![Jing Xiangfeng](/assets/img/avatar_default.png)
After commit 9f51c05dc4
("pvcalls-front: Avoid
get_free_pages(GFP_KERNEL) under spinlock"), the variable ret is being
initialized with '-ENOMEM' that is meaningless. So remove it.
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Link: https://lore.kernel.org/r/20200919031702.32192-1-jingxiangfeng@huawei.com
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
1295 lines
32 KiB
C
1295 lines
32 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* (c) 2017 Stefano Stabellini <stefano@aporeto.com>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/net.h>
|
|
#include <linux/socket.h>
|
|
|
|
#include <net/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>
|
|
|
|
#include "pvcalls-front.h"
|
|
|
|
#define PVCALLS_INVALID_ID UINT_MAX
|
|
#define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER
|
|
#define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE)
|
|
#define PVCALLS_FRONT_MAX_SPIN 5000
|
|
|
|
static struct proto pvcalls_proto = {
|
|
.name = "PVCalls",
|
|
.owner = THIS_MODULE,
|
|
.obj_size = sizeof(struct sock),
|
|
};
|
|
|
|
struct pvcalls_bedata {
|
|
struct xen_pvcalls_front_ring ring;
|
|
grant_ref_t ref;
|
|
int irq;
|
|
|
|
struct list_head socket_mappings;
|
|
spinlock_t socket_lock;
|
|
|
|
wait_queue_head_t inflight_req;
|
|
struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING];
|
|
};
|
|
/* Only one front/back connection supported. */
|
|
static struct xenbus_device *pvcalls_front_dev;
|
|
static atomic_t pvcalls_refcount;
|
|
|
|
/* first increment refcount, then proceed */
|
|
#define pvcalls_enter() { \
|
|
atomic_inc(&pvcalls_refcount); \
|
|
}
|
|
|
|
/* first complete other operations, then decrement refcount */
|
|
#define pvcalls_exit() { \
|
|
atomic_dec(&pvcalls_refcount); \
|
|
}
|
|
|
|
struct sock_mapping {
|
|
bool active_socket;
|
|
struct list_head list;
|
|
struct socket *sock;
|
|
atomic_t refcount;
|
|
union {
|
|
struct {
|
|
int irq;
|
|
grant_ref_t ref;
|
|
struct pvcalls_data_intf *ring;
|
|
struct pvcalls_data data;
|
|
struct mutex in_mutex;
|
|
struct mutex out_mutex;
|
|
|
|
wait_queue_head_t inflight_conn_req;
|
|
} active;
|
|
struct {
|
|
/*
|
|
* Socket status, needs to be 64-bit aligned due to the
|
|
* test_and_* functions which have this requirement on arm64.
|
|
*/
|
|
#define PVCALLS_STATUS_UNINITALIZED 0
|
|
#define PVCALLS_STATUS_BIND 1
|
|
#define PVCALLS_STATUS_LISTEN 2
|
|
uint8_t status __attribute__((aligned(8)));
|
|
/*
|
|
* Internal state-machine flags.
|
|
* Only one accept operation can be inflight for a socket.
|
|
* Only one poll operation can be inflight for a given socket.
|
|
* flags needs to be 64-bit aligned due to the test_and_*
|
|
* functions which have this requirement on arm64.
