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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 2/3] xen-sockback: add support of the xen-sockback driver
This driver will allow to use xensock sockets for the
server application for the dom0/domD domain.
Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx>
---
drivers/net/Kconfig | 19 +
drivers/net/Makefile | 1 +
drivers/net/xen-sockback/Makefile | 3 +
drivers/net/xen-sockback/common.h | 150 ++++
drivers/net/xen-sockback/interface.c | 245 ++++++
drivers/net/xen-sockback/sockback.c | 1527 ++++++++++++++++++++++++++++++++++
drivers/net/xen-sockback/xenbus.c | 348 ++++++++
include/xen/interface/io/sockif.h | 74 ++
8 files changed, 2367 insertions(+)
create mode 100644 drivers/net/xen-sockback/Makefile
create mode 100644 drivers/net/xen-sockback/common.h
create mode 100644 drivers/net/xen-sockback/interface.c
create mode 100644 drivers/net/xen-sockback/sockback.c
create mode 100644 drivers/net/xen-sockback/xenbus.c
create mode 100644 include/xen/interface/io/sockif.h
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 420981a..e643f42 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -348,9 +348,28 @@ config XEN_NETDEV_BACKEND
compile this driver as a module, chose M here: the module
will be called xen-netback.
+config XEN_SOCKDEV_BACKEND
+ tristate "Xen backend socket device"
+ depends on XEN_BACKEND
+ select XEN_SOCKDEV_PROTO
+ help
+ This driver allows the kernel to act as a Xen socket driver
+ domain which exports paravirtual network devices to other
+ Xen domains. These devices can be accessed by any operating
+ system that implements a compatible front end.
+
+ The corresponding Linux frontend driver is enabled by the
+ CONFIG_XEN_SOCKDEV_FRONTEND configuration option.
+
+ If you are compiling a kernel to run in a Xen socket driver
+ domain (often this is domain 0) you should say Y here. To
+ compile this driver as a module, chose M here: the module
+ will be called xen-sockback.
+
config XEN_SOCKDEV_PROTO
bool
default n
+ depends on XEN_SOCKDEV_BACKEND
config VMXNET3
tristate "VMware VMXNET3 ethernet driver"
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 43bf910..96c6c97 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_XEN_NETDEV_FRONTEND) += xen-netfront.o
obj-$(CONFIG_XEN_NETDEV_BACKEND) += xen-netback/
obj-$(CONFIG_XEN_SOCKDEV_PROTO) += xensock/
+obj-$(CONFIG_XEN_SOCKDEV_BACKEND) += xen-sockback/
obj-$(CONFIG_USB_CATC) += usb/
obj-$(CONFIG_USB_KAWETH) += usb/
diff --git a/drivers/net/xen-sockback/Makefile
b/drivers/net/xen-sockback/Makefile
new file mode 100644
index 0000000..c255867
--- /dev/null
+++ b/drivers/net/xen-sockback/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_XEN_SOCKDEV_BACKEND) := xen-sockback.o
+
+xen-sockback-y := sockback.o xenbus.o interface.o
diff --git a/drivers/net/xen-sockback/common.h
b/drivers/net/xen-sockback/common.h
new file mode 100644
index 0000000..b5b09bb
--- /dev/null
+++ b/drivers/net/xen-sockback/common.h
@@ -0,0 +1,150 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef __XEN_SOCKBACK__COMMON_H__
+#define __XEN_SOCKBACK__COMMON_H__
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/io.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+#include <xen/interface/io/sockif.h>
+#include <xen/interface/grant_table.h>
+#include <xen/grant_table.h>
+#include <xen/xenbus.h>
+
+#include <net/xensock.h>
+#include <net/af_xensock.h>
+
+struct xen_sockbk;
+
+struct xenvsock {
+ /* Unique identifier for this interface. */
+ domid_t domid;
+
+ /* Reference to xensock processing backend. */
+ struct xen_sockbk *sockbk;
+
+ /* Physical parameters of the comms window. */
+ unsigned int irq;
+
+ /* Back pointer to the xenbus_device. */
+ struct xenbus_device *xbdev;
+
+ /* List of frontends to notify after a batch of frames sent. */
+ struct list_head notify_list;
+
+ /* The shared rings and indexes. */
+ struct xen_sockif_tx_back_ring tx;
+ struct xen_sockif_rx_back_ring rx;
+
+ /* Internal feature information. */
+ u8 can_queue:1; /* can queue packets for receiver? */
+
+ /* Allow xenvsock_start_xmit() to peek ahead in the rx request
+ * ring. This is a prediction of what rx_req_cons will be
+ * once all queued skbs are put on the ring.
+ */
+ RING_IDX rx_req_cons_peek;
+
+ /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
+ unsigned long credit_bytes;
+ unsigned long credit_usec;
+ unsigned long remaining_credit;
+ struct timer_list credit_timeout;
+
+ /* Statistics */
+ unsigned long rx_gso_checksum_fixup;
+
+ /* Miscellaneous private stuff. */
+ struct list_head schedule_list;
+ atomic_t refcnt;
+ struct xen_sock_dev *dev;
+
+ wait_queue_head_t waiting_to_free;
+};
+
+#define XEN_SOCKIF_TX_RING_SIZE __CONST_RING_SIZE(xen_sockif_tx, PAGE_SIZE)
+#define XEN_SOCKIF_RX_RING_SIZE __CONST_RING_SIZE(xen_sockif_rx, PAGE_SIZE)
+
+struct xenvsock *xenvsock_alloc(struct device *parent,
+ domid_t domid,
+ unsigned int handle);
+
+int xenvsock_connect(struct xenvsock *vsock, unsigned long tx_ring_ref,
+ unsigned long rx_ring_ref, unsigned int evtchn);
+void xenvsock_disconnect(struct xenvsock *vsock);
+
+void xenvsock_get(struct xenvsock *vsock);
+void xenvsock_put(struct xenvsock *vsock);
+
+int xenvsock_xenbus_init(void);
+
+int xenvsock_schedulable(struct xenvsock *vsock);
+
+int xen_sockbk_rx_ring_full(struct xenvsock *vsock);
+
+int xen_sockbk_must_stop_queue(struct xenvsock *vsock);
+
+/* (Un)Map communication rings. */
+void xen_sockbk_unmap_frontend_rings(struct xenvsock *vsock);
+int xen_sockbk_map_frontend_rings(struct xenvsock *vsock,
+ grant_ref_t tx_ring_ref,
+ grant_ref_t rx_ring_ref);
+
+/* (De)Register a xenvsock with the xensock backend. */
+void xen_sockbk_add_xenvsock(struct xenvsock *vsock);
+void xen_sockbk_remove_xenvsock(struct xenvsock *vsock);
+
+/* (De)Schedule backend processing for a xenvsock */
+void xen_sockbk_schedule_xenvsock(struct xenvsock *vsock);
+void xen_sockbk_deschedule_xenvsock(struct xenvsock *vsock);
+
+/* Check for SKBs from frontend and schedule backend processing */
+void xen_sockbk_check_rx_xenvsock(struct xenvsock *vsock);
+/* Receive an SKB from the frontend */
+void xenvsock_receive_skb(struct xenvsock *vsock, struct sk_buff *skb);
+
+/* Queue an SKB for transmission to the frontend */
+void xen_sockbk_queue_tx_skb(struct xenvsock *vsock, struct sk_buff *skb);
+/* Notify xenvsock that ring now has space to send an skb to the frontend */
+void xenvsock_notify_tx_completion(struct xenvsock *vsock);
+
+/* Prevent the device from generating any further traffic. */
+void xenvsock_carrier_off(struct xenvsock *vsock);
+
+/* Returns number of ring slots required to send an skb to the frontend */
+unsigned int xen_sockbk_count_skb_slots(struct xenvsock *vsock,
+ struct sk_buff *skb);
+
+#endif /* __XEN_SOCKBACK__COMMON_H__ */
diff --git a/drivers/net/xen-sockback/interface.c
b/drivers/net/xen-sockback/interface.c
new file mode 100644
index 0000000..995fb22
--- /dev/null
+++ b/drivers/net/xen-sockback/interface.c
@@ -0,0 +1,245 @@
+/*
+ * Xenvsock-device interface management.
