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d8da26671a
'destroy_workqueue()' already drains the queue before destroying it, so there is no need to flush it explicitly. Remove the redundant 'flush_workqueue()' calls. This was generated with coccinelle: @@ expression E; @@ - flush_workqueue(E); destroy_workqueue(E); Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/2d6c2e031e4aa2acf2ac4e0bbbc17cfdcc8dbee2.1634236560.git.christophe.jaillet@wanadoo.fr Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
1244 lines
30 KiB
C
1244 lines
30 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* (c) 2017 Stefano Stabellini <stefano@aporeto.com>
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*/
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#include <linux/inet.h>
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#include <linux/kthread.h>
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#include <linux/list.h>
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#include <linux/radix-tree.h>
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#include <linux/module.h>
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#include <linux/semaphore.h>
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#include <linux/wait.h>
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#include <net/sock.h>
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#include <net/inet_common.h>
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#include <net/inet_connection_sock.h>
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#include <net/request_sock.h>
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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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#define PVCALLS_VERSIONS "1"
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#define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER
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static struct pvcalls_back_global {
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struct list_head frontends;
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struct semaphore frontends_lock;
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} pvcalls_back_global;
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/*
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* Per-frontend data structure. It contains pointers to the command
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* ring, its event channel, a list of active sockets and a tree of
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* passive sockets.
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*/
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struct pvcalls_fedata {
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struct list_head list;
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struct xenbus_device *dev;
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struct xen_pvcalls_sring *sring;
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struct xen_pvcalls_back_ring ring;
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int irq;
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struct list_head socket_mappings;
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struct radix_tree_root socketpass_mappings;
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struct semaphore socket_lock;
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};
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struct pvcalls_ioworker {
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struct work_struct register_work;
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struct workqueue_struct *wq;
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};
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struct sock_mapping {
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struct list_head list;
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struct pvcalls_fedata *fedata;
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struct sockpass_mapping *sockpass;
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struct socket *sock;
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uint64_t id;
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grant_ref_t ref;
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struct pvcalls_data_intf *ring;
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void *bytes;
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struct pvcalls_data data;
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uint32_t ring_order;
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int irq;
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atomic_t read;
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atomic_t write;
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atomic_t io;
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atomic_t release;
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atomic_t eoi;
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void (*saved_data_ready)(struct sock *sk);
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struct pvcalls_ioworker ioworker;
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};
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struct sockpass_mapping {
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struct list_head list;
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struct pvcalls_fedata *fedata;
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struct socket *sock;
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uint64_t id;
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struct xen_pvcalls_request reqcopy;
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spinlock_t copy_lock;
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struct workqueue_struct *wq;
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struct work_struct register_work;
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void (*saved_data_ready)(struct sock *sk);
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};
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static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map);
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static int pvcalls_back_release_active(struct xenbus_device *dev,
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struct pvcalls_fedata *fedata,
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struct sock_mapping *map);
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static bool pvcalls_conn_back_read(void *opaque)
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{
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struct sock_mapping *map = (struct sock_mapping *)opaque;
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struct msghdr msg;
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struct kvec vec[2];
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RING_IDX cons, prod, size, wanted, array_size, masked_prod, masked_cons;
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int32_t error;
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struct pvcalls_data_intf *intf = map->ring;
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struct pvcalls_data *data = &map->data;
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unsigned long flags;
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int ret;
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array_size = XEN_FLEX_RING_SIZE(map->ring_order);
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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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/* read the indexes first, then deal with the data */
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virt_mb();
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if (error)
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return false;
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size = pvcalls_queued(prod, cons, array_size);
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if (size >= array_size)
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return false;
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spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
