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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [NET] front: Allow packets to be copied on the receive path instead of flipped.
# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID d4efff1beedbabd379a620586e56adc2800b9cb8
# Parent 6217dbbba0affcb64aeae7803fc1d3cadf231d51
[NET] front: Allow packets to be copied on the receive path instead of flipped.
Signed-off-by: Steven Smith <ssmith@xxxxxxxxxxxxx>
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c | 253 +++++++++++--------
1 files changed, 158 insertions(+), 95 deletions(-)
diff -r 6217dbbba0af -r d4efff1beedb
linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c Wed Aug 16
16:11:12 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c Wed Aug 16
16:11:53 2006 +0100
@@ -83,6 +83,7 @@ struct netfront_info {
unsigned int handle;
unsigned int evtchn, irq;
+ unsigned int copying_receiver;
/* Receive-ring batched refills. */
#define RX_MIN_TARGET 8
@@ -171,7 +172,7 @@ static inline grant_ref_t xennet_get_rx_
static int talk_to_backend(struct xenbus_device *, struct netfront_info *);
static int setup_device(struct xenbus_device *, struct netfront_info *);
-static struct net_device *create_netdev(int, struct xenbus_device *);
+static struct net_device *create_netdev(int, int, struct xenbus_device *);
static void netfront_closing(struct xenbus_device *);
@@ -213,6 +214,7 @@ static int __devinit netfront_probe(stru
struct net_device *netdev;
struct netfront_info *info;
unsigned int handle;
+ unsigned feature_rx_copy;
err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%u", &handle);
if (err != 1) {
@@ -220,7 +222,22 @@ static int __devinit netfront_probe(stru
return err;
}
- netdev = create_netdev(handle, dev);
+#ifndef CONFIG_XEN
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "feature-rx-copy", "%u",
+ &feature_rx_copy);
+ if (err != 1) {
+ xenbus_dev_fatal(dev, err, "reading feature-rx-copy");
+ return err;
+ }
+ if (!feature_rx_copy) {
+ xenbus_dev_fatal(dev, 0, "need a copy-capable backend");
+ return -EINVAL;
+ }
+#else
+ feature_rx_copy = 0;
+#endif
+
+ netdev = create_netdev(handle, feature_rx_copy, dev);
if (IS_ERR(netdev)) {
err = PTR_ERR(netdev);
xenbus_dev_fatal(dev, err, "creating netdev");
@@ -323,6 +340,13 @@ again:
"event-channel", "%u", info->evtchn);
if (err) {
message = "writing event-channel";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
+ info->copying_receiver);
+ if (err) {
+ message = "writing request-rx-copy";
goto abort_transaction;
}
@@ -597,6 +621,8 @@ static void network_alloc_rx_buffers(str
grant_ref_t ref;
unsigned long pfn;
void *vaddr;
+ int nr_flips;
+ netif_rx_request_t *req;
if (unlikely(!netif_carrier_ok(dev)))
return;
@@ -652,7 +678,7 @@ no_skb:
np->rx_target = np->rx_max_target;
refill:
- for (i = 0; ; i++) {
+ for (nr_flips = i = 0; ; i++) {
if ((skb = __skb_dequeue(&np->rx_batch)) == NULL)
break;
@@ -663,7 +689,6 @@ no_skb:
BUG_ON(np->rx_skbs[id]);
np->rx_skbs[id] = skb;
- RING_GET_REQUEST(&np->rx, req_prod + i)->id = id;
ref = gnttab_claim_grant_reference(&np->gref_rx_head);
BUG_ON((signed short)ref < 0);
np->grant_rx_ref[id] = ref;
@@ -671,49 +696,67 @@ no_skb:
pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page);
vaddr = page_address(skb_shinfo(skb)->frags[0].page);
- gnttab_grant_foreign_transfer_ref(ref,
- np->xbdev->otherend_id, pfn);
- RING_GET_REQUEST(&np->rx, req_prod + i)->gref = ref;
- np->rx_pfn_array[i] = pfn_to_mfn(pfn);
+ req = RING_GET_REQUEST(&np->rx, req_prod + i);
+ if (!np->copying_receiver) {
+ gnttab_grant_foreign_transfer_ref(ref,
+
np->xbdev->otherend_id,
+ pfn);
+ np->rx_pfn_array[nr_flips] = pfn_to_mfn(pfn);
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ /* Remove this page before passing
+ * back to Xen. */
+ set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+ MULTI_update_va_mapping(np->rx_mcl+i,
+ (unsigned long)vaddr,
+ __pte(0), 0);
+ }
+ } else {
+ gnttab_grant_foreign_access_ref(ref,
+ np->xbdev->otherend_id,
+ pfn,
+ 0);
+ }