+ *
+ * Copyright (c) 2004-2005, Keir Fraser
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#include <xen/events.h>
+#include <asm/xen/hypercall.h>
+
+#define XENVSOCK_QUEUE_LENGTH 32
+
+void xenvsock_get(struct xenvsock *vsock)
+{
+ atomic_inc(&vsock->refcnt);
+}
+
+void xenvsock_put(struct xenvsock *vsock)
+{
+ if (atomic_dec_and_test(&vsock->refcnt))
+ wake_up(&vsock->waiting_to_free);
+}
+
+int xenvsock_schedulable(struct xenvsock *vsock)
+{
+ return sockif_carrier_ok(vsock->dev);
+}
+
+static int xenvsock_rx_schedulable(struct xenvsock *vsock)
+{
+ return xenvsock_schedulable(vsock) && !xen_sockbk_rx_ring_full(vsock);
+}
+
+static irqreturn_t xenvsock_interrupt(int irq, void *dev_id)
+{
+ struct xenvsock *vsock = dev_id;
+
+ if (vsock->sockbk == NULL)
+ return IRQ_NONE;
+
+ xen_sockbk_schedule_xenvsock(vsock);
+
+ if (xenvsock_rx_schedulable(vsock))
+ sockif_wake_queue(vsock->dev);
+
+ return IRQ_HANDLED;
+}
+
+static int xenvsock_start_xmit(struct sk_buff *skb, struct xen_sock_dev *dev)
+{
+ struct xenvsock *vsock = xensock_dev_priv(dev);
+
+ if (vsock->sockbk == NULL)
+ goto drop;
+
+ /* Drop the packet if the target domain has no receive buffers. */
+ if (!xenvsock_rx_schedulable(vsock))
+ goto drop;
+
+ skb->dev = (struct net_device *)dev;
+
+ /* Reserve ring slots for the worst-case number of fragments. */
+ vsock->rx_req_cons_peek += xen_sockbk_count_skb_slots(vsock, skb);
+ xenvsock_get(vsock);
+
+ if (vsock->can_queue && xen_sockbk_must_stop_queue(vsock))
+ sockif_stop_queue(dev);
+
+ xen_sockbk_queue_tx_skb(vsock, skb);
+
+ return 0;
+
+ drop:
+ dev_kfree_skb(skb);
+ return 0;
+}
+
+void xenvsock_receive_skb(struct xenvsock *vsock, struct sk_buff *skb)
+{
+ xensock_dev_queue_rx_skb(skb, vsock->dev);
+}
+
+void xenvsock_notify_tx_completion(struct xenvsock *vsock)
+{
+ if (sockif_queue_stopped(vsock->dev) && xenvsock_rx_schedulable(vsock))
+ sockif_wake_queue(vsock->dev);
+}
+
+static void xenvsock_up(struct xenvsock *vsock)
+{
+ xen_sockbk_add_xenvsock(vsock);
+ enable_irq(vsock->irq);
+ xen_sockbk_check_rx_xenvsock(vsock);
+}
+
+static void xenvsock_down(struct xenvsock *vsock)
+{
+ disable_irq(vsock->irq);
+ del_timer_sync(&vsock->credit_timeout);
+ xen_sockbk_deschedule_xenvsock(vsock);
+ xen_sockbk_remove_xenvsock(vsock);
+}
+
+static const struct xenvsock_stat {
+ char name[ETH_GSTRING_LEN];
+ u16 offset;
+} xenvsock_stats[] = {
+ {
+ "rx_gso_checksum_fixup",
+ offsetof(struct xenvsock, rx_gso_checksum_fixup)
+ },
+};
+
+struct xenvsock *xenvsock_alloc(struct device *parent, domid_t domid,
+ unsigned int handle)
+{
+ int err;
+ struct xen_sock_dev *dev;
+ struct xenvsock *vsock;
+ char name[IFNAMSIZ] = {};
+
+ snprintf(name, IFNAMSIZ - 1, "vsock%u.%u", domid, handle);
+ dev = alloc_xen_sock_dev(sizeof(struct xenvsock), name);
+ if (dev == NULL) {
+ pr_warn("Could not allocate sockdev\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ vsock = xensock_dev_priv(dev);
+ vsock->domid = domid;
+ vsock->sockbk = NULL;
+ atomic_set(&vsock->refcnt, 1);
+ init_waitqueue_head(&vsock->waiting_to_free);
+ vsock->dev = dev;
+ INIT_LIST_HEAD(&vsock->schedule_list);
+ INIT_LIST_HEAD(&vsock->notify_list);
+
+ vsock->credit_bytes = ~0UL;
+ vsock->remaining_credit = ~0UL;
+ vsock->credit_usec = 0UL;
+ init_timer(&vsock->credit_timeout);
+ /* Initialize 'expires' now: it's used to track the credit window. */
+ vsock->credit_timeout.expires = jiffies;
+
+ dev->start_xmit = xenvsock_start_xmit;
+
+ dev->tx_queue_len = XENVSOCK_QUEUE_LENGTH;
+
+ sockif_carrier_off(dev);
+
+ err = xensock_register_dev(dev);
+ if (err) {
+ pr_warn("Could not register device: err=%d\n", err);
+ free_xen_sock_dev(dev);
+ return ERR_PTR(err);
+ }
+
+ pr_warn("Successfully created xenvsock\n");
+ return vsock;
+}
+
+int xenvsock_connect(struct xenvsock *vsock, unsigned long tx_ring_ref,
+ unsigned long rx_ring_ref, unsigned int evtchn)
+{
+ int err = -ENOMEM;
+
+ /* Already connected through? */
+ if (vsock->irq)
+ return 0;
+
+ err = xen_sockbk_map_frontend_rings(vsock, tx_ring_ref, rx_ring_ref);
+ if (err < 0)
+ goto err;
+
+ err = bind_interdomain_evtchn_to_irqhandler(
+ vsock->domid, evtchn, xenvsock_interrupt, 0,
+ vsock->dev->name, vsock);
+ if (err < 0)
+ goto err_unmap;
+ vsock->irq = err;
+ disable_irq(vsock->irq);
+
+ xenvsock_get(vsock);
+
+ sockif_carrier_on(vsock->dev);
+ xenvsock_up(vsock);
+
+ return 0;
+err_unmap:
+ xen_sockbk_unmap_frontend_rings(vsock);
+err:
+ return err;
+}
+
+void xenvsock_carrier_off(struct xenvsock *vsock)
+{
+ struct xen_sock_dev *dev = vsock->dev;
+
+ sockif_carrier_off(dev); /* discard queued packets */
+ xenvsock_down(vsock);
+ xenvsock_put(vsock);
+}
+
+void xenvsock_disconnect(struct xenvsock *vsock)
+{
+ if (sockif_carrier_ok(vsock->dev))
+ xenvsock_carrier_off(vsock);
+
+ atomic_dec(&vsock->refcnt);
+ wait_event(vsock->waiting_to_free, atomic_read(&vsock->refcnt) == 0);
+
+ if (vsock->irq)
+ unbind_from_irqhandler(vsock->irq, vsock);
+
+ xensock_unregister_dev(vsock->dev);
+
+ xen_sockbk_unmap_frontend_rings(vsock);
+
+ free_xen_sock_dev(vsock->dev);
+}
diff --git a/drivers/net/xen-sockback/sockback.c
b/drivers/net/xen-sockback/sockback.c
new file mode 100644
index 0000000..84f5848
--- /dev/null
+++ b/drivers/net/xen-sockback/sockback.c
@@ -0,0 +1,1527 @@
+/*
+ * Back-end of the driver for xensock devices. A
+ * reference front-end implementation can be found in:
+ * drivers/net/xen-sockfront.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#include <linux/kthread.h>
+#include <linux/if_vlan.h>
+
+#include <net/tcp.h>
+
+#include <xen/xen.h>
+#include <xen/events.h>
+#include <xen/interface/memory.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/page.h>
+
+struct pending_tx_info {
+ struct xen_sockif_tx_request req;
+ struct xenvsock *vsock;
+};
+typedef unsigned int pending_ring_idx_t;
+
+struct sockbk_rx_meta {
+ int id;
+ int size;
+};
+
+#define SOCK_DEV_SKB(skb) ((struct xen_sock_dev *)((skb)->dev))
+
+#define MAX_PENDING_REQS 256
+
+/* Discriminate from any valid pending_idx value. */
+#define INVALID_PENDING_IDX 0xFFFF
+
+#define MAX_BUFFER_OFFSET PAGE_SIZE
+
+/* extra field used in struct page */
+union page_ext {
+ struct {
+#if BITS_PER_LONG < 64
+#define IDX_WIDTH 8
+#define GROUP_WIDTH (BITS_PER_LONG - IDX_WIDTH)
+ unsigned int group:GROUP_WIDTH;
+ unsigned int idx:IDX_WIDTH;
+#else
+ unsigned int group, idx;
+#endif
+ } e;
+ void *mapping;
+};
+
+struct xen_sockbk {
+ wait_queue_head_t wq;
+ struct task_struct *task;
+
+ struct sk_buff_head rx_queue;
+ struct sk_buff_head tx_queue;
+
+ struct timer_list sock_timer;
+
+ struct page *mmap_pages[MAX_PENDING_REQS];
+
+ pending_ring_idx_t pending_prod;
+ pending_ring_idx_t pending_cons;
+ struct list_head sock_schedule_list;
+
+ /* Protect the sock_schedule_list in sockbk. */
+ spinlock_t sock_schedule_list_lock;
+
+ atomic_t sockfront_count;
+
+ struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
+ struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
+
+ u16 pending_ring[MAX_PENDING_REQS];
+
+ /* Given MAX_BUFFER_OFFSET of 4096 the worst case is that each
+ * head/fragment page uses 2 copy operations because it
+ * straddles two buffers in the frontend.
