diff options
| -rw-r--r-- | drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 57 |
1 files changed, 50 insertions, 7 deletions
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c index c996e750dc02..00d7d72713be 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c @@ -46,6 +46,7 @@ struct vdpasim_blk { struct vdpasim vdpasim; void *buffer; + bool shared_backend; }; static struct vdpasim_blk *sim_to_blk(struct vdpasim *vdpasim) @@ -55,6 +56,26 @@ static struct vdpasim_blk *sim_to_blk(struct vdpasim *vdpasim) static char vdpasim_blk_id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim"; +static bool shared_backend; +module_param(shared_backend, bool, 0444); +MODULE_PARM_DESC(shared_backend, "Enable the shared backend between virtio-blk devices"); + +static void *shared_buffer; +/* mutex to synchronize shared_buffer access */ +static DEFINE_MUTEX(shared_buffer_mutex); + +static void vdpasim_blk_buffer_lock(struct vdpasim_blk *blk) +{ + if (blk->shared_backend) + mutex_lock(&shared_buffer_mutex); +} + +static void vdpasim_blk_buffer_unlock(struct vdpasim_blk *blk) +{ + if (blk->shared_backend) + mutex_unlock(&shared_buffer_mutex); +} + static bool vdpasim_blk_check_range(struct vdpasim *vdpasim, u64 start_sector, u64 num_sectors, u64 max_sectors) { @@ -154,8 +175,10 @@ static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim, break; } + vdpasim_blk_buffer_lock(blk); bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov, blk->buffer + offset, to_push); + vdpasim_blk_buffer_unlock(blk); if (bytes < 0) { dev_dbg(&vdpasim->vdpa.dev, "vringh_iov_push_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n", @@ -175,8 +198,10 @@ static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim, break; } + vdpasim_blk_buffer_lock(blk); bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->out_iov, blk->buffer + offset, to_pull); + vdpasim_blk_buffer_unlock(blk); if (bytes < 0) { dev_dbg(&vdpasim->vdpa.dev, "vringh_iov_pull_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n", @@ -256,8 +281,10 @@ static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim, } if (type == VIRTIO_BLK_T_WRITE_ZEROES) { + vdpasim_blk_buffer_lock(blk); memset(blk->buffer + offset, 0, num_sectors << SECTOR_SHIFT); + vdpasim_blk_buffer_unlock(blk); } break; @@ -366,7 +393,8 @@ static void vdpasim_blk_free(struct vdpasim *vdpasim) { struct vdpasim_blk *blk = sim_to_blk(vdpasim); - kvfree(blk->buffer); + if (!blk->shared_backend) + kvfree(blk->buffer); } static void vdpasim_blk_mgmtdev_release(struct device *dev) @@ -404,12 +432,17 @@ static int vdpasim_blk_dev_add(struct vdpa_mgmt_dev *mdev, const char *name, return PTR_ERR(simdev); blk = sim_to_blk(simdev); - - blk->buffer = kvmalloc(VDPASIM_BLK_CAPACITY << SECTOR_SHIFT, - GFP_KERNEL); - if (!blk->buffer) { - ret = -ENOMEM; - goto put_dev; + blk->shared_backend = shared_backend; + + if (blk->shared_backend) { + blk->buffer = shared_buffer; + } else { + blk->buffer = kvmalloc(VDPASIM_BLK_CAPACITY << SECTOR_SHIFT, + GFP_KERNEL); + if (!blk->buffer) { + ret = -ENOMEM; + goto put_dev; + } } ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_BLK_VQ_NUM); @@ -461,6 +494,15 @@ static int __init vdpasim_blk_init(void) if (ret) goto parent_err; + if (shared_backend) { + shared_buffer = kvmalloc(VDPASIM_BLK_CAPACITY << SECTOR_SHIFT, + GFP_KERNEL); + if (!shared_buffer) { + ret = -ENOMEM; + goto parent_err; + } + } + return 0; parent_err: @@ -470,6 +512,7 @@ parent_err: static void __exit vdpasim_blk_exit(void) { + kvfree(shared_buffer); vdpa_mgmtdev_unregister(&mgmt_dev); device_unregister(&vdpasim_blk_mgmtdev); } |