1 /******************************************************************************
2 * Copyright (c) 2011 IBM Corporation
4 * This program and the accompanying materials
5 * are made available under the terms of the BSD License
6 * which accompanies this distribution, and is available at
7 * http://www.opensource.org/licenses/bsd-license.php
10 * IBM Corporation - initial implementation
11 *****************************************************************************/
16 #include <byteorder.h>
18 #include "virtio-blk.h"
19 #include "virtio-internal.h"
21 #define DEFAULT_SECTOR_SIZE 512
22 #define DRIVER_FEATURE_SUPPORT (VIRTIO_BLK_F_BLK_SIZE | VIRTIO_F_VERSION_1)
27 * Initialize virtio-block device.
28 * @param dev pointer to virtio device information
31 virtioblk_init(struct virtio_device *dev)
33 struct vring_avail *vq_avail;
34 int blk_size = DEFAULT_SECTOR_SIZE;
36 int status = VIRTIO_STAT_ACKNOWLEDGE;
39 virtio_reset_device(dev);
41 /* Acknowledge device. */
42 virtio_set_status(dev, status);
44 /* Tell HV that we know how to drive the device. */
45 status |= VIRTIO_STAT_DRIVER;
46 virtio_set_status(dev, status);
49 /* Negotiate features and sets FEATURES_OK if successful */
50 if (virtio_negotiate_guest_features(dev, DRIVER_FEATURE_SUPPORT))
53 virtio_get_status(dev, &status);
55 /* Device specific setup - we support F_BLK_SIZE */
56 virtio_set_guest_features(dev, VIRTIO_BLK_F_BLK_SIZE);
59 if (virtio_queue_init_vq(dev, &vq, 0))
62 vq_avail = virtio_get_vring_avail(dev, 0);
63 vq_avail->flags = virtio_cpu_to_modern16(dev, VRING_AVAIL_F_NO_INTERRUPT);
66 /* Tell HV that setup succeeded */
67 status |= VIRTIO_STAT_DRIVER_OK;
68 virtio_set_status(dev, status);
70 features = virtio_get_host_features(dev);
71 if (features & VIRTIO_BLK_F_BLK_SIZE) {
72 blk_size = virtio_get_config(dev,
73 offset_of(struct virtio_blk_cfg, blk_size),
79 printf("%s: failed\n", __func__);
80 status |= VIRTIO_STAT_FAILED;
81 virtio_set_status(dev, status);
87 * Shutdown the virtio-block device.
88 * @param dev pointer to virtio device information
91 virtioblk_shutdown(struct virtio_device *dev)
94 virtio_set_status(dev, VIRTIO_STAT_FAILED);
97 virtio_reset_device(dev);
100 static void fill_blk_hdr(struct virtio_blk_req *blkhdr, bool is_modern,
101 uint32_t type, uint32_t ioprio, uint32_t sector)
104 blkhdr->type = cpu_to_le32(type);
105 blkhdr->ioprio = cpu_to_le32(ioprio);
106 blkhdr->sector = cpu_to_le64(sector);
109 blkhdr->ioprio = ioprio;
110 blkhdr->sector = sector;
116 * @param reg pointer to "reg" property
117 * @param buf pointer to destination buffer
118 * @param blocknum block number of the first block that should be read
119 * @param cnt amount of blocks that should be read
120 * @return number of blocks that have been read successfully
123 virtioblk_read(struct virtio_device *dev, char *buf, uint64_t blocknum, long cnt)
125 struct vring_desc *desc;
127 static struct virtio_blk_req blkhdr;
128 //struct virtio_blk_config *blkconf;
130 uint32_t vq_size, time;
131 struct vring_desc *vq_desc; /* Descriptor vring */
132 struct vring_avail *vq_avail; /* "Available" vring */
133 struct vring_used *vq_used; /* "Used" vring */
134 volatile uint8_t status = -1;
135 volatile uint16_t *current_used_idx;
136 uint16_t last_used_idx, avail_idx;
137 int blk_size = DEFAULT_SECTOR_SIZE;
139 //printf("virtioblk_read: dev=%p buf=%p blocknum=%li count=%li\n",
140 // dev, buf, blocknum, cnt);
142 /* Check whether request is within disk capacity */
143 capacity = virtio_get_config(dev,
144 offset_of(struct virtio_blk_cfg, capacity),
146 if (blocknum + cnt - 1 > capacity) {
147 puts("virtioblk_read: Access beyond end of device!");
151 blk_size = virtio_get_config(dev,
152 offset_of(struct virtio_blk_cfg, blk_size),
154 if (blk_size % DEFAULT_SECTOR_SIZE) {
155 fprintf(stderr, "virtio-blk: Unaligned sector read %d\n", blk_size);
159 vq_size = virtio_get_qsize(dev, 0);
160 vq_desc = virtio_get_vring_desc(dev, 0);
161 vq_avail = virtio_get_vring_avail(dev, 0);
162 vq_used = virtio_get_vring_used(dev, 0);
164 avail_idx = virtio_modern16_to_cpu(dev, vq_avail->idx);
166 last_used_idx = vq_used->idx;
167 current_used_idx = &vq_used->idx;
170 fill_blk_hdr(&blkhdr, dev->is_modern, VIRTIO_BLK_T_IN | VIRTIO_BLK_T_BARRIER,
171 1, blocknum * blk_size / DEFAULT_SECTOR_SIZE);
173 /* Determine descriptor index */
174 id = (avail_idx * 3) % vq_size;
176 /* Set up virtqueue descriptor for header */
178 virtio_fill_desc(desc, dev->is_modern, (uint64_t)&blkhdr,
179 sizeof(struct virtio_blk_req),
180 VRING_DESC_F_NEXT, (id + 1) % vq_size);
182 /* Set up virtqueue descriptor for data */
183 desc = &vq_desc[(id + 1) % vq_size];
184 virtio_fill_desc(desc, dev->is_modern, (uint64_t)buf, cnt * blk_size,
185 VRING_DESC_F_NEXT | VRING_DESC_F_WRITE,
188 /* Set up virtqueue descriptor for status */
189 desc = &vq_desc[(id + 2) % vq_size];
190 virtio_fill_desc(desc, dev->is_modern, (uint64_t)&status, 1,
191 VRING_DESC_F_WRITE, 0);
193 vq_avail->ring[avail_idx % vq_size] = virtio_cpu_to_modern16 (dev, id);
195 vq_avail->idx = virtio_cpu_to_modern16(dev, avail_idx + 1);
197 /* Tell HV that the queue is ready */
198 virtio_queue_notify(dev, 0);
200 /* Wait for host to consume the descriptor */
201 time = SLOF_GetTimer() + VIRTIO_TIMEOUT;
202 while (*current_used_idx == last_used_idx) {
203 // do something better
205 if (time < SLOF_GetTimer())
212 printf("virtioblk_read failed! status = %i\n", status);