path: root/drivers/xen/pvcalls-back.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * (c) 2017 Stefano Stabellini <stefano@aporeto.com>
 */

#include <linux/inet.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/radix-tree.h>
#include <linux/module.h>
#include <linux/semaphore.h>
#include <linux/wait.h>
#include <net/sock.h>
#include <net/inet_common.h>
#include <net/inet_connection_sock.h>
#include <net/request_sock.h>
#include <trace/events/sock.h>

#include <xen/events.h>
#include <xen/grant_table.h>
#include <xen/xen.h>
#include <xen/xenbus.h>
#include <xen/interface/io/pvcalls.h>

#define PVCALLS_VERSIONS "1"
#define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER

static struct pvcalls_back_global {
	struct list_head frontends;
	struct semaphore frontends_lock;
} pvcalls_back_global;

/*
 * Per-frontend data structure. It contains pointers to the command
 * ring, its event channel, a list of active sockets and a tree of
 * passive sockets.
 */
struct pvcalls_fedata {
	struct list_head list;
	struct xenbus_device *dev;
	struct xen_pvcalls_sring *sring;
	struct xen_pvcalls_back_ring ring;
	int irq;
	struct list_head socket_mappings;
	struct radix_tree_root socketpass_mappings;
	struct semaphore socket_lock;
};

struct pvcalls_ioworker {
	struct work_struct register_work;
	struct workqueue_struct *wq;
};

struct sock_mapping {
	struct list_head list;
	struct pvcalls_fedata *fedata;
	struct sockpass_mapping *sockpass;
	struct socket *sock;
	uint64_t id;
	grant_ref_t ref;
	struct pvcalls_data_intf *ring;
	void *bytes;
	struct pvcalls_data data;
	uint32_t ring_order;
	int irq;
	atomic_t read;
	atomic_t write;
	atomic_t io;
	atomic_t release;
	atomic_t eoi;
	void (*saved_data_ready)(struct sock *sk);
	struct pvcalls_ioworker ioworker;
};

struct sockpass_mapping {
	struct list_head list;
	struct pvcalls_fedata *fedata;
	struct socket *sock;
	uint64_t id;
	struct xen_pvcalls_request reqcopy;
	spinlock_t copy_lock;
	struct workqueue_struct *wq;
	struct work_struct register_work;
	void (*saved_data_ready)(struct sock *sk);
};

static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map);
static int pvcalls_back_release_active(struct xenbus_device *dev,
				       struct pvcalls_fedata *fedata,
				       struct sock_mapping *map);

static bool pvcalls_conn_back_read(void *opaque)
{
	struct sock_mapping *map = (struct sock_mapping *)opaque;
	struct msghdr msg;
	struct kvec