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if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) {
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atomic_set(&map->read, 0);
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spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock,
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flags);
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return true;
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}
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spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
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wanted = array_size - size;
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masked_prod = pvcalls_mask(prod, array_size);
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masked_cons = pvcalls_mask(cons, array_size);
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memset(&msg, 0, sizeof(msg));
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if (masked_prod < masked_cons) {
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vec[0].iov_base = data->in + masked_prod;
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vec[0].iov_len = wanted;
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iov_iter_kvec(&msg.msg_iter, WRITE, vec, 1, wanted);
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} else {
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vec[0].iov_base = data->in + masked_prod;
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vec[0].iov_len = array_size - masked_prod;
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vec[1].iov_base = data->in;
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vec[1].iov_len = wanted - vec[0].iov_len;
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iov_iter_kvec(&msg.msg_iter, WRITE, vec, 2, wanted);
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}
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atomic_set(&map->read, 0);
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ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT);
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WARN_ON(ret > wanted);
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if (ret == -EAGAIN) /* shouldn't happen */
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return true;
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if (!ret)
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ret = -ENOTCONN;
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spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
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if (ret > 0 && !skb_queue_empty(&map->sock->sk->sk_receive_queue))
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atomic_inc(&map->read);
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spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
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/* write the data, then modify the indexes */
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virt_wmb();
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if (ret < 0) {
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atomic_set(&map->read, 0);
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intf->in_error = ret;
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} else
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intf->in_prod = prod + ret;
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/* update the indexes, then notify the other end */
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virt_wmb();
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notify_remote_via_irq(map->irq);
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return true;
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}
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static bool pvcalls_conn_back_write(struct sock_mapping *map)
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{
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struct pvcalls_data_intf *intf = map->ring;
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struct pvcalls_data *data = &map->data;
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struct msghdr msg;
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struct kvec vec[2];
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RING_IDX cons, prod, size, array_size;
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int ret;
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cons = intf->out_cons;
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prod = intf->out_prod;
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/* read the indexes before dealing with the data */
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virt_mb();
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array_size = XEN_FLEX_RING_SIZE(map->ring_order);
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size = pvcalls_queued(prod, cons, array_size);
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if (size == 0)
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return false;
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memset(&msg, 0, sizeof(msg));
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msg.msg_flags |= MSG_DONTWAIT;
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if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) {
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vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
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vec[0].iov_len = size;
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iov_iter_kvec(&msg.msg_iter, READ, vec, 1, size);
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} else {
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vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
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vec[0].iov_len = array_size - pvcalls_mask(cons, array_size);
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vec[1].iov_base = data->out;
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vec[1].iov_len = size - vec[0].iov_len;
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iov_iter_kvec(&msg.msg_iter, READ, vec, 2, size);
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}
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atomic_set(&map->write, 0);
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ret = inet_sendmsg(map->sock, &msg, size);
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if (ret == -EAGAIN) {
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atomic_inc(&map->write);
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atomic_inc(&map->io);
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return true;
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}
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/* write the data, then update the indexes */
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virt_wmb();
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if (ret < 0) {
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intf->out_error = ret;
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} else {
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intf->out_error = 0;
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intf->out_cons = cons + ret;
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prod = intf->out_prod;
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}
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/* update the indexes, then notify the other end */
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virt_wmb();
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if (prod != cons + ret) {
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atomic_inc(&map->write);
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atomic_inc(&map->io);
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}
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notify_remote_via_irq(map->irq);
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return true;
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}
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static void pvcalls_back_ioworker(struct work_struct *work)
