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From:   Stefano Garzarella <sgarzare@redhat.com>
To:     virtualization@lists.linux-foundation.org
Cc:     stefanha@redhat.com, Jason Wang <jasowang@redhat.com>,
        linux-kernel@vger.kernel.org,
        Andrey Zhadchenko <andrey.zhadchenko@virtuozzo.com>,
        "Michael S. Tsirkin" <mst@redhat.com>, kvm@vger.kernel.org,
        netdev@vger.kernel.org, eperezma@redhat.com,
        Stefano Garzarella <sgarzare@redhat.com>
Subject: [PATCH v4 4/9] vringh: define the stride used for translation
Date:   Fri, 24 Mar 2023 16:36:02 +0100
Message-Id: <20230324153607.46836-5-sgarzare@redhat.com>
In-Reply-To: <20230324153607.46836-1-sgarzare@redhat.com>
References: <20230324153607.46836-1-sgarzare@redhat.com>
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Define a macro to be reused in the different parts of the code.

Useful for the next patches where we add more arrays to manage also
translations with user VA.

Suggested-by: Eugenio Perez Martin <eperezma@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---

Notes:
    v4:
    - added this patch with the changes extracted from the next patch [Eugenio]
    - used _STRIDE instead of _SIZE [Eugenio]

 drivers/vhost/vringh.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 0ba3ef809e48..4aee230f7622 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -1141,13 +1141,15 @@ static int iotlb_translate(const struct vringh *vrh,
 	return ret;
 }
 
+#define IOTLB_IOV_STRIDE 16
+
 static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
 				  void *src, size_t len)
 {
 	u64 total_translated = 0;
 
 	while (total_translated < len) {
-		struct bio_vec iov[16];
+		struct bio_vec iov[IOTLB_IOV_STRIDE];
 		struct iov_iter iter;
 		u64 translated;
 		int ret;
@@ -1180,7 +1182,7 @@ static inline int copy_to_iotlb(const struct vringh *vrh, void *dst,
 	u64 total_translated = 0;
 
 	while (total_translated < len) {
-		struct bio_vec iov[16];
+		struct bio_vec iov[IOTLB_IOV_STRIDE];
 		struct iov_iter iter;
 		u64 translated;
 		int ret;
-- 
2.39.2