+ */
+ struct gnttab_copy grant_copy_op[2*XEN_SOCKIF_RX_RING_SIZE];
+ struct sockbk_rx_meta meta[2*XEN_SOCKIF_RX_RING_SIZE];
+};
+
+static struct xen_sockbk *xen_sockbk;
+static int xen_sockbk_group_nr;
+
+void xen_sockbk_add_xenvsock(struct xenvsock *vsock)
+{
+ int i;
+ int min_sockfront_count;
+ int min_group = 0;
+ struct xen_sockbk *sockbk;
+
+ min_sockfront_count = atomic_read(&xen_sockbk[0].sockfront_count);
+ for (i = 0; i < xen_sockbk_group_nr; i++) {
+ int sockfront_count;
+
+ sockfront_count = atomic_read(&xen_sockbk[i].sockfront_count);
+ if (sockfront_count < min_sockfront_count) {
+ min_group = i;
+ min_sockfront_count = sockfront_count;
+ }
+ }
+
+ sockbk = &xen_sockbk[min_group];
+
+ vsock->sockbk = sockbk;
+ atomic_inc(&sockbk->sockfront_count);
+}
+
+void xen_sockbk_remove_xenvsock(struct xenvsock *vsock)
+{
+ struct xen_sockbk *sockbk = vsock->sockbk;
+
+ vsock->sockbk = NULL;
+ atomic_dec(&sockbk->sockfront_count);
+}
+
+static void xen_sockbk_idx_release(struct xen_sockbk *sockbk, u16 pending_idx,
+ u8 status);
+static void make_tx_response(struct xenvsock *vsock,
+ struct xen_sockif_tx_request *txp,
+ s8 st);
+static struct xen_sockif_rx_response *make_rx_response(struct xenvsock *vsock,
+ u16 id, s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags);
+
+static inline unsigned long idx_to_pfn(struct xen_sockbk *sockbk,
+ u16 idx)
+{
+ return page_to_pfn(sockbk->mmap_pages[idx]);
+}
+
+static inline unsigned long idx_to_kaddr(struct xen_sockbk *sockbk,
+ u16 idx)
+{
+ return (unsigned long)pfn_to_kaddr(idx_to_pfn(sockbk, idx));
+}
+
+/* extra field used in struct page */
+static inline void set_page_ext(struct page *pg, struct xen_sockbk *sockbk,
+ unsigned int idx)
+{
+ unsigned int group = sockbk - xen_sockbk;
+ union page_ext ext = { .e = { .group = group + 1, .idx = idx } };
+
+ BUILD_BUG_ON(sizeof(ext) > sizeof(ext.mapping));
+ pg->mapping = ext.mapping;
+}
+
+static int get_page_ext(struct page *pg,
+ unsigned int *pgroup, unsigned int *pidx)
+{
+ union page_ext ext = { .mapping = pg->mapping };
+ struct xen_sockbk *sockbk;
+ unsigned int group, idx;
+
+ group = ext.e.group - 1;
+
+ if (group < 0 || group >= xen_sockbk_group_nr)
+ return 0;
+
+ sockbk = &xen_sockbk[group];
+
+ idx = ext.e.idx;
+
+ if ((idx < 0) || (idx >= MAX_PENDING_REQS))
+ return 0;
+
+ if (sockbk->mmap_pages[idx] != pg)
+ return 0;
+
+ *pgroup = group;
+ *pidx = idx;
+
+ return 1;
+}
+
+/* This is the amount of packet we copy rather than map, so that the
+ * guest can't fiddle with the contents of the headers while we do
+ * packet processing on them.
+ */
+#define PKT_PROT_LEN (ETH_HLEN + \
+ VLAN_HLEN + \
+ sizeof(struct iphdr) + MAX_IPOPTLEN + \
+ sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE)
+
+static u16 frag_get_pending_idx(skb_frag_t *frag)
+{
+ return (u16)frag->page_offset;
+}
+
+static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
+{
+ frag->page_offset = pending_idx;
+}
+
+static inline pending_ring_idx_t pending_index(unsigned i)
+{
+ return i & (MAX_PENDING_REQS-1);
+}
+
+static inline pending_ring_idx_t nr_pending_reqs(struct xen_sockbk *sockbk)
+{
+ return MAX_PENDING_REQS -
+ sockbk->pending_prod + sockbk->pending_cons;
+}
+
+static void xen_sockbk_kick_thread(struct xen_sockbk *sockbk)
+{
+ wake_up(&sockbk->wq);
+}
+
+static int max_required_rx_slots(struct xenvsock *vsock)
+{
+ int max = DIV_ROUND_UP(XENSOCK_MTU, PAGE_SIZE);
+ return max;
+}
+
+int xen_sockbk_rx_ring_full(struct xenvsock *vsock)
+{
+ RING_IDX peek = vsock->rx_req_cons_peek;
+ RING_IDX needed = max_required_rx_slots(vsock);
+ RING_IDX rsp_prod = vsock->rx.rsp_prod_pvt + XEN_SOCKIF_RX_RING_SIZE;
+
+ return ((vsock->rx.sring->req_prod - peek) < needed) ||
+ ((rsp_prod - peek) < needed);
+}
+
+int xen_sockbk_must_stop_queue(struct xenvsock *vsock)
+{
+ if (!xen_sockbk_rx_ring_full(vsock))
+ return 0;
+
+ vsock->rx.sring->req_event = vsock->rx_req_cons_peek +
+ max_required_rx_slots(vsock);
+ mb(); /* request notification /then/ check the queue */
+
+ return xen_sockbk_rx_ring_full(vsock);
+}
+
+/* Returns true if we should start a new receive buffer instead of
+ * adding 'size' bytes to a buffer which currently contains 'offset'
+ * bytes.
+ */
+static bool start_new_rx_buffer(int offset, unsigned long size, int head)
+{
+ /* simple case: we have completely filled the current buffer. */
+ if (offset == MAX_BUFFER_OFFSET)
+ return true;
+
+ /* complex case: start a fresh buffer if the current frag
+ * would overflow the current buffer but only if:
+ * (i) this frag would fit completely in the next buffer
+ * and (ii) there is already some data in the current buffer
+ * and (iii) this is not the head buffer.
+ *
+ * Where:
+ * - (i) stops us splitting a frag into two copies
+ * unless the frag is too large for a single buffer.
+ * - (ii) stops us from leaving a buffer pointlessly empty.
+ * - (iii) stops us leaving the first buffer
+ * empty. Strictly speaking this is already covered
+ * by (ii) but is explicitly checked because
+ * sock front relies on the first buffer being
+ * non-empty and can crash otherwise.
+ *
+ * This means we will effectively linearise small
+ * frags but do not needlessly split large buffers
+ * into multiple copies tend to give large frags their
+ * own buffers as before.
+ */
+ if ((offset + size > MAX_BUFFER_OFFSET) &&
+ (size <= MAX_BUFFER_OFFSET) && offset && !head)
+ return true;
+
+ return false;
+}
+
+/* Figure out how many ring slots we're going to need to send @skb to
+ * the guest. This function is essentially a dry run of
+ * sockbk_gop_frag_copy.
+ */
+unsigned int xen_sockbk_count_skb_slots(struct xenvsock *vsock,
+ struct sk_buff *skb)
+{
+ unsigned int count;
+ int i, copy_off;
+
+ count = DIV_ROUND_UP(skb_headlen(skb), PAGE_SIZE);
+
+ copy_off = skb_headlen(skb) % PAGE_SIZE;
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ unsigned long size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+ unsigned long offset = skb_shinfo(skb)->frags[i].page_offset;
+ unsigned long bytes;
+
+ offset &= ~PAGE_MASK;
+
+ while (size > 0) {
+ BUG_ON(offset >= PAGE_SIZE);
+ BUG_ON(copy_off > MAX_BUFFER_OFFSET);
+
+ bytes = PAGE_SIZE - offset;
+
+ if (bytes > size)
+ bytes = size;
+
+ if (start_new_rx_buffer(copy_off, bytes, 0)) {
+ count++;
+ copy_off = 0;
+ }
+
+ if (copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - copy_off;
+
+ copy_off += bytes;
+
+ offset += bytes;
+ size -= bytes;
+
+ if (offset == PAGE_SIZE)
+ offset = 0;
+ }
+ }
+ return count;
+}
+
+struct sockrx_pending_operations {
+ unsigned copy_prod, copy_cons;
+ unsigned meta_prod, meta_cons;
+ struct gnttab_copy *copy;
+ struct sockbk_rx_meta *meta;
+ int copy_off;
+ grant_ref_t copy_gref;
+};
+
+static
+struct sockbk_rx_meta *get_next_rx_buf(struct xenvsock *vsock,
+ struct sockrx_pending_operations *spo)
+{
+ struct sockbk_rx_meta *meta;
+ struct xen_sockif_rx_request *req;
+
+ req = RING_GET_REQUEST(&vsock->rx, vsock->rx.req_cons++);
+
+ meta = spo->meta + spo->meta_prod++;
+ meta->size = 0;
+ meta->id = req->id;
+
+ spo->copy_off = 0;
+ spo->copy_gref = req->gref;
+
+ return meta;
+}
+
+/* Set up the grant operations for this fragment. If it's a flipping
+ * interface, we also set up the unmap request from here.
+ */
+static void sockbk_gop_frag_copy(struct xenvsock *vsock, struct sk_buff *skb,
+ struct sockrx_pending_operations *spo,
+ struct page *page, unsigned long size,
+ unsigned long offset, int *head)
+{
+ struct gnttab_copy *copy_gop;
+ struct sockbk_rx_meta *meta;
+ /* These variables are used iff get_page_ext returns true,
+ * in which case they are guaranteed to be initialized.
+ */
+ unsigned int uninitialized_var(group), uninitialized_var(idx);
+ int foreign = get_page_ext(page, &group, &idx);
+ unsigned long bytes;
+
+ /* Data must not cross a page boundary. */
+ BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
+
+ meta = spo->meta + spo->meta_prod - 1;
+
+ /* Skip unused frames from start of page */
+ page += offset >> PAGE_SHIFT;
+ offset &= ~PAGE_MASK;
+
+ while (size > 0) {
+ BUG_ON(offset >= PAGE_SIZE);
+ BUG_ON(spo->copy_off > MAX_BUFFER_OFFSET);
+
+ bytes = PAGE_SIZE - offset;
+
+ if (bytes > size)
+ bytes = size;
+
+ if (start_new_rx_buffer(spo->copy_off, bytes, *head)) {
+ /* Sockfront requires there to be some data in the head
+ * buffer.