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{
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struct pvcalls_ioworker *ioworker = container_of(work,
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struct pvcalls_ioworker, register_work);
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struct sock_mapping *map = container_of(ioworker, struct sock_mapping,
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ioworker);
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unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
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while (atomic_read(&map->io) > 0) {
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if (atomic_read(&map->release) > 0) {
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atomic_set(&map->release, 0);
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return;
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}
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if (atomic_read(&map->read) > 0 &&
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pvcalls_conn_back_read(map))
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eoi_flags = 0;
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if (atomic_read(&map->write) > 0 &&
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pvcalls_conn_back_write(map))
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eoi_flags = 0;
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if (atomic_read(&map->eoi) > 0 && !atomic_read(&map->write)) {
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atomic_set(&map->eoi, 0);
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xen_irq_lateeoi(map->irq, eoi_flags);
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eoi_flags = XEN_EOI_FLAG_SPURIOUS;
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}
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atomic_dec(&map->io);
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}
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}
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static int pvcalls_back_socket(struct xenbus_device *dev,
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struct xen_pvcalls_request *req)
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{
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struct pvcalls_fedata *fedata;
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int ret;
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struct xen_pvcalls_response *rsp;
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fedata = dev_get_drvdata(&dev->dev);
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if (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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req->u.socket.protocol != AF_INET))
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ret = -EAFNOSUPPORT;
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else
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ret = 0;
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/* leave the actual socket allocation for later */
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rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
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rsp->req_id = req->req_id;
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rsp->cmd = req->cmd;
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rsp->u.socket.id = req->u.socket.id;
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rsp->ret = ret;
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return 0;
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}
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static void pvcalls_sk_state_change(struct sock *sock)
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{
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struct sock_mapping *map = sock->sk_user_data;
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if (map == NULL)
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return;
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atomic_inc(&map->read);
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notify_remote_via_irq(map->irq);
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}
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static void pvcalls_sk_data_ready(struct sock *sock)
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{
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struct sock_mapping *map = sock->sk_user_data;
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struct pvcalls_ioworker *iow;
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if (map == NULL)
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return;
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iow = &map->ioworker;
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atomic_inc(&map->read);
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atomic_inc(&map->io);
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queue_work(iow->wq, &iow->register_work);
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}
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static struct sock_mapping *pvcalls_new_active_socket(
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struct pvcalls_fedata *fedata,
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uint64_t id,
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grant_ref_t ref,
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evtchn_port_t evtchn,
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struct socket *sock)
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{
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int ret;
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struct sock_mapping *map;
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void *page;
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map = kzalloc(sizeof(*map), GFP_KERNEL);
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if (map == NULL)
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return NULL;
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map->fedata = fedata;
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map->sock = sock;
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map->id = id;
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map->ref = ref;
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ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page);
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if (ret < 0)
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goto out;
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map->ring = page;
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map->ring_order = map->ring->ring_order;
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/* first read the order, then map the data ring */
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virt_rmb();
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if (map->ring_order > MAX_RING_ORDER) {
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pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n",
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__func__, map->ring_order, MAX_RING_ORDER);
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goto out;
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}
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ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref,
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(1 << map->ring_order), &page);
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if (ret < 0)
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goto out;
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map->bytes = page;
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ret = bind_interdomain_evtchn_to_irqhandler_lateeoi(
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fedata->dev, evtchn,
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pvcalls_back_conn_event, 0, "pvcalls-backend", map);
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if (ret < 0)
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goto out;
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map->irq = ret;
