[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/drivers/xen/pvcalls-front.c b/src/kernel/linux/v4.19/drivers/xen/pvcalls-front.c
new file mode 100644
index 0000000..d7438fd
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/xen/pvcalls-front.c
@@ -0,0 +1,1300 @@
+/*
+ * (c) 2017 Stefano Stabellini <stefano@aporeto.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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, int *evtchn)
+{
+ void *bytes;
+ int ret = -ENOMEM, irq = -1, i;
+
+ *evtchn = -1;
+ 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;
+
+ 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, evtchn, nonblock;
+
+ 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, evtchn, i;
+ unsigned int max_page_order, function_calls, len;
+ char *versions;
+ grant_ref_t gref_head = 0;
+ struct xenbus_transaction xbt;
+ struct pvcalls_bedata *bedata = NULL;
+ struct xen_pvcalls_sring *sring;
+
+ if (pvcalls_front_dev != NULL) {
+ dev_err(&dev->dev, "only one PV Calls connection supported\n");
+ return -EINVAL;
+ }
+
+ versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
+ if (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 */
+ /* fall through */
+ case XenbusStateClosing:
+ xenbus_frontend_closed(dev);
+ break;
+ }
+}
+
+static struct xenbus_driver pvcalls_front_driver = {
+ .ids = pvcalls_front_ids,
+ .probe = pvcalls_front_probe,
+ .remove = pvcalls_front_remove,
+ .otherend_changed = pvcalls_front_changed,
+};
+
+static int __init pvcalls_frontend_init(void)
+{
+ if (!xen_domain())
+ return -ENODEV;
+
+ pr_info("Initialising Xen pvcalls frontend driver\n");
+
+ return xenbus_register_frontend(&pvcalls_front_driver);
+}
+
+module_init(pvcalls_frontend_init);
+
+MODULE_DESCRIPTION("Xen PV Calls frontend driver");
+MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>");
+MODULE_LICENSE("GPL");