EWRITEA:
+        rc = handle_payload_3270_write(dev, &ccw);
+        break;
+    case TC_RDBUF:
+    case TC_READMOD:
+        rc = handle_payload_3270_read(dev, &ccw);
+        break;
+    default:
+        rc = -ENOSYS;
+        break;
+    }
+
+    if (rc == -EIO) {
+        /* I/O error, specific devices generate specific conditions */
+        SCSW *s = &sch->curr_status.scsw;
+
+        sch->curr_status.scsw.dstat = SCSW_DSTAT_UNIT_CHECK;
+        sch->sense_data[0] = 0x40;    /* intervention-req */
+        s->ctrl &= ~SCSW_ACTL_START_PEND;
+        s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
+        s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
+                   SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
+    }
+
+    return rc;
+}
+
 static void emulated_ccw_3270_realize(DeviceState *ds, Error **errp)
 {
     uint16_t chpid;
@@ -48,6 +122,7 @@ static void emulated_ccw_3270_realize(DeviceState *ds, Error **errp)
     sch->id.cu_type = EMULATED_CCW_3270_CU_TYPE;
     css_sch_build_virtual_schib(sch, (uint8_t)chpid,
                                 EMULATED_CCW_3270_CHPID_TYPE);
+    sch->ccw_cb = emulated_ccw_3270_cb;
 
     ck->init(dev, &err);
     if (err) {
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index d94498a..15c4f4b 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -576,6 +576,9 @@ static void sch_handle_start_func(SubchDev *sch, ORB *orb)
             s->dstat = SCSW_DSTAT_CHANNEL_END | SCSW_DSTAT_DEVICE_END;
             s->cpa = sch->channel_prog + 8;
             break;
+        case -EIO:
+            /* I/O errors, status depends on specific devices */
+            break;
         case -ENOSYS:
             /* unsupported command, generate unit check (command reject) */
             s->ctrl &= ~SCSW_ACTL_START_PEND;