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map->data.in = map->bytes;
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map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order);
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map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1);
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if (!map->ioworker.wq)
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goto out;
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atomic_set(&map->io, 1);
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INIT_WORK(&map->ioworker.register_work, pvcalls_back_ioworker);
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down(&fedata->socket_lock);
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list_add_tail(&map->list, &fedata->socket_mappings);
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up(&fedata->socket_lock);
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write_lock_bh(&map->sock->sk->sk_callback_lock);
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map->saved_data_ready = map->sock->sk->sk_data_ready;
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map->sock->sk->sk_user_data = map;
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map->sock->sk->sk_data_ready = pvcalls_sk_data_ready;
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map->sock->sk->sk_state_change = pvcalls_sk_state_change;
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write_unlock_bh(&map->sock->sk->sk_callback_lock);
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return map;
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out:
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down(&fedata->socket_lock);
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list_del(&map->list);
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pvcalls_back_release_active(fedata->dev, fedata, map);
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up(&fedata->socket_lock);
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return NULL;
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}
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static int pvcalls_back_connect(struct xenbus_device *dev,
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struct xen_pvcalls_request *req)
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{
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struct pvcalls_fedata *fedata;
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int ret = -EINVAL;
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struct socket *sock;
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struct sock_mapping *map;
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struct xen_pvcalls_response *rsp;
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struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr;
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fedata = dev_get_drvdata(&dev->dev);
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if (req->u.connect.len < sizeof(sa->sa_family) ||
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req->u.connect.len > sizeof(req->u.connect.addr) ||
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sa->sa_family != AF_INET)
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goto out;
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ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock);
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if (ret < 0)
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goto out;
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ret = inet_stream_connect(sock, sa, req->u.connect.len, 0);
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if (ret < 0) {
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sock_release(sock);
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goto out;
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}
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map = pvcalls_new_active_socket(fedata,
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req->u.connect.id,
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req->u.connect.ref,
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req->u.connect.evtchn,
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sock);
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if (!map) {
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ret = -EFAULT;
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sock_release(sock);
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}
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out:
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rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
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rsp->req_id = req->req_id;
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rsp->cmd = req->cmd;
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rsp->u.connect.id = req->u.connect.id;
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rsp->ret = ret;
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return 0;
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}
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static int pvcalls_back_release_active(struct xenbus_device *dev,
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struct pvcalls_fedata *fedata,
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struct sock_mapping *map)
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{
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disable_irq(map->irq);
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if (map->sock->sk != NULL) {
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write_lock_bh(&map->sock->sk->sk_callback_lock);
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map->sock->sk->sk_user_data = NULL;
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map->sock->sk->sk_data_ready = map->saved_data_ready;
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write_unlock_bh(&map->sock->sk->sk_callback_lock);
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}
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atomic_set(&map->release, 1);
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flush_work(&map->ioworker.register_work);
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xenbus_unmap_ring_vfree(dev, map->bytes);
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xenbus_unmap_ring_vfree(dev, (void *)map->ring);
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unbind_from_irqhandler(map->irq, map);
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sock_release(map->sock);
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kfree(map);
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return 0;
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}
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static int pvcalls_back_release_passive(struct xenbus_device *dev,
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struct pvcalls_fedata *fedata,
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struct sockpass_mapping *mappass)
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{
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if (mappass->sock->sk != NULL) {
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write_lock_bh(&mappass->sock->sk->sk_callback_lock);
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mappass->sock->sk->sk_user_data = NULL;
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mappass->sock->sk->sk_data_ready = mappass->saved_data_ready;
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write_unlock_bh(&mappass->sock->sk->sk_callback_lock);
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}
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sock_release(mappass->sock);
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destroy_workqueue(mappass->wq);
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kfree(mappass);
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return 0;
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}
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|
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static int pvcalls_back_release(struct xenbus_device *dev,
