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authorJulien Grall <julien.grall@citrix.com>2015-05-05 13:15:29 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2015-10-23 14:20:41 +0100
commitd0089e8a0e4c9723d85b01713671358e3d6960df (patch)
treea183a66197f3400504934c8e29c6b04a5c240622 /drivers/net/xen-netback/netback.c
parentnet/xen-netfront: Make it running on 64KB page granularity (diff)
downloadlinux-dev-d0089e8a0e4c9723d85b01713671358e3d6960df.tar.xz
linux-dev-d0089e8a0e4c9723d85b01713671358e3d6960df.zip
net/xen-netback: Make it running on 64KB page granularity
The PV network protocol is using 4KB page granularity. The goal of this patch is to allow a Linux using 64KB page granularity working as a network backend on a non-modified Xen. It's only necessary to adapt the ring size and break skb data in small chunk of 4KB. The rest of the code is relying on the grant table code. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r--drivers/net/xen-netback/netback.c157
1 files changed, 100 insertions, 57 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index c4e6c025d64d..e481f3710bd3 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -152,9 +152,9 @@ static inline pending_ring_idx_t pending_index(unsigned i)
static int xenvif_rx_ring_slots_needed(struct xenvif *vif)
{
if (vif->gso_mask)
- return DIV_ROUND_UP(vif->dev->gso_max_size, PAGE_SIZE) + 1;
+ return DIV_ROUND_UP(vif->dev->gso_max_size, XEN_PAGE_SIZE) + 1;
else
- return DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE);
+ return DIV_ROUND_UP(vif->dev->mtu, XEN_PAGE_SIZE);
}
static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
@@ -274,6 +274,80 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
return meta;
}
+struct gop_frag_copy {
+ struct xenvif_queue *queue;
+ struct netrx_pending_operations *npo;
+ struct xenvif_rx_meta *meta;
+ int head;
+ int gso_type;
+
+ struct page *page;
+};
+
+static void xenvif_setup_copy_gop(unsigned long gfn,
+ unsigned int offset,
+ unsigned int *len,
+ struct gop_frag_copy *info)
+{
+ struct gnttab_copy *copy_gop;
+ struct xen_page_foreign *foreign;
+ /* Convenient aliases */
+ struct xenvif_queue *queue = info->queue;
+ struct netrx_pending_operations *npo = info->npo;
+ struct page *page = info->page;
+
+ BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
+
+ if (npo->copy_off == MAX_BUFFER_OFFSET)
+ info->meta = get_next_rx_buffer(queue, npo);
+
+ if (npo->copy_off + *len > MAX_BUFFER_OFFSET)
+ *len = MAX_BUFFER_OFFSET - npo->copy_off;
+
+ copy_gop = npo->copy + npo->copy_prod++;
+ copy_gop->flags = GNTCOPY_dest_gref;
+ copy_gop->len = *len;
+
+ foreign = xen_page_foreign(page);
+ if (foreign) {
+ copy_gop->source.domid = foreign->domid;
+ copy_gop->source.u.ref = foreign->gref;
+ copy_gop->flags |= GNTCOPY_source_gref;
+ } else {
+ copy_gop->source.domid = DOMID_SELF;
+ copy_gop->source.u.gmfn = gfn;
+ }
+ copy_gop->source.offset = offset;
+
+ copy_gop->dest.domid = queue->vif->domid;
+ copy_gop->dest.offset = npo->copy_off;
+ copy_gop->dest.u.ref = npo->copy_gref;
+
+ npo->copy_off += *len;
+ info->meta->size += *len;
+
+ /* Leave a gap for the GSO descriptor. */
+ if (info->head && ((1 << info->gso_type) & queue->vif->gso_mask))
+ queue->rx.req_cons++;
+
+ info->head = 0; /* There must be something in this buffer now */
+}
+
+static void xenvif_gop_frag_copy_grant(unsigned long gfn,
+ unsigned offset,
+ unsigned int len,
+ void *data)
+{
+ unsigned int bytes;
+
+ while (len) {
+ bytes = len;
+ xenvif_setup_copy_gop(gfn, offset, &bytes, data);
+ offset += bytes;
+ len -= bytes;
+ }
+}
+
/*
* Set up the grant operations for this fragment. If it's a flipping
* interface, we also set up the unmap request from here.
