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@@ -0,0 +1,1278 @@
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+/*
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+ * (c) 2017 Stefano Stabellini <stefano@aporeto.com>
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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+ *
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ */
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+
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+#include <linux/module.h>
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+#include <linux/net.h>
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+#include <linux/socket.h>
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+
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+#include <net/sock.h>
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+
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+#include <xen/events.h>
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+#include <xen/grant_table.h>
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+#include <xen/xen.h>
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+#include <xen/xenbus.h>
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+#include <xen/interface/io/pvcalls.h>
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+
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+#include "pvcalls-front.h"
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+
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+#define PVCALLS_INVALID_ID UINT_MAX
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+#define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER
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+#define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE)
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+#define PVCALLS_FRONT_MAX_SPIN 5000
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+
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+struct pvcalls_bedata {
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+ struct xen_pvcalls_front_ring ring;
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+ grant_ref_t ref;
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+ int irq;
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+
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+ struct list_head socket_mappings;
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+ spinlock_t socket_lock;
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+
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+ wait_queue_head_t inflight_req;
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+ struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING];
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+};
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+/* Only one front/back connection supported. */
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+static struct xenbus_device *pvcalls_front_dev;
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+static atomic_t pvcalls_refcount;
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+
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+/* first increment refcount, then proceed */
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+#define pvcalls_enter() { \
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+ atomic_inc(&pvcalls_refcount); \
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+}
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+
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+/* first complete other operations, then decrement refcount */
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+#define pvcalls_exit() { \
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+ atomic_dec(&pvcalls_refcount); \
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+}
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+
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+struct sock_mapping {
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+ bool active_socket;
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+ struct list_head list;
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+ struct socket *sock;
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+ union {
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+ struct {
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+ int irq;
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+ grant_ref_t ref;
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+ struct pvcalls_data_intf *ring;
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+ struct pvcalls_data data;
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+ struct mutex in_mutex;
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+ struct mutex out_mutex;
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+
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+ wait_queue_head_t inflight_conn_req;
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+ } active;
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+ struct {
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+ /* Socket status */
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+#define PVCALLS_STATUS_UNINITALIZED 0
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+#define PVCALLS_STATUS_BIND 1
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+#define PVCALLS_STATUS_LISTEN 2
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+ uint8_t status;
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+ /*
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+ * Internal state-machine flags.
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+ * Only one accept operation can be inflight for a socket.
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+ * Only one poll operation can be inflight for a given socket.
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+ */
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+#define PVCALLS_FLAG_ACCEPT_INFLIGHT 0
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+#define PVCALLS_FLAG_POLL_INFLIGHT 1
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+#define PVCALLS_FLAG_POLL_RET 2
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+ uint8_t flags;
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+ uint32_t inflight_req_id;
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+ struct sock_mapping *accept_map;
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+ wait_queue_head_t inflight_accept_req;
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+ } passive;
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+ };
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+};
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+
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+static inline int get_request(struct pvcalls_bedata *bedata, int *req_id)
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+{
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+ *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
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+ if (RING_FULL(&bedata->ring) ||
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+ bedata->rsp[*req_id].req_id != PVCALLS_INVALID_ID)
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+ return -EAGAIN;
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+ return 0;
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+}
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+
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+static bool pvcalls_front_write_todo(struct sock_mapping *map)
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+{
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+ struct pvcalls_data_intf *intf = map->active.ring;
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+ RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
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+ int32_t error;
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+
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+ error = intf->out_error;
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+ if (error == -ENOTCONN)
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+ return false;
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+ if (error != 0)
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+ return true;
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+
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+ cons = intf->out_cons;
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+ prod = intf->out_prod;
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+ return !!(size - pvcalls_queued(prod, cons, size));
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+}
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+
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+static bool pvcalls_front_read_todo(struct sock_mapping *map)
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+{
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+ struct pvcalls_data_intf *intf = map->active.ring;
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+ RING_IDX cons, prod;
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+ int32_t error;
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+
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+ cons = intf->in_cons;
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+ prod = intf->in_prod;
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+ error = intf->in_error;
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+ return (error != 0 ||
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+ pvcalls_queued(prod, cons,
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+ XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0);
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+}
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+
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+static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id)
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+{
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+ struct xenbus_device *dev = dev_id;
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+ struct pvcalls_bedata *bedata;
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+ struct xen_pvcalls_response *rsp;
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+ uint8_t *src, *dst;
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+ int req_id = 0, more = 0, done = 0;
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+
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+ if (dev == NULL)
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+ return IRQ_HANDLED;
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+
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+ pvcalls_enter();
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+ bedata = dev_get_drvdata(&dev->dev);
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+ if (bedata == NULL) {
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+ pvcalls_exit();
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+ return IRQ_HANDLED;
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+ }
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+
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+again:
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+ while (RING_HAS_UNCONSUMED_RESPONSES(&bedata->ring)) {
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+ rsp = RING_GET_RESPONSE(&bedata->ring, bedata->ring.rsp_cons);
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+
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+ req_id = rsp->req_id;
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+ if (rsp->cmd == PVCALLS_POLL) {
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+ struct sock_mapping *map = (struct sock_mapping *)(uintptr_t)
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+ rsp->u.poll.id;
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+
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+ clear_bit(PVCALLS_FLAG_POLL_INFLIGHT,
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+ (void *)&map->passive.flags);
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+ /*
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+ * clear INFLIGHT, then set RET. It pairs with
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+ * the checks at the beginning of
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+ * pvcalls_front_poll_passive.