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struct xen_pvcalls_request *req)
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
struct sock_mapping *map, *n;
|
|
struct sockpass_mapping *mappass;
|
|
int ret = 0;
|
|
struct xen_pvcalls_response *rsp;
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
|
|
down(&fedata->socket_lock);
|
|
list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) {
|
|
if (map->id == req->u.release.id) {
|
|
list_del(&map->list);
|
|
up(&fedata->socket_lock);
|
|
ret = pvcalls_back_release_active(dev, fedata, map);
|
|
goto out;
|
|
}
|
|
}
|
|
mappass = radix_tree_lookup(&fedata->socketpass_mappings,
|
|
req->u.release.id);
|
|
if (mappass != NULL) {
|
|
radix_tree_delete(&fedata->socketpass_mappings, mappass->id);
|
|
up(&fedata->socket_lock);
|
|
ret = pvcalls_back_release_passive(dev, fedata, mappass);
|
|
} else
|
|
up(&fedata->socket_lock);
|
|
|
|
out:
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->u.release.id = req->u.release.id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->ret = ret;
|
|
return 0;
|
|
}
|
|
|
|
static void __pvcalls_back_accept(struct work_struct *work)
|
|
{
|
|
struct sockpass_mapping *mappass = container_of(
|
|
work, struct sockpass_mapping, register_work);
|
|
struct sock_mapping *map;
|
|
struct pvcalls_ioworker *iow;
|
|
struct pvcalls_fedata *fedata;
|
|
struct socket *sock;
|
|
struct xen_pvcalls_response *rsp;
|
|
struct xen_pvcalls_request *req;
|
|
int notify;
|
|
int ret = -EINVAL;
|
|
unsigned long flags;
|
|
|
|
fedata = mappass->fedata;
|
|
/*
|
|
* __pvcalls_back_accept can race against pvcalls_back_accept.
|
|
* We only need to check the value of "cmd" on read. It could be
|
|
* done atomically, but to simplify the code on the write side, we
|
|
* use a spinlock.
|
|
*/
|
|
spin_lock_irqsave(&mappass->copy_lock, flags);
|
|
req = &mappass->reqcopy;
|
|
if (req->cmd != PVCALLS_ACCEPT) {
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
return;
|
|
}
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
|
|
sock = sock_alloc();
|
|
if (sock == NULL)
|
|
goto out_error;
|
|
sock->type = mappass->sock->type;
|
|
sock->ops = mappass->sock->ops;
|
|
|
|
ret = inet_accept(mappass->sock, sock, O_NONBLOCK, true);
|
|
if (ret == -EAGAIN) {
|
|
sock_release(sock);
|
|
return;
|
|
}
|
|
|
|
map = pvcalls_new_active_socket(fedata,
|
|
req->u.accept.id_new,
|
|
req->u.accept.ref,
|
|
req->u.accept.evtchn,
|
|
sock);
|
|
if (!map) {
|
|
ret = -EFAULT;
|
|
sock_release(sock);
|
|
goto out_error;
|
|
}
|
|
|
|
map->sockpass = mappass;
|
|
iow = &map->ioworker;
|
|
atomic_inc(&map->read);
|
|
atomic_inc(&map->io);
|
|
queue_work(iow->wq, &iow->register_work);
|
|
|
|
out_error:
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->u.accept.id = req->u.accept.id;
|
|
rsp->ret = ret;
|
|
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify);
|
|
if (notify)
|
|
notify_remote_via_irq(fedata->irq);
|
|
|
|
mappass->reqcopy.cmd = 0;
|
|
}
|
|
|
|
static void pvcalls_pass_sk_data_ready(struct sock *sock)
|
|
{
|
|
struct sockpass_mapping *mappass = sock->sk_user_data;
|
|
struct pvcalls_fedata *fedata;
|
|
struct xen_pvcalls_response *rsp;
|
|
unsigned long flags;
|
|
int notify;
|
|
|
|
if (mappass == NULL)
|
|
return;
|
|
|
|
fedata = mappass->fedata;
|
|
spin_lock_irqsave(&mappass->copy_lock, flags);
|
|
if (mappass->reqcopy.cmd == PVCALLS_POLL) {
|
|
rsp = RING_GET_RESPONSE(&fedata->ring,
|
|
fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = mappass->reqcopy.req_id;
|
|
rsp->u.poll.id = mappass->reqcopy.u.poll.id;
|
|
rsp->cmd = mappass->reqcopy.cmd;
|
|
rsp->ret = 0;
|
|
|
|
mappass->reqcopy.cmd = 0;
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
|
|
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify);
|
|
if (notify)
|
|
notify_remote_via_irq(mappass->fedata->irq);
|
|
} else {
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
queue_work(mappass->wq, &mappass->register_work);
|
|
}
|
|
}
|
|
|
|
static int pvcalls_back_bind(struct xenbus_device *dev,
|
|
struct xen_pvcalls_request *req)
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
int ret;
|
|
struct sockpass_mapping *map;
|
|
struct xen_pvcalls_response *rsp;
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
|
|
map = kzalloc(sizeof(*map), GFP_KERNEL);
|
|
if (map == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
INIT_WORK(&map->register_work, __pvcalls_back_accept);
|
|
spin_lock_init(&map->copy_lock);
|
|
map->wq = alloc_workqueue("pvcalls_wq", WQ_UNBOUND, 1);
|
|
if (!map->wq) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = sock_create(AF_INET, SOCK_STREAM, 0, &map->sock);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = inet_bind(map->sock, (struct sockaddr *)&req->u.bind.addr,
|
|
req->u.bind.len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
map->fedata = fedata;
|
|
map->id = req->u.bind.id;
|
|
|
|
down(&fedata->socket_lock);
|
|
ret = radix_tree_insert(&fedata->socketpass_mappings, map->id,
|
|
map);
|
|
up(&fedata->socket_lock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
write_lock_bh(&map->sock->sk->sk_callback_lock);
|
|
map->saved_data_ready = map->sock->sk->sk_data_ready;
|
|
map->sock->sk->sk_user_data = map;
|
|
map->sock->sk->sk_data_ready = pvcalls_pass_sk_data_ready;
|
|
write_unlock_bh(&map->sock->sk->sk_callback_lock);
|
|
|
|
out:
|
|
if (ret) {
|
|
if (map && map->sock)
|
|
sock_release(map->sock);
|
|
if (map && map->wq)
|
|
destroy_workqueue(map->wq);
|
|
kfree(map);
|
|
}
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->u.bind.id = req->u.bind.id;
|
|
rsp->ret = ret;
|
|
return 0;
|
|
}
|
|
|
|
static int pvcalls_back_listen(struct xenbus_device *dev,
|
|
struct xen_pvcalls_request *req)
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
int ret = -EINVAL;
|
|
struct sockpass_mapping *map;
|
|
struct xen_pvcalls_response *rsp;
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
|
|
down(&fedata->socket_lock);
|
|
map = radix_tree_lookup(&fedata->socketpass_mappings, req->u.listen.id);
|
|
up(&fedata->socket_lock);
|
|
if (map == NULL)
|
|
goto out;
|
|
|
|
ret = inet_listen(map->sock, req->u.listen.backlog);
|
|
|
|
out:
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->u.listen.id = req->u.listen.id;
|
|
rsp->ret = ret;
|
|
return 0;
|
|
}
|
|
|
|
static int pvcalls_back_accept(struct xenbus_device *dev,
|
|
struct xen_pvcalls_request *req)
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
struct sockpass_mapping *mappass;
|
|
int ret = -EINVAL;
|
|
struct xen_pvcalls_response *rsp;
|
|
unsigned long flags;
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
|
|
down(&fedata->socket_lock);
|
|
mappass = radix_tree_lookup(&fedata->socketpass_mappings,
|
|
req->u.accept.id);
|
|
up(&fedata->socket_lock);
|
|
if (mappass == NULL)
|
|
goto out_error;
|
|
|
|
/*
|
|
* Limitation of the current implementation: only support one
|
|
* concurrent accept or poll call on one socket.
|
|
*/
|
|
spin_lock_irqsave(&mappass->copy_lock, flags);
|
|
if (mappass->reqcopy.cmd != 0) {
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
ret = -EINTR;
|
|
goto out_error;
|
|
}
|
|
|
|
mappass->reqcopy = *req;
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
queue_work(mappass->wq, &mappass->register_work);
|
|
|
|
/* Tell the caller we don't need to send back a notification yet */
|
|
return -1;
|
|
|
|
out_error:
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->u.accept.id = req->u.accept.id;
|
|
rsp->ret = ret;
|
|
return 0;
|
|
}
|
|
|
|
static int pvcalls_back_poll(struct xenbus_device *dev,
|
|
struct xen_pvcalls_request *req)
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
struct sockpass_mapping *mappass;
|
|
struct xen_pvcalls_response *rsp;
|
|
struct inet_connection_sock *icsk;
|
|
struct request_sock_queue *queue;
|
|
unsigned long flags;
|
|
int ret;
|
|
bool data;
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
|
|
down(&fedata->socket_lock);
|
|
mappass = radix_tree_lookup(&fedata->socketpass_mappings,
|
|
req->u.poll.id);
|
|
up(&fedata->socket_lock);
|
|
if (mappass == NULL)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Limitation of the current implementation: only support one
|
|
* concurrent accept or poll call on one socket.
