1 files changed, 21 insertions, 5 deletions

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d66c8e6d0ef3..2e7689bb933b 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/hrtimer.h>
 #include <linux/dma-mapping.h>
+#include <linux/kmsan.h>
 #include <linux/spinlock.h>
 #include <xen/xen.h>
 
@@ -352,8 +353,15 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
 				   struct scatterlist *sg,
 				   enum dma_data_direction direction)
 {
-	if (!vq->use_dma_api)
+	if (!vq->use_dma_api) {
+		/*
+		 * If DMA is not used, KMSAN doesn't know that the scatterlist
+		 * is initialized by the hardware. Explicitly check/unpoison it
+		 * depending on the direction.
+		 */
+		kmsan_handle_dma(sg_page(sg), sg->offset, sg->length, direction);
 		return (dma_addr_t)sg_phys(sg);
+	}
 
 	/*
 	 * We can't use dma_map_sg, because we don't use scatterlists in
@@ -1066,7 +1074,7 @@ static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
 	if (!queue) {
 		/* Try to get a single page. You are my only hope! */
 		queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
-					  &dma_addr, GFP_KERNEL|__GFP_ZERO);
+					  &dma_addr, GFP_KERNEL | __GFP_ZERO);
 	}
 	if (!queue)
 		return -ENOMEM;
@@ -1867,7 +1875,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
 
 	ring = vring_alloc_queue(vdev, ring_size_in_bytes,
 				 &ring_dma_addr,
-				 GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+				 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
 	if (!ring)
 		goto err;
 
@@ -1879,7 +1887,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
 
 	driver = vring_alloc_queue(vdev, event_size_in_bytes,
 				   &driver_event_dma_addr,
-				   GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+				   GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
 	if (!driver)
 		goto err;
 
@@ -1889,7 +1897,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
 
 	device = vring_alloc_queue(vdev, event_size_in_bytes,
 				   &device_event_dma_addr,
-				   GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+				   GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
 	if (!device)
 		goto err;
 
@@ -2426,6 +2434,14 @@ static inline bool more_used(const struct vring_virtqueue *vq)
 	return vq->packed_ring ? more_used_packed(vq) : more_used_split(vq);
 }
 
+/**
+ * vring_interrupt - notify a virtqueue on an interrupt
+ * @irq: the IRQ number (ignored)
+ * @_vq: the struct virtqueue to notify
+ *
+ * Calls the callback function of @_vq to process the virtqueue
+ * notification.
+ */
 irqreturn_t vring_interrupt(int irq, void *_vq)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);