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xen/pvcalls: implement connect command

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Allocate a socket. Keep track of socket <-> ring mappings with a new data
structure, called sock_mapping. Implement the connect command by calling
inet_stream_connect, and mapping the new indexes page and data ring.
Allocate a workqueue and a work_struct, called ioworker, to perform
reads and writes to the socket.

When an active socket is closed (sk_state_change), set in_error to
-ENOTCONN and notify the other end, as specified by the protocol.

sk_data_ready and pvcalls_back_ioworker will be implemented later.

[ boris: fixed whitespaces ]

Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
CC: boris.ostrovsky@oracle.com
CC: jgross@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Stefano Stabellini 2017-07-06 11:01:06 -07:00 committed by Boris Ostrovsky
parent fb0298754a
commit 5db4d286a8
1 changed files with 179 additions and 0 deletions
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179
drivers/xen/pvcalls-back.c
View File

@ -54,6 +54,39 @@ struct pvcalls_fedata {
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 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;
void (*saved_data_ready)(struct sock *sk);
struct pvcalls_ioworker ioworker;
};
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 void pvcalls_back_ioworker(struct work_struct *work)
{
}
static int pvcalls_back_socket(struct xenbus_device *dev,
struct xen_pvcalls_request *req)
{
@ -82,8 +115,149 @@ static int pvcalls_back_socket(struct xenbus_device *dev,
return 0;
}
static void pvcalls_sk_state_change(struct sock *sock)
{
struct sock_mapping *map = sock->sk_user_data;
struct pvcalls_data_intf *intf;
if (map == NULL)
return;
intf = map->ring;
intf->in_error = -ENOTCONN;
notify_remote_via_irq(map->irq);
}
static void pvcalls_sk_data_ready(struct sock *sock)
{
}
static struct sock_mapping *pvcalls_new_active_socket(
struct pvcalls_fedata *fedata,
uint64_t id,
grant_ref_t ref,
uint32_t evtchn,
struct socket *sock)
{
int ret;
struct sock_mapping *map;
void *page;
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (map == NULL)
return NULL;
map->fedata = fedata;
map->sock = sock;
map->id = id;
map->ref = ref;
ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page);
if (ret < 0)
goto out;
map->ring = page;
map->ring_order = map->ring->ring_order;
/* first read the order, then map the data ring */
virt_rmb();
if (map->ring_order > MAX_RING_ORDER) {
pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n",
__func__, map->ring_order, MAX_RING_ORDER);
goto out;
}
ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref,
(1 << map->ring_order), &page);
if (ret < 0)
goto out;
map->bytes = page;
ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id,
evtchn,
pvcalls_back_conn_event,
0,
"pvcalls-backend",
map);
if (ret < 0)
goto out;
map->irq = ret;
map->data.in = map->bytes;
map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order);
map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1);
if (!map->ioworker.wq)
goto out;
atomic_set(&map->io, 1);
INIT_WORK(&map->ioworker.register_work, pvcalls_back_ioworker);
down(&fedata->socket_lock);
list_add_tail(&map->list, &fedata->socket_mappings);
up(&fedata->socket_lock);
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_sk_data_ready;
map->sock->sk->sk_state_change = pvcalls_sk_state_change;
write_unlock_bh(&map->sock->sk->sk_callback_lock);
return map;
out:
down(&fedata->socket_lock);
list_del(&map->list);
pvcalls_back_release_active(fedata->dev, fedata, map);
up(&fedata->socket_lock);
return NULL;
}
static int pvcalls_back_connect(struct xenbus_device *dev,
struct xen_pvcalls_request *req)
{
struct pvcalls_fedata *fedata;
int ret = -EINVAL;
struct socket *sock;
struct sock_mapping *map;
struct xen_pvcalls_response *rsp;
struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr;
fedata = dev_get_drvdata(&dev->dev);
if (req->u.connect.len < sizeof(sa->sa_family) ||
req->u.connect.len > sizeof(req->u.connect.addr) ||
sa->sa_family != AF_INET)
goto out;
ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock);
if (ret < 0)
goto out;
ret = inet_stream_connect(sock, sa, req->u.connect.len, 0);
if (ret < 0) {
sock_release(sock);
goto out;
}
map = pvcalls_new_active_socket(fedata,
req->u.connect.id,
req->u.connect.ref,
req->u.connect.evtchn,
sock);
if (!map) {
ret = -EFAULT;
sock_release(map->sock);
}
out:
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
rsp->req_id = req->req_id;
rsp->cmd = req->cmd;
rsp->u.connect.id = req->u.connect.id;
rsp->ret = ret;
return 0;
}
static int pvcalls_back_release_active(struct xenbus_device *dev,
struct pvcalls_fedata *fedata,
struct sock_mapping *map)
{
return 0;
}
@ -206,6 +380,11 @@ static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
return IRQ_HANDLED;
}
static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
{
return IRQ_HANDLED;
}
static int backend_connect(struct xenbus_device *dev)
{
int err, evtchn;