|
|
*/
|
|
spin_lock_irqsave(&mappass->copy_lock, flags);
|
|
if (mappass->reqcopy.cmd != 0) {
|
|
ret = -EINTR;
|
|
goto out;
|
|
}
|
|
|
|
mappass->reqcopy = *req;
|
|
icsk = inet_csk(mappass->sock->sk);
|
|
queue = &icsk->icsk_accept_queue;
|
|
data = READ_ONCE(queue->rskq_accept_head) != NULL;
|
|
if (data) {
|
|
mappass->reqcopy.cmd = 0;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
|
|
/* Tell the caller we don't need to send back a notification yet */
|
|
return -1;
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&mappass->copy_lock, flags);
|
|
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->u.poll.id = req->u.poll.id;
|
|
rsp->ret = ret;
|
|
return 0;
|
|
}
|
|
|
|
static int pvcalls_back_handle_cmd(struct xenbus_device *dev,
|
|
struct xen_pvcalls_request *req)
|
|
{
|
|
int ret = 0;
|
|
|
|
switch (req->cmd) {
|
|
case PVCALLS_SOCKET:
|
|
ret = pvcalls_back_socket(dev, req);
|
|
break;
|
|
case PVCALLS_CONNECT:
|
|
ret = pvcalls_back_connect(dev, req);
|
|
break;
|
|
case PVCALLS_RELEASE:
|
|
ret = pvcalls_back_release(dev, req);
|
|
break;
|
|
case PVCALLS_BIND:
|
|
ret = pvcalls_back_bind(dev, req);
|
|
break;
|
|
case PVCALLS_LISTEN:
|
|
ret = pvcalls_back_listen(dev, req);
|
|
break;
|
|
case PVCALLS_ACCEPT:
|
|
ret = pvcalls_back_accept(dev, req);
|
|
break;
|
|
case PVCALLS_POLL:
|
|
ret = pvcalls_back_poll(dev, req);
|
|
break;
|
|
default:
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
struct xen_pvcalls_response *rsp;
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
rsp = RING_GET_RESPONSE(
|
|
&fedata->ring, fedata->ring.rsp_prod_pvt++);
|
|
rsp->req_id = req->req_id;
|
|
rsp->cmd = req->cmd;
|
|
rsp->ret = -ENOTSUPP;
|
|
break;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void pvcalls_back_work(struct pvcalls_fedata *fedata)
|
|
{
|
|
int notify, notify_all = 0, more = 1;
|
|
struct xen_pvcalls_request req;
|
|
struct xenbus_device *dev = fedata->dev;
|
|
|
|
while (more) {
|
|
while (RING_HAS_UNCONSUMED_REQUESTS(&fedata->ring)) {
|
|
RING_COPY_REQUEST(&fedata->ring,
|
|
fedata->ring.req_cons++,
|
|
&req);
|
|
|
|
if (!pvcalls_back_handle_cmd(dev, &req)) {
|
|
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(
|
|
&fedata->ring, notify);
|
|
notify_all += notify;
|
|
}
|
|
}
|
|
|
|
if (notify_all) {
|
|
notify_remote_via_irq(fedata->irq);
|
|
notify_all = 0;
|
|
}
|
|
|
|
RING_FINAL_CHECK_FOR_REQUESTS(&fedata->ring, more);
|
|
}
|
|
}
|
|
|
|
static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
|
|
{
|
|
struct xenbus_device *dev = dev_id;
|
|
struct pvcalls_fedata *fedata = NULL;
|
|
unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
|
|
|
|
if (dev) {
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
if (fedata) {
|
|
pvcalls_back_work(fedata);
|
|
eoi_flags = 0;
|
|
}
|
|
}
|
|
|
|
xen_irq_lateeoi(irq, eoi_flags);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
|
|
{
|
|
struct sock_mapping *map = sock_map;
|
|
struct pvcalls_ioworker *iow;
|
|
|
|
if (map == NULL || map->sock == NULL || map->sock->sk == NULL ||
|
|
map->sock->sk->sk_user_data != map) {
|
|
xen_irq_lateeoi(irq, 0);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
iow = &map->ioworker;
|
|
|
|
atomic_inc(&map->write);
|
|
atomic_inc(&map->eoi);
|
|
atomic_inc(&map->io);
|
|
queue_work(iow->wq, &iow->register_work);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int backend_connect(struct xenbus_device *dev)
|
|
{
|
|
int err;
|
|
evtchn_port_t evtchn;
|
|
grant_ref_t ring_ref;
|
|
struct pvcalls_fedata *fedata = NULL;
|
|
|
|
fedata = kzalloc(sizeof(struct pvcalls_fedata), GFP_KERNEL);
|
|
if (!fedata)
|
|
return -ENOMEM;
|
|
|
|
fedata->irq = -1;
|
|
err = xenbus_scanf(XBT_NIL, dev->otherend, "port", "%u",
|
|
&evtchn);
|
|
if (err != 1) {
|
|
err = -EINVAL;
|
|
xenbus_dev_fatal(dev, err, "reading %s/event-channel",
|
|
