virgl: Support copy transfers

Support transfers that use a different resource as the source of data to
transfer. This will be used in upcoming commits to send data to host
buffers through a transfer upload buffer, in order to avoid waiting
when the buffer resource is busy.

Note that we don't support queueing copy transfers in the transfer
queue. Copy transfers should be emitted directly in the command queue,
allowing us to avoid flushes before them and leads to better
performance.

Signed-off-by: Alexandros Frantzis <[email protected]>
Reviewed-by: Chia-I Wu <[email protected]>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/gallium/drivers/virgl/virgl_resource.c b/src/gallium/drivers/virgl/virgl_resource.c
index e334d55fa79..fd01df1c10a 100644
--- a/src/gallium/drivers/virgl/virgl_resource.c
+++ b/src/gallium/drivers/virgl/virgl_resource.c
@@ -401,6 +401,8 @@ virgl_resource_create_transfer(struct slab_child_pool *pool,
    trans->base.layer_stride = metadata->layer_stride[level];
    trans->offset = offset;
    util_range_init(&trans->range);
+   trans->copy_src_res = NULL;
+   trans->copy_src_offset = 0;
 
    if (trans->base.resource->target != PIPE_TEXTURE_3D &&
        trans->base.resource->target != PIPE_TEXTURE_CUBE &&
@@ -417,6 +419,7 @@ virgl_resource_create_transfer(struct slab_child_pool *pool,
 void virgl_resource_destroy_transfer(struct slab_child_pool *pool,
                                      struct virgl_transfer *trans)
 {
+   pipe_resource_reference(&trans->copy_src_res, NULL);
    util_range_destroy(&trans->range);
    slab_free(pool, trans);
 }