From f36c374782e40a3812f729838b5b80d2ce601725 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Wed, 21 Nov 2012 02:02:16 +0000 Subject: xen/netfront: handle compound page fragments on transmit An SKB paged fragment can consist of a compound page with order > 0. However the netchannel protocol deals only in PAGE_SIZE frames. Handle this in xennet_make_frags by iterating over the frames which make up the page. This is the netfront equivalent to 6a8ed462f16b for netback. Signed-off-by: Ian Campbell Cc: netdev@vger.kernel.org Cc: xen-devel@lists.xen.org Cc: Eric Dumazet Cc: Konrad Rzeszutek Wilk Cc: ANNIE LI Cc: Sander Eikelenboom Cc: Stefan Bader Acked-by: Eric Dumazet Acked-by: Konrad Rzeszutek Wilk Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 98 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 77 insertions(+), 21 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index caa011008cd0..fc24eb9b3948 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -452,29 +452,85 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, /* Grant backend access to each skb fragment page. */ for (i = 0; i < frags; i++) { skb_frag_t *frag = skb_shinfo(skb)->frags + i; + struct page *page = skb_frag_page(frag); - tx->flags |= XEN_NETTXF_more_data; + len = skb_frag_size(frag); + offset = frag->page_offset; - id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); - np->tx_skbs[id].skb = skb_get(skb); - tx = RING_GET_REQUEST(&np->tx, prod++); - tx->id = id; - ref = gnttab_claim_grant_reference(&np->gref_tx_head); - BUG_ON((signed short)ref < 0); + /* Data must not cross a page boundary. */ + BUG_ON(len + offset > PAGE_SIZE<xbdev->otherend_id, - mfn, GNTMAP_readonly); + /* Skip unused frames from start of page */ + page += offset >> PAGE_SHIFT; + offset &= ~PAGE_MASK; - tx->gref = np->grant_tx_ref[id] = ref; - tx->offset = frag->page_offset; - tx->size = skb_frag_size(frag); - tx->flags = 0; + while (len > 0) { + unsigned long bytes; + + BUG_ON(offset >= PAGE_SIZE); + + bytes = PAGE_SIZE - offset; + if (bytes > len) + bytes = len; + + tx->flags |= XEN_NETTXF_more_data; + + id = get_id_from_freelist(&np->tx_skb_freelist, + np->tx_skbs); + np->tx_skbs[id].skb = skb_get(skb); + tx = RING_GET_REQUEST(&np->tx, prod++); + tx->id = id; + ref = gnttab_claim_grant_reference(&np->gref_tx_head); + BUG_ON((signed short)ref < 0); + + mfn = pfn_to_mfn(page_to_pfn(page)); + gnttab_grant_foreign_access_ref(ref, + np->xbdev->otherend_id, + mfn, GNTMAP_readonly); + + tx->gref = np->grant_tx_ref[id] = ref; + tx->offset = offset; + tx->size = bytes; + tx->flags = 0; + + offset += bytes; + len -= bytes; + + /* Next frame */ + if (offset == PAGE_SIZE && len) { + BUG_ON(!PageCompound(page)); + page++; + offset = 0; + } + } } np->tx.req_prod_pvt = prod; } +/* + * Count how many ring slots are required to send the frags of this + * skb. Each frag might be a compound page. + */ +static int xennet_count_skb_frag_slots(struct sk_buff *skb) +{ + int i, frags = skb_shinfo(skb)->nr_frags; + int pages = 0; + + for (i = 0; i < frags; i++) { + skb_frag_t *frag = skb_shinfo(skb)->frags + i; + unsigned long size = skb_frag_size(frag); + unsigned long offset = frag->page_offset; + + /* Skip unused frames from start of page */ + offset &= ~PAGE_MASK; + + pages += PFN_UP(offset + size); + } + + return pages; +} + static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned short id; @@ -487,23 +543,23 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) grant_ref_t ref; unsigned long mfn; int notify; - int frags = skb_shinfo(skb)->nr_frags; + int slots; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); unsigned long flags; - frags += DIV_ROUND_UP(offset + len, PAGE_SIZE); - if (unlikely(frags > MAX_SKB_FRAGS + 1)) { - printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n", - frags); - dump_stack(); + slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + + xennet_count_skb_frag_slots(skb); + if (unlikely(slots > MAX_SKB_FRAGS + 1)) { + net_alert_ratelimited( + "xennet: skb rides the rocket: %d slots\n", slots); goto drop; } spin_lock_irqsave(&np->tx_lock, flags); if (unlikely(!netif_carrier_ok(dev) || - (frags > 1 && !xennet_can_sg(dev)) || + (slots > 1 && !xennet_can_sg(dev)) || netif_needs_gso(skb, netif_skb_features(skb)))) { spin_unlock_irqrestore(&np->tx_lock, flags); goto drop; -- cgit v1.2.3 From 8e0e46bb3224057fd65f3041977163b6ee13346d Mon Sep 17 00:00:00 2001 From: Bill Pemberton Date: Mon, 3 Dec 2012 09:24:22 -0500 Subject: xen-netfront: remove __dev* attributes CONFIG_HOTPLUG is going away as an option. As result the __dev* markings will be going away. Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit. Signed-off-by: Bill Pemberton Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netfront.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index fc24eb9b3948..53451dd7b602 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1311,7 +1311,7 @@ static const struct net_device_ops xennet_netdev_ops = { #endif }; -static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev) +static struct net_device *xennet_create_dev(struct xenbus_device *dev) { int i, err; struct net_device *netdev; @@ -1407,7 +1407,7 @@ static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev * structures and the ring buffers for communication with the backend, and * inform the backend of the appropriate details for those. */ -static int __devinit netfront_probe(struct xenbus_device *dev, +static int netfront_probe(struct xenbus_device *dev, const struct xenbus_device_id *id) { int err; @@ -1967,7 +1967,7 @@ static const struct xenbus_device_id netfront_ids[] = { }; -static int __devexit xennet_remove(struct xenbus_device *dev) +static int xennet_remove(struct xenbus_device *dev) { struct netfront_info *info = dev_get_drvdata(&dev->dev); @@ -1990,7 +1990,7 @@ static int __devexit xennet_remove(struct xenbus_device *dev) static DEFINE_XENBUS_DRIVER(netfront, , .probe = netfront_probe, - .remove = __devexit_p(xennet_remove), + .remove = xennet_remove, .resume = netfront_resume, .otherend_changed = netback_changed, ); -- cgit v1.2.3 From 1dd06ae8db716e17ec7e06244b858606edf378c0 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 6 Dec 2012 14:30:56 +0000 Subject: drivers/net: fix up function prototypes after __dev* removals The __dev* removal patches for the network drivers ended up messing up the function prototypes for a bunch of drivers. This patch fixes all of them back up to be properly aligned. Bonus is that this almost removes 100 lines of code, always a nice surprise. Signed-off-by: Greg Kroah-Hartman Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 53451dd7b602..c26e28b4bd9f 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1408,7 +1408,7 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev) * inform the backend of the appropriate details for those. */ static int netfront_probe(struct xenbus_device *dev, - const struct xenbus_device_id *id) + const struct xenbus_device_id *id) { int err; struct net_device *netdev; -- cgit v1.2.3 From d9a58a782e396a0f04e8445b7ba3763c8a48c7fe Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Mon, 7 Jan 2013 05:32:06 +0000 Subject: xen/netfront: improve truesize tracking Using RX_COPY_THRESHOLD is incorrect if the SKB is actually smaller than that. We have already accounted for this in NETFRONT_SKB_CB(skb)->pull_to so use that instead. Fixes WARN_ON from skb_try_coalesce. Signed-off-by: Ian Campbell Cc: Sander Eikelenboom Cc: Konrad Rzeszutek Wilk Cc: annie li Cc: xen-devel@lists.xen.org Cc: netdev@vger.kernel.org Cc: stable@kernel.org # 3.7.x only Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index c26e28b4bd9f..7ffa43bd7cf9 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1015,29 +1015,10 @@ err: i = xennet_fill_frags(np, skb, &tmpq); /* - * Truesize approximates the size of true data plus - * any supervisor overheads. Adding hypervisor - * overheads has been shown to significantly reduce - * achievable bandwidth with the default receive - * buffer size. It is therefore not wise to account - * for it here. - * - * After alloc_skb(RX_COPY_THRESHOLD), truesize is set - * to RX_COPY_THRESHOLD + the supervisor - * overheads. Here, we add the size of the data pulled - * in xennet_fill_frags(). - * - * We also adjust for any unused space in the main - * data area by subtracting (RX_COPY_THRESHOLD - - * len). This is especially important with drivers - * which split incoming packets into header and data, - * using only 66 bytes of the main data area (see the - * e1000 driver for example.) On such systems, - * without this last adjustement, our achievable - * receive throughout using the standard receive - * buffer size was cut by 25%(!!!). - */ - skb->truesize += skb->data_len - RX_COPY_THRESHOLD; + * Truesize is the actual allocation size, even if the + * allocation is only partially used. + */ + skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags; skb->len += skb->data_len; if (rx->flags & XEN_NETRXF_csum_blank) -- cgit v1.2.3