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From:   Jason Wang <jasowang@redhat.com>
To:     mst@redhat.com, jasowang@redhat.com
Cc:     lulu@redhat.com, kvm@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, rob.miller@broadcom.com,
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        mhabets@solarflare.com, eli@mellanox.com, amorenoz@redhat.com,
        maxime.coquelin@redhat.com, stefanha@redhat.com,
        sgarzare@redhat.com
Subject: [RFC PATCH 23/24] vdpa_sim: filter destination mac address
Date:   Thu, 24 Sep 2020 11:21:24 +0800
Message-Id: <20200924032125.18619-24-jasowang@redhat.com>
In-Reply-To: <20200924032125.18619-1-jasowang@redhat.com>
References: <20200924032125.18619-1-jasowang@redhat.com>
MIME-Version: 1.0
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Precedence: bulk

Add a simple unicast filter to filter out the dest MAC doesn't match
to the one stored in the config.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 49 ++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index b21670e054ba..66d901fb4c57 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -171,6 +171,22 @@ static void vdpasim_complete(struct vdpasim_virtqueue *vq, size_t len)
 	local_bh_enable();
 }
 
+static bool receive_filter(struct vdpasim *vdpasim, size_t len)
+{
+	bool modern = vdpasim->features & (1ULL << VIRTIO_F_VERSION_1);
+	size_t hdr_len = modern ? sizeof(struct virtio_net_hdr_v1) :
+				  sizeof(struct virtio_net_hdr);
+
+	if (len < ETH_ALEN + hdr_len)
+		return false;
+
+	if (!strncmp(vdpasim->buffer + hdr_len,
+		     vdpasim->config.mac, ETH_ALEN))
+		return true;
+
+	return false;
+}
+
 static void vdpasim_work(struct work_struct *work)
 {
 	struct vdpasim *vdpasim = container_of(work, struct
@@ -178,7 +194,6 @@ static void vdpasim_work(struct work_struct *work)
 	struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
 	struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
 	ssize_t read, write;
-	size_t total_write;
 	int pkts = 0;
 	int err;
 
@@ -191,36 +206,34 @@ static void vdpasim_work(struct work_struct *work)
 		goto out;
 
 	while (true) {
-		total_write = 0;
 		err = vringh_getdesc_iotlb(&txq->vring, &txq->riov, NULL,
 					   &txq->head, GFP_ATOMIC);
 		if (err <= 0)
 			break;
 
+		read = vringh_iov_pull_iotlb(&txq->vring, &txq->riov,
+					     vdpasim->buffer,
+					     PAGE_SIZE);
+
+		if (!receive_filter(vdpasim, read)) {
+			vdpasim_complete(txq, 0);
+			continue;
+		}
+
 		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->wiov,
 					   &rxq->head, GFP_ATOMIC);
 		if (err <= 0) {
-			vringh_complete_iotlb(&txq->vring, txq->head, 0);
+			vdpasim_complete(txq, 0);
 			break;
 		}
 
-		while (true) {
-			read = vringh_iov_pull_iotlb(&txq->vring, &txq->riov,
-						     vdpasim->buffer,
-						     PAGE_SIZE);
-			if (read <= 0)
-				break;
-
-			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->wiov,
-						      vdpasim->buffer, read);
-			if (write <= 0)
-				break;
-
-			total_write += write;
-		}
+		write = vringh_iov_push_iotlb(&rxq->vring, &rxq->wiov,
+					      vdpasim->buffer, read);
+		if (write <= 0)
+			break;
 
 		vdpasim_complete(txq, 0);
-		vdpasim_complete(rxq, total_write);
+		vdpasim_complete(rxq, write);
 
 		if (++pkts > 4) {
 			schedule_work(&vdpasim->work);
-- 
2.20.1