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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
commitd635711daa98be86d4c7fd01499c34f566b54ccb (patch)
treeaa5cc3760a27c3d57146498cb82fa549547de06c /drivers/vhost
parentc91265cd0efb83778f015b4d4b1129bd2cfd075e (diff)
Linux-libre 4.6.2-gnu
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/net.c80
-rw-r--r--drivers/vhost/scsi.c101
-rw-r--r--drivers/vhost/test.c2
-rw-r--r--drivers/vhost/vhost.c69
-rw-r--r--drivers/vhost/vhost.h5
5 files changed, 182 insertions, 75 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 9eda69e40..f744eeb3e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -287,6 +287,43 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
rcu_read_unlock_bh();
}
+static inline unsigned long busy_clock(void)
+{
+ return local_clock() >> 10;
+}
+
+static bool vhost_can_busy_poll(struct vhost_dev *dev,
+ unsigned long endtime)
+{
+ return likely(!need_resched()) &&
+ likely(!time_after(busy_clock(), endtime)) &&
+ likely(!signal_pending(current)) &&
+ !vhost_has_work(dev);
+}
+
+static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
+ struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num)
+{
+ unsigned long uninitialized_var(endtime);
+ int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+ out_num, in_num, NULL, NULL);
+
+ if (r == vq->num && vq->busyloop_timeout) {
+ preempt_disable();
+ endtime = busy_clock() + vq->busyloop_timeout;
+ while (vhost_can_busy_poll(vq->dev, endtime) &&
+ vhost_vq_avail_empty(vq->dev, vq))
+ cpu_relax_lowlatency();
+ preempt_enable();
+ r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+ out_num, in_num, NULL, NULL);
+ }
+
+ return r;
+}
+
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
static void handle_tx(struct vhost_net *net)
@@ -331,10 +368,9 @@ static void handle_tx(struct vhost_net *net)
% UIO_MAXIOV == nvq->done_idx))
break;
- head = vhost_get_vq_desc(vq, vq->iov,
- ARRAY_SIZE(vq->iov),
- &out, &in,
- NULL, NULL);
+ head = vhost_net_tx_get_vq_desc(net, vq, vq->iov,
+ ARRAY_SIZE(vq->iov),
+ &out, &in);
/* On error, stop handling until the next kick. */
if (unlikely(head < 0))
break;
@@ -435,6 +471,38 @@ static int peek_head_len(struct sock *sk)
return len;
}
+static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk)
+{
+ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
+ struct vhost_virtqueue *vq = &nvq->vq;
+ unsigned long uninitialized_var(endtime);
+ int len = peek_head_len(sk);
+
+ if (!len && vq->busyloop_timeout) {
+ /* Both tx vq and rx socket were polled here */
+ mutex_lock(&vq->mutex);
+ vhost_disable_notify(&net->dev, vq);
+
+ preempt_disable();
+ endtime = busy_clock() + vq->busyloop_timeout;
+
+ while (vhost_can_busy_poll(&net->dev, endtime) &&
+ skb_queue_empty(&sk->sk_receive_queue) &&
+ vhost_vq_avail_empty(&net->dev, vq))
+ cpu_relax_lowlatency();
+
+ preempt_enable();
+
+ if (vhost_enable_notify(&net->dev, vq))
+ vhost_poll_queue(&vq->poll);
+ mutex_unlock(&vq->mutex);
+
+ len = peek_head_len(sk);
+ }
+
+ return len;
+}
+
/* This is a multi-buffer version of vhost_get_desc, that works if
* vq has read descriptors only.