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+ */
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+ smp_wmb();
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+ set_bit(PVCALLS_FLAG_POLL_RET,
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+ (void *)&map->passive.flags);
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+ } else {
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+ dst = (uint8_t *)&bedata->rsp[req_id] +
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+ sizeof(rsp->req_id);
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+ src = (uint8_t *)rsp + sizeof(rsp->req_id);
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+ memcpy(dst, src, sizeof(*rsp) - sizeof(rsp->req_id));
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+ /*
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+ * First copy the rest of the data, then req_id. It is
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+ * paired with the barrier when accessing bedata->rsp.
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+ */
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+ smp_wmb();
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+ bedata->rsp[req_id].req_id = req_id;
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+ }
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+
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+ done = 1;
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+ bedata->ring.rsp_cons++;
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+ }
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+
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+ RING_FINAL_CHECK_FOR_RESPONSES(&bedata->ring, more);
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+ if (more)
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+ goto again;
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+ if (done)
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+ wake_up(&bedata->inflight_req);
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+ pvcalls_exit();
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+ return IRQ_HANDLED;
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+}
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+
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+static void pvcalls_front_free_map(struct pvcalls_bedata *bedata,
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+ struct sock_mapping *map)
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+{
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+ int i;
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+
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+ unbind_from_irqhandler(map->active.irq, map);
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+
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+ spin_lock(&bedata->socket_lock);
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+ if (!list_empty(&map->list))
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+ list_del_init(&map->list);
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+ spin_unlock(&bedata->socket_lock);
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+
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+ for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++)
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+ gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0);
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+ gnttab_end_foreign_access(map->active.ref, 0, 0);
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+ free_page((unsigned long)map->active.ring);
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+
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+ kfree(map);
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+}
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+
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+static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map)
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+{
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+ struct sock_mapping *map = sock_map;
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+
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+ if (map == NULL)
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+ return IRQ_HANDLED;
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+
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+ wake_up_interruptible(&map->active.inflight_conn_req);
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+
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+ return IRQ_HANDLED;
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+}
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+
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+int pvcalls_front_socket(struct socket *sock)
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+{
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+ struct pvcalls_bedata *bedata;
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+ struct sock_mapping *map = NULL;
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+ struct xen_pvcalls_request *req;
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+ int notify, req_id, ret;
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+
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+ /*
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+ * PVCalls only supports domain AF_INET,
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+ * type SOCK_STREAM and protocol 0 sockets for now.
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+ *
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+ * Check socket type here, AF_INET and protocol checks are done
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+ * by the caller.
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+ */
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+ if (sock->type != SOCK_STREAM)
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+ return -EOPNOTSUPP;
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+
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+ pvcalls_enter();
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+ if (!pvcalls_front_dev) {
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+ pvcalls_exit();
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+ return -EACCES;
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+ }
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+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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+
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+ map = kzalloc(sizeof(*map), GFP_KERNEL);
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+ if (map == NULL) {
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+ pvcalls_exit();
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+ return -ENOMEM;
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+ }
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+
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+ spin_lock(&bedata->socket_lock);
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+
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+ ret = get_request(bedata, &req_id);
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+ if (ret < 0) {
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+ kfree(map);
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+ spin_unlock(&bedata->socket_lock);
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+ pvcalls_exit();
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+ return ret;
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+ }
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+
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+ /*
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+ * sock->sk->sk_send_head is not used for ip sockets: reuse the
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+ * field to store a pointer to the struct sock_mapping
