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From:   Stefano Garzarella <sgarzare@redhat.com>
To:     virtualization@lists.linux-foundation.org
Cc:     Xie Yongji <xieyongji@bytedance.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Stefano Garzarella <sgarzare@redhat.com>,
        Laurent Vivier <lvivier@redhat.com>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        linux-kernel@vger.kernel.org, Max Gurtovoy <mgurtovoy@nvidia.com>,
        Jason Wang <jasowang@redhat.com>, kvm@vger.kernel.org
Subject: [PATCH RFC v2 05/10] vringh: add vringh_kiov_length() helper
Date:   Thu, 28 Jan 2021 15:41:22 +0100
Message-Id: <20210128144127.113245-6-sgarzare@redhat.com>
In-Reply-To: <20210128144127.113245-1-sgarzare@redhat.com>
References: <20210128144127.113245-1-sgarzare@redhat.com>
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This new helper returns the total number of bytes covered by
a vringh_kiov.

Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/linux/vringh.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 755211ebd195..84db7b8f912f 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -199,6 +199,17 @@ static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov)
 	kiov->iov = NULL;
 }
 
+static inline size_t vringh_kiov_length(struct vringh_kiov *kiov)
+{
+	size_t len = 0;
+	int i;
+
+	for (i = kiov->i; i < kiov->used; i++)
+		len += kiov->iov[i].iov_len;
+
+	return len;
+}
+
 void vringh_kiov_advance(struct vringh_kiov *kiov, size_t len);
 
 int vringh_getdesc_kern(struct vringh *vrh,
-- 
2.29.2