* @vq - the relevant virtqueue
@@ -553,7 +621,7 @@ static void handle_rx(struct vhost_net *net)
vq->log : NULL;
mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
- while ((sock_len = peek_head_len(sock->sk))) {
+ while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
sock_len += sock_hlen;
vhost_len = sock_len + vhost_hlen;
headcount = get_rx_bufs(vq, vq->heads, vhost_len,
@@ -917,7 +985,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
vhost_net_disable_vq(n, vq);
vq->private_data = sock;
- r = vhost_init_used(vq);
+ r = vhost_vq_init_access(vq);
if (r)
goto err_used;
r = vhost_net_enable_vq(n, vq);
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 29cfc57d4..0e6fd556c 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1274,7 +1274,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs,
vq = &vs->vqs[i].vq;
mutex_lock(&vq->mutex);
vq->private_data = vs_tpg;
- vhost_init_used(vq);
+ vhost_vq_init_access(vq);
mutex_unlock(&vq->mutex);
}
ret = 0;
@@ -1664,8 +1664,7 @@ static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
mutex_unlock(&vhost_scsi_mutex);
}
-static void vhost_scsi_free_cmd_map_res(struct vhost_scsi_nexus *nexus,
- struct se_session *se_sess)
+static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
{
struct vhost_scsi_cmd *tv_cmd;
unsigned int i;
@@ -1721,98 +1720,82 @@ static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
NULL,
};
-static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
- const char *name)
+static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
+ struct se_session *se_sess, void *p)
{
- struct se_portal_group *se_tpg;
- struct se_session *se_sess;
- struct vhost_scsi_nexus *tv_nexus;
struct vhost_scsi_cmd *tv_cmd;
unsigned int i;
- mutex_lock(&tpg->tv_tpg_mutex);
- if (tpg->tpg_nexus) {
- mutex_unlock(&tpg->tv_tpg_mutex);
- pr_debug("tpg->tpg_nexus already exists\n");
- return -EEXIST;
- }
- se_tpg = &tpg->se_tpg;
-
- tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
- if (!tv_nexus) {
- mutex_unlock(&tpg->tv_tpg_mutex);
- pr_err("Unable to allocate struct vhost_scsi_nexus\n");
- return -ENOMEM;
- }
- /*
- * Initialize the struct se_session pointer and setup tagpool
- * for struct vhost_scsi_cmd descriptors
- */
- tv_nexus->tvn_se_sess = transport_init_session_tags(
- VHOST_SCSI_DEFAULT_TAGS,
- sizeof(struct vhost_scsi_cmd),
- TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
- if (IS_ERR(tv_nexus->tvn_se_sess)) {
- mutex_unlock(&tpg->tv_tpg_mutex);
- kfree(tv_nexus);
- return -ENOMEM;
- }
- se_sess = tv_nexus->tvn_se_sess;
for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
VHOST_SCSI_PREALLOC_SGLS, GFP_KERNEL);
if (!tv_cmd->tvc_sgl) {
- mutex_unlock(&tpg->tv_tpg_mutex);
pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
goto out;
}
tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
- VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
+ VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
if (!tv_cmd->tvc_upages) {
- mutex_unlock(&tpg->tv_tpg_mutex);
pr_err("Unable to allocate tv_cmd->tvc_upages\n");
goto out;
}
tv_cmd->tvc_prot_sgl = kzalloc(sizeof(struct scatterlist) *
- VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
+ VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
if (!tv_cmd->tvc_prot_sgl) {
- mutex_unlock(&tpg->tv_tpg_mutex);
pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
goto out;
}
}
+ return 0;
+out:
+ vhost_scsi_free_cmd_map_res(se_sess);
+ return -ENOMEM;
+}
+
+static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
+ const char *name)
+{
+ struct se_portal_group *se_tpg;
+ struct vhost_scsi_nexus *tv_nexus;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ if (tpg->tpg_nexus) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_debug("tpg->tpg_nexus already exists\n");
+ return -EEXIST;
+ }
+ se_tpg = &tpg->se_tpg;
+
+ tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
+ if (!tv_nexus) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_err("Unable to allocate struct vhost_scsi_nexus\n");
+ return -ENOMEM;
+ }
/*
* Since we are running in 'demo mode' this call with generate a
* struct se_node_acl for the vhost_scsi struct se_portal_group with
* the SCSI Initiator port name of the passed configfs group 'name'.
*/
- tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
- se_tpg, (unsigned char *)name);
- if (!tv_nexus->tvn_se_sess->se_node_acl) {
+ tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,
+ VHOST_SCSI_DEFAULT_TAGS,
+ sizeof(struct vhost_scsi_cmd),
+ TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
+ (unsigned char *)name, tv_nexus,
+ vhost_scsi_nexus_cb);
+ if (IS_ERR(tv_nexus->tvn_se_sess)) {
mutex_unlock(&tpg->tv_tpg_mutex);
- pr_debug("core_tpg_check_initiator_node_acl() failed"
- " for %s\n", name);
- goto out;
+ kfree(tv_nexus);
+ return -ENOMEM;
}
- /*
- * Now register the TCM vhost virtual I_T Nexus as active.
