If the premapped mode is enabled, the dma array(struct vring_desc_dma) of virtio core will not be allocated. That is judged when find_vqs() is called. To avoid allocating dma array in find_vqs() and releasing it immediately by virtqueue_set_dma_premapped(). This patch introduces a new parameter to find_vqs(). Then we can judge should we allocate the dma array(struct vring_desc_dma) or not inside find_vqs(). The driver must check the premapped mode of every vq after find_vqs(). Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> --- drivers/virtio/virtio_ring.c | 4 ++-- include/linux/virtio_config.h | 1 + 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 769ec6360d7f..e5e9672b4ab2 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2145,7 +2145,7 @@ static struct virtqueue *vring_create_virtqueue_packed(struct virtio_device *vde vq->packed_ring = true; vq->dma_dev = dma_dev; vq->use_dma_api = vring_use_dma_api(vdev); - vq->premapped = false; + vq->premapped = vq->use_dma_api && cfg_vq_get(cfg, premapped); vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && !cfg_vq_get(cfg, ctx); @@ -2687,7 +2687,7 @@ static struct virtqueue *__vring_new_virtqueue(struct virtio_device *vdev, #endif vq->dma_dev = tp_cfg->dma_dev; vq->use_dma_api = vring_use_dma_api(vdev); - vq->premapped = false; + vq->premapped = vq->use_dma_api && cfg_vq_get(cfg, premapped); vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && !cfg_vq_get(cfg, ctx); diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index e2c72e125dae..f462c3f1691c 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -105,6 +105,7 @@ struct virtio_vq_config { vq_callback_t **callbacks; const char *const *names; const bool *ctx; + const bool *premapped; struct irq_affinity *desc; }; -- 2.32.0.3.g01195cf9f