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+ * corresponding to the socket. This way, we can easily get the
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+ * struct sock_mapping from the struct socket.
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+ */
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+ sock->sk->sk_send_head = (void *)map;
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+ list_add_tail(&map->list, &bedata->socket_mappings);
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+
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+ req = RING_GET_REQUEST(&bedata->ring, req_id);
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+ req->req_id = req_id;
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+ req->cmd = PVCALLS_SOCKET;
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+ req->u.socket.id = (uintptr_t) map;
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+ req->u.socket.domain = AF_INET;
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+ req->u.socket.type = SOCK_STREAM;
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+ req->u.socket.protocol = IPPROTO_IP;
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+
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+ bedata->ring.req_prod_pvt++;
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+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
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+ spin_unlock(&bedata->socket_lock);
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+ if (notify)
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+ notify_remote_via_irq(bedata->irq);
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+
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+ wait_event(bedata->inflight_req,
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+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
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+
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+ /* read req_id, then the content */
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+ smp_rmb();
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+ ret = bedata->rsp[req_id].ret;
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+ bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
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+
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+ pvcalls_exit();
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+ return ret;
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+}
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+
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+static int create_active(struct sock_mapping *map, int *evtchn)
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+{
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+ void *bytes;
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+ int ret = -ENOMEM, irq = -1, i;
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+
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+ *evtchn = -1;
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+ init_waitqueue_head(&map->active.inflight_conn_req);
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+
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+ map->active.ring = (struct pvcalls_data_intf *)
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+ __get_free_page(GFP_KERNEL | __GFP_ZERO);
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+ if (map->active.ring == NULL)
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+ goto out_error;
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+ map->active.ring->ring_order = PVCALLS_RING_ORDER;
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+ bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
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+ PVCALLS_RING_ORDER);
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+ if (bytes == NULL)
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+ goto out_error;
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+ for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++)
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+ map->active.ring->ref[i] = gnttab_grant_foreign_access(
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+ pvcalls_front_dev->otherend_id,
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+ pfn_to_gfn(virt_to_pfn(bytes) + i), 0);
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+
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+ map->active.ref = gnttab_grant_foreign_access(
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+ pvcalls_front_dev->otherend_id,
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+ pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0);
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+
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+ map->active.data.in = bytes;
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+ map->active.data.out = bytes +
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+ XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
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+
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+ ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn);
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+ if (ret)
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+ goto out_error;
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+ irq = bind_evtchn_to_irqhandler(*evtchn, pvcalls_front_conn_handler,
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+ 0, "pvcalls-frontend", map);
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+ if (irq < 0) {
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+ ret = irq;
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+ goto out_error;
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+ }
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+
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+ map->active.irq = irq;
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+ map->active_socket = true;
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+ mutex_init(&map->active.in_mutex);
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+ mutex_init(&map->active.out_mutex);
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+
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+ return 0;
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+
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+out_error:
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+ if (*evtchn >= 0)
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+ xenbus_free_evtchn(pvcalls_front_dev, *evtchn);
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+ kfree(map->active.data.in);
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+ kfree(map->active.ring);
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+ return ret;
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+}
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+
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+int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
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+ int addr_len, int flags)
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+{
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+ struct pvcalls_bedata *bedata;
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+ struct sock_mapping *map = NULL;
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+ struct xen_pvcalls_request *req;
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+ int notify, req_id, ret, evtchn;
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+
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+ if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
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+ return -EOPNOTSUPP;
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+
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+ pvcalls_enter();
