Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / SLOF / lib / libvirtio / virtio-scsi.c

diff --git a/qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c b/qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c
new file mode 100644 (file)
index 0000000..4828928
--- /dev/null
+++ b/qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c
@@ -0,0 +1,145 @@
+/******************************************************************************
+ * Copyright (c) 2012 IBM Corporation
+ * All rights reserved.
+ * This program and the accompanying materials
+ * are made available under the terms of the BSD License
+ * which accompanies this distribution, and is available at
+ * http://www.opensource.org/licenses/bsd-license.php
+ *
+ * Contributors:
+ *     IBM Corporation - initial implementation
+ *****************************************************************************/
+
+#include <stdio.h>
+#include <string.h>
+#include <cpu.h>
+#include <helpers.h>
+#include "virtio.h"
+#include "virtio-scsi.h"
+
+int virtioscsi_send(struct virtio_device *dev,
+                   struct virtio_scsi_req_cmd *req,
+                   struct virtio_scsi_resp_cmd *resp,
+                   int is_read, void *buf, uint64_t buf_len)
+{
+        struct vring_desc *desc;
+        struct vring_desc *vq_desc;            /* Descriptor vring */
+        struct vring_avail *vq_avail;          /* "Available" vring */
+        struct vring_used *vq_used;            /* "Used" vring */
+
+        volatile uint16_t *current_used_idx;
+        uint16_t last_used_idx;
+        int id;
+        uint32_t vq_size, time;
+
+        int vq = VIRTIO_SCSI_REQUEST_VQ;
+
+        vq_size = virtio_get_qsize(dev, vq);
+        vq_desc = virtio_get_vring_desc(dev, vq);
+        vq_avail = virtio_get_vring_avail(dev, vq);
+        vq_used = virtio_get_vring_used(dev, vq);
+
+        last_used_idx = vq_used->idx;
+        current_used_idx = &vq_used->idx;
+
+        /* Determine descriptor index */
+        id = (vq_avail->idx * 3) % vq_size;
+
+        desc = &vq_desc[id];
+        desc->addr = (uint64_t)req;
+        desc->len = sizeof(*req);
+        desc->flags = VRING_DESC_F_NEXT;
+        desc->next = (id + 1) % vq_size;
+
+        /* Set up virtqueue descriptor for data */
+        desc = &vq_desc[(id + 1) % vq_size];
+        desc->addr = (uint64_t)resp;
+        desc->len = sizeof(*resp);
+        desc->flags = VRING_DESC_F_NEXT | VRING_DESC_F_WRITE;
+        desc->next = (id + 2) % vq_size;
+
+        if (buf && buf_len) {
+                /* Set up virtqueue descriptor for status */
+                desc = &vq_desc[(id + 2) % vq_size];
+                desc->addr = (uint64_t)buf;
+                desc->len = buf_len;
+                desc->flags = is_read ? VRING_DESC_F_WRITE : 0;
+                desc->next = 0;
+        } else
+                desc->flags &= ~VRING_DESC_F_NEXT;
+
+        vq_avail->ring[vq_avail->idx % vq_size] = id;
+        mb();
+        vq_avail->idx += 1;
+
+        /* Tell HV that the vq is ready */
+        virtio_queue_notify(dev, vq);
+
+       /* Wait for host to consume the descriptor */
+       time = SLOF_GetTimer() + VIRTIO_TIMEOUT;
+       while (*current_used_idx == last_used_idx) {
+               // do something better
+               mb();
+               if (time < SLOF_GetTimer())
+                       break;
+       }
+
+        return 0;
+}
+
+/**
+ * Initialize virtio-block device.
+ * @param  dev  pointer to virtio device information
+ */
+int virtioscsi_init(struct virtio_device *dev)
+{
+        struct vring_avail *vq_avail;
+        unsigned int idx = 0;
+        int qsize = 0;
+
+        /* Reset device */
+        // XXX That will clear the virtq base. We need to move
+        //     initializing it to here anyway
+        //
+        //     virtio_reset_device(dev);
+
+        /* Acknowledge device. */
+        virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE);
+
+        /* Tell HV that we know how to drive the device. */
+        virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE|VIRTIO_STAT_DRIVER);
+
+        /* Device specific setup - we do not support special features right now */
+        virtio_set_guest_features(dev,  0);
+
+        while(1) {
+                qsize = virtio_get_qsize(dev, idx);
+                if (!qsize)
+                        break;
+                virtio_vring_size(qsize);
+
+                vq_avail = virtio_get_vring_avail(dev, 0);
+                vq_avail->flags = VRING_AVAIL_F_NO_INTERRUPT;
+                vq_avail->idx = 0;
+                idx++;
+        }
+
+       /* Tell HV that setup succeeded */
+       virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE|VIRTIO_STAT_DRIVER
+                          |VIRTIO_STAT_DRIVER_OK);
+
+       return 0;
+}
+
+/**
+ * Shutdown the virtio-block device.
+ * @param  dev  pointer to virtio device information
+ */
+void virtioscsi_shutdown(struct virtio_device *dev)
+{
+       /* Quiesce device */
+       virtio_set_status(dev, VIRTIO_STAT_FAILED);
+
+       /* Reset device */
+       virtio_reset_device(dev);
+}