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From: xiaohui.xin@intel.com
To: netdev@vger.kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, mst@redhat.com, mingo@elte.hu,
	davem@davemloft.net, herbert@gondor.hengli.com.au,
	jdike@linux.intel.com
Cc: Xin Xiaohui <xiaohui.xin@intel.com>
Subject: [PATCH v13 16/16] An example how to alloc user buffer based on napi_gro_frags() interface.
Date: Fri, 15 Oct 2010 17:12:17 +0800	[thread overview]
Message-ID: <cdda4947e455993bf342a22d388ef05d44e6dfde.1287132437.git.xiaohui.xin@intel.com> (raw)
In-Reply-To: <1287133937-5538-1-git-send-email-xiaohui.xin@intel.com>
In-Reply-To: <fc6e95d63a2c62aaf77f8ded22fc43ccefcdbbff.1287132437.git.xiaohui.xin@intel.com>

From: Xin Xiaohui <xiaohui.xin@intel.com>

This example is made on ixgbe driver which using napi_gro_frags().
It can get buffers from guest side directly using netdev_alloc_page()
and release guest buffers using netdev_free_page().

Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
---
 drivers/net/ixgbe/ixgbe_main.c |   24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index a4a5263..47663ac 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -1032,7 +1032,14 @@ static inline void ixgbe_release_rx_desc(struct ixgbe_hw *hw,
 static bool is_rx_buffer_mapped_as_page(struct ixgbe_rx_buffer *bi,
 					struct net_device *dev)
 {
-	return true;
+	return dev_is_mpassthru(dev);
+}
+
+static u32 get_page_skb_offset(struct net_device *dev)
+{
+	if (!dev_is_mpassthru(dev))
+		return 0;
+	return dev->mp_port->vnet_hlen;
 }
 
 /**
@@ -1105,7 +1112,8 @@ static void ixgbe_alloc_rx_buffers(struct ixgbe_adapter *adapter,
 				adapter->alloc_rx_page_failed++;
 				goto no_buffers;
 			}
-			bi->page_skb_offset = 0;
+			bi->page_skb_offset =
+				get_page_skb_offset(adapter->netdev);
 			bi->dma = dma_map_page(&pdev->dev, bi->page_skb,
 					bi->page_skb_offset,
 					(PAGE_SIZE / 2),
@@ -1242,8 +1250,10 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 			len = le16_to_cpu(rx_desc->wb.upper.length);
 		}
 
-		if (is_no_buffer(rx_buffer_info))
+		if (is_no_buffer(rx_buffer_info)) {
+			printk("no buffers\n");
 			break;
+		}
 		cleaned = true;
 
 		if (!rx_buffer_info->mapped_as_page) {
@@ -1299,6 +1309,11 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 						rx_buffer_info->page_skb,
 						rx_buffer_info->page_skb_offset,
 						len);
+				if (dev_is_mpassthru(netdev) &&
+						netdev->mp_port->hash)
+					skb_shinfo(skb)->destructor_arg =
+						netdev->mp_port->hash(netdev,
+						rx_buffer_info->page_skb);
 				rx_buffer_info->page_skb = NULL;
 				skb->len += len;
 				skb->data_len += len;
@@ -1316,7 +1331,8 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 			                   upper_len);
 
 			if ((rx_ring->rx_buf_len > (PAGE_SIZE / 2)) ||
-			    (page_count(rx_buffer_info->page) != 1))
+			    (page_count(rx_buffer_info->page) != 1) ||
+				dev_is_mpassthru(netdev))
 				rx_buffer_info->page = NULL;
 			else
 				get_page(rx_buffer_info->page);
-- 
1.7.3


      parent reply	other threads:[~2010-10-15  8:53 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-15  9:12 [PATCH v13 00/16] Provide a zero-copy method on KVM virtio-net xiaohui.xin
2010-10-15  9:12 ` [PATCH v13 01/16] Add a new structure for skb buffer from external xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 02/16] Add a new struct for device to manipulate external buffer xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 03/16] Add a ndo_mp_port_prep pointer to net_device_ops xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 04/16] Add a function make external buffer owner to query capability xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 05/16] Add a function to indicate if device use external buffer xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 06/16]Use callback to deal with skb_release_data() specially xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 07/16] Modify netdev_alloc_page() to get external buffer xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 08/16] Modify netdev_free_page() to release " xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 09/16]Don't do skb recycle, if device use " xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 10/16] Add a hook to intercept external buffers from NIC driver xiaohui.xin
2010-10-19 15:24     ` David Miller
2010-10-27  1:33       ` Xin, Xiaohui
2010-10-29 20:28         ` David Miller
2010-11-08  7:43           ` Xin, Xiaohui
2010-10-15  9:12   ` [PATCH v13 11/16] Add header file for mp device xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 12/16] Add mp(mediate passthru) device xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 13/16] Add a kconfig entry and make entry for mp device xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 14/16]Provides multiple submits and asynchronous notifications xiaohui.xin
2010-10-15  9:12   ` [PATCH v13 15/16] An example how to modifiy NIC driver to use napi_gro_frags() interface xiaohui.xin
2010-10-15  9:12   ` xiaohui.xin [this message]

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