+ */
+ BUG_ON(*head);
+
+ meta = get_next_rx_buf(vsock, spo);
+ }
+
+ if (spo->copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - spo->copy_off;
+
+ copy_gop = spo->copy + spo->copy_prod++;
+ copy_gop->flags = GNTCOPY_dest_gref;
+ if (foreign) {
+ struct xen_sockbk *sockbk = &xen_sockbk[group];
+ struct pending_tx_info *src_pend;
+
+ src_pend = &sockbk->pending_tx_info[idx];
+
+ copy_gop->source.domid = src_pend->vsock->domid;
+ copy_gop->source.u.ref = src_pend->req.gref;
+ copy_gop->flags |= GNTCOPY_source_gref;
+ } else {
+ void *vaddr = page_address(page);
+
+ copy_gop->source.domid = DOMID_SELF;
+ copy_gop->source.u.gmfn = virt_to_mfn(vaddr);
+ }
+ copy_gop->source.offset = offset;
+ copy_gop->dest.domid = vsock->domid;
+
+ copy_gop->dest.offset = spo->copy_off;
+ copy_gop->dest.u.ref = spo->copy_gref;
+ copy_gop->len = bytes;
+
+ spo->copy_off += bytes;
+ meta->size += bytes;
+
+ offset += bytes;
+ size -= bytes;
+
+ /* Next frame */
+ if (offset == PAGE_SIZE && size) {
+ BUG_ON(!PageCompound(page));
+ page++;
+ offset = 0;
+ }
+
+ *head = 0; /* There must be something in this buffer now. */
+ }
+}
+
+/* Prepare an SKB to be transmitted to the frontend.
+ *
+ * This function is responsible for allocating grant operations, meta
+ * structures, etc.
+ *
+ * It returns the number of meta structures consumed. The number of
+ * ring slots used is always equal to the number of meta slots used
+ * plus the number of GSO descriptors used. Currently, we use either
+ * zero GSO descriptors (for non-GSO packets) or one descriptor (for
+ * frontend-side LRO).
+ */
+static int sockbk_gop_skb(struct sk_buff *skb,
+ struct sockrx_pending_operations *spo)
+{
+ struct xenvsock *vsock = xensock_dev_priv(SOCK_DEV_SKB(skb));
+ int nr_frags = skb_shinfo(skb)->nr_frags;
+ int i;
+ struct xen_sockif_rx_request *req;
+ struct sockbk_rx_meta *meta;
+ unsigned char *data;
+ int head = 1;
+ int old_meta_prod;
+
+ old_meta_prod = spo->meta_prod;
+
+ req = RING_GET_REQUEST(&vsock->rx, vsock->rx.req_cons++);
+ meta = spo->meta + spo->meta_prod++;
+
+ meta->size = 0;
+ meta->id = req->id;
+ spo->copy_off = 0;
+ spo->copy_gref = req->gref;
+
+ data = skb->data;
+ while (data < skb_tail_pointer(skb)) {
+ unsigned int offset = offset_in_page(data);
+ unsigned int len = PAGE_SIZE - offset;
+
+ if (data + len > skb_tail_pointer(skb))
+ len = skb_tail_pointer(skb) - data;
+
+ sockbk_gop_frag_copy(vsock, skb, spo,
+ virt_to_page(data), len, offset, &head);
+ data += len;
+ }
+
+ for (i = 0; i < nr_frags; i++) {
+ sockbk_gop_frag_copy(vsock, skb, spo,
+ skb_frag_page(&skb_shinfo(skb)->frags[i]),
+ skb_frag_size(&skb_shinfo(skb)->frags[i]),
+ skb_shinfo(skb)->frags[i].page_offset,
+ &head);
+ }
+
+ return spo->meta_prod - old_meta_prod;
+}
+
+/* This is a twin to sockbk_gop_skb. Assume that sockbk_gop_skb was
+ * used to set up the operations on the top of
+ * sockrx_pending_operations, which have since been done. Check that
+ * they didn't give any errors and advance over them.
+ */
+static int sockbk_check_gop(struct xenvsock *vsock, int nr_meta_slots,
+ struct sockrx_pending_operations *spo)
+{
+ struct gnttab_copy *copy_op;
+ int status = XEN_SOCKIF_RSP_OKAY;
+ int i;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ copy_op = spo->copy + spo->copy_cons++;
+ if (copy_op->status != GNTST_okay) {
+ dev_dbg(&vsock->xbdev->dev,
+ "Bad status %d from copy to DOM%d.\n",
+ copy_op->status, vsock->domid);
+ status = XEN_SOCKIF_RSP_ERROR;
+ }
+ }
+
+ return status;
+}
+
+static void sockbk_add_frag_responses(struct xenvsock *vsock, int status,
+ struct sockbk_rx_meta *meta,
+ int nr_meta_slots)
+{
+ int i;
+ unsigned long offset;
+
+ /* No fragments used */
+ if (nr_meta_slots <= 1)
+ return;
+
+ nr_meta_slots--;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ int flags;
+
+ if (i == nr_meta_slots - 1)
+ flags = 0;
+ else
+ flags = XEN_SOCKRXF_more_data;
+
+ offset = 0;
+ make_rx_response(vsock, meta[i].id, status, offset,
+ meta[i].size, flags);
+ }
+}
+
+struct skb_cb_overlay {
+ int meta_slots_used;
+};
+
+static void xen_sockbk_rx_action(struct xen_sockbk *sockbk)
+{
+ struct xenvsock *vsock = NULL, *tmp;
+ s8 status;
+ u16 irq, flags;
+ struct xen_sockif_rx_response *resp;
+ struct sk_buff_head rxq;
+ struct sk_buff *skb;
+ LIST_HEAD(notify);
+ int ret;
+ int nr_frags;
+ int count;
+ unsigned long offset;
+ struct skb_cb_overlay *sco;
+
+ struct sockrx_pending_operations spo = {
+ .copy = sockbk->grant_copy_op,
+ .meta = sockbk->meta,
+ };
+
+ skb_queue_head_init(&rxq);
+
+ count = 0;
+
+ while ((skb = skb_dequeue(&sockbk->rx_queue)) != NULL) {
+ vsock = xensock_dev_priv(SOCK_DEV_SKB(skb));
+
+ nr_frags = skb_shinfo(skb)->nr_frags;
+
+ sco = (struct skb_cb_overlay *)skb->cb;
+ sco->meta_slots_used = sockbk_gop_skb(skb, &spo);
+
+ count += nr_frags + 1;
+
+ __skb_queue_tail(&rxq, skb);
+
+ /* Filled the batch queue? */
+ if (count + MAX_SKB_FRAGS >= XEN_SOCKIF_RX_RING_SIZE)
+ break;
+ }
+
+ BUG_ON(spo.meta_prod > ARRAY_SIZE(sockbk->meta));
+
+ if (!spo.copy_prod)
+ return;
+
+ BUG_ON(spo.copy_prod > ARRAY_SIZE(sockbk->grant_copy_op));
+ gnttab_batch_copy(sockbk->grant_copy_op, spo.copy_prod);
+
+ while ((skb = __skb_dequeue(&rxq)) != NULL) {
+ sco = (struct skb_cb_overlay *)skb->cb;
+
+ vsock = xensock_dev_priv(SOCK_DEV_SKB(skb));
+
+ status = sockbk_check_gop(vsock, sco->meta_slots_used, &spo);
+
+ if (sco->meta_slots_used == 1)
+ flags = 0;
+ else
+ flags = XEN_SOCKRXF_more_data;
+
+ offset = 0;
+ resp = make_rx_response(vsock, sockbk->meta[spo.meta_cons].id,
+ status, offset,
+ sockbk->meta[spo.meta_cons].size,
+ flags);
+
+ sockbk_add_frag_responses(vsock, status,
+ sockbk->meta + spo.meta_cons + 1,
+ sco->meta_slots_used);
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vsock->rx, ret);
+ irq = vsock->irq;
+ if (ret && list_empty(&vsock->notify_list))
+ list_add_tail(&vsock->notify_list, ¬ify);
+
+ xenvsock_notify_tx_completion(vsock);
+
+ xenvsock_put(vsock);
+ spo.meta_cons += sco->meta_slots_used;
+ dev_kfree_skb(skb);
+ }
+
+ list_for_each_entry_safe(vsock, tmp, ¬ify, notify_list) {
+ notify_remote_via_irq(vsock->irq);
+ list_del_init(&vsock->notify_list);
+ }
+
+ /* More work to do? */
+ if (!skb_queue_empty(&sockbk->rx_queue) &&
+ !timer_pending(&sockbk->sock_timer))
+ xen_sockbk_kick_thread(sockbk);
+}
+
+void xen_sockbk_queue_tx_skb(struct xenvsock *vsock, struct sk_buff *skb)
+{
+ struct xen_sockbk *sockbk = vsock->sockbk;
+
+ skb_queue_tail(&sockbk->rx_queue, skb);
+ xen_sockbk_kick_thread(sockbk);
+}
+
+static void xen_sockbk_alarm(unsigned long data)
+{
+ struct xen_sockbk *sockbk = (struct xen_sockbk *)data;
+
+ xen_sockbk_kick_thread(sockbk);
+}
+
+static int __on_sock_schedule_list(struct xenvsock *vsock)
+{
+ return !list_empty(&vsock->schedule_list);
+}
+
+/* Must be called with sock_schedule_list_lock held */
+static void remove_from_sock_schedule_list(struct xenvsock *vsock)
+{
+ if (likely(__on_sock_schedule_list(vsock))) {
+ list_del_init(&vsock->schedule_list);
+ xenvsock_put(vsock);
+ }
+}
+
+static struct xenvsock *poll_sock_schedule_list(struct xen_sockbk *sockbk)
+{
+ struct xenvsock *vsock = NULL;
+
+ spin_lock_irq(&sockbk->sock_schedule_list_lock);
+ if (list_empty(&sockbk->sock_schedule_list))
+ goto out;
+
+ vsock = list_first_entry(&sockbk->sock_schedule_list,
+ struct xenvsock, schedule_list);
+ if (!vsock)
+ goto out;
+
+ xenvsock_get(vsock);
+
+ remove_from_sock_schedule_list(vsock);
+out:
+ spin_unlock_irq(&sockbk->sock_schedule_list_lock);
+ return vsock;
+}
+
+void xen_sockbk_schedule_xenvsock(struct xenvsock *vsock)
+{
+ unsigned long flags;
+ struct xen_sockbk *sockbk = vsock->sockbk;
+ struct list_head *sockbk_schedule_list = &sockbk->sock_schedule_list;
+
+ if (__on_sock_schedule_list(vsock))
+ goto kick;
+
+ spin_lock_irqsave(&sockbk->sock_schedule_list_lock, flags);
+ if (!__on_sock_schedule_list(vsock) &&
+ likely(xenvsock_schedulable(vsock))) {
+ list_add_tail(&vsock->schedule_list, sockbk_schedule_list);
+ xenvsock_get(vsock);
+ }
+ spin_unlock_irqrestore(&sockbk->sock_schedule_list_lock, flags);
+
+kick:
+ smp_mb(); /* Ensure that an item is added to the shedule list */
+ if ((nr_pending_reqs(sockbk) < (MAX_PENDING_REQS/2)) &&
+ !list_empty(sockbk_schedule_list))
+ xen_sockbk_kick_thread(sockbk);
+}
+
+void xen_sockbk_deschedule_xenvsock(struct xenvsock *vsock)
+{
+ struct xen_sockbk *sockbk = vsock->sockbk;
+
+ spin_lock_irq(&sockbk->sock_schedule_list_lock);
+ remove_from_sock_schedule_list(vsock);
+ spin_unlock_irq(&sockbk->sock_schedule_list_lock);
+}
+
+void xen_sockbk_check_rx_xenvsock(struct xenvsock *vsock)
+{
+ int more_to_do;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&vsock->tx, more_to_do);
+
+ if (more_to_do)
+ xen_sockbk_schedule_xenvsock(vsock);
+}
+
+static void tx_add_credit(struct xenvsock *vsock)
+{
+ unsigned long max_burst, max_credit;
+
+ /* Allow a burst big enough to transmit a jumbo packet of up to 128kB.