+
+ req->id = id;
+ req->gref = ref;
+ }
+
+ if ( nr_flips != 0 ) {
+ /* Tell the ballon driver what is going on. */
+ balloon_update_driver_allowance(i);
+
+ set_xen_guest_handle(reservation.extent_start,
+ np->rx_pfn_array);
+ reservation.nr_extents = nr_flips;
+ reservation.extent_order = 0;
+ reservation.address_bits = 0;
+ reservation.domid = DOMID_SELF;
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
- /* Remove this page before passing back to Xen. */
- set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
- MULTI_update_va_mapping(np->rx_mcl+i,
- (unsigned long)vaddr,
- __pte(0), 0);
+ /* After all PTEs have been zapped, flush the TLB. */
+ np->rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] =
+ UVMF_TLB_FLUSH|UVMF_ALL;
+
+ /* Give away a batch of pages. */
+ np->rx_mcl[i].op = __HYPERVISOR_memory_op;
+ np->rx_mcl[i].args[0] = XENMEM_decrease_reservation;
+ np->rx_mcl[i].args[1] = (unsigned long)&reservation;
+
+ /* Zap PTEs and give away pages in one big
+ * multicall. */
+ (void)HYPERVISOR_multicall(np->rx_mcl, i+1);
+
+ /* Check return status of HYPERVISOR_memory_op(). */
+ if (unlikely(np->rx_mcl[i].result != i))
+ panic("Unable to reduce memory reservation\n");
+ } else {
+ if (HYPERVISOR_memory_op(XENMEM_decrease_reservation,
+ &reservation) != i)
+ panic("Unable to reduce memory reservation\n");
}
- }
-
- /* Tell the ballon driver what is going on. */
- balloon_update_driver_allowance(i);
-
- set_xen_guest_handle(reservation.extent_start, np->rx_pfn_array);
- reservation.nr_extents = i;
- reservation.extent_order = 0;
- reservation.address_bits = 0;
- reservation.domid = DOMID_SELF;
-
- if (!xen_feature(XENFEAT_auto_translated_physmap)) {
- /* After all PTEs have been zapped, flush the TLB. */
- np->rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] =
- UVMF_TLB_FLUSH|UVMF_ALL;
-
- /* Give away a batch of pages. */
- np->rx_mcl[i].op = __HYPERVISOR_memory_op;
- np->rx_mcl[i].args[0] = XENMEM_decrease_reservation;
- np->rx_mcl[i].args[1] = (unsigned long)&reservation;
-
- /* Zap PTEs and give away pages in one big multicall. */
- (void)HYPERVISOR_multicall(np->rx_mcl, i+1);
-
- /* Check return status of HYPERVISOR_memory_op(). */
- if (unlikely(np->rx_mcl[i].result != i))
- panic("Unable to reduce memory reservation\n");
- } else
- if (HYPERVISOR_memory_op(XENMEM_decrease_reservation,
- &reservation) != i)
- panic("Unable to reduce memory reservation\n");
+ } else {
+ wmb();
+ }
/* Above is a suitable barrier to ensure backend will see requests. */
np->rx.req_prod_pvt = req_prod + i;
@@ -961,10 +1004,11 @@ int xennet_get_extras(struct netfront_in
static int xennet_get_responses(struct netfront_info *np,
struct netfront_rx_info *rinfo, RING_IDX rp,
- struct sk_buff_head *list, int count)
-{
- struct mmu_update *mmu = np->rx_mmu + count;
- struct multicall_entry *mcl = np->rx_mcl + count;
+ struct sk_buff_head *list, int *mcl_offset_p)
+{
+ int mcl_offset = *mcl_offset_p;
+ struct mmu_update *mmu;
+ struct multicall_entry *mcl;
struct netif_rx_response *rx = &rinfo->rx;
struct netif_extra_info *extras = rinfo->extras;
RING_IDX cons = np->rx.rsp_cons;
@@ -973,6 +1017,7 @@ static int xennet_get_responses(struct n
int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
int frags = 1;
int err = 0;
+ unsigned long ret;
if (rx->flags & NETRXF_extra_info) {
err = xennet_get_extras(np, extras, rp);
@@ -988,6 +1033,7 @@ static int xennet_get_responses(struct n
WPRINTK("rx->offset: %x, size: %u\n",
rx->offset, rx->status);
err = -EINVAL;
+ goto next;
}
/*
@@ -1001,35 +1047,47 @@ static int xennet_get_responses(struct n
goto next;
}
- /* Memory pressure, insufficient buffer headroom, ... */
- if ((mfn = gnttab_end_foreign_transfer_ref(ref)) == 0) {
- if (net_ratelimit())
- WPRINTK("Unfulfilled rx req (id=%d, st=%d).\n",
- rx->id, rx->status);
- xennet_move_rx_slot(np, skb, ref);
- err = -ENOMEM;
- goto next;
+ if (!np->copying_receiver) {
+ /* Memory pressure, insufficient buffer
+ * headroom, ... */
