Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...

[linux-2.6.git] / drivers / xen / netback / loopback.c

diff --git a/drivers/xen/netback/loopback.c b/drivers/xen/netback/loopback.c
index e4e438b..8f7c890 100644 (file)
--- a/drivers/xen/netback/loopback.c
+++ b/drivers/xen/netback/loopback.c
@@ -45,7 +45,6 @@
  * IN THE SOFTWARE.
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/inetdevice.h>
@@ -53,8 +52,10 @@
 #include <linux/skbuff.h>
 #include <linux/ethtool.h>
 #include <net/dst.h>
+#include <net/xfrm.h>          /* secpath_reset() */
+#include <asm/hypervisor.h>    /* is_initial_xendomain() */
 
-static int nloopbacks = 8;
+static int nloopbacks = -1;
 module_param(nloopbacks, int, 0);
 MODULE_PARM_DESC(nloopbacks, "Number of netback-loopback devices to create");
 
@@ -77,10 +78,60 @@ static int loopback_close(struct net_device *dev)
        return 0;
 }
 
+#ifdef CONFIG_X86
+static int is_foreign(unsigned long pfn)
+{
+       /* NB. Play it safe for auto-translation mode. */
+       return (xen_feature(XENFEAT_auto_translated_physmap) ||
+               (phys_to_machine_mapping[pfn] & FOREIGN_FRAME_BIT));
+}
+#else
+/* How to detect a foreign mapping? Play it safe. */
+#define is_foreign(pfn)        (1)
+#endif
+
+static int skb_remove_foreign_references(struct sk_buff *skb)
+{
+       struct page *page;
+       unsigned long pfn;
+       int i, off;
+       char *vaddr;
+
+       BUG_ON(skb_shinfo(skb)->frag_list);
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               pfn = page_to_pfn(skb_shinfo(skb)->frags[i].page);
+               if (!is_foreign(pfn))
+                       continue;
+               
+               page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
+               if (unlikely(!page))
+                       return 0;
+
+               vaddr = kmap_skb_frag(&skb_shinfo(skb)->frags[i]);
+               off = skb_shinfo(skb)->frags[i].page_offset;
+               memcpy(page_address(page) + off,
+                      vaddr + off,
+                      skb_shinfo(skb)->frags[i].size);
+               kunmap_skb_frag(vaddr);
+
+               put_page(skb_shinfo(skb)->frags[i].page);
+               skb_shinfo(skb)->frags[i].page = page;
+       }
+
+       return 1;
+}
+
 static int loopback_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct net_private *np = netdev_priv(dev);
 
+       if (!skb_remove_foreign_references(skb)) {
+               np->stats.tx_dropped++;
+               dev_kfree_skb(skb);
+               return 0;
+       }
+
        dst_release(skb->dst);
        skb->dst = NULL;
 
@@ -110,6 +161,11 @@ static int loopback_start_xmit(struct sk_buff *skb, struct net_device *dev)
        skb->protocol = eth_type_trans(skb, dev);
        skb->dev      = dev;
        dev->last_rx  = jiffies;
+
+       /* Flush netfilter context: rx'ed skbuffs not expected to have any. */
+       nf_reset(skb);
+       secpath_reset(skb);
+
        netif_rx(skb);
 
        return 0;
@@ -218,7 +274,7 @@ static int __init make_loopback(int i)
        return err;
 }
 
-static void __init clean_loopback(int i)
+static void __exit clean_loopback(int i)
 {
        struct net_device *dev1, *dev2;
        char dev_name[IFNAMSIZ];
@@ -239,6 +295,9 @@ static int __init loopback_init(void)
 {
        int i, err = 0;
 
+       if (nloopbacks == -1)
+               nloopbacks = is_initial_xendomain() ? 4 : 0;
+
        for (i = 0; i < nloopbacks; i++)
                if ((err = make_loopback(i)) != 0)
                        break;