- */
- transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
- tv_nexus->tvn_se_sess, tv_nexus);
tpg->tpg_nexus = tv_nexus;
mutex_unlock(&tpg->tv_tpg_mutex);
return 0;
-
-out:
- vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
- transport_free_session(se_sess);
- kfree(tv_nexus);
- return -ENOMEM;
}
static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
@@ -1853,7 +1836,7 @@ static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
" %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
- vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
+ vhost_scsi_free_cmd_map_res(se_sess);
/*
* Release the SCSI I_T Nexus to the emulated vhost Target Port
*/
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index f2882ac98..388eec4e1 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -196,7 +196,7 @@ static long vhost_test_run(struct vhost_test *n, int test)
oldpriv = vq->private_data;
vq->private_data = priv;
- r = vhost_init_used(&n->vqs[index]);
+ r = vhost_vq_init_access(&n->vqs[index]);
mutex_unlock(&vq->mutex);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 236553e81..669fef1e2 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -43,11 +43,21 @@ enum {
#define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num])
#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
-static void vhost_vq_reset_user_be(struct vhost_virtqueue *vq)
+static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
{
vq->user_be = !virtio_legacy_is_little_endian();
}
+static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq)
+{
+ vq->user_be = true;
+}
+
+static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq)
+{
+ vq->user_be = false;
+}
+
static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)
{
struct vhost_vring_state s;
@@ -62,7 +72,10 @@ static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)
s.num != VHOST_VRING_BIG_ENDIAN)
return -EINVAL;
- vq->user_be = s.num;
+ if (s.num == VHOST_VRING_BIG_ENDIAN)
+ vhost_enable_cross_endian_big(vq);
+ else
+ vhost_enable_cross_endian_little(vq);
return 0;
}
@@ -91,7 +104,7 @@ static void vhost_init_is_le(struct vhost_virtqueue *vq)
vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be;
}
#else
-static void vhost_vq_reset_user_be(struct vhost_virtqueue *vq)
+static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
{
}
@@ -113,6 +126,11 @@ static void vhost_init_is_le(struct vhost_virtqueue *vq)
}
#endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */
+static void vhost_reset_is_le(struct vhost_virtqueue *vq)
+{
+ vq->is_le = virtio_legacy_is_little_endian();
+}
+
static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
poll_table *pt)
{
@@ -245,6 +263,13 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
}
EXPORT_SYMBOL_GPL(vhost_work_queue);
+/* A lockless hint for busy polling code to exit the loop */
+bool vhost_has_work(struct vhost_dev *dev)
+{
+ return !list_empty(&dev->work_list);
+}
+EXPORT_SYMBOL_GPL(vhost_has_work);
+
void vhost_poll_queue(struct vhost_poll *poll)
{
vhost_work_queue(poll->dev, &poll->work);
@@ -276,8 +301,9 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->call = NULL;
vq->log_ctx = NULL;
vq->memory = NULL;
- vq->is_le = virtio_legacy_is_little_endian();
- vhost_vq_reset_user_be(vq);
+ vhost_reset_is_le(vq);
+ vhost_disable_cross_endian(vq);
+ vq->busyloop_timeout = 0;
}
static int vhost_worker(void *data)
@@ -912,6 +938,19 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
case VHOST_GET_VRING_ENDIAN:
r = vhost_get_vring_endian(vq, idx, argp);
break;
+ case VHOST_SET_VRING_BUSYLOOP_TIMEOUT:
+ if (copy_from_user(&s, argp, sizeof(s))) {
+ r = -EFAULT;
+ break;
+ }
+ vq->busyloop_timeout = s.num;
+ break;
+ case VHOST_GET_VRING_BUSYLOOP_TIMEOUT:
+ s.index = idx;
+ s.num = vq->busyloop_timeout;
+ if (copy_to_user(argp, &s, sizeof(s)))
+ r = -EFAULT;
+ break;
default:
r = -ENOIOCTLCMD;
}
@@ -1152,14 +1191,14 @@ static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)
return 0;
}
-int vhost_init_used(struct vhost_virtqueue *vq)
+int vhost_vq_init_access(struct vhost_virtqueue *vq)
{
__virtio16 last_used_idx;
int r;
bool is_le = vq->is_le;
if (!vq->private_data) {
- vq->is_le = virtio_legacy_is_little_endian();
+ vhost_reset_is_le(vq);
return 0;
}
@@ -1182,7 +1221,7 @@ err:
vq->is_le = is_le;
return r;
}
-EXPORT_SYMBOL_GPL(vhost_init_used);
+EXPORT_SYMBOL_GPL(vhost_vq_init_access);
static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
struct iovec iov[], int iov_size)
@@ -1633,6 +1672,20 @@ void vhost_add_used_and_signal_n(struct vhost_dev *dev,
}
EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n);
+/* return true if we're sure that avaiable ring is empty */
+bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+{
+ __virtio16 avail_idx;
+ int r;
+
+ r = __get_user(avail_idx, &vq->avail->idx);
+ if (r)
+ return false;
+
+ return vhost16_to_cpu(vq, avail_idx) == vq->avail_idx;
+}
+EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
+
/* OK, now we need to know about added descriptors. */
bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
{
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index d3f767448..d36d8beb3 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -37,6 +37,7 @@ struct vhost_poll {
void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
+bool vhost_has_work(struct vhost_dev *dev);
void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
unsigned long mask, struct vhost_dev *dev);
@@ -114,6 +115,7 @@ struct vhost_virtqueue {
/* Ring endianness requested by userspace for cross-endian support. */
bool user_be;
#endif
+ u32 busyloop_timeout;
};
struct vhost_dev {
@@ -148,7 +150,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *,
struct vhost_log *log, unsigned int *log_num);
void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
-int vhost_init_used(struct vhost_virtqueue *);
+int vhost_vq_init_access(struct vhost_virtqueue *);
int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
unsigned count);
@@ -158,6 +160,7 @@ void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
struct vring_used_elem *heads, unsigned count);
void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
+bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,