|
|
*/
|
|
#define PVCALLS_FLAG_ACCEPT_INFLIGHT 0
|
|
#define PVCALLS_FLAG_POLL_INFLIGHT 1
|
|
#define PVCALLS_FLAG_POLL_RET 2
|
|
uint8_t flags __attribute__((aligned(8)));
|
|
uint32_t inflight_req_id;
|
|
struct sock_mapping *accept_map;
|
|
wait_queue_head_t inflight_accept_req;
|
|
} passive;
|
|
};
|
|
};
|
|
|
|
static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock)
|
|
{
|
|
struct sock_mapping *map;
|
|
|
|
if (!pvcalls_front_dev ||
|
|
dev_get_drvdata(&pvcalls_front_dev->dev) == NULL)
|
|
return ERR_PTR(-ENOTCONN);
|
|
|
|
map = (struct sock_mapping *)sock->sk->sk_send_head;
|
|
if (map == NULL)
|
|
return ERR_PTR(-ENOTSOCK);
|
|
|
|
pvcalls_enter();
|
|
atomic_inc(&map->refcount);
|
|
return map;
|
|
}
|
|
|
|
static inline void pvcalls_exit_sock(struct socket *sock)
|
|
{
|
|
struct sock_mapping *map;
|
|
|
|
map = (struct sock_mapping *)sock->sk->sk_send_head;
|
|
atomic_dec(&map->refcount);
|
|
pvcalls_exit();
|
|
}
|
|
|
|
static inline int get_request(struct pvcalls_bedata *bedata, int *req_id)
|
|
{
|
|
*req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
|
|
if (RING_FULL(&bedata->ring) ||
|
|
bedata->rsp[*req_id].req_id != PVCALLS_INVALID_ID)
|
|
return -EAGAIN;
|
|
return 0;
|
|
}
|
|
|
|
static bool pvcalls_front_write_todo(struct sock_mapping *map)
|
|
{
|
|
struct pvcalls_data_intf *intf = map->active.ring;
|
|
RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
|
|
int32_t error;
|
|
|
|
error = intf->out_error;
|
|
if (error == -ENOTCONN)
|
|
return false;
|
|
if (error != 0)
|
|
return true;
|
|
|
|
cons = intf->out_cons;
|
|
prod = intf->out_prod;
|
|
return !!(size - pvcalls_queued(prod, cons, size));
|
|
}
|
|
|
|
static bool pvcalls_front_read_todo(struct sock_mapping *map)
|
|
{
|
|
struct pvcalls_data_intf *intf = map->active.ring;
|
|
RING_IDX cons, prod;
|
|
int32_t error;
|
|
|
|
cons = intf->in_cons;
|
|
prod = intf->in_prod;
|
|
error = intf->in_error;
|
|
return (error != 0 ||
|
|
pvcalls_queued(prod, cons,
|
|
XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0);
|
|
}
|
|
|
|
static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id)
|
|
{
|
|
struct xenbus_device *dev = dev_id;
|
|
struct pvcalls_bedata *bedata;
|
|
struct xen_pvcalls_response *rsp;
|
|
uint8_t *src, *dst;
|
|
int req_id = 0, more = 0, done = 0;
|
|
|
|
if (dev == NULL)
|
|
return IRQ_HANDLED;
|
|
|
|
pvcalls_enter();
|
|
bedata = dev_get_drvdata(&dev->dev);
|
|
if (bedata == NULL) {
|
|
pvcalls_exit();
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
again:
|
|
while (RING_HAS_UNCONSUMED_RESPONSES(&bedata->ring)) {
|
|
rsp = RING_GET_RESPONSE(&bedata->ring, bedata->ring.rsp_cons);
|
|
|
|
req_id = rsp->req_id;
|
|
if (rsp->cmd == PVCALLS_POLL) {
|
|
struct sock_mapping *map = (struct sock_mapping *)(uintptr_t)
|
|
rsp->u.poll.id;
|
|
|
|
clear_bit(PVCALLS_FLAG_POLL_INFLIGHT,
|
|
(void *)&map->passive.flags);
|
|
/*
|
|
* clear INFLIGHT, then set RET. It pairs with
|
|
* the checks at the beginning of
|
|
* pvcalls_front_poll_passive.
|
|
*/
|
|
smp_wmb();
|
|
set_bit(PVCALLS_FLAG_POLL_RET,
|
|
(void *)&map->passive.flags);
|
|
} else {
|
|
dst = (uint8_t *)&bedata->rsp[req_id] +
|
|
sizeof(rsp->req_id);
|
|
src = (uint8_t *)rsp + sizeof(rsp->req_id);
|
|
memcpy(dst, src, sizeof(*rsp) - sizeof(rsp->req_id));
|
|
/*
|
|
* First copy the rest of the data, then req_id. It is
|
|
* paired with the barrier when accessing bedata->rsp.