+ * Otherwise the interface can seize up due to insufficient credit.
+ */
+ max_burst = RING_GET_REQUEST(&vsock->tx, vsock->tx.req_cons)->size;
+ max_burst = min(max_burst, 131072UL);
+ max_burst = max(max_burst, vsock->credit_bytes);
+
+ /* Take care that adding a new chunk of credit doesn't wrap to zero. */
+ max_credit = vsock->remaining_credit + vsock->credit_bytes;
+ if (max_credit < vsock->remaining_credit)
+ max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
+
+ vsock->remaining_credit = min(max_credit, max_burst);
+}
+
+static void tx_credit_callback(unsigned long data)
+{
+ struct xenvsock *vsock = (struct xenvsock *)data;
+
+ tx_add_credit(vsock);
+ xen_sockbk_check_rx_xenvsock(vsock);
+}
+
+static void sockbk_tx_err(struct xenvsock *vsock,
+ struct xen_sockif_tx_request *txp, RING_IDX end)
+{
+ RING_IDX cons = vsock->tx.req_cons;
+
+ do {
+ make_tx_response(vsock, txp, XEN_SOCKIF_RSP_ERROR);
+ if (cons == end)
+ break;
+ txp = RING_GET_REQUEST(&vsock->tx, cons++);
+ } while (1);
+ vsock->tx.req_cons = cons;
+ xen_sockbk_check_rx_xenvsock(vsock);
+ xenvsock_put(vsock);
+}
+
+static void sockbk_fatal_tx_err(struct xenvsock *vsock)
+{
+ dev_err(&vsock->xbdev->dev, "fatal error; disabling device\n");
+ xenvsock_carrier_off(vsock);
+ xenvsock_put(vsock);
+}
+
+static int sockbk_count_requests(struct xenvsock *vsock,
+ struct xen_sockif_tx_request *first,
+ struct xen_sockif_tx_request *txp,
+ int work_to_do)
+{
+ RING_IDX cons = vsock->tx.req_cons;
+ int frags = 0;
+
+ if (!(first->flags & XEN_SOCKTXF_more_data))
+ return 0;
+
+ do {
+ if (frags >= work_to_do) {
+ dev_err(&vsock->xbdev->dev, "Need more frags\n");
+ sockbk_fatal_tx_err(vsock);
+ return -ENODATA;
+ }
+
+ if (unlikely(frags >= MAX_SKB_FRAGS)) {
+ dev_err(&vsock->xbdev->dev, "Too many frags\n");
+ sockbk_fatal_tx_err(vsock);
+ return -E2BIG;
+ }
+
+ memcpy(txp, RING_GET_REQUEST(&vsock->tx, cons + frags),
+ sizeof(*txp));
+ if (txp->size > first->size) {
+ dev_err(&vsock->xbdev->dev, "Frag is bigger than
frame.\n");
+ sockbk_fatal_tx_err(vsock);
+ return -EIO;
+ }
+
+ first->size -= txp->size;
+ frags++;
+
+ if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
+ dev_err(&vsock->xbdev->dev, "txp->offset: %x, size:
%u\n",
+ txp->offset, txp->size);
+ sockbk_fatal_tx_err(vsock);
+ return -EINVAL;
+ }
+ } while ((txp++)->flags & XEN_SOCKTXF_more_data);
+ return frags;
+}
+
+static struct page *xen_sockbk_alloc_page(struct xen_sockbk *sockbk,
+ struct sk_buff *skb,
+ u16 pending_idx)
+{
+ struct page *page;
+
+ page = alloc_page(GFP_KERNEL|__GFP_COLD);
+ if (!page)
+ return NULL;
+ set_page_ext(page, sockbk, pending_idx);
+ sockbk->mmap_pages[pending_idx] = page;
+ return page;
+}
+
+static
+struct gnttab_copy *xen_sockbk_get_requests(struct xen_sockbk *sockbk,
+ struct xenvsock *vsock,
+ struct sk_buff *skb,
+ struct xen_sockif_tx_request *txp,
+ struct gnttab_copy *gop)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ skb_frag_t *frags = shinfo->frags;
+ u16 pending_idx = *((u16 *)skb->data);
+ int i, start;
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
+
+ for (i = start; i < shinfo->nr_frags; i++, txp++) {
+ struct page *page;
+ pending_ring_idx_t index;
+ struct pending_tx_info *pending_tx_info =
+ sockbk->pending_tx_info;
+
+ index = pending_index(sockbk->pending_cons++);
+ pending_idx = sockbk->pending_ring[index];
+ page = xen_sockbk_alloc_page(sockbk, skb, pending_idx);
+ if (!page)
+ goto err;
+
+ gop->source.u.ref = txp->gref;
+ gop->source.domid = vsock->domid;
+ gop->source.offset = txp->offset;
+
+ gop->dest.u.gmfn = virt_to_mfn(page_address(page));
+ gop->dest.domid = DOMID_SELF;
+ gop->dest.offset = txp->offset;
+
+ gop->len = txp->size;
+ gop->flags = GNTCOPY_source_gref;
+
+ gop++;
+
+ memcpy(&pending_tx_info[pending_idx].req, txp, sizeof(*txp));
+ xenvsock_get(vsock);
+ pending_tx_info[pending_idx].vsock = vsock;
+ frag_set_pending_idx(&frags[i], pending_idx);
+ }
+
+ return gop;
+err:
+ /* Unwind, freeing all pages and sending error responses. */
+ while (i-- > start) {
+ xen_sockbk_idx_release(sockbk, frag_get_pending_idx(&frags[i]),
+ XEN_SOCKIF_RSP_ERROR);
+ }
+ /* The head too, if necessary. */
+ if (start)
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_ERROR);
+
+ return NULL;
+}
+
+static int xen_sockbk_tx_check_gop(struct xen_sockbk *sockbk,
+ struct sk_buff *skb,
+ struct gnttab_copy **gopp)
+{
+ struct gnttab_copy *gop = *gopp;
+ u16 pending_idx = *((u16 *)skb->data);
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
+ int i, err, start;
+
+ /* Check status of header. */
+ err = gop->status;
+ if (unlikely(err))
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_ERROR);
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
+
+ for (i = start; i < nr_frags; i++) {
+ int j, newerr;
+
+ pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
+
+ /* Check error status: if okay then remember grant handle. */
+ newerr = (++gop)->status;
+ if (likely(!newerr)) {
+ /* Had a previous error? Invalidate this fragment. */
+ if (unlikely(err))
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_OKAY);
+ continue;
+ }
+
+ /* Error on this fragment: respond to client with an error. */
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_ERROR);
+
+ /* Not the first error? Preceding frags already invalidated. */
+ if (err)
+ continue;
+
+ /* First error: invalidate header and preceding fragments. */
+ pending_idx = *((u16 *)skb->data);
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_OKAY);
+ for (j = start; j < i; j++) {
+ pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_OKAY);
+ }
+
+ /* Remember the error: invalidate all subsequent fragments. */
+ err = newerr;
+ }
+
+ *gopp = gop + 1;
+ return err;
+}
+
+static void xen_sockbk_fill_frags(struct xen_sockbk *sockbk,
+ struct sk_buff *skb)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
+ int i;
+
+ for (i = 0; i < nr_frags; i++) {
+ skb_frag_t *frag = shinfo->frags + i;
+ struct xen_sockif_tx_request *txp;
+ struct page *page;
+ u16 pending_idx;
+
+ pending_idx = frag_get_pending_idx(frag);
+
+ txp = &sockbk->pending_tx_info[pending_idx].req;
+ page = virt_to_page(idx_to_kaddr(sockbk, pending_idx));
+ __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
+ skb->len += txp->size;
+ skb->data_len += txp->size;
+ skb->truesize += txp->size;
+
+ /* Take an extra reference to offset xen_sockbk_idx_release */
+ get_page(sockbk->mmap_pages[pending_idx]);
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_OKAY);
+ }
+}
+
+static bool tx_credit_exceeded(struct xenvsock *vsock, unsigned size)
+{
+ unsigned long now = jiffies;
+ unsigned long next_credit =
+ vsock->credit_timeout.expires +
+ msecs_to_jiffies(vsock->credit_usec / 1000);
+
+ /* Timer could already be pending in rare cases. */
+ if (timer_pending(&vsock->credit_timeout))
+ return true;
+
+ /* Passed the point where we can replenish credit? */
+ if (time_after_eq(now, next_credit)) {
+ vsock->credit_timeout.expires = now;
+ tx_add_credit(vsock);
+ }
+
+ /* Still too big to send right now? Set a callback. */
+ if (size > vsock->remaining_credit) {
+ vsock->credit_timeout.data =
+ (unsigned long)vsock;
+ vsock->credit_timeout.function =
+ tx_credit_callback;
+ mod_timer(&vsock->credit_timeout,
+ next_credit);
+
+ return true;
+ }
+
+ return false;
+}
+
+static unsigned xen_sockbk_tx_build_gops(struct xen_sockbk *sockbk)
+{
+ struct gnttab_copy *gop = sockbk->tx_copy_ops, *request_gop;
+ struct sk_buff *skb;
+ int ret;
+
+ while (((nr_pending_reqs(sockbk) + MAX_SKB_FRAGS) < MAX_PENDING_REQS) &&
+ !list_empty(&sockbk->sock_schedule_list)) {
+ struct xenvsock *vsock;
+ struct xen_sockif_tx_request txreq;
+ struct xen_sockif_tx_request txfrags[MAX_SKB_FRAGS];
+ struct page *page;
+ u16 pending_idx;
+ RING_IDX idx;
+ int work_to_do;
+ unsigned int data_len;
+ pending_ring_idx_t index;
+
+ /* Get a vsock from the list with work to do. */
+ vsock = poll_sock_schedule_list(sockbk);
+ /* This can sometimes happen because the test of
+ * list_empty(sock_schedule_list) at the top of the
+ * loop is unlocked. Just go back and have another
+ * look.
