[RFC PATCH v8 16/16] An example how to alloc user buffer based on napi_gro_frags() interface.
From: <hidden>
Date: 2010-07-29 11:02:08
Also in:
kvm, lkml
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Xin Xiaohui <redacted> 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(). --- drivers/net/ixgbe/ixgbe_main.c | 19 +++++++++++++++---- 1 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index cfe6853..de5c6d0 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c@@ -691,7 +691,14 @@ 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; } /**
@@ -764,7 +771,8 @@ 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 = pci_map_page(pdev, bi->page_skb, bi->page_skb_offset, (PAGE_SIZE / 2),
@@ -899,8 +907,10 @@ 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;
@@ -962,7 +972,8 @@ 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);
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1.5.4.4