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+ if (!pvcalls_front_dev) {
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+ pvcalls_exit();
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+ return -ENOTCONN;
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+ }
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+
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+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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+
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+ map = (struct sock_mapping *)sock->sk->sk_send_head;
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+ if (!map) {
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+ pvcalls_exit();
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+ return -ENOTSOCK;
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+ }
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+
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+ spin_lock(&bedata->socket_lock);
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+ ret = get_request(bedata, &req_id);
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+ if (ret < 0) {
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+ spin_unlock(&bedata->socket_lock);
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+ pvcalls_exit();
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+ return ret;
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+ }
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+ ret = create_active(map, &evtchn);
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+ if (ret < 0) {
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+ spin_unlock(&bedata->socket_lock);
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+ pvcalls_exit();
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|
|
+ return ret;
|
|
|
+ }
|
|
|
+
|
|
|
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
|
+ req->req_id = req_id;
|
|
|
+ req->cmd = PVCALLS_CONNECT;
|
|
|
+ req->u.connect.id = (uintptr_t)map;
|
|
|
+ req->u.connect.len = addr_len;
|
|
|
+ req->u.connect.flags = flags;
|
|
|
+ req->u.connect.ref = map->active.ref;
|
|
|
+ req->u.connect.evtchn = evtchn;
|
|
|
+ memcpy(req->u.connect.addr, addr, sizeof(*addr));
|
|
|
+
|
|
|
+ map->sock = sock;
|
|
|
+
|
|
|
+ bedata->ring.req_prod_pvt++;
|
|
|
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+
|
|
|
+ if (notify)
|
|
|
+ notify_remote_via_irq(bedata->irq);
|
|
|
+
|
|
|
+ wait_event(bedata->inflight_req,
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
|
|
|
+
|
|
|
+ /* read req_id, then the content */
|
|
|
+ smp_rmb();
|
|
|
+ ret = bedata->rsp[req_id].ret;
|
|
|
+ bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+static int __write_ring(struct pvcalls_data_intf *intf,
|
|
|
+ struct pvcalls_data *data,
|
|
|
+ struct iov_iter *msg_iter,
|
|
|
+ int len)
|
|
|
+{
|
|
|
+ RING_IDX cons, prod, size, masked_prod, masked_cons;
|
|
|
+ RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
|
|
|
+ int32_t error;
|
|
|
+
|
|
|
+ error = intf->out_error;
|
|
|
+ if (error < 0)
|
|
|
+ return error;
|
|
|
+ cons = intf->out_cons;
|
|
|
+ prod = intf->out_prod;
|
|
|
+ /* read indexes before continuing */
|
|
|
+ virt_mb();
|
|
|
+
|
|
|
+ size = pvcalls_queued(prod, cons, array_size);
|
|
|
+ if (size >= array_size)
|
|
|
+ return -EINVAL;
|
|
|
+ if (len > array_size - size)
|
|
|
+ len = array_size - size;
|
|
|
+
|
|
|
+ masked_prod = pvcalls_mask(prod, array_size);
|
|
|
+ masked_cons = pvcalls_mask(cons, array_size);
|
|
|
+
|
|
|
+ if (masked_prod < masked_cons) {
|
|
|
+ len = copy_from_iter(data->out + masked_prod, len, msg_iter);
|
|
|
+ } else {
|
|
|
+ if (len > array_size - masked_prod) {
|
|
|
+ int ret = copy_from_iter(data->out + masked_prod,
|
|
|
+ array_size - masked_prod, msg_iter);
|
|
|
+ if (ret != array_size - masked_prod) {
|
|
|
+ len = ret;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ len = ret + copy_from_iter(data->out, len - ret, msg_iter);
|
|
|
+ } else {
|
|
|
+ len = copy_from_iter(data->out + masked_prod, len, msg_iter);
|
|
|
+ }
|
|
|
+ }
|
|
|
+out:
|
|
|
+ /* write to ring before updating pointer */
|
|
|
+ virt_wmb();
|
|
|
+ intf->out_prod += len;
|
|
|
+
|
|
|
+ return len;
|
|
|
+}
|
|
|
+
|
|
|
+int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
|
|
|
+ size_t len)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map;
|
|
|
+ int sent, tot_sent = 0;
|
|
|
+ int count = 0, flags;
|
|
|
+
|
|
|
+ flags = msg->msg_flags;
|
|
|
+ if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB))
|
|
|
+ return -EOPNOTSUPP;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTCONN;
|
|
|
+ }
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (!map) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTSOCK;
|
|
|
+ }
|
|
|
+
|
|
|
+ mutex_lock(&map->active.out_mutex);
|
|
|
+ if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) {
|
|
|
+ mutex_unlock(&map->active.out_mutex);
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EAGAIN;
|
|
|
+ }
|
|
|
+ if (len > INT_MAX)
|
|
|
+ len = INT_MAX;
|
|
|
+
|
|
|
+again:
|
|
|
+ count++;
|
|
|
+ sent = __write_ring(map->active.ring,
|
|
|
+ &map->active.data, &msg->msg_iter,
|
|
|
+ len);
|
|
|
+ if (sent > 0) {
|
|
|
+ len -= sent;
|
|
|
+ tot_sent += sent;
|
|
|
+ notify_remote_via_irq(map->active.irq);
|
|
|
+ }
|
|
|
+ if (sent >= 0 && len > 0 && count < PVCALLS_FRONT_MAX_SPIN)
|
|
|
+ goto again;
|
|
|
+ if (sent < 0)
|
|
|
+ tot_sent = sent;
|
|
|
+
|
|
|
+ mutex_unlock(&map->active.out_mutex);
|
|
|
+ pvcalls_exit();
|
|
|
+ return tot_sent;
|
|
|
+}
|
|
|
+
|
|
|
+static int __read_ring(struct pvcalls_data_intf *intf,
|
|
|
+ struct pvcalls_data *data,
|
|
|
+ struct iov_iter *msg_iter,
|
|
|
+ size_t len, int flags)
|
|
|
+{
|
|
|
+ RING_IDX cons, prod, size, masked_prod, masked_cons;
|
|
|
+ RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
|
|
|
+ int32_t error;
|
|
|
+
|
|
|
+ cons = intf->in_cons;
|
|
|
+ prod = intf->in_prod;
|
|
|
+ error = intf->in_error;
|
|
|
+ /* get pointers before reading from the ring */
|
|
|
+ virt_rmb();
|
|
|
+ if (error < 0)
|
|
|
+ return error;
|
|
|
+
|
|
|
+ size = pvcalls_queued(prod, cons, array_size);
|
|
|
+ masked_prod = pvcalls_mask(prod, array_size);
|
|
|
+ masked_cons = pvcalls_mask(cons, array_size);
|
|
|
+
|
|
|
+ if (size == 0)
|
|
|
+ return 0;
|
|
|
+
|
|
|
+ if (len > size)
|
|
|
+ len = size;
|
|
|
+
|
|
|
+ if (masked_prod > masked_cons) {
|
|
|
+ len = copy_to_iter(data->in + masked_cons, len, msg_iter);
|
|
|
+ } else {
|
|
|
+ if (len > (array_size - masked_cons)) {
|
|
|
+ int ret = copy_to_iter(data->in + masked_cons,
|
|
|
+ array_size - masked_cons, msg_iter);
|
|
|
+ if (ret != array_size - masked_cons) {
|
|
|
+ len = ret;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ len = ret + copy_to_iter(data->in, len - ret, msg_iter);
|
|
|
+ } else {
|
|
|
+ len = copy_to_iter(data->in + masked_cons, len, msg_iter);
|
|
|
+ }
|
|
|
+ }
|
|
|
+out:
|
|
|
+ /* read data from the ring before increasing the index */
|
|
|
+ virt_mb();
|
|
|
+ if (!(flags & MSG_PEEK))
|
|
|
+ intf->in_cons += len;
|
|
|
+
|
|
|
+ return len;
|
|
|
+}
|
|
|
+
|
|
|
+int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
|
|
|
+ int flags)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ int ret;
|
|
|
+ struct sock_mapping *map;
|
|
|
+
|
|
|
+ if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC))
|
|
|
+ return -EOPNOTSUPP;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTCONN;
|
|
|
+ }
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (!map) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTSOCK;
|
|
|
+ }
|
|
|
+
|
|
|
+ mutex_lock(&map->active.in_mutex);
|
|
|
+ if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER))
|
|
|
+ len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
|
|
|
+
|
|
|
+ while (!(flags & MSG_DONTWAIT) && !pvcalls_front_read_todo(map)) {
|
|
|
+ wait_event_interruptible(map->active.inflight_conn_req,