+ */
+ if (!vsock)
+ continue;
+
+ if (vsock->tx.sring->req_prod - vsock->tx.req_cons >
+ XEN_SOCKIF_TX_RING_SIZE) {
+ dev_err(&vsock->xbdev->dev,
+ "Impossible number of requests. "
+ "req_prod %d, req_cons %d, size %ld\n",
+ vsock->tx.sring->req_prod,
+ vsock->tx.req_cons,
+ XEN_SOCKIF_TX_RING_SIZE);
+ sockbk_fatal_tx_err(vsock);
+ continue;
+ }
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&vsock->tx, work_to_do);
+ if (!work_to_do) {
+ xenvsock_put(vsock);
+ continue;
+ }
+
+ idx = vsock->tx.req_cons;
+ rmb(); /* Ensure that we see the request before we copy it. */
+ memcpy(&txreq, RING_GET_REQUEST(&vsock->tx, idx),
+ sizeof(txreq));
+
+ /* Credit-based scheduling. */
+ if (txreq.size > vsock->remaining_credit &&
+ tx_credit_exceeded(vsock, txreq.size)) {
+ xenvsock_put(vsock);
+ continue;
+ }
+
+ vsock->remaining_credit -= txreq.size;
+
+ work_to_do--;
+ vsock->tx.req_cons = ++idx;
+
+ ret = sockbk_count_requests(vsock, &txreq, txfrags, work_to_do);
+ if (unlikely(ret < 0))
+ continue;
+
+ idx += ret;
+
+ if (unlikely(txreq.size == 0)) {
+ dev_dbg(&vsock->xbdev->dev,
+ "Bad packet size: %d\n", txreq.size);
+ sockbk_tx_err(vsock, &txreq, idx);
+ continue;
+ }
+
+ /* No crossing a page as the payload mustn't fragment. */
+ if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
+ dev_err(&vsock->xbdev->dev,
+ "txreq.offset: %x, size: %u, end: %lu\n",
+ txreq.offset, txreq.size,
+ (txreq.offset&~PAGE_MASK) + txreq.size);
+ sockbk_fatal_tx_err(vsock);
+ continue;
+ }
+
+ index = pending_index(sockbk->pending_cons);
+ pending_idx = sockbk->pending_ring[index];
+
+ data_len = (txreq.size > PKT_PROT_LEN &&
+ ret < MAX_SKB_FRAGS) ?
+ PKT_PROT_LEN : txreq.size;
+
+ skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(skb == NULL)) {
+ dev_dbg(&vsock->xbdev->dev,
+ "Can't allocate a skb in start_xmit.\n");
+ sockbk_tx_err(vsock, &txreq, idx);
+ break;
+ }
+
+ /* Packets passed to sockif_rx() must have some headroom. */
+ skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+
+ /* XXX could copy straight to head */
+ page = xen_sockbk_alloc_page(sockbk, skb, pending_idx);
+ if (!page) {
+ kfree_skb(skb);
+ sockbk_tx_err(vsock, &txreq, idx);
+ continue;
+ }
+
+ gop->source.u.ref = txreq.gref;
+ gop->source.domid = vsock->domid;
+ gop->source.offset = txreq.offset;
+
+ gop->dest.u.gmfn = virt_to_mfn(page_address(page));
+ gop->dest.domid = DOMID_SELF;
+ gop->dest.offset = txreq.offset;
+
+ gop->len = txreq.size;
+ gop->flags = GNTCOPY_source_gref;
+
+ gop++;
+
+ memcpy(&sockbk->pending_tx_info[pending_idx].req,
+ &txreq, sizeof(txreq));
+ sockbk->pending_tx_info[pending_idx].vsock = vsock;
+ *((u16 *)skb->data) = pending_idx;
+
+ __skb_put(skb, data_len);
+
+ skb_shinfo(skb)->nr_frags = ret;
+ if (data_len < txreq.size) {
+ skb_shinfo(skb)->nr_frags++;
+ frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
+ pending_idx);
+ } else {
+ frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
+ INVALID_PENDING_IDX);
+ }
+
+ sockbk->pending_cons++;
+
+ request_gop = xen_sockbk_get_requests(sockbk, vsock,
+ skb, txfrags, gop);
+ if (request_gop == NULL) {
+ kfree_skb(skb);
+ sockbk_tx_err(vsock, &txreq, idx);
+ continue;
+ }
+ gop = request_gop;
+
+ __skb_queue_tail(&sockbk->tx_queue, skb);
+
+ vsock->tx.req_cons = idx;
+ xen_sockbk_check_rx_xenvsock(vsock);
+
+ if (gop-sockbk->tx_copy_ops >= ARRAY_SIZE(sockbk->tx_copy_ops))
+ break;
+ }
+
+ return gop - sockbk->tx_copy_ops;
+}
+
+static void xen_sockbk_tx_submit(struct xen_sockbk *sockbk)
+{
+ struct gnttab_copy *gop = sockbk->tx_copy_ops;
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue(&sockbk->tx_queue)) != NULL) {
+ struct xen_sockif_tx_request *txp;
+ struct xenvsock *vsock;
+ u16 pending_idx;
+ unsigned data_len;
+
+ pending_idx = *((u16 *)skb->data);
+ vsock = sockbk->pending_tx_info[pending_idx].vsock;
+ txp = &sockbk->pending_tx_info[pending_idx].req;
+
+ /* Check the remap error code. */
+ if (unlikely(xen_sockbk_tx_check_gop(sockbk, skb, &gop))) {
+ dev_dbg(&vsock->xbdev->dev, "sockback grant failed.\n");
+ skb_shinfo(skb)->nr_frags = 0;
+ kfree_skb(skb);
+ continue;
+ }
+
+ data_len = skb->len;
+ memcpy(skb->data,
+ (void *)(idx_to_kaddr(sockbk, pending_idx)|txp->offset),
+ data_len);
+ if (data_len < txp->size) {
+ /* Append the packet payload as a fragment. */
+ txp->offset += data_len;
+ txp->size -= data_len;
+ } else {
+ /* Schedule a response immediately. */
+ xen_sockbk_idx_release(sockbk, pending_idx,
+ XEN_SOCKIF_RSP_OKAY);
+ }
+
+ xen_sockbk_fill_frags(sockbk, skb);
+
+ /* If the initial fragment was < PKT_PROT_LEN then
+ * pull through some bytes from the other fragments to
+ * increase the linear region to PKT_PROT_LEN bytes.