dev->otherend);
|
|
goto error;
|
|
}
|
|
|
|
err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", "%u", &ring_ref);
|
|
if (err != 1) {
|
|
err = -EINVAL;
|
|
xenbus_dev_fatal(dev, err, "reading %s/ring-ref",
|
|
dev->otherend);
|
|
goto error;
|
|
}
|
|
|
|
err = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn);
|
|
if (err < 0)
|
|
goto error;
|
|
fedata->irq = err;
|
|
|
|
err = request_threaded_irq(fedata->irq, NULL, pvcalls_back_event,
|
|
IRQF_ONESHOT, "pvcalls-back", dev);
|
|
if (err < 0)
|
|
goto error;
|
|
|
|
err = xenbus_map_ring_valloc(dev, &ring_ref, 1,
|
|
(void **)&fedata->sring);
|
|
if (err < 0)
|
|
goto error;
|
|
|
|
BACK_RING_INIT(&fedata->ring, fedata->sring, XEN_PAGE_SIZE * 1);
|
|
fedata->dev = dev;
|
|
|
|
INIT_LIST_HEAD(&fedata->socket_mappings);
|
|
INIT_RADIX_TREE(&fedata->socketpass_mappings, GFP_KERNEL);
|
|
sema_init(&fedata->socket_lock, 1);
|
|
dev_set_drvdata(&dev->dev, fedata);
|
|
|
|
down(&pvcalls_back_global.frontends_lock);
|
|
list_add_tail(&fedata->list, &pvcalls_back_global.frontends);
|
|
up(&pvcalls_back_global.frontends_lock);
|
|
|
|
return 0;
|
|
|
|
error:
|
|
if (fedata->irq >= 0)
|
|
unbind_from_irqhandler(fedata->irq, dev);
|
|
if (fedata->sring != NULL)
|
|
xenbus_unmap_ring_vfree(dev, fedata->sring);
|
|
kfree(fedata);
|
|
return err;
|
|
}
|
|
|
|
static int backend_disconnect(struct xenbus_device *dev)
|
|
{
|
|
struct pvcalls_fedata *fedata;
|
|
struct sock_mapping *map, *n;
|
|
struct sockpass_mapping *mappass;
|
|
struct radix_tree_iter iter;
|
|
void **slot;
|
|
|
|
|
|
fedata = dev_get_drvdata(&dev->dev);
|
|
|
|
down(&fedata->socket_lock);
|
|
list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) {
|
|
list_del(&map->list);
|
|
pvcalls_back_release_active(dev, fedata, map);
|
|
}
|
|
|
|
radix_tree_for_each_slot(slot, &fedata->socketpass_mappings, &iter, 0) {
|
|
mappass = radix_tree_deref_slot(slot);
|
|
if (!mappass)
|
|
continue;
|
|
if (radix_tree_exception(mappass)) {
|
|
if (radix_tree_deref_retry(mappass))
|
|
slot = radix_tree_iter_retry(&iter);
|
|
} else {
|
|
radix_tree_delete(&fedata->socketpass_mappings,
|
|
mappass->id);
|
|
pvcalls_back_release_passive(dev, fedata, mappass);
|
|
}
|
|
}
|
|
up(&fedata->socket_lock);
|
|
|
|
unbind_from_irqhandler(fedata->irq, dev);
|
|
xenbus_unmap_ring_vfree(dev, fedata->sring);
|
|
|
|
list_del(&fedata->list);
|
|
kfree(fedata);
|
|
dev_set_drvdata(&dev->dev, NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pvcalls_back_probe(struct xenbus_device *dev,
|
|
const struct xenbus_device_id *id)
|
|
{
|
|
int err, abort;
|
|
struct xenbus_transaction xbt;
|
|
|
|
again:
|
|
abort = 1;
|
|
|
|
err = xenbus_transaction_start(&xbt);
|
|
if (err) {
|
|
pr_warn("%s cannot create xenstore transaction\n", __func__);
|
|
return err;
|
|
}
|
|
|
|
err = xenbus_printf(xbt, dev->nodename, "versions", "%s",
|
|
PVCALLS_VERSIONS);
|
|
if (err) {
|
|
pr_warn("%s write out 'versions' failed\n", __func__);
|
|
goto abort;
|
|
}
|
|
|
|
err = xenbus_printf(xbt, dev->nodename, "max-page-order", "%u",
|
|
MAX_RING_ORDER);
|
|
if (err) {
|
|
pr_warn("%s write out 'max-page-order' failed\n", __func__);
|
|
goto abort;
|
|
}
|
|
|
|
err = xenbus_printf(xbt, dev->nodename, "function-calls",
|
|
XENBUS_FUNCTIONS_CALLS);
|
|
if (err) {
|
|
pr_warn("%s write out 'function-calls' failed\n", __func__);
|
|
goto abort;
|
|
}
|
|
|
|
abort = 0;
|
|
abort:
|
|
err = xenbus_transaction_end(xbt, abort);
|
|
if (err) {
|
|
if (err == -EAGAIN && !abort)
|
|
goto again;
|
|
pr_warn("%s cannot complete xenstore transaction\n", __func__);
|
|
return err;
|
|
}
|
|
|
|
if (abort)
|
|
return -EFAULT;
|
|
|
|
xenbus_switch_state(dev, XenbusStateInitWait);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void set_backend_state(struct xenbus_device *dev,
|
|
enum xenbus_state state)
|
|
{
|
|