|
|
|
+ pvcalls_front_read_todo(map));
|
|
|
+ }
|
|
|
+ ret = __read_ring(map->active.ring, &map->active.data,
|
|
|
+ &msg->msg_iter, len, flags);
|
|
|
+
|
|
|
+ if (ret > 0)
|
|
|
+ notify_remote_via_irq(map->active.irq);
|
|
|
+ if (ret == 0)
|
|
|
+ ret = (flags & MSG_DONTWAIT) ? -EAGAIN : 0;
|
|
|
+ if (ret == -ENOTCONN)
|
|
|
+ ret = 0;
|
|
|
+
|
|
|
+ mutex_unlock(&map->active.in_mutex);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map = NULL;
|
|
|
+ struct xen_pvcalls_request *req;
|
|
|
+ int notify, req_id, ret;
|
|
|
+
|
|
|
+ if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
|
|
|
+ return -EOPNOTSUPP;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTCONN;
|
|
|
+ }
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (map == NULL) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTSOCK;
|
|
|
+ }
|
|
|
+
|
|
|
+ spin_lock(&bedata->socket_lock);
|
|
|
+ ret = get_request(bedata, &req_id);
|
|
|
+ if (ret < 0) {
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
|
+ req->req_id = req_id;
|
|
|
+ map->sock = sock;
|
|
|
+ req->cmd = PVCALLS_BIND;
|
|
|
+ req->u.bind.id = (uintptr_t)map;
|
|
|
+ memcpy(req->u.bind.addr, addr, sizeof(*addr));
|
|
|
+ req->u.bind.len = addr_len;
|
|
|
+
|
|
|
+ init_waitqueue_head(&map->passive.inflight_accept_req);
|
|
|
+
|
|
|
+ map->active_socket = false;
|
|
|
+
|
|
|
+ bedata->ring.req_prod_pvt++;
|
|
|
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ if (notify)
|
|
|
+ notify_remote_via_irq(bedata->irq);
|
|
|
+
|
|
|
+ wait_event(bedata->inflight_req,
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
|
|
|
+
|
|
|
+ /* read req_id, then the content */
|
|
|
+ smp_rmb();
|
|
|
+ ret = bedata->rsp[req_id].ret;
|
|
|
+ bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
|
|
|
+
|
|
|
+ map->passive.status = PVCALLS_STATUS_BIND;
|
|
|
+ pvcalls_exit();
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+int pvcalls_front_listen(struct socket *sock, int backlog)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map;
|
|
|
+ struct xen_pvcalls_request *req;
|
|
|
+ int notify, req_id, ret;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTCONN;
|
|
|
+ }
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (!map) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTSOCK;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (map->passive.status != PVCALLS_STATUS_BIND) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EOPNOTSUPP;
|
|
|
+ }
|
|
|
+
|
|
|
+ spin_lock(&bedata->socket_lock);
|
|
|
+ ret = get_request(bedata, &req_id);
|
|
|
+ if (ret < 0) {
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
|
+ req->req_id = req_id;
|
|
|
+ req->cmd = PVCALLS_LISTEN;
|
|
|
+ req->u.listen.id = (uintptr_t) map;
|
|
|
+ req->u.listen.backlog = backlog;
|
|
|
+
|
|
|
+ bedata->ring.req_prod_pvt++;
|
|
|
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ if (notify)
|
|
|
+ notify_remote_via_irq(bedata->irq);
|
|
|
+
|
|
|
+ wait_event(bedata->inflight_req,
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
|
|
|
+
|
|
|
+ /* read req_id, then the content */
|
|
|
+ smp_rmb();
|
|
|
+ ret = bedata->rsp[req_id].ret;
|
|
|
+ bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
|
|
|
+
|
|
|
+ map->passive.status = PVCALLS_STATUS_LISTEN;
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map;
|
|
|
+ struct sock_mapping *map2 = NULL;
|
|
|
+ struct xen_pvcalls_request *req;
|
|
|
+ int notify, req_id, ret, evtchn, nonblock;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTCONN;
|
|
|
+ }
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (!map) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOTSOCK;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (map->passive.status != PVCALLS_STATUS_LISTEN) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EINVAL;
|
|
|
+ }
|
|
|
+
|
|
|
+ nonblock = flags & SOCK_NONBLOCK;
|
|
|
+ /*
|
|
|
+ * Backend only supports 1 inflight accept request, will return
|
|
|
+ * errors for the others
|
|
|
+ */
|
|
|
+ if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags)) {
|
|
|
+ req_id = READ_ONCE(map->passive.inflight_req_id);
|
|
|
+ if (req_id != PVCALLS_INVALID_ID &&
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id) {
|
|
|
+ map2 = map->passive.accept_map;
|
|
|
+ goto received;
|
|
|
+ }
|
|
|
+ if (nonblock) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EAGAIN;
|
|
|
+ }
|
|
|
+ if (wait_event_interruptible(map->passive.inflight_accept_req,
|
|
|
+ !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags))) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EINTR;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ spin_lock(&bedata->socket_lock);
|
|
|
+ ret = get_request(bedata, &req_id);
|
|
|
+ if (ret < 0) {
|
|
|
+ clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+ map2 = kzalloc(sizeof(*map2), GFP_KERNEL);
|
|
|
+ if (map2 == NULL) {
|
|
|
+ clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOMEM;
|
|
|
+ }
|
|
|
+ ret = create_active(map2, &evtchn);
|
|
|
+ if (ret < 0) {
|
|
|
+ kfree(map2);
|
|
|
+ clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+ list_add_tail(&map2->list, &bedata->socket_mappings);
|
|
|
+
|
|
|
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
|
+ req->req_id = req_id;
|
|
|
+ req->cmd = PVCALLS_ACCEPT;
|
|
|
+ req->u.accept.id = (uintptr_t) map;
|
|
|
+ req->u.accept.ref = map2->active.ref;
|
|
|
+ req->u.accept.id_new = (uintptr_t) map2;
|
|
|
+ req->u.accept.evtchn = evtchn;
|
|
|
+ map->passive.accept_map = map2;
|
|
|
+
|
|
|
+ bedata->ring.req_prod_pvt++;
|
|
|
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ if (notify)
|
|
|
+ notify_remote_via_irq(bedata->irq);
|
|
|
+ /* We could check if we have received a response before returning. */
|
|
|
+ if (nonblock) {
|
|
|
+ WRITE_ONCE(map->passive.inflight_req_id, req_id);
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EAGAIN;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (wait_event_interruptible(bedata->inflight_req,
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EINTR;
|
|
|
+ }
|
|
|
+ /* read req_id, then the content */
|
|
|
+ smp_rmb();
|
|
|
+
|
|
|
+received:
|
|
|
+ map2->sock = newsock;
|
|
|
+ newsock->sk = kzalloc(sizeof(*newsock->sk), GFP_KERNEL);
|
|
|
+ if (!newsock->sk) {
|
|
|
+ bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
|
|
|
+ map->passive.inflight_req_id = PVCALLS_INVALID_ID;
|
|
|
+ clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags);
|
|
|
+ pvcalls_front_free_map(bedata, map2);
|
|
|
+ pvcalls_exit();
|
|
|
+ return -ENOMEM;
|
|
|
+ }
|
|
|
+ newsock->sk->sk_send_head = (void *)map2;
|
|
|
+
|
|
|
+ ret = bedata->rsp[req_id].ret;
|
|
|
+ bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
|
|
|
+ map->passive.inflight_req_id = PVCALLS_INVALID_ID;
|
|
|
+
|
|
|
+ clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags);
|
|
|
+ wake_up(&map->passive.inflight_accept_req);
|
|
|
+
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+static unsigned int pvcalls_front_poll_passive(struct file *file,
|
|
|
+ struct pvcalls_bedata *bedata,
|
|
|
+ struct sock_mapping *map,
|
|
|
+ poll_table *wait)
|
|
|
+{
|
|
|
+ int notify, req_id, ret;
|
|
|
+ struct xen_pvcalls_request *req;
|
|
|
+
|
|
|
+ if (test_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags)) {
|
|
|
+ uint32_t req_id = READ_ONCE(map->passive.inflight_req_id);
|
|
|
+
|
|
|
+ if (req_id != PVCALLS_INVALID_ID &&
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id)
|
|
|
+ return POLLIN | POLLRDNORM;
|
|
|
+
|
|
|
+ poll_wait(file, &map->passive.inflight_accept_req, wait);
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (test_and_clear_bit(PVCALLS_FLAG_POLL_RET,
|
|
|
+ (void *)&map->passive.flags))
|
|
|
+ return POLLIN | POLLRDNORM;
|
|
|
+
|
|
|
+ /*
|
|
|
+ * First check RET, then INFLIGHT. No barriers necessary to
|
|
|
+ * ensure execution ordering because of the conditional
|
|
|
+ * instructions creating control dependencies.
