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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-07 10:24:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-07 10:24:21 -0700
commit3ee31b89d9b12c01aa03dda7a923ef07a800eedd (patch)
tree3eff45b4147cb74a72c382414a15c5f91e2ec228 /drivers/xen
parentbac65d9d87b383471d8d29128319508d71b74180 (diff)
parentd785d9ec7894d0e92f0d0eecc8add9c84131daa4 (diff)
Merge tag 'for-linus-4.14b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross: - the new pvcalls backend for routing socket calls from a guest to dom0 - some cleanups of Xen code - a fix for wrong usage of {get,put}_cpu() * tag 'for-linus-4.14b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (27 commits) xen/mmu: set MMU_NORMAL_PT_UPDATE in remap_area_mfn_pte_fn xen: Don't try to call xen_alloc_p2m_entry() on autotranslating guests xen/events: events_fifo: Don't use {get,put}_cpu() in xen_evtchn_fifo_init() xen/pvcalls: use WARN_ON(1) instead of __WARN() xen: remove not used trace functions xen: remove unused function xen_set_domain_pte() xen: remove tests for pvh mode in pure pv paths xen-platform: constify pci_device_id. xen: cleanup xen.h xen: introduce a Kconfig option to enable the pvcalls backend xen/pvcalls: implement write xen/pvcalls: implement read xen/pvcalls: implement the ioworker functions xen/pvcalls: disconnect and module_exit xen/pvcalls: implement release command xen/pvcalls: implement poll command xen/pvcalls: implement accept command xen/pvcalls: implement listen command xen/pvcalls: implement bind command xen/pvcalls: implement connect command ...
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/Kconfig12
-rw-r--r--drivers/xen/Makefile1
-rw-r--r--drivers/xen/balloon.c8
-rw-r--r--drivers/xen/events/events_fifo.c7
-rw-r--r--drivers/xen/platform-pci.c2
-rw-r--r--drivers/xen/pvcalls-back.c1240
6 files changed, 1262 insertions, 8 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index f15bb3b789d5..4545561954ee 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -196,6 +196,18 @@ config XEN_PCIDEV_BACKEND
If in doubt, say m.
+config XEN_PVCALLS_BACKEND
+ bool "XEN PV Calls backend driver"
+ depends on INET && XEN && XEN_BACKEND
+ default n
+ help
+ Experimental backend for the Xen PV Calls protocol
+ (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
+ allows PV Calls frontends to send POSIX calls to the backend,
+ which implements them.
+
+ If in doubt, say n.
+
config XEN_SCSI_BACKEND
tristate "XEN SCSI backend driver"
depends on XEN && XEN_BACKEND && TARGET_CORE
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 7f188b8d0c67..caaa15dc37bc 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_XEN_ACPI_PROCESSOR) += xen-acpi-processor.o
obj-$(CONFIG_XEN_EFI) += efi.o
obj-$(CONFIG_XEN_SCSI_BACKEND) += xen-scsiback.o
obj-$(CONFIG_XEN_AUTO_XLATE) += xlate_mmu.o
+obj-$(CONFIG_XEN_PVCALLS_BACKEND) += pvcalls-back.o
xen-evtchn-y := evtchn.o
xen-gntdev-y := gntdev.o
xen-gntalloc-y := gntalloc.o
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index ab609255a0f3..f77e499afddd 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -664,9 +664,11 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages)
*/
BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
- ret = xen_alloc_p2m_entry(page_to_pfn(page));
- if (ret < 0)
- goto out_undo;
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ ret = xen_alloc_p2m_entry(page_to_pfn(page));
+ if (ret < 0)
+ goto out_undo;
+ }
#endif
} else {
ret = add_ballooned_pages(nr_pages - pgno);
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index 3c41470c7fc4..76b318e88382 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -432,12 +432,12 @@ static int xen_evtchn_cpu_dead(unsigned int cpu)
int __init xen_evtchn_fifo_init(void)
{
- int cpu = get_cpu();
+ int cpu = smp_processor_id();
int ret;
ret = evtchn_fifo_alloc_control_block(cpu);
if (ret < 0)
- goto out;
+ return ret;
pr_info("Using FIFO-based ABI\n");
@@ -446,7 +446,6 @@ int __init xen_evtchn_fifo_init(void)
cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
"xen/evtchn:prepare",
xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