|
|
*/
|
|
smp_wmb();
|
|
bedata->rsp[req_id].req_id = req_id;
|
|
}
|
|
|
|
done = 1;
|
|
bedata->ring.rsp_cons++;
|
|
}
|
|
|
|
RING_FINAL_CHECK_FOR_RESPONSES(&bedata->ring, more);
|
|
if (more)
|
|
goto again;
|
|
if (done)
|
|
wake_up(&bedata->inflight_req);
|
|
pvcalls_exit();
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static void pvcalls_front_free_map(struct pvcalls_bedata *bedata,
|
|
struct sock_mapping *map)
|
|
{
|
|
int i;
|
|
|
|
unbind_from_irqhandler(map->active.irq, map);
|
|
|
|
spin_lock(&bedata->socket_lock);
|
|
if (!list_empty(&map->list))
|
|
list_del_init(&map->list);
|
|
spin_unlock(&bedata->socket_lock);
|
|
|
|
for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++)
|
|
gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0);
|
|
gnttab_end_foreign_access(map->active.ref, 0, 0);
|
|
free_page((unsigned long)map->active.ring);
|
|
|
|
kfree(map);
|
|
}
|
|
|
|
static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map)
|
|
{
|
|
struct sock_mapping *map = sock_map;
|
|
|
|
if (map == NULL)
|
|
return IRQ_HANDLED;
|
|
|
|
wake_up_interruptible(&map->active.inflight_conn_req);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
int pvcalls_front_socket(struct socket *sock)
|
|
{
|
|
struct pvcalls_bedata *bedata;
|
|
struct sock_mapping *map = NULL;
|
|
struct xen_pvcalls_request *req;
|
|
int notify, req_id, ret;
|
|
|
|
/*
|
|
* PVCalls only supports domain AF_INET,
|
|
* type SOCK_STREAM and protocol 0 sockets for now.
|
|
*
|
|
* Check socket type here, AF_INET and protocol checks are done
|
|
* by the caller.
|
|
*/
|
|
if (sock->type != SOCK_STREAM)
|
|
return -EOPNOTSUPP;
|
|
|
|
pvcalls_enter();
|
|
if (!pvcalls_front_dev) {
|
|
pvcalls_exit();
|
|
return -EACCES;
|
|
}
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
|
map = kzalloc(sizeof(*map), GFP_KERNEL);
|
|
if (map == NULL) {
|
|
pvcalls_exit();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&bedata->socket_lock);
|
|
|
|
ret = get_request(bedata, &req_id);
|
|
if (ret < 0) {
|
|
kfree(map);
|
|
spin_unlock(&bedata->socket_lock);
|
|
pvcalls_exit();
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* sock->sk->sk_send_head is not used for ip sockets: reuse the
|
|
* field to store a pointer to the struct sock_mapping
|
|
* corresponding to the socket. This way, we can easily get the
|
|
* struct sock_mapping from the struct socket.
|
|
*/
|
|
sock->sk->sk_send_head = (void *)map;
|
|
list_add_tail(&map->list, &bedata->socket_mappings);
|
|
|
|
req = RING_GET_REQUEST(&bedata->ring, req_id);
|
|
req->req_id = req_id;
|
|
req->cmd = PVCALLS_SOCKET;
|
|
req->u.socket.id = (uintptr_t) map;
|
|
req->u.socket.domain = AF_INET;
|
|
req->u.socket.type = SOCK_STREAM;
|
|
req->u.socket.protocol = IPPROTO_IP;
|
|
|
|
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 void free_active_ring(struct sock_mapping *map)
|
|
{
|
|
if (!map->active.ring)
|
|
return;
|
|
|
|
free_pages((unsigned long)map->active.data.in,
|
|
map->active.ring->ring_order);
|
|
free_page((unsigned long)map->active.ring);
|
|
}
|
|
|
|
static int alloc_active_ring(struct sock_mapping *map)
|
|
{
|
|
void *bytes;
|
|
|
|
map->active.ring = (struct pvcalls_data_intf *)
|
|
get_zeroed_page(GFP_KERNEL);
|
|
if (!map->active.ring)
|
|
goto out;
|
|
|
|
map->active.ring->ring_order = PVCALLS_RING_ORDER;
|
|
bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
|
|
PVCALLS_RING_ORDER);
|
|
if (!bytes)
|
|
goto out;
|
|
|
|
map->active.data.in = bytes;
|
|
map->active.data.out = bytes +
|
|
XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
|
|
|
|
return 0;
|
|
|
|
out:
|
|
free_active_ring(map);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int create_active(struct sock_mapping *map, evtchn_port_t *evtchn)
|
|
{
|
|
void *bytes;
|
|
int ret, irq = -1, i;
|
|
|
|
*evtchn = 0;
|
|
init_waitqueue_head(&map->active.inflight_conn_req);
|
|
|
|
bytes = map->active.data.in;
|
|
for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++)