|
|
|
+ */
|
|
|
+
|
|
|
+ if (test_and_set_bit(PVCALLS_FLAG_POLL_INFLIGHT,
|
|
|
+ (void *)&map->passive.flags)) {
|
|
|
+ poll_wait(file, &bedata->inflight_req, wait);
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ spin_lock(&bedata->socket_lock);
|
|
|
+ ret = get_request(bedata, &req_id);
|
|
|
+ if (ret < 0) {
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
|
+ req->req_id = req_id;
|
|
|
+ req->cmd = PVCALLS_POLL;
|
|
|
+ req->u.poll.id = (uintptr_t) map;
|
|
|
+
|
|
|
+ bedata->ring.req_prod_pvt++;
|
|
|
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ if (notify)
|
|
|
+ notify_remote_via_irq(bedata->irq);
|
|
|
+
|
|
|
+ poll_wait(file, &bedata->inflight_req, wait);
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static unsigned int pvcalls_front_poll_active(struct file *file,
|
|
|
+ struct pvcalls_bedata *bedata,
|
|
|
+ struct sock_mapping *map,
|
|
|
+ poll_table *wait)
|
|
|
+{
|
|
|
+ unsigned int mask = 0;
|
|
|
+ int32_t in_error, out_error;
|
|
|
+ struct pvcalls_data_intf *intf = map->active.ring;
|
|
|
+
|
|
|
+ out_error = intf->out_error;
|
|
|
+ in_error = intf->in_error;
|
|
|
+
|
|
|
+ poll_wait(file, &map->active.inflight_conn_req, wait);
|
|
|
+ if (pvcalls_front_write_todo(map))
|
|
|
+ mask |= POLLOUT | POLLWRNORM;
|
|
|
+ if (pvcalls_front_read_todo(map))
|
|
|
+ mask |= POLLIN | POLLRDNORM;
|
|
|
+ if (in_error != 0 || out_error != 0)
|
|
|
+ mask |= POLLERR;
|
|
|
+
|
|
|
+ return mask;
|
|
|
+}
|
|
|
+
|
|
|
+unsigned int pvcalls_front_poll(struct file *file, struct socket *sock,
|
|
|
+ poll_table *wait)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map;
|
|
|
+ int ret;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return POLLNVAL;
|
|
|
+ }
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (!map) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return POLLNVAL;
|
|
|
+ }
|
|
|
+ if (map->active_socket)
|
|
|
+ ret = pvcalls_front_poll_active(file, bedata, map, wait);
|
|
|
+ else
|
|
|
+ ret = pvcalls_front_poll_passive(file, bedata, map, wait);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int pvcalls_front_release(struct socket *sock)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map;
|
|
|
+ int req_id, notify, ret;
|
|
|
+ struct xen_pvcalls_request *req;
|
|
|
+
|
|
|
+ if (sock->sk == NULL)
|
|
|
+ return 0;
|
|
|
+
|
|
|
+ pvcalls_enter();
|
|
|
+ if (!pvcalls_front_dev) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return -EIO;
|
|
|
+ }
|
|
|
+
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+
|
|
|
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
|
|
|
+ if (map == NULL) {
|
|
|
+ pvcalls_exit();
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ spin_lock(&bedata->socket_lock);
|
|
|
+ ret = get_request(bedata, &req_id);
|
|
|
+ if (ret < 0) {
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ pvcalls_exit();
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+ sock->sk->sk_send_head = NULL;
|
|
|
+
|
|
|
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
|
+ req->req_id = req_id;
|
|
|
+ req->cmd = PVCALLS_RELEASE;
|
|
|
+ req->u.release.id = (uintptr_t)map;
|
|
|
+
|
|
|
+ bedata->ring.req_prod_pvt++;
|
|
|
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ if (notify)
|
|
|
+ notify_remote_via_irq(bedata->irq);
|
|
|
+
|
|
|
+ wait_event(bedata->inflight_req,
|
|
|
+ READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
|
|
|
+
|
|
|
+ if (map->active_socket) {
|
|
|
+ /*
|
|
|
+ * Set in_error and wake up inflight_conn_req to force
|
|
|
+ * recvmsg waiters to exit.
