diff options
Diffstat (limited to 'qemu/roms/SLOF/lib/libvirtio/virtio-blk.c')
| -rw-r--r-- | qemu/roms/SLOF/lib/libvirtio/virtio-blk.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/qemu/roms/SLOF/lib/libvirtio/virtio-blk.c b/qemu/roms/SLOF/lib/libvirtio/virtio-blk.c new file mode 100644 index 000000000..826f2ea0e --- /dev/null +++ b/qemu/roms/SLOF/lib/libvirtio/virtio-blk.c @@ -0,0 +1,185 @@ +/****************************************************************************** + * Copyright (c) 2011 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 <cpu.h> +#include <helpers.h> +#include "virtio.h" +#include "virtio-blk.h" + +#define DEFAULT_SECTOR_SIZE 512 + +/** + * Initialize virtio-block device. + * @param dev pointer to virtio device information + */ +int +virtioblk_init(struct virtio_device *dev) +{ + struct vring_avail *vq_avail; + int blk_size = DEFAULT_SECTOR_SIZE; + int features; + + /* 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 support F_BLK_SIZE */ + virtio_set_guest_features(dev, VIRTIO_BLK_F_BLK_SIZE); + + vq_avail = virtio_get_vring_avail(dev, 0); + vq_avail->flags = VRING_AVAIL_F_NO_INTERRUPT; + vq_avail->idx = 0; + + /* Tell HV that setup succeeded */ + virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE|VIRTIO_STAT_DRIVER + |VIRTIO_STAT_DRIVER_OK); + + virtio_get_host_features(dev, &features); + if (features & VIRTIO_BLK_F_BLK_SIZE) { + blk_size = virtio_get_config(dev, + offset_of(struct virtio_blk_cfg, blk_size), + sizeof(blk_size)); + } + + return blk_size; +} + + +/** + * Shutdown the virtio-block device. + * @param dev pointer to virtio device information + */ +void +virtioblk_shutdown(struct virtio_device *dev) +{ + /* Quiesce device */ + virtio_set_status(dev, VIRTIO_STAT_FAILED); + + /* Reset device */ + virtio_reset_device(dev); +} + + +/** + * Read blocks + * @param reg pointer to "reg" property + * @param buf pointer to destination buffer + * @param blocknum block number of the first block that should be read + * @param cnt amount of blocks that should be read + * @return number of blocks that have been read successfully + */ +int +virtioblk_read(struct virtio_device *dev, char *buf, long blocknum, long cnt) +{ + struct vring_desc *desc; + int id; + static struct virtio_blk_req blkhdr; + //struct virtio_blk_config *blkconf; + uint64_t capacity; + uint32_t vq_size, time; + struct vring_desc *vq_desc; /* Descriptor vring */ + struct vring_avail *vq_avail; /* "Available" vring */ + struct vring_used *vq_used; /* "Used" vring */ + volatile uint8_t status = -1; + volatile uint16_t *current_used_idx; + uint16_t last_used_idx; + int blk_size = DEFAULT_SECTOR_SIZE; + + //printf("virtioblk_read: dev=%p buf=%p blocknum=%li count=%li\n", + // dev, buf, blocknum, cnt); + + /* Check whether request is within disk capacity */ + capacity = virtio_get_config(dev, + offset_of(struct virtio_blk_cfg, capacity), + sizeof(capacity)); + if (blocknum + cnt - 1 > capacity) { + puts("virtioblk_read: Access beyond end of device!"); + return 0; + } + + blk_size = virtio_get_config(dev, + offset_of(struct virtio_blk_cfg, blk_size), + sizeof(blk_size)); + if (blk_size % DEFAULT_SECTOR_SIZE) { + fprintf(stderr, "virtio-blk: Unaligned sector read %d\n", blk_size); + return 0; + } + + vq_size = virtio_get_qsize(dev, 0); + vq_desc = virtio_get_vring_desc(dev, 0); + vq_avail = virtio_get_vring_avail(dev, 0); + vq_used = virtio_get_vring_used(dev, 0); + + last_used_idx = vq_used->idx; + current_used_idx = &vq_used->idx; + + /* Set up header */ + blkhdr.type = VIRTIO_BLK_T_IN | VIRTIO_BLK_T_BARRIER; + blkhdr.ioprio = 1; + blkhdr.sector = blocknum * blk_size / DEFAULT_SECTOR_SIZE; + + /* Determine descriptor index */ + id = (vq_avail->idx * 3) % vq_size; + + /* Set up virtqueue descriptor for header */ + desc = &vq_desc[id]; + desc->addr = (uint64_t)&blkhdr; + desc->len = sizeof(struct virtio_blk_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)buf; + desc->len = cnt * blk_size; + desc->flags = VRING_DESC_F_NEXT | VRING_DESC_F_WRITE; + desc->next = (id + 2) % vq_size; + + /* Set up virtqueue descriptor for status */ + desc = &vq_desc[(id + 2) % vq_size]; + desc->addr = (uint64_t)&status; + desc->len = 1; + desc->flags = VRING_DESC_F_WRITE; + desc->next = 0; + + vq_avail->ring[vq_avail->idx % vq_size] = id; + mb(); + vq_avail->idx += 1; + + /* Tell HV that the queue is ready */ + virtio_queue_notify(dev, 0); + + /* 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; + } + + if (status == 0) + return cnt; + + printf("virtioblk_read failed! status = %i\n", status); + + return 0; +} |