|
|
map->active.ring->ref[i] = gnttab_grant_foreign_access(
|
|
pvcalls_front_dev->otherend_id,
|
|
pfn_to_gfn(virt_to_pfn(bytes) + i), 0);
|
|
|
|
map->active.ref = gnttab_grant_foreign_access(
|
|
pvcalls_front_dev->otherend_id,
|
|
pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0);
|
|
|
|
ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn);
|
|
if (ret)
|
|
goto out_error;
|
|
irq = bind_evtchn_to_irqhandler(*evtchn, pvcalls_front_conn_handler,
|
|
0, "pvcalls-frontend", map);
|
|
if (irq < 0) {
|
|
ret = irq;
|
|
goto out_error;
|
|
}
|
|
|
|
map->active.irq = irq;
|
|
map->active_socket = true;
|
|
mutex_init(&map->active.in_mutex);
|
|
mutex_init(&map->active.out_mutex);
|
|
|
|
return 0;
|
|
|
|
out_error:
|
|
if (*evtchn > 0)
|
|
xenbus_free_evtchn(pvcalls_front_dev, *evtchn);
|
|
return ret;
|
|
}
|
|
|
|
int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
|
|
int addr_len, int flags)
|
|
{
|
|
struct pvcalls_bedata *bedata;
|
|
struct sock_mapping *map = NULL;
|
|
struct xen_pvcalls_request *req;
|
|
int notify, req_id, ret;
|
|
evtchn_port_t evtchn;
|
|
|
|
if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
|
|
return -EOPNOTSUPP;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
ret = alloc_active_ring(map);
|
|
if (ret < 0) {
|
|
pvcalls_exit_sock(sock);
|
|
return ret;
|
|
}
|
|
|
|
spin_lock(&bedata->socket_lock);
|
|
ret = get_request(bedata, &req_id);
|
|
if (ret < 0) {
|
|
spin_unlock(&bedata->socket_lock);
|
|
free_active_ring(map);
|
|
pvcalls_exit_sock(sock);
|
|
return ret;
|
|
}
|
|
ret = create_active(map, &evtchn);
|
|
if (ret < 0) {
|
|
spin_unlock(&bedata->socket_lock);
|
|
free_active_ring(map);
|
|
pvcalls_exit_sock(sock);
|
|
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_sock(sock);
|
|
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 (size == array_size)
|
|
return 0;
|
|
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 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;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
mutex_lock(&map->active.out_mutex);
|
|
if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) {
|
|
mutex_unlock(&map->active.out_mutex);
|
|
pvcalls_exit_sock(sock);
|
|
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_sock(sock);
|
|
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();
|
|
|
|
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 error ?: size;
|
|
|
|
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)
|
|
{
|
|
int ret;
|
|
struct sock_mapping *map;
|
|
|
|
if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC))
|
|
return -EOPNOTSUPP;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
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_sock(sock);
|
|
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;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
|
spin_lock(&bedata->socket_lock);
|
|
ret = get_request(bedata, &req_id);
|
|
if (ret < 0) {
|
|
spin_unlock(&bedata->socket_lock);
|
|
pvcalls_exit_sock(sock);
|
|
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_sock(sock);
|
|
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;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
|
if (map->passive.status != PVCALLS_STATUS_BIND) {
|
|
pvcalls_exit_sock(sock);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
spin_lock(&bedata->socket_lock);
|
|
ret = get_request(bedata, &req_id);
|
|
if (ret < 0) {
|
|
spin_unlock(&bedata->socket_lock);
|
|
pvcalls_exit_sock(sock);
|
|
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_sock(sock);
|
|
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, nonblock;
|
|
evtchn_port_t evtchn;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
|
if (map->passive.status != PVCALLS_STATUS_LISTEN) {
|
|
pvcalls_exit_sock(sock);
|
|
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_sock(sock);
|
|
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_sock(sock);
|
|