|
|
|
+ */
|
|
|
+ map->active.ring->in_error = -EBADF;
|
|
|
+ wake_up_interruptible(&map->active.inflight_conn_req);
|
|
|
+
|
|
|
+ /*
|
|
|
+ * We need to make sure that sendmsg/recvmsg on this socket have
|
|
|
+ * not started before we've cleared sk_send_head here. The
|
|
|
+ * easiest (though not optimal) way to guarantee this is to see
|
|
|
+ * that no pvcall (other than us) is in progress.
|
|
|
+ */
|
|
|
+ while (atomic_read(&pvcalls_refcount) > 1)
|
|
|
+ cpu_relax();
|
|
|
+
|
|
|
+ pvcalls_front_free_map(bedata, map);
|
|
|
+ } else {
|
|
|
+ spin_lock(&bedata->socket_lock);
|
|
|
+ list_del(&map->list);
|
|
|
+ spin_unlock(&bedata->socket_lock);
|
|
|
+ if (READ_ONCE(map->passive.inflight_req_id) !=
|
|
|
+ PVCALLS_INVALID_ID) {
|
|
|
+ pvcalls_front_free_map(bedata,
|
|
|
+ map->passive.accept_map);
|
|
|
+ }
|
|
|
+ kfree(map);
|
|
|
+ }
|
|
|
+ WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID);
|
|
|
+
|
|
|
+ pvcalls_exit();
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static const struct xenbus_device_id pvcalls_front_ids[] = {
|
|
|
+ { "pvcalls" },
|
|
|
+ { "" }
|
|
|
+};
|
|
|
+
|
|
|
+static int pvcalls_front_remove(struct xenbus_device *dev)
|
|
|
+{
|
|
|
+ struct pvcalls_bedata *bedata;
|
|
|
+ struct sock_mapping *map = NULL, *n;
|
|
|
+
|
|
|
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
+ dev_set_drvdata(&dev->dev, NULL);
|
|
|
+ pvcalls_front_dev = NULL;
|
|
|
+ if (bedata->irq >= 0)
|
|
|
+ unbind_from_irqhandler(bedata->irq, dev);
|
|
|
+
|
|
|
+ list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) {
|
|
|
+ map->sock->sk->sk_send_head = NULL;
|
|
|
+ if (map->active_socket) {
|
|
|
+ map->active.ring->in_error = -EBADF;
|
|
|
+ wake_up_interruptible(&map->active.inflight_conn_req);
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ smp_mb();
|
|
|
+ while (atomic_read(&pvcalls_refcount) > 0)
|
|
|
+ cpu_relax();
|
|
|
+ list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) {
|
|
|
+ if (map->active_socket) {
|
|
|
+ /* No need to lock, refcount is 0 */
|
|
|
+ pvcalls_front_free_map(bedata, map);
|
|
|
+ } else {
|
|
|
+ list_del(&map->list);
|
|
|
+ kfree(map);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ if (bedata->ref >= 0)
|
|
|
+ gnttab_end_foreign_access(bedata->ref, 0, 0);
|
|
|
+ kfree(bedata->ring.sring);
|
|
|
+ kfree(bedata);
|
|
|
+ xenbus_switch_state(dev, XenbusStateClosed);
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static int pvcalls_front_probe(struct xenbus_device *dev,
|
|
|
+ const struct xenbus_device_id *id)
|
|
|
+{
|
|
|
+ int ret = -ENOMEM, evtchn, i;
|
|
|
+ unsigned int max_page_order, function_calls, len;
|
|
|
+ char *versions;
|
|
|
+ grant_ref_t gref_head = 0;
|
|
|
+ struct xenbus_transaction xbt;
|
|
|
+ struct pvcalls_bedata *bedata = NULL;
|
|
|
+ struct xen_pvcalls_sring *sring;
|
|
|
+
|
|
|
+ if (pvcalls_front_dev != NULL) {
|
|
|
+ dev_err(&dev->dev, "only one PV Calls connection supported\n");
|
|
|
+ return -EINVAL;
|
|
|
+ }
|
|
|
+
|
|
|
+ versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
|
|
|
+ if (!len)
|
|
|
+ return -EINVAL;
|
|
|
+ if (strcmp(versions, "1")) {
|
|
|
+ kfree(versions);
|
|
|
+ return -EINVAL;
|
|
|
+ }
|
|
|
+ kfree(versions);
|
|
|
+ max_page_order = xenbus_read_unsigned(dev->otherend,
|
|
|
+ "max-page-order", 0);
|
|
|
+ if (max_page_order < PVCALLS_RING_ORDER)
|
|
|
+ return -ENODEV;
|
|
|
+ function_calls = xenbus_read_unsigned(dev->otherend,
|
|
|
+ "function-calls", 0);
|
|
|
+ /* See XENBUS_FUNCTIONS_CALLS in pvcalls.h */
|
|
|
+ if (function_calls != 1)
|
|
|
+ return -ENODEV;
|
|
|
+ pr_info("%s max-page-order is %u\n", __func__, max_page_order);
|
|
|
+
|
|
|
+ bedata = kzalloc(sizeof(struct pvcalls_bedata), GFP_KERNEL);
|
|
|
+ if (!bedata)
|
|
|
+ return -ENOMEM;
|
|
|
+
|
|
|
+ dev_set_drvdata(&dev->dev, bedata);