-out:
- put_cpu();
+
return ret;
}
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index 1275df83070f..5d7dcad0b0a0 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -175,7 +175,7 @@ pci_out:
return ret;
}
-static struct pci_device_id platform_pci_tbl[] = {
+static const struct pci_device_id platform_pci_tbl[] = {
{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
{0,}
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
new file mode 100644
index 000000000000..b209cd44bb8d
--- /dev/null
+++ b/drivers/xen/pvcalls-back.c
@@ -0,0 +1,1240 @@
+/*
+ * (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/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 <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
+
+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;
+ 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 void pvcalls_conn_back_read(void *opaque)
+{
+ struct sock_mapping *map = (struct sock_mapping *)opaque;
+ struct msghdr msg;
+ struct kvec vec[2];
+ RING_IDX cons, prod, size, wanted, array_size, masked_prod, masked_cons;
+ int32_t error;
+ struct pvcalls_data_intf *intf = map->ring;
+ struct pvcalls_data *data = &map->data;
+ unsigned long flags;
+ int ret;
+
+ array_size = XEN_FLEX_RING_SIZE(map->ring_order);
+ cons = intf->in_cons;
+ prod = intf->in_prod;
+ error = intf->in_error;
+ /* read the indexes first, then deal with the data */
+ virt_mb();
+
+ if (error)
+ return;
+
+ size = pvcalls_queued(prod, cons, array_size);
+ if (size >= array_size)
+ return;
+ spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
+ if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) {
+ atomic_set(&map->read, 0);
+ spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock,
+ flags);
+ return;
+ }
+ spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
+ wanted = array_size - size;
+ masked_prod = pvcalls_mask(prod, array_size);
+ masked_cons = pvcalls_mask(cons, array_size);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_iter.type = ITER_KVEC|WRITE;
+ msg.msg_iter.count = wanted;
+ if (masked_prod < masked_cons) {
+ vec[0].iov_base = data->in + masked_prod;
+ vec[0].iov_len = wanted;
+ msg.msg_iter.kvec = vec;
+ msg.msg_iter.nr_segs = 1;
+ } else {
+ vec[0].iov_base = data->in + masked_prod;
+ vec[0].iov_len = array_size - masked_prod;
+ vec[1].iov_base = data->in;
+ vec[1].iov_len = wanted - vec[0].iov_len;
+ msg.msg_iter.kvec = vec;
+ msg.msg_iter.nr_segs = 2;
+ }
+
+ atomic_set(&map->read, 0);
+ ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT);
+ WARN_ON(ret > wanted);
+ if (ret == -EAGAIN) /* shouldn't happen */
+ return;
+ if (!ret)
+ ret = -ENOTCONN;
+ spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
+ if (ret > 0 && !skb_queue_empty(&map->sock->sk->sk_receive_queue))
+ atomic_inc(&map->read);
+ spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
+
+ /* write the data, then modify the indexes */
+ virt_wmb();
+ if (ret < 0)
+ intf->in_error = ret;
+ else
+ intf->in_prod = prod + ret;
+ /* update the indexes, then notify the other end */
+ virt_wmb();
+ notify_remote_via_irq(map->irq);
+
+ return;
+}
+
+static void pvcalls_conn_back_write(struct sock_mapping *map)
+{
+ struct pvcalls_data_intf *intf = map->ring;
+ struct pvcalls_data *data = &map->data;
+ struct msghdr msg;
+ struct kvec vec[2];
+ RING_IDX cons, prod, size, array_size;
+ int ret;
+
+ cons = intf->out_cons;
+ prod = intf->out_prod;
+ /* read the indexes before dealing with the data */
+ virt_mb();
+
+ array_size = XEN_FLEX_RING_SIZE(map->ring_order);
+ size = pvcalls_queued(prod, cons, array_size);
+ if (size == 0)
+ return;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_flags |= MSG_DONTWAIT;
+ msg.msg_iter.type = ITER_KVEC|READ;
+ msg.msg_iter.count = size;
+ if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) {
+ vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
+ vec[0].iov_len = size;
+ msg.msg_iter.kvec = vec;
+ msg.msg_iter.nr_segs = 1;
+ } else {
+ vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
+ vec[0].iov_len = array_size - pvcalls_mask(cons, array_size);
+ vec[1].iov_base = data->out;