+ if (!(mfn = gnttab_end_foreign_transfer_ref(ref))) {
+ if (net_ratelimit())
+ WPRINTK("Unfulfilled rx req (id=%d,
st=%d).\n",
+ rx->id, rx->status);
+ xennet_move_rx_slot(np, skb, ref);
+ err = -ENOMEM;
+ goto next;
+ }
+
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ /* Remap the page. */
+ struct page *page =
+ skb_shinfo(skb)->frags[0].page;
+ unsigned long pfn = page_to_pfn(page);
+ void *vaddr = page_address(page);
+
+ mcl = np->rx_mcl + mcl_offset;
+ mmu = np->rx_mmu + mcl_offset;
+
+ MULTI_update_va_mapping(mcl,
+ (unsigned long)vaddr,
+ pfn_pte_ma(mfn,
+ PAGE_KERNEL),
+ 0);
+ mmu->ptr = ((maddr_t)mfn << PAGE_SHIFT)
+ | MMU_MACHPHYS_UPDATE;
+ mmu->val = pfn;
+
+ mcl_offset++;
+
+ set_phys_to_machine(pfn, mfn);
+ }
+ } else {
+ ret = gnttab_end_foreign_access_ref(ref, 0);
+ BUG_ON(!ret);
}
gnttab_release_grant_reference(&np->gref_rx_head, ref);
-
- if (!xen_feature(XENFEAT_auto_translated_physmap)) {
- /* Remap the page. */
- struct page *page = skb_shinfo(skb)->frags[0].page;
- unsigned long pfn = page_to_pfn(page);
- void *vaddr = page_address(page);
-
- MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
- pfn_pte_ma(mfn, PAGE_KERNEL),
- 0);
- mcl++;
- mmu->ptr = ((maddr_t)mfn << PAGE_SHIFT)
- | MMU_MACHPHYS_UPDATE;
- mmu->val = pfn;
- mmu++;
-
- set_phys_to_machine(pfn, mfn);
- }
__skb_queue_tail(list, skb);
@@ -1055,6 +1113,8 @@ next:
WPRINTK("Too many frags\n");
err = -E2BIG;
}
+
+ *mcl_offset_p = mcl_offset;
return err;
}
@@ -1155,8 +1215,7 @@ static int netif_poll(struct net_device
memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
memset(extras, 0, sizeof(extras));
- err = xennet_get_responses(np, &rinfo, rp, &tmpq, pages_done);
- pages_done += skb_queue_len(&tmpq);
+ err = xennet_get_responses(np, &rinfo, rp, &tmpq, &pages_done);
if (unlikely(err)) {
err:
@@ -1383,6 +1442,7 @@ static void network_connect(struct net_d
int i, requeue_idx;
struct sk_buff *skb;
grant_ref_t ref;
+ netif_rx_request_t *req;
xennet_set_features(dev);
@@ -1390,12 +1450,12 @@ static void network_connect(struct net_d
spin_lock(&np->rx_lock);
/*
- * Recovery procedure:
+ * Recovery procedure:
* NB. Freelist index entries are always going to be less than
* PAGE_OFFSET, whereas pointers to skbs will always be equal or
* greater than PAGE_OFFSET: we use this property to distinguish
* them.
- */
+ */
/* Step 1: Discard all pending TX packet fragments. */
for (requeue_idx = 0, i = 1; i <= NET_TX_RING_SIZE; i++) {
@@ -1419,13 +1479,20 @@ static void network_connect(struct net_d
skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
-
- gnttab_grant_foreign_transfer_ref(
- ref, np->xbdev->otherend_id,
- page_to_pfn(skb_shinfo(skb)->frags->page));
-
- RING_GET_REQUEST(&np->rx, requeue_idx)->gref = ref;
- RING_GET_REQUEST(&np->rx, requeue_idx)->id = requeue_idx;
+ req = RING_GET_REQUEST(&np->rx, requeue_idx);
+
+ if (!np->copying_receiver) {
+ gnttab_grant_foreign_transfer_ref(
+ ref, np->xbdev->otherend_id,
+ page_to_pfn(skb_shinfo(skb)->frags->page));
+ } else {
+ gnttab_grant_foreign_access_ref(
+ ref, np->xbdev->otherend_id,
+ page_to_pfn(skb_shinfo(skb)->frags->page),
+ 0);
+ }
+ req->gref = ref;
+ req->id = requeue_idx;
requeue_idx++;
}
@@ -1608,13 +1675,8 @@ static void network_set_multicast_list(s
{
}
-/** Create a network device.
- * @param handle device handle
- * @param val return parameter for created device
- * @return 0 on success, error code otherwise
- */
-static struct net_device * __devinit create_netdev(int handle,
- struct xenbus_device *dev)
+static struct net_device * __devinit
+create_netdev(int handle, int copying_receiver, struct xenbus_device *dev)
{
int i, err = 0;
struct net_device *netdev = NULL;
@@ -1627,9 +1689,10 @@ static struct net_device * __devinit cre
return ERR_PTR(-ENOMEM);
}
- np = netdev_priv(netdev);
- np->handle = handle;
- np->xbdev = dev;
+ np = netdev_priv(netdev);
+ np->handle = handle;
+ np->xbdev = dev;
+ np->copying_receiver = copying_receiver;
netif_carrier_off(netdev);
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