Merge remote-tracking branch 'cohuck/tags/s390x-3270-20170504' into staging

Basic support for using channel-attached 3270 'green-screen'
devices via tn3270. Actual handling of the data stream is
delegated to x3270; more info at http://wiki.qemu.org/Features/3270

# gpg: Signature made Thu 04 May 2017 11:36:51 AM BST
# gpg:                using RSA key 0xDECF6B93C6F02FAF
# gpg: Good signature from "Cornelia Huck <conny@cornelia-huck.de>"
# gpg:                 aka "Cornelia Huck <cohuck@kernel.org>"
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>"
# gpg:                 aka "Cornelia Huck <huckc@linux.vnet.ibm.com>"
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0  18CE DECF 6B93 C6F0 2FAF

* cohuck/tags/s390x-3270-20170504:
  s390x/3270: Mark non-migratable and enable the device
  s390x/3270: Detect for continued presence of a 3270 client
  s390x/3270: Add the TCP socket events handler for 3270
  s390x/3270: 3270 data stream handling
  s390x/3270: Add emulated terminal3270 device
  s390x/3270: Add abstract emulated ccw-attached 3270 device
  s390x/css: Add an algorithm to find a free chpid
  chardev: Basic support for TN3270

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

3 files changed, 199 insertions, 0 deletions

diff --git a/hw/s390x/3270-ccw.c b/hw/s390x/3270-ccw.c
new file mode 100644
index 0000000000..a7a5b412e4
--- /dev/null
+++ b/hw/s390x/3270-ccw.c
@@ -0,0 +1,174 @@
+/*
+ * Emulated ccw-attached 3270 implementation
+ *
+ * Copyright 2017 IBM Corp.
+ * Author(s): Yang Chen <bjcyang@linux.vnet.ibm.com>
+ *            Jing Liu <liujbjl@linux.vnet.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 "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "cpu.h"
+#include "hw/s390x/css.h"
+#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;
+    EmulatedCcw3270Device *dev = EMULATED_CCW_3270(ds);
+    EmulatedCcw3270Class *ck = EMULATED_CCW_3270_GET_CLASS(dev);
+    CcwDevice *cdev = CCW_DEVICE(ds);
+    CCWDeviceClass *cdk = CCW_DEVICE_GET_CLASS(cdev);
+    SubchDev *sch = css_create_virtual_sch(cdev->devno, errp);
+    Error *err = NULL;
+
+    if (!sch) {
+        return;
+    }
+
+    if (!ck->init) {
+        goto out_err;
+    }
+
+    sch->driver_data = dev;
+    cdev->sch = sch;
+    chpid = css_find_free_chpid(sch->cssid);
+
+    if (chpid > MAX_CHPID) {
+        error_setg(&err, "No available chpid to use.");
+        goto out_err;
+    }
+
+    sch->id.reserved = 0xff;
+    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) {
+        goto out_err;
+    }
+
+    cdk->realize(cdev, &err);
+    if (err) {
+        goto out_err;
+    }
+
+    return;
+
+out_err:
+    error_propagate(errp, err);
+    css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
+    cdev->sch = NULL;
+    g_free(sch);
+}
+
+static Property emulated_ccw_3270_properties[] = {
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void emulated_ccw_3270_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->props = emulated_ccw_3270_properties;
+    dc->bus_type = TYPE_VIRTUAL_CSS_BUS;
+    dc->realize = emulated_ccw_3270_realize;
+    dc->hotpluggable = false;
+}
+
+static const TypeInfo emulated_ccw_3270_info = {
+    .name = TYPE_EMULATED_CCW_3270,
+    .parent = TYPE_CCW_DEVICE,
+    .instance_size = sizeof(EmulatedCcw3270Device),
+    .class_init = emulated_ccw_3270_class_init,
+    .class_size = sizeof(EmulatedCcw3270Class),
+    .abstract = true,
+};
+
+static void emulated_ccw_register(void)
+{
+    type_register_static(&emulated_ccw_3270_info);
+}
+
+type_init(emulated_ccw_register)
diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index 41ac4ec325..36bd4b1645 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -7,6 +7,7 @@ obj-y += sclpcpu.o
 obj-y += ipl.o
 obj-y += css.o
 obj-y += s390-virtio-ccw.o
+obj-y += 3270-ccw.o
 obj-y += virtio-ccw.o
 obj-y += css-bridge.o
 obj-y += ccw-device.o
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index c03bb20bc9..15c4f4b249 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;
@@ -1302,6 +1305,27 @@ bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid)
                                  (MAX_SCHID + 1) / sizeof(unsigned long));
 }
 
+unsigned int css_find_free_chpid(uint8_t cssid)
+{
+    CssImage *css = channel_subsys.css[cssid];
+    unsigned int chpid;
+
+    if (!css) {
+        return MAX_CHPID + 1;
+    }
+
+    for (chpid = 0; chpid <= MAX_CHPID; chpid++) {
+        /* skip reserved chpid */
+        if (chpid == VIRTIO_CCW_CHPID) {
+            continue;
+        }
+        if (!css->chpids[chpid].in_use) {
+            return chpid;
+        }
+    }
+    return MAX_CHPID + 1;
+}
+
 static int css_add_virtual_chpid(uint8_t cssid, uint8_t chpid, uint8_t type)
 {
     CssImage *css;