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[Qemu-devel] [PATCH 1/4] introduce virtqueue_unmap_sg
From: |
Stefano Stabellini |
Subject: |
[Qemu-devel] [PATCH 1/4] introduce virtqueue_unmap_sg |
Date: |
Tue, 25 Nov 2014 14:43:20 +0000 |
Introduce a function to unmap an sg previously mapped with
virtqueue_map_sg.
Signed-off-by: Stefano Stabellini <address@hidden>
CC: address@hidden
CC: address@hidden
CC: address@hidden
CC: address@hidden
---
hw/virtio/virtio.c | 22 ++++++++++++++++++++++
include/hw/virtio/virtio.h | 2 ++
2 files changed, 24 insertions(+)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 3e4b70c..2621ae6 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -446,6 +446,28 @@ void virtqueue_map_sg(struct iovec *sg, hwaddr *addr,
}
}
+void virtqueue_unmap_sg(const struct iovec *sg, size_t num_sg,
+ int is_write, unsigned int len)
+{
+ unsigned int i;
+ unsigned int offset;
+
+ if (num_sg > VIRTQUEUE_MAX_SIZE) {
+ error_report("virtio: unmap attempt out of bounds: %zd > %d",
+ num_sg, VIRTQUEUE_MAX_SIZE);
+ exit(1);
+ }
+
+ offset = 0;
+ for (i = 0; i < num_sg; i++) {
+ size_t size = MIN(len - offset, sg[i].iov_len);
+
+ cpu_physical_memory_unmap(sg[i].iov_base, sg[i].iov_len, is_write,
size);
+
+ offset += size;
+ }
+}
+
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
{
unsigned int i, head, max;
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 3e54e90..2325053 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -173,6 +173,8 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement
*elem,
void virtqueue_map_sg(struct iovec *sg, hwaddr *addr,
size_t num_sg, int is_write);
+void virtqueue_unmap_sg(const struct iovec *sg, size_t num_sg,
+ int is_write, unsigned int len);
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
unsigned int out_bytes);
--
1.7.10.4