@@ -283,83 +357,52 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
struct page *page, unsigned long size,
unsigned long offset, int *head)
{
- struct gnttab_copy *copy_gop;
- struct xenvif_rx_meta *meta;
+ struct gop_frag_copy info = {
+ .queue = queue,
+ .npo = npo,
+ .head = *head,
+ .gso_type = XEN_NETIF_GSO_TYPE_NONE,
+ };
unsigned long bytes;
- int gso_type = XEN_NETIF_GSO_TYPE_NONE;
if (skb_is_gso(skb)) {
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
- gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+ info.gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
- gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+ info.gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
}
/* Data must not cross a page boundary. */
BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
- meta = npo->meta + npo->meta_prod - 1;
+ info.meta = npo->meta + npo->meta_prod - 1;
/* Skip unused frames from start of page */
page += offset >> PAGE_SHIFT;
offset &= ~PAGE_MASK;
while (size > 0) {
- struct xen_page_foreign *foreign;
-
BUG_ON(offset >= PAGE_SIZE);
- BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
-
- if (npo->copy_off == MAX_BUFFER_OFFSET)
- meta = get_next_rx_buffer(queue, npo);
bytes = PAGE_SIZE - offset;
if (bytes > size)
bytes = size;
- if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
- bytes = MAX_BUFFER_OFFSET - npo->copy_off;
-
- copy_gop = npo->copy + npo->copy_prod++;
- copy_gop->flags = GNTCOPY_dest_gref;
- copy_gop->len = bytes;
-
- foreign = xen_page_foreign(page);
- if (foreign) {
- copy_gop->source.domid = foreign->domid;
- copy_gop->source.u.ref = foreign->gref;
- copy_gop->flags |= GNTCOPY_source_gref;
- } else {
- copy_gop->source.domid = DOMID_SELF;
- copy_gop->source.u.gmfn =
- virt_to_gfn(page_address(page));
- }
- copy_gop->source.offset = offset;
-
- copy_gop->dest.domid = queue->vif->domid;
- copy_gop->dest.offset = npo->copy_off;
- copy_gop->dest.u.ref = npo->copy_gref;
-
- npo->copy_off += bytes;
- meta->size += bytes;
-
- offset += bytes;
+ info.page = page;
+ gnttab_foreach_grant_in_range(page, offset, bytes,
+ xenvif_gop_frag_copy_grant,
+ &info);
size -= bytes;
+ offset = 0;
- /* Next frame */
- if (offset == PAGE_SIZE && size) {
+ /* Next page */
+ if (size) {
BUG_ON(!PageCompound(page));
page++;
- offset = 0;
}
-
- /* Leave a gap for the GSO descriptor. */
- if (*head && ((1 << gso_type) & queue->vif->gso_mask))
- queue->rx.req_cons++;
-
- *head = 0; /* There must be something in this buffer now. */
-
}
+
+ *head = info.head;
}
/*
@@ -758,7 +801,7 @@ static int xenvif_count_requests(struct xenvif_queue *queue,
first->size -= txp->size;
slots++;
- if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
+ if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
txp->offset, txp->size);
xenvif_fatal_tx_err(queue->vif);
@@ -1339,11 +1382,11 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
}
/* No crossing a page as the payload mustn't fragment. */
- if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
+ if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
netdev_err(queue->vif->dev,
"txreq.offset: %u, size: %u, end: %lu\n",
txreq.offset, txreq.size,
- (unsigned long)(txreq.offset&~PAGE_MASK) + txreq.size);
+ (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size);
xenvif_fatal_tx_err(queue->vif);
break;
}
@@ -1409,7 +1452,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
virt_to_gfn(skb->data);
queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF;
queue->tx_copy_ops[*copy_ops].dest.offset =
- offset_in_page(skb->data);
+ offset_in_page(skb->data) & ~XEN_PAGE_MASK;
queue->tx_copy_ops[*copy_ops].len = data_len;
queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref;
@@ -1894,7 +1937,7 @@ int xenvif_map_frontend_rings(struct xenvif_queue *queue,
goto err;
txs = (struct xen_netif_tx_sring *)addr;
- BACK_RING_INIT(&queue->tx, txs, PAGE_SIZE);
+ BACK_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
&rx_ring_ref, 1, &addr);
@@ -1902,7 +1945,7 @@ int xenvif_map_frontend_rings(struct xenvif_queue *queue,
goto err;
rxs = (struct xen_netif_rx_sring *)addr;
- BACK_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
+ BACK_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
return 0;