|
|
|
+ pvcalls_front_dev = dev;
|
|
|
+ init_waitqueue_head(&bedata->inflight_req);
|
|
|
+ INIT_LIST_HEAD(&bedata->socket_mappings);
|
|
|
+ spin_lock_init(&bedata->socket_lock);
|
|
|
+ bedata->irq = -1;
|
|
|
+ bedata->ref = -1;
|
|
|
+
|
|
|
+ for (i = 0; i < PVCALLS_NR_RSP_PER_RING; i++)
|
|
|
+ bedata->rsp[i].req_id = PVCALLS_INVALID_ID;
|
|
|
+
|
|
|
+ sring = (struct xen_pvcalls_sring *) __get_free_page(GFP_KERNEL |
|
|
|
+ __GFP_ZERO);
|
|
|
+ if (!sring)
|
|
|
+ goto error;
|
|
|
+ SHARED_RING_INIT(sring);
|
|
|
+ FRONT_RING_INIT(&bedata->ring, sring, XEN_PAGE_SIZE);
|
|
|
+
|
|
|
+ ret = xenbus_alloc_evtchn(dev, &evtchn);
|
|
|
+ if (ret)
|
|
|
+ goto error;
|
|
|
+
|
|
|
+ bedata->irq = bind_evtchn_to_irqhandler(evtchn,
|
|
|
+ pvcalls_front_event_handler,
|
|
|
+ 0, "pvcalls-frontend", dev);
|
|
|
+ if (bedata->irq < 0) {
|
|
|
+ ret = bedata->irq;
|
|
|
+ goto error;
|
|
|
+ }
|
|
|
+
|
|
|
+ ret = gnttab_alloc_grant_references(1, &gref_head);
|
|
|
+ if (ret < 0)
|
|
|
+ goto error;
|
|
|
+ ret = gnttab_claim_grant_reference(&gref_head);
|
|
|
+ if (ret < 0)
|
|
|
+ goto error;
|
|
|
+ bedata->ref = ret;
|
|
|
+ gnttab_grant_foreign_access_ref(bedata->ref, dev->otherend_id,
|
|
|
+ virt_to_gfn((void *)sring), 0);
|
|
|
+
|
|
|
+ again:
|
|
|
+ ret = xenbus_transaction_start(&xbt);
|
|
|
+ if (ret) {
|
|
|
+ xenbus_dev_fatal(dev, ret, "starting transaction");
|
|
|
+ goto error;
|
|
|
+ }
|
|
|
+ ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1);
|
|
|
+ if (ret)
|
|
|
+ goto error_xenbus;
|
|
|
+ ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", bedata->ref);
|
|
|
+ if (ret)
|
|
|
+ goto error_xenbus;
|
|
|
+ ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
|
|
|
+ evtchn);
|
|
|
+ if (ret)
|
|
|
+ goto error_xenbus;
|
|
|
+ ret = xenbus_transaction_end(xbt, 0);
|
|
|
+ if (ret) {
|
|
|
+ if (ret == -EAGAIN)
|
|
|
+ goto again;
|
|
|
+ xenbus_dev_fatal(dev, ret, "completing transaction");
|
|
|
+ goto error;
|
|
|
+ }
|
|
|
+ xenbus_switch_state(dev, XenbusStateInitialised);
|
|
|
+
|
|
|
+ return 0;
|
|
|
+
|
|
|
+ error_xenbus:
|
|
|
+ xenbus_transaction_end(xbt, 1);
|
|
|
+ xenbus_dev_fatal(dev, ret, "writing xenstore");
|
|
|
+ error:
|
|
|
+ pvcalls_front_remove(dev);
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+static void pvcalls_front_changed(struct xenbus_device *dev,
|
|
|
+ enum xenbus_state backend_state)
|
|
|
+{
|
|
|
+ switch (backend_state) {
|
|
|
+ case XenbusStateReconfiguring:
|
|
|
+ case XenbusStateReconfigured:
|
|
|
+ case XenbusStateInitialising:
|
|
|
+ case XenbusStateInitialised:
|
|
|
+ case XenbusStateUnknown:
|
|
|
+ break;
|
|
|
+
|
|
|
+ case XenbusStateInitWait:
|
|
|
+ break;
|
|
|
+
|
|
|
+ case XenbusStateConnected:
|
|
|
+ xenbus_switch_state(dev, XenbusStateConnected);
|
|
|
+ break;
|
|
|
+
|
|
|
+ case XenbusStateClosed:
|
|
|
+ if (dev->state == XenbusStateClosed)
|
|
|
+ break;
|
|
|
+ /* Missed the backend's CLOSING state */
|
|
|
+ /* fall through */
|
|
|
+ case XenbusStateClosing:
|
|
|
+ xenbus_frontend_closed(dev);
|
|
|
+ break;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+static struct xenbus_driver pvcalls_front_driver = {
|
|
|
+ .ids = pvcalls_front_ids,
|
|
|
+ .probe = pvcalls_front_probe,
|
|
|
+ .remove = pvcalls_front_remove,
|
|
|
+ .otherend_changed = pvcalls_front_changed,
|
|
|
+};
|
|
|
+
|
|
|
+static int __init pvcalls_frontend_init(void)
|
|
|
+{
|
|
|
+ if (!xen_domain())
|
|
|
+ return -ENODEV;
|
|
|
+
|
|
|
+ pr_info("Initialising Xen pvcalls frontend driver\n");
|
|
|
+
|
|
|
+ return xenbus_register_frontend(&pvcalls_front_driver);
|
|
|
+}
|
|
|
+
|
|
|
+module_init(pvcalls_frontend_init);
|
|
|
+
|
|
|
+MODULE_DESCRIPTION("Xen PV Calls frontend driver");
|
|
|
+MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>");
|
|
|
+MODULE_LICENSE("GPL");
|
Linus Torvalds