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From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com
Cc: virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org, xieyongji@bytedance.com,
	stefanha@redhat.com, file@sect.tu-berlin.de,
	ashish.kalra@amd.com, martin.radev@aisec.fraunhofer.de,
	konrad.wilk@oracle.com, kvm@vger.kernel.org
Subject: [RFC PATCH 3/7] virtio-ring: factor out desc_extra allocation
Date: Wed, 21 Apr 2021 11:21:13 +0800
Message-ID: <20210421032117.5177-4-jasowang@redhat.com> (raw)
In-Reply-To: <20210421032117.5177-1-jasowang@redhat.com>

A helper is introduced for the logic of allocating the descriptor
extra data. This will be reused by split virtqueue.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/virtio_ring.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c25ea5776687..0cdd965dba58 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1550,6 +1550,25 @@ static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq)
 	return NULL;
 }
 
+static struct vring_desc_extra *vring_alloc_desc_extra(struct vring_virtqueue *vq,
+						       unsigned int num)
+{
+	struct vring_desc_extra *desc_extra;
+	unsigned int i;
+
+	desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra),
+				   GFP_KERNEL);
+	if (!desc_extra)
+		return NULL;
+
+	memset(desc_extra, 0, num * sizeof(struct vring_desc_extra));
+
+	for (i = 0; i < num - 1; i++)
+		desc_extra[i].next = i + 1;
+
+	return desc_extra;
+}
+
 static struct virtqueue *vring_create_virtqueue_packed(
 	unsigned int index,
 	unsigned int num,
@@ -1567,7 +1586,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	struct vring_packed_desc_event *driver, *device;
 	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
 	size_t ring_size_in_bytes, event_size_in_bytes;
-	unsigned int i;
 
 	ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
 
@@ -1650,18 +1668,10 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	/* Put everything in free lists. */
 	vq->free_head = 0;
 
-	vq->packed.desc_extra = kmalloc_array(num,
-			sizeof(struct vring_desc_extra),
-			GFP_KERNEL);
+	vq->packed.desc_extra = vring_alloc_desc_extra(vq, num);
 	if (!vq->packed.desc_extra)
 		goto err_desc_extra;
 
-	memset(vq->packed.desc_extra, 0,
-		num * sizeof(struct vring_desc_extra));
-
-	for (i = 0; i < num - 1; i++)
-		vq->packed.desc_extra[i].next = i + 1;
-
 	/* No callback?  Tell other side not to bother us. */
 	if (!callback) {
 		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
-- 
2.25.1


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-21  3:21 [RFC PATCH 0/7] Untrusted device support for virtio Jason Wang
2021-04-21  3:21 ` [RFC PATCH 1/7] virtio-ring: maintain next in extra state for packed virtqueue Jason Wang
2021-04-21  3:21 ` [RFC PATCH 2/7] virtio_ring: rename vring_desc_extra_packed Jason Wang
2021-04-21  3:21 ` Jason Wang [this message]
2021-04-21  3:21 ` [RFC PATCH 4/7] virtio_ring: secure handling of mapping errors Jason Wang
2021-04-21  3:21 ` [RFC PATCH 5/7] virtio_ring: introduce virtqueue_desc_add_split() Jason Wang
2021-04-21  3:21 ` [RFC PATCH 6/7] virtio: use err label in __vring_new_virtqueue() Jason Wang
2021-04-21  3:21 ` [RFC PATCH 7/7] virtio-ring: store DMA metadata in desc_extra for split virtqueue Jason Wang
2021-04-22  6:31 ` [RFC PATCH 0/7] Untrusted device support for virtio Christoph Hellwig
2021-04-22  8:19   ` Jason Wang
2021-04-23 20:14     ` Michael S. Tsirkin
2021-04-25  1:43       ` Jason Wang
2021-04-28 21:06 ` Konrad Rzeszutek Wilk
2021-04-29  4:16   ` Jason Wang
2021-06-04 15:17     ` Konrad Rzeszutek Wilk
2021-06-07  2:46       ` Jason Wang

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