2 files changed, 169 insertions, 0 deletions
diff --git a/hw/virtio-console.c b/hw/virtio-console.c
new file mode 100644
index 0000000..deae76d
--- /dev/null
+++ b/hw/virtio-console.c
@@ -0,0 +1,147 @@
+/*
+ * Virtio Console Device
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ *  Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw.h"
+#include "qemu-char.h"
+#include "virtio.h"
+#include "virtio-console.h"
+
+
+typedef struct VirtIOConsole
+{
+    VirtIODevice vdev;
+    VirtQueue *ivq, *dvq;
+    CharDriverState *chr;
+} VirtIOConsole;
+
+static VirtIOConsole *to_virtio_console(VirtIODevice *vdev)
+{
+    return (VirtIOConsole *)vdev;
+}
+
+static void virtio_console_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIOConsole *s = to_virtio_console(vdev);
+    VirtQueueElement elem;
+
+    while (virtqueue_pop(vq, &elem)) {
+        ssize_t len = 0;
+        int d;
+
+        for (d=0; d < elem.out_num; d++)
+            len += qemu_chr_write(s->chr, elem.out_sg[d].iov_base,elem.out_sg[d].iov_len);
+        virtqueue_push(vq, &elem, len);
+        virtio_notify(vdev, vq);
+    }
+}
+
+static void virtio_console_handle_input(VirtIODevice *vdev, VirtQueue *vq)
+{
+}
+
+static uint32_t virtio_console_get_features(VirtIODevice *vdev)
+{
+    return 0;
+}
+
+static int vcon_can_read(void *opaque)
+{
+    VirtIOConsole *s = (VirtIOConsole *) opaque;
+
+    if (!virtio_queue_ready(s->ivq) ||
+        !(s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
+        virtio_queue_empty(s->ivq))
+        return 0;
+
+    /* current implementations have a page sized buffer.
+     * We fall back to a one byte per read if there is not enough room.
+     * It would be cool to have a function that returns the available byte
+     * instead of checking for a limit */
+    if (virtqueue_avail_bytes(s->ivq, TARGET_PAGE_SIZE, 0))
+        return TARGET_PAGE_SIZE;
+    if (virtqueue_avail_bytes(s->ivq, 1, 0))
+        return 1;
+    return 0;
+}
+
+static void vcon_read(void *opaque, const uint8_t *buf, int size)
+{
+    VirtIOConsole *s = (VirtIOConsole *) opaque;
+    VirtQueueElement elem;
+    int offset = 0;
+
+    /* The current kernel implementation has only one outstanding input
+     * buffer of PAGE_SIZE. Nevertheless, this function is prepared to
+     * handle multiple buffers with multiple sg element for input */
+    while (offset < size) {
+        int i = 0;
+        if (!virtqueue_pop(s->ivq, &elem))
+                break;
+        while (offset < size && i < elem.in_num) {
+            int len = MIN(elem.in_sg[i].iov_len, size - offset);
+            memcpy(elem.in_sg[i].iov_base, buf + offset, len);
+            offset += len;
+            i++;
+        }
+        virtqueue_push(s->ivq, &elem, size);
+    }
+    virtio_notify(&s->vdev, s->ivq);
+}
+
+static void vcon_event(void *opaque, int event)
+{
+    /* we will ignore any event for the time being */
+}
+
+static void virtio_console_save(QEMUFile *f, void *opaque)
+{
+    VirtIOConsole *s = opaque;
+
+    virtio_save(&s->vdev, f);
+}
+
+static int virtio_console_load(QEMUFile *f, void *opaque, int version_id)
+{
+    VirtIOConsole *s = opaque;
+
+    if (version_id != 1)
+        return -EINVAL;
+
+    virtio_load(&s->vdev, f);
+    return 0;
+}
+
+void *virtio_console_init(PCIBus *bus, CharDriverState *chr)
+{
+    VirtIOConsole *s;
+
+    s = (VirtIOConsole *)virtio_init_pci(bus, "virtio-console",
+                                         6900, 0x1003,
+                                         0, VIRTIO_ID_CONSOLE,
+                                         0x03, 0x80, 0x00,
+                                         0, sizeof(VirtIOConsole));
+    if (s == NULL)
+        return NULL;
+
+    s->vdev.get_features = virtio_console_get_features;
+
+    s->ivq = virtio_add_queue(&s->vdev, 128, virtio_console_handle_input);
+    s->dvq = virtio_add_queue(&s->vdev, 128, virtio_console_handle_output);
+
+    s->chr = chr;
+    qemu_chr_add_handlers(chr, vcon_can_read, vcon_read, vcon_event, s);
+
+    register_savevm("virtio-console", -1, 1, virtio_console_save, virtio_console_load, s);
+
+    return &s->vdev;
+}
diff --git a/hw/virtio-console.h b/hw/virtio-console.h
new file mode 100644
index 0000000..2de9520
--- /dev/null
+++ b/hw/virtio-console.h
@@ -0,0 +1,22 @@
+/*
+ * Virtio Console Support
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ *  Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+#ifndef _QEMU_VIRTIO_CONSOLE_H
+#define _QEMU_VIRTIO_CONSOLE_H
+
+/* The ID for virtio console */
+#define VIRTIO_ID_CONSOLE 3
+
+/* Creates a virtio console */
+void *virtio_console_init(PCIBus *bus, CharDriverState *chr);
+
+#endif