+ */
+ if (skb_headlen(skb) < PKT_PROT_LEN && skb_is_nonlinear(skb)) {
+ int target = min_t(int, skb->len, PKT_PROT_LEN);
+
+ __pskb_pull_tail(skb, target - skb_headlen(skb));
+ }
+
+ xenvsock_receive_skb(vsock, skb);
+ }
+}
+
+/* Called after sockfront has transmitted */
+static void xen_sockbk_tx_action(struct xen_sockbk *sockbk)
+{
+ unsigned nr_gops;
+
+ nr_gops = xen_sockbk_tx_build_gops(sockbk);
+
+ if (nr_gops == 0)
+ return;
+
+ gnttab_batch_copy(sockbk->tx_copy_ops, nr_gops);
+
+ xen_sockbk_tx_submit(sockbk);
+}
+
+static void xen_sockbk_idx_release(struct xen_sockbk *sockbk, u16 pending_idx,
+ u8 status)
+{
+ struct xenvsock *vsock;
+ struct pending_tx_info *pending_tx_info;
+ pending_ring_idx_t index;
+
+ /* Already complete? */
+ if (sockbk->mmap_pages[pending_idx] == NULL)
+ return;
+
+ pending_tx_info = &sockbk->pending_tx_info[pending_idx];
+
+ vsock = pending_tx_info->vsock;
+
+ make_tx_response(vsock, &pending_tx_info->req, status);
+
+ index = pending_index(sockbk->pending_prod++);
+ sockbk->pending_ring[index] = pending_idx;
+
+ xenvsock_put(vsock);
+
+ sockbk->mmap_pages[pending_idx]->mapping = 0;
+ put_page(sockbk->mmap_pages[pending_idx]);
+ sockbk->mmap_pages[pending_idx] = NULL;
+}
+
+static void make_tx_response(struct xenvsock *vsock,
+ struct xen_sockif_tx_request *txp,
+ s8 st)
+{
+ RING_IDX i = vsock->tx.rsp_prod_pvt;
+ struct xen_sockif_tx_response *resp;
+ int notify;
+
+ resp = RING_GET_RESPONSE(&vsock->tx, i);
+ resp->id = txp->id;
+ resp->status = st;
+
+ vsock->tx.rsp_prod_pvt = ++i;
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vsock->tx, notify);
+ if (notify)
+ notify_remote_via_irq(vsock->irq);
+}
+
+static struct xen_sockif_rx_response *make_rx_response(struct xenvsock *vsock,
+ u16 id, s8 st,
+ u16 offset, u16 size,
+ u16 flags)
+{
+ RING_IDX i = vsock->rx.rsp_prod_pvt;
+ struct xen_sockif_rx_response *resp;
+
+ resp = RING_GET_RESPONSE(&vsock->rx, i);
+ resp->offset = offset;
+ resp->flags = flags;
+ resp->id = id;
+ resp->status = (s16)size;
+ if (st < 0)
+ resp->status = (s16)st;
+
+ vsock->rx.rsp_prod_pvt = ++i;
+
+ return resp;
+}
+
+static inline int rx_work_todo(struct xen_sockbk *sockbk)
+{
+ return !skb_queue_empty(&sockbk->rx_queue);
+}
+
+static inline int tx_work_todo(struct xen_sockbk *sockbk)
+{
+ if (((nr_pending_reqs(sockbk) + MAX_SKB_FRAGS) < MAX_PENDING_REQS) &&
+ !list_empty(&sockbk->sock_schedule_list))
+ return 1;
+
+ return 0;
+}
+
+static int xen_sockbk_kthread(void *data)
+{
+ struct xen_sockbk *sockbk = data;
+
+ while (!kthread_should_stop()) {
+ wait_event_interruptible(sockbk->wq,
+ rx_work_todo(sockbk) ||
+ tx_work_todo(sockbk) ||
+ kthread_should_stop());
+ cond_resched();
+
+ if (kthread_should_stop())
+ break;
+
+ if (rx_work_todo(sockbk))
+ xen_sockbk_rx_action(sockbk);
+
+ if (tx_work_todo(sockbk))
+ xen_sockbk_tx_action(sockbk);
+ }
+
+ return 0;
+}
+
+void xen_sockbk_unmap_frontend_rings(struct xenvsock *vsock)
+{
+ if (vsock->tx.sring)
+ xenbus_unmap_ring_vfree(vsock->xbdev, vsock->tx.sring);
+ if (vsock->rx.sring)
+ xenbus_unmap_ring_vfree(vsock->xbdev, vsock->rx.sring);
+}
+
+int xen_sockbk_map_frontend_rings(struct xenvsock *vsock,
+ grant_ref_t tx_ring_ref,
+ grant_ref_t rx_ring_ref)
+{
+ void *addr;
+ struct xen_sockif_tx_sring *txs;
+ struct xen_sockif_rx_sring *rxs;
+
+ int err = -ENOMEM;
+
+ err = xenbus_map_ring_valloc(vsock->xbdev, tx_ring_ref, &addr);
+ if (err)
+ goto err;
+
+ txs = (struct xen_sockif_tx_sring *)addr;
+ BACK_RING_INIT(&vsock->tx, txs, PAGE_SIZE);
+
+ err = xenbus_map_ring_valloc(vsock->xbdev, rx_ring_ref, &addr);
+ if (err)
+ goto err;
+
+ rxs = (struct xen_sockif_rx_sring *)addr;
+ BACK_RING_INIT(&vsock->rx, rxs, PAGE_SIZE);
+
+ vsock->rx_req_cons_peek = 0;
+
+ return 0;
+
+err:
+ xen_sockbk_unmap_frontend_rings(vsock);
+ return err;
+}
+
+static int __init sockback_init(void)
+{
+ int i;
+ int rc = 0;
+ int group;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ xen_sockbk_group_nr = num_online_cpus();
+ xen_sockbk = vzalloc(sizeof(*xen_sockbk) * xen_sockbk_group_nr);
+ if (!xen_sockbk)
+ return -ENOMEM;
+
+ for (group = 0; group < xen_sockbk_group_nr; group++) {
+ struct xen_sockbk *sockbk = &xen_sockbk[group];
+
+ skb_queue_head_init(&sockbk->rx_queue);
+ skb_queue_head_init(&sockbk->tx_queue);
+
+ init_timer(&sockbk->sock_timer);
+ sockbk->sock_timer.data = (unsigned long)sockbk;
+ sockbk->sock_timer.function = xen_sockbk_alarm;
+
+ sockbk->pending_cons = 0;
+ sockbk->pending_prod = MAX_PENDING_REQS;
+ for (i = 0; i < MAX_PENDING_REQS; i++)
+ sockbk->pending_ring[i] = i;
+
+ init_waitqueue_head(&sockbk->wq);
+ sockbk->task = kthread_create(xen_sockbk_kthread,
+ (void *)sockbk,
+ "sockback/%u", group);
+
+ if (IS_ERR(sockbk->task)) {
+ pr_alert("kthread_create() fails at sockback\n");
+ del_timer(&sockbk->sock_timer);
+ rc = PTR_ERR(sockbk->task);
+ goto failed_init;
+ }
+
+ kthread_bind(sockbk->task, group);
+
+ INIT_LIST_HEAD(&sockbk->sock_schedule_list);
+
+ spin_lock_init(&sockbk->sock_schedule_list_lock);
+
+ atomic_set(&sockbk->sockfront_count, 0);
+
+ wake_up_process(sockbk->task);
+ }
+
+ rc = xenvsock_xenbus_init();
+ if (rc)
+ goto failed_init;
+
+ rc = xensock_proto_server_init();
+ if (rc)
+ goto failed_init;
+
+ return 0;
+
+failed_init:
+ while (--group >= 0) {
+ struct xen_sockbk *sockbk = &xen_sockbk[group];
+
+ for (i = 0; i < MAX_PENDING_REQS; i++) {
+ if (sockbk->mmap_pages[i])
+ __free_page(sockbk->mmap_pages[i]);
+ }
+ del_timer(&sockbk->sock_timer);
+ kthread_stop(sockbk->task);
+ }
+ vfree(xen_sockbk);
+ return rc;
+}
+
+module_init(sockback_init);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vsock");
diff --git a/drivers/net/xen-sockback/xenbus.c
b/drivers/net/xen-sockback/xenbus.c
new file mode 100644
index 0000000..7bd9a06
--- /dev/null
+++ b/drivers/net/xen-sockback/xenbus.c
@@ -0,0 +1,348 @@
+/*
+ * Xenbus code for sockif backend
+ *
+ * Copyright (C) 2005 Rusty Russell <rusty@xxxxxxxxxxxxxxx>
+ * Copyright (C) 2005 XenSource Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+*/
+#include "common.h"
+
+struct backend_info {
+ struct xenbus_device *dev;
+ struct xenvsock *vsock;
+ enum xenbus_state frontend_state;
+};
+
+static int connect_rings(struct backend_info *);
+static void connect(struct backend_info *);
+static int backend_create_xenvsock(struct backend_info *be);
+
+static int sockback_remove(struct xenbus_device *dev)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ if (be->vsock) {
+ xenvsock_disconnect(be->vsock);
+ be->vsock = NULL;
+ }
+ kfree(be);
+ dev_set_drvdata(&dev->dev, NULL);
+ return 0;
+}
+
+
+/**
+ * Entry point to this code when a new device is created. Allocate the basic
+ * structures and switch to InitWait.
+ */
+static int sockback_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ const char *message;
+ struct xenbus_transaction xbt;
+ int err;
+ int sg;
+ struct backend_info *be = kzalloc(sizeof(*be), GFP_KERNEL);
+
+ if (!be) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "allocating backend structure");
+ return -ENOMEM;
+ }
+
+ be->dev = dev;
+ dev_set_drvdata(&dev->dev, be);
+
+ sg = 1;
+
+ do {
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto fail;
+ }
+
+ /* We support rx-copy path. */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-rx-copy", "%d", 1);
+ if (err) {
+ message = "writing feature-rx-copy";
+ goto abort_transaction;
+ }
+
+ /* We don't support rx-flip path (except old guests who don't
+ * grok this feature flag).