return -EINTR;
|
|
}
|
|
}
|
|
|
|
map2 = kzalloc(sizeof(*map2), GFP_KERNEL);
|
|
if (map2 == NULL) {
|
|
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
(void *)&map->passive.flags);
|
|
pvcalls_exit_sock(sock);
|
|
return -ENOMEM;
|
|
}
|
|
ret = alloc_active_ring(map2);
|
|
if (ret < 0) {
|
|
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
(void *)&map->passive.flags);
|
|
kfree(map2);
|
|
pvcalls_exit_sock(sock);
|
|
return ret;
|
|
}
|
|
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);
|
|
free_active_ring(map2);
|
|
kfree(map2);
|
|
pvcalls_exit_sock(sock);
|
|
return ret;
|
|
}
|
|
|
|
ret = create_active(map2, &evtchn);
|
|
if (ret < 0) {
|
|
free_active_ring(map2);
|
|
kfree(map2);
|
|
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
|
|
(void *)&map->passive.flags);
|
|
spin_unlock(&bedata->socket_lock);
|
|
pvcalls_exit_sock(sock);
|
|
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_sock(sock);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
if (wait_event_interruptible(bedata->inflight_req,
|
|
READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) {
|
|
pvcalls_exit_sock(sock);
|
|
return -EINTR;
|
|
}
|
|
/* read req_id, then the content */
|
|
smp_rmb();
|
|
|
|
received:
|
|
map2->sock = newsock;
|
|
newsock->sk = sk_alloc(sock_net(sock->sk), PF_INET, GFP_KERNEL, &pvcalls_proto, false);
|
|
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_sock(sock);
|
|
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_sock(sock);
|
|
return ret;
|
|
}
|
|
|
|
static __poll_t 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 EPOLLIN | EPOLLRDNORM;
|
|
|
|
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 EPOLLIN | EPOLLRDNORM;
|
|
|
|
/*
|
|
* 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 __poll_t pvcalls_front_poll_active(struct file *file,
|
|
struct pvcalls_bedata *bedata,
|
|
struct sock_mapping *map,
|
|
poll_table *wait)
|
|
{
|
|
__poll_t 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 |= EPOLLOUT | EPOLLWRNORM;
|
|
if (pvcalls_front_read_todo(map))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
if (in_error != 0 || out_error != 0)
|
|
mask |= EPOLLERR;
|
|
|
|
return mask;
|
|
}
|
|
|
|
__poll_t pvcalls_front_poll(struct file *file, struct socket *sock,
|
|
poll_table *wait)
|
|
{
|
|
struct pvcalls_bedata *bedata;
|
|
struct sock_mapping *map;
|
|
__poll_t ret;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map))
|
|
return EPOLLNVAL;
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
|
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_sock(sock);
|
|
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;
|
|
|
|
map = pvcalls_enter_sock(sock);
|
|
if (IS_ERR(map)) {
|
|
if (PTR_ERR(map) == -ENOTCONN)
|
|
return -EIO;
|
|
else
|
|
return 0;
|
|
}
|
|
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
|
|
|
|
spin_lock(&bedata->socket_lock);
|
|
ret = get_request(bedata, &req_id);
|
|
if (ret < 0) {
|
|
spin_unlock(&bedata->socket_lock);
|
|
pvcalls_exit_sock(sock);
|
|
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 way to guarantee this is to see that no pvcalls
|
|
* (other than us) is in progress on this socket.
|
|
*/
|
|
while (atomic_read(&map->refcount) > 1)
|
|
cpu_relax();
|
|
|
|
pvcalls_front_free_map(bedata, map);
|
|
} else {
|
|
wake_up(&bedata->inflight_req);
|
|
wake_up(&map->passive.inflight_accept_req);
|
|
|
|
while (atomic_read(&map->refcount) > 1)
|
|
cpu_relax();
|
|
|
|
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 &&
|
|
READ_ONCE(map->passive.inflight_req_id) != 0) {
|
|
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 != -1)
|
|
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, i;
|
|
evtchn_port_t evtchn;
|
|
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 (IS_ERR(versions))
|
|
return PTR_ERR(versions);
|
|
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 */
|
|
fallthrough;
|
|
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");
|