vfio-ccw: Add support for the CRW region and IRQ

The crw region can be used to obtain information about
Channel Report Words (CRW) from vfio-ccw driver.

Currently only channel-path related CRWs are passed to
QEMU from vfio-ccw driver.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505125757.98209-7-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

hw/vfio/ccw.c

@@ -44,7 +44,11 @@ struct VFIOCCWDevice {
     uint64_t schib_region_size;
     uint64_t schib_region_offset;
     struct ccw_schib_region *schib_region;
+    uint64_t crw_region_size;
+    uint64_t crw_region_offset;
+    struct ccw_crw_region *crw_region;
     EventNotifier io_notifier;
+    EventNotifier crw_notifier;
     bool force_orb_pfch;
     bool warned_orb_pfch;
 };
@@ -254,6 +258,44 @@ static void vfio_ccw_reset(DeviceState *dev)
     ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
 }
 
+static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev)
+{
+    struct ccw_crw_region *region = vcdev->crw_region;
+    CRW crw;
+    int size;
+
+    /* Keep reading CRWs as long as data is returned */
+    do {
+        memset(region, 0, sizeof(*region));
+        size = pread(vcdev->vdev.fd, region, vcdev->crw_region_size,
+                     vcdev->crw_region_offset);
+
+        if (size == -1) {
+            error_report("vfio-ccw: Read crw region failed with errno=%d",
+                         errno);
+            break;
+        }
+
+        if (region->crw == 0) {
+            /* No more CRWs to queue */
+            break;
+        }
+
+        memcpy(&crw, &region->crw, sizeof(CRW));
+
+        css_crw_add_to_queue(crw);
+    } while (1);
+}
+
+static void vfio_ccw_crw_notifier_handler(void *opaque)
+{
+    VFIOCCWDevice *vcdev = opaque;
+
+    while (event_notifier_test_and_clear(&vcdev->crw_notifier)) {
+        vfio_ccw_crw_read(vcdev);
+    }
+}
+
 static void vfio_ccw_io_notifier_handler(void *opaque)
 {
     VFIOCCWDevice *vcdev = opaque;
@@ -340,6 +382,10 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
         notifier = &vcdev->io_notifier;
         fd_read = vfio_ccw_io_notifier_handler;
         break;
+    case VFIO_CCW_CRW_IRQ_INDEX:
+        notifier = &vcdev->crw_notifier;
+        fd_read = vfio_ccw_crw_notifier_handler;
+        break;
     default:
         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
         return;
@@ -391,6 +437,9 @@ static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
     case VFIO_CCW_IO_IRQ_INDEX:
         notifier = &vcdev->io_notifier;
         break;
+    case VFIO_CCW_CRW_IRQ_INDEX:
+        notifier = &vcdev->crw_notifier;
+        break;
     default:
         error_report("vfio: Unsupported device irq(%d)", irq);
         return;
@@ -468,10 +517,24 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
         vcdev->schib_region = g_malloc(info->size);
     }
 
+    ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
+                                   VFIO_REGION_SUBTYPE_CCW_CRW, &info);
+
+    if (!ret) {
+        vcdev->crw_region_size = info->size;
+        if (sizeof(*vcdev->crw_region) != vcdev->crw_region_size) {
+            error_setg(errp, "vfio: Unexpected size of the CRW region");
+            goto out_err;
+        }
+        vcdev->crw_region_offset = info->offset;
+        vcdev->crw_region = g_malloc(info->size);
+    }
+
     g_free(info);
     return;
 
 out_err:
+    g_free(vcdev->crw_region);
     g_free(vcdev->schib_region);
     g_free(vcdev->async_cmd_region);
     g_free(vcdev->io_region);
@@ -481,6 +544,7 @@ out_err:
 
 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
 {
+    g_free(vcdev->crw_region);
     g_free(vcdev->schib_region);
     g_free(vcdev->async_cmd_region);
     g_free(vcdev->io_region);
@@ -596,6 +660,14 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
         goto out_notifier_err;
     }
 
+    if (vcdev->crw_region) {
+        vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
+        if (err) {
+            vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
+            goto out_notifier_err;
+        }
+    }
+
     return;
 
 out_notifier_err:
@@ -620,6 +692,7 @@ static void vfio_ccw_unrealize(DeviceState *dev)
     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
     VFIOGroup *group = vcdev->vdev.group;
 
+    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
     vfio_ccw_put_region(vcdev);
     vfio_ccw_put_device(vcdev);