With indirect vring descriptors, one can no longer assume that the
maximum number of requests is VRING_MAX / 2 (outhdr and inhdr). Now a
single indirect descriptor can contain the outhdr and inhdr so max
requests becomes VRING_MAX.
Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxxxxxxxxxx>
---
hw/virtio-blk.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 591eace..7ae3c56 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -26,7 +26,9 @@
enum {
SEG_MAX = 126, /* maximum number of I/O segments */
VRING_MAX = SEG_MAX + 2, /* maximum number of vring descriptors */
- REQ_MAX = VRING_MAX / 2, /* maximum number of requests in the vring */
+ REQ_MAX = VRING_MAX, /* maximum number of requests in the vring,
+ * is VRING_MAX / 2 with traditional and
+ * VRING_MAX with indirect descriptors */
};
typedef struct {
--
1.7.10.4
--
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