[v5,10/10] vring: Add a module parameter to force-enable the DMA API

Commit Message

Andy Lutomirski Jan. 29, 2016, 2:31 a.m. UTC

This will be useful for testing.

Signed-off-by: Andy Lutomirski <[e-mail]>
---
 drivers/virtio/virtio_ring.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 305c05cc249a..46fb77d824e9 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -45,6 +45,10 @@ 
  * API.
  */
 
+static bool force_dma_api = false;
+module_param(force_dma_api, bool, 0644);
+MODULE_PARM_DESC(force_dma_api, "force-enable the DMA API");
+
 static bool vring_use_dma_api(void)
 {
 #if defined(CONFIG_X86) && defined(CONFIG_XEN)
@@ -59,7 +63,7 @@  static bool vring_use_dma_api(void)
 	return static_cpu_has(X86_FEATURE_XENPV);
 #endif
 
-	return false;
+	return force_dma_api;
 }
 
 #ifdef DEBUG