+ vec[1].iov_len = size - vec[0].iov_len;
+ msg.msg_iter.kvec = vec;
+ msg.msg_iter.nr_segs = 2;
+ }
+
+ atomic_set(&map->write, 0);
+ ret = inet_sendmsg(map->sock, &msg, size);
+ if (ret == -EAGAIN || (ret >= 0 && ret < size)) {
+ atomic_inc(&map->write);
+ atomic_inc(&map->io);
+ }
+ if (ret == -EAGAIN)
+ return;
+
+ /* write the data, then update the indexes */
+ virt_wmb();
+ if (ret < 0) {
+ intf->out_error = ret;
+ } else {
+ intf->out_error = 0;
+ intf->out_cons = cons + ret;
+ prod = intf->out_prod;
+ }
+ /* update the indexes, then notify the other end */
+ virt_wmb();
+ if (prod != cons + ret)
+ atomic_inc(&map->write);
+ notify_remote_via_irq(map->irq);
+}
+
+static void pvcalls_back_ioworker(struct work_struct *work)
+{
+ struct pvcalls_ioworker *ioworker = container_of(work,
+ struct pvcalls_ioworker, register_work);
+ struct sock_mapping *map = container_of(ioworker, struct sock_mapping,
+ ioworker);
+
+ while (atomic_read(&map->io) > 0) {
+ if (atomic_read(&map->release) > 0) {
+ atomic_set(&map->release, 0);
+ return;
+ }
+
+ if (atomic_read(&map->read) > 0)
+ pvcalls_conn_back_read(map);
+ if (atomic_read(&map->write) > 0)
+ pvcalls_conn_back_write(map);
+
+ atomic_dec(&map->io);
+ }
+}
+
+static int pvcalls_back_socket(struct xenbus_device *dev,
+ struct xen_pvcalls_request *req)
+{
+ struct pvcalls_fedata *fedata;
+ int ret;
+ struct xen_pvcalls_response *rsp;
+
+ fedata = dev_get_drvdata(&dev->dev);
+
+ if (req->u.socket.domain != AF_INET ||
+ req->u.socket.type != SOCK_STREAM ||
+ (req->u.socket.protocol != IPPROTO_IP &&
+ req->u.socket.protocol != AF_INET))
+ ret = -EAFNOSUPPORT;
+ else
+ ret = 0;
+
+ /* leave the actual socket allocation for later */
+
+ rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
+ rsp->req_id = req->req_id;
+ rsp->cmd = req->cmd;
+ rsp->u.socket.id = req->u.socket.id;
+ rsp->ret = ret;
+
+ 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)
+{
+ struct sock_mapping *map = sock->sk_user_data;
+ struct pvcalls_ioworker *iow;
+
+ if (map == NULL)
+ return;
+
+ iow = &map->ioworker;
+ atomic_inc(&map->read);
+ atomic_inc(&map->io);
+ queue_work(iow->wq, &iow->register_work);
+}
+
+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)
+{
+ disable_irq(map->irq);
+ if (map->sock->sk != NULL) {
+ write_lock_bh(&map->sock->sk->sk_callback_lock);
+ map->sock->sk->sk_user_data = NULL;
+ map->sock->sk->sk_data_ready = map->saved_data_ready;
+ write_unlock_bh(&map->sock->sk->sk_callback_lock);
+ }
+
+ atomic_set(&map->release, 1);
+ flush_work(&map->ioworker.register_work);
+
+ xenbus_unmap_ring_vfree(dev, map->bytes);
+ xenbus_unmap_ring_vfree(dev, (void *)map->ring);
+ unbind_from_irqhandler(map->irq, map);
+
+ sock_release(map->sock);
+ kfree(map);
+
+ return 0;
+}
+
+static int pvcalls_back_release_passive(struct xenbus_device *dev,
+ struct pvcalls_fedata *fedata,
+ struct sockpass_mapping *mappass)
+{
+ if (mappass->sock->sk != NULL) {
+ write_lock_bh(&mappass->sock->sk->sk_callback_lock);
+ mappass->sock->sk->sk_user_data = NULL;
+ mappass->sock->sk->sk_data_ready = mappass->saved_data_ready;
+ write_unlock_bh(&mappass->sock->sk->sk_callback_lock);
+ }
+ sock_release(mappass->sock);
+ flush_workqueue(mappass->wq);
+ destroy_workqueue(mappass->wq);
+ kfree(mappass);
+
+ return 0;
+}
+
+static int pvcalls_back_release(struct xenbus_device *dev,
+ 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);
+ goto out_error;
+ }
+
+ 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 = 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;
+
+ if (dev == NULL)
+ return IRQ_HANDLED;
+
+ fedata = dev_get_drvdata(&dev->dev);
+ if (fedata == NULL)
+ return IRQ_HANDLED;
+
+ pvcalls_back_work(fedata);
+ 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)
+ return IRQ_HANDLED;
+
+ iow = &map->ioworker;
+
+ atomic_inc(&map->write);
+ 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;
+ 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(dev->otherend_id, 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:
+ backend_connect(dev);
+ 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);