From b53f16361ee59bfd47873e47b9f6089c07fef3b3 Mon Sep 17 00:00:00 2001
From: Amos Kong <akong@redhat.com>
Date: Tue, 10 Sep 2013 06:08:00 +0200
Subject: [PATCH 18/39] virtio: Introduce virtqueue_get_avail_bytes()
RH-Author: Amos Kong <akong@redhat.com>
Message-id: <1378793288-3371-19-git-send-email-akong@redhat.com>
Patchwork-id: 54253
O-Subject: [RHEL-6.5 qemu-kvm PATCH v3 18/26] virtio: Introduce virtqueue_get_avail_bytes()
Bugzilla: 786407
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
From: Amit Shah <amit.shah@redhat.com>
The current virtqueue_avail_bytes() is oddly named, and checks if a
particular number of bytes are available in a vq. A better API is to
fetch the number of bytes available in the vq, and let the caller do
what's interesting with the numbers.
Introduce virtqueue_get_avail_bytes(), which returns the number of bytes
for buffers marked for both, in as well as out. virtqueue_avail_bytes()
is made a wrapper over this new function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 0d8d7690850eb0cf2b2b60933cf47669a6b6f18f)
---
hw/virtio.c | 28 +++++++++++++++++++++-------
hw/virtio.h | 5 ++++-
2 files changed, 25 insertions(+), 8 deletions(-)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
hw/virtio.c | 28 +++++++++++++++++++++-------
hw/virtio.h | 5 ++++-
2 files changed, 25 insertions(+), 8 deletions(-)
diff --git a/hw/virtio.c b/hw/virtio.c
index 4060226..0bd3912 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -339,7 +339,8 @@ static unsigned virtqueue_next_desc(target_phys_addr_t desc_pa,
return next;
}
-int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes)
{
unsigned int idx;
unsigned int total_bufs, in_total, out_total;
@@ -384,13 +385,9 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
}
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
- if (in_bytes > 0 &&
- (in_total += vring_desc_len(desc_pa, i)) >= in_bytes)
- return 1;
+ in_total += vring_desc_len(desc_pa, i);
} else {
- if (out_bytes > 0 &&
- (out_total += vring_desc_len(desc_pa, i)) >= out_bytes)
- return 1;
+ out_total += vring_desc_len(desc_pa, i);
}
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
@@ -399,7 +396,24 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
else
total_bufs++;
}
+ if (in_bytes) {
+ *in_bytes = in_total;
+ }
+ if (out_bytes) {
+ *out_bytes = out_total;
+ }
+}
+int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+ unsigned int out_bytes)
+{
+ unsigned int in_total, out_total;
+
+ virtqueue_get_avail_bytes(vq, &in_total, &out_total);
+ if ((in_bytes && in_bytes < in_total)
+ || (out_bytes && out_bytes < out_total)) {
+ return 1;
+ }
return 0;
}
diff --git a/hw/virtio.h b/hw/virtio.h
index f603208..fbf3aea 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -153,7 +153,10 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
void virtqueue_map_sg(struct iovec *sg, target_phys_addr_t *addr,
size_t num_sg, int is_write);
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
-int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes);
+int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+ unsigned int out_bytes);
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes);
void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
--
1.7.1