+ */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-rx-flip", "%d", 0);
+ if (err) {
+ message = "writing feature-rx-flip";
+ goto abort_transaction;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ } while (err == -EAGAIN);
+
+ if (err) {
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto fail;
+ }
+
+ err = xenbus_switch_state(dev, XenbusStateInitWait);
+ if (err)
+ goto fail;
+
+ return 0;
+
+abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, err, "%s", message);
+fail:
+ pr_debug("failed");
+ sockback_remove(dev);
+ return err;
+}
+
+static int backend_create_xenvsock(struct backend_info *be)
+{
+ int err;
+ long handle;
+ struct xenbus_device *dev = be->dev;
+
+ if (be->vsock != NULL)
+ return 0;
+
+ err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
+ if (err != 1) {
+ err = -EINVAL;
+ xenbus_dev_fatal(dev, err, "reading handle");
+ goto fail;
+ }
+
+ be->vsock = xenvsock_alloc(&dev->dev, dev->otherend_id, handle);
+ if (IS_ERR(be->vsock)) {
+ err = PTR_ERR(be->vsock);
+ be->vsock = NULL;
+ xenbus_dev_fatal(dev, err, "creating interface");
+ goto fail;
+ }
+
+ /* setup back pointer */
+ be->vsock->xbdev = dev;
+
+ err = 0;
+fail:
+ return err;
+}
+
+
+static void disconnect_backend(struct xenbus_device *dev)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ if (be->vsock) {
+ xenvsock_disconnect(be->vsock);
+ be->vsock = NULL;
+ }
+}
+
+/**
+ * Callback received when the frontend's state changes.
+ */
+static void frontend_changed(struct xenbus_device *dev,
+ enum xenbus_state frontend_state)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ pr_debug("frontend state %s", xenbus_strstate(frontend_state));
+
+ be->frontend_state = frontend_state;
+
+ switch (frontend_state) {
+ case XenbusStateInitialising:
+ if (dev->state == XenbusStateClosed) {
+ pr_alert("%s: %s: prepare for reconnect\n",
+ __func__, dev->nodename);
+ xenbus_switch_state(dev, XenbusStateInitWait);
+ }
+ break;
+
+ case XenbusStateInitialised:
+ case XenbusStateConnected:
+ /* Ensure we connect even when two watches fire in
+ * close succession and we miss the intermediate value
+ * of frontend_state.
+ */
+ if (dev->state == XenbusStateConnected)
+ break;
+
+ /* Enforce precondition before potential leak point.
+ * disconnect_backend() is idempotent.
+ */
+ disconnect_backend(dev);
+
+ if (backend_create_xenvsock(be))
+ break;
+
+ connect(be);
+ break;
+
+ case XenbusStateClosing:
+ xenbus_switch_state(dev, XenbusStateClosing);
+ break;
+
+ case XenbusStateClosed:
+ disconnect_backend(dev);
+ xenbus_switch_state(dev, XenbusStateClosed);
+ if (xenbus_dev_is_online(dev))
+ break;
+ /* fall through if not online */
+ case XenbusStateUnknown:
+ device_unregister(&dev->dev);
+ break;
+
+ default:
+ xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+ frontend_state);
+ break;
+ }
+}
+
+static void xen_sock_read_rate(struct xenbus_device *dev,
+ unsigned long *bytes, unsigned long *usec)
+{
+ char *s, *e;
+ unsigned long b, u;
+ char *ratestr;
+
+ /* Default to unlimited bandwidth. */
+ *bytes = ~0UL;
+ *usec = 0;
+
+ ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
+ if (IS_ERR(ratestr))
+ return;
+
+ s = ratestr;
+ e = strchr(s, ',');
+ if (e == NULL)
+ goto fail;
+
+ e[0] = '\0';
+
+ if (kstrtoul(s, 10, &b))
+ goto fail;
+
+ s = e + 1;
+ if (kstrtoul(s, 10, &u))
+ goto fail;
+
+ *bytes = b;
+ *usec = u;
+
+ kfree(ratestr);
+ return;
+
+ fail:
+ pr_warn("Failed to parse socket data rate limit. Traffic unlimited.\n");
+ kfree(ratestr);
+}
+
+static void connect(struct backend_info *be)
+{
+ int err;
+ struct xenbus_device *dev = be->dev;
+
+ err = connect_rings(be);
+ if (err)
+ return;
+
+ xen_sock_read_rate(dev, &be->vsock->credit_bytes,
+ &be->vsock->credit_usec);
+ be->vsock->remaining_credit = be->vsock->credit_bytes;
+
+ sockif_wake_queue(be->vsock->dev);
+ xenbus_switch_state(dev, XenbusStateConnected);
+}
+
+static int connect_rings(struct backend_info *be)
+{
+ struct xenvsock *vsock = be->vsock;
+ struct xenbus_device *dev = be->dev;
+ unsigned long tx_ring_ref, rx_ring_ref;
+ unsigned int evtchn, rx_copy;
+ int err;
+ int val;
+
+ err = xenbus_gather(XBT_NIL, dev->otherend,
+ "tx-ring-ref", "%lu", &tx_ring_ref,
+ "rx-ring-ref", "%lu", &rx_ring_ref,
+ "event-channel", "%u", &evtchn, NULL);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "reading %s/ring-ref and event-channel",
+ dev->otherend);
+ return err;
+ }
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
+ &rx_copy);
+ if (err == -ENOENT) {
+ err = 0;
+ rx_copy = 0;
+ }
+ if (err < 0) {
+ xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
+ dev->otherend);
+ return err;
+ }
+ if (!rx_copy)
+ return -EOPNOTSUPP;
+
+ if (vsock->dev->tx_queue_len != 0) {
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
+ "feature-rx-notify", "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vsock->can_queue = 1;
+ else
+ /* Must be non-zero for pfifo_fast to work. */
+ vsock->dev->tx_queue_len = 1;
+ }
+
+ /* Map the shared frame, irq etc. */
+ err = xenvsock_connect(vsock, tx_ring_ref, rx_ring_ref, evtchn);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "mapping shared-frames %lu/%lu port %u",
+ tx_ring_ref, rx_ring_ref, evtchn);
+ return err;
+ }
+ return 0;
+}
+
+/* ** Driver Registration ** */
+static const struct xenbus_device_id sockback_ids[] = {
+ { "vsock" },
+ { "" }
+};
+
+static DEFINE_XENBUS_DRIVER(sockback, ,
+ .probe = sockback_probe,
+ .remove = sockback_remove,
+ .otherend_changed = frontend_changed,
+);
+
+int xenvsock_xenbus_init(void)
+{
+ return xenbus_register_backend(&sockback_driver);
+}
diff --git a/include/xen/interface/io/sockif.h
b/include/xen/interface/io/sockif.h
new file mode 100644
index 0000000..c12ce11
--- /dev/null
+++ b/include/xen/interface/io/sockif.h
@@ -0,0 +1,74 @@
+/******************************************************************************
+ * sockif.h
+ *
+ * Unified xensock I/O interface for Xen guest OSes.
+ *
+ */
+#ifndef __XEN_PUBLIC_IO_SOCKIF_H__
+#define __XEN_PUBLIC_IO_SOCKIF_H__
+
+#include <linux/types.h>
+#include <linux/spinlock.h>
+
+#include <net/sock.h>
+
+#include <xen/interface/io/ring.h>
+#include <xen/interface/grant_table.h>
+
+/*
+ * REQUEST CODES.
+ */
+#define SOCKIF_OP_SENDMSG 0
+#define SOCKIF_OP_RECVMSG 1
+
+#define SOCKIF_MAX_PAGES_PER_REQUEST 10
+
+#define SOCKIF_DEV_ID_CNT 5
+
+
+/* Packet continues in the next request descriptor. */
+#define _XEN_SOCKTXF_more_data (2)
+#define XEN_SOCKTXF_more_data (1U<<_XEN_SOCKTXF_more_data)
+
+struct xen_sockif_tx_request {
+ grant_ref_t gref; /* Reference to buffer page */
+ uint16_t offset; /* Offset within buffer page */
+ uint16_t flags; /* XEN_SOCKTXF_* */
+ uint16_t id; /* Echoed in response message. */
+ uint16_t size; /* Packet size in bytes. */
+};
+
+struct xen_sockif_tx_response {
+ uint16_t id;
+ int16_t status; /* XEN_SOCKIF_RSP_* */
+};
+
+struct xen_sockif_rx_request {
+ uint16_t id; /* Echoed in response message. */
+ grant_ref_t gref; /* Reference to incoming granted frame */
+};
+
+/* Packet continues in the next request descriptor. */
+#define _XEN_SOCKRXF_more_data (0)
+#define XEN_SOCKRXF_more_data (1U<<_XEN_SOCKRXF_more_data)
+
+struct xen_sockif_rx_response {
+ uint16_t id;
+ uint16_t offset; /* Offset in page of start of received packet */
+ uint16_t flags; /* XEN_SOCKRXF_* */
+ int16_t status; /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
+};
+
+DEFINE_RING_TYPES(xen_sockif_tx,
+ struct xen_sockif_tx_request,
+ struct xen_sockif_tx_response);
+
+DEFINE_RING_TYPES(xen_sockif_rx,
+ struct xen_sockif_rx_request,
+ struct xen_sockif_rx_response);
+
+#define XEN_SOCKIF_RSP_DROPPED -2
+#define XEN_SOCKIF_RSP_ERROR -1
+#define XEN_SOCKIF_RSP_OKAY 0
+
+#endif /* __XEN_PUBLIC_IO_SOCKIF_H__ */
--
1.8.2.rc2
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