while (dev->state != state) {
|
|
switch (dev->state) {
|
|
case XenbusStateClosed:
|
|
switch (state) {
|
|
case XenbusStateInitWait:
|
|
case XenbusStateConnected:
|
|
xenbus_switch_state(dev, XenbusStateInitWait);
|
|
break;
|
|
case XenbusStateClosing:
|
|
xenbus_switch_state(dev, XenbusStateClosing);
|
|
break;
|
|
default:
|
|
WARN_ON(1);
|
|
}
|
|
break;
|
|
case XenbusStateInitWait:
|
|
case XenbusStateInitialised:
|
|
switch (state) {
|
|
case XenbusStateConnected:
|
|
if (backend_connect(dev))
|
|
return;
|
|
xenbus_switch_state(dev, XenbusStateConnected);
|
|
break;
|
|
case XenbusStateClosing:
|
|
case XenbusStateClosed:
|
|
xenbus_switch_state(dev, XenbusStateClosing);
|
|
break;
|
|
default:
|
|
WARN_ON(1);
|
|
}
|
|
break;
|
|
case XenbusStateConnected:
|
|
switch (state) {
|
|
case XenbusStateInitWait:
|
|
case XenbusStateClosing:
|
|
case XenbusStateClosed:
|
|
down(&pvcalls_back_global.frontends_lock);
|
|
backend_disconnect(dev);
|
|
up(&pvcalls_back_global.frontends_lock);
|
|
xenbus_switch_state(dev, XenbusStateClosing);
|
|
break;
|
|
default:
|
|
WARN_ON(1);
|
|
}
|
|
break;
|
|
case XenbusStateClosing:
|
|
switch (state) {
|
|
case XenbusStateInitWait:
|
|
case XenbusStateConnected:
|
|
case XenbusStateClosed:
|
|
xenbus_switch_state(dev, XenbusStateClosed);
|
|
break;
|
|
default:
|
|
WARN_ON(1);
|
|
}
|
|
break;
|
|
default:
|
|
WARN_ON(1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void pvcalls_back_changed(struct xenbus_device *dev,
|
|
enum xenbus_state frontend_state)
|
|
{
|
|
switch (frontend_state) {
|
|
case XenbusStateInitialising:
|
|
set_backend_state(dev, XenbusStateInitWait);
|
|
break;
|
|
|
|
case XenbusStateInitialised:
|
|
case XenbusStateConnected:
|
|
set_backend_state(dev, XenbusStateConnected);
|
|
break;
|
|
|
|
case XenbusStateClosing:
|
|
set_backend_state(dev, XenbusStateClosing);
|
|
break;
|
|
|
|
case XenbusStateClosed:
|
|
set_backend_state(dev, XenbusStateClosed);
|
|
if (xenbus_dev_is_online(dev))
|
|
break;
|
|
device_unregister(&dev->dev);
|
|
break;
|
|
case XenbusStateUnknown:
|
|
set_backend_state(dev, XenbusStateClosed);
|
|
device_unregister(&dev->dev);
|
|
break;
|
|
|
|
default:
|
|
xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
|
|
frontend_state);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int pvcalls_back_remove(struct xenbus_device *dev)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int pvcalls_back_uevent(struct xenbus_device *xdev,
|
|
struct kobj_uevent_env *env)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct xenbus_device_id pvcalls_back_ids[] = {
|
|
{ "pvcalls" },
|
|
{ "" }
|
|
};
|
|
|
|
static struct xenbus_driver pvcalls_back_driver = {
|
|
.ids = pvcalls_back_ids,
|
|
.probe = pvcalls_back_probe,
|
|
.remove = pvcalls_back_remove,
|
|
.uevent = pvcalls_back_uevent,
|
|
.otherend_changed = pvcalls_back_changed,
|
|
};
|
|
|
|
static int __init pvcalls_back_init(void)
|
|
{
|
|
int ret;
|
|
|
|
if (!xen_domain())
|
|
return -ENODEV;
|
|
|
|
ret = xenbus_register_backend(&pvcalls_back_driver);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
sema_init(&pvcalls_back_global.frontends_lock, 1);
|
|
INIT_LIST_HEAD(&pvcalls_back_global.frontends);
|
|
return 0;
|
|
}
|
|
module_init(pvcalls_back_init);
|
|
|
|
static void __exit pvcalls_back_fin(void)
|
|
{
|
|
struct pvcalls_fedata *fedata, *nfedata;
|
|
|
|
down(&pvcalls_back_global.frontends_lock);
|
|
list_for_each_entry_safe(fedata, nfedata,
|
|
&pvcalls_back_global.frontends, list) {
|
|
backend_disconnect(fedata->dev);
|
|
}
|
|
up(&pvcalls_back_global.frontends_lock);
|
|
|
|
xenbus_unregister_driver(&pvcalls_back_driver);
|
|
}
|
|
|
|
module_exit(pvcalls_back_fin);
|
|
|
|
MODULE_DESCRIPTION("Xen PV Calls backend driver");
|
|
MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>");
|
|
MODULE_LICENSE("GPL");
|