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-rw-r--r--drivers/vhost/net.c147
-rw-r--r--drivers/vhost/tcm_vhost.c11
-rw-r--r--drivers/vhost/vhost.c61
-rw-r--r--drivers/vhost/vhost.h14
4 files changed, 156 insertions, 77 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7f93f34b7f9..ebd08b21b23 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -30,9 +30,10 @@
#include "vhost.h"
-static int experimental_zcopytx;
+static int experimental_zcopytx = 1;
module_param(experimental_zcopytx, int, 0444);
-MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
+MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
+ " 1 -Enable; 0 - Disable");
/* Max number of bytes transferred before requeueing the job.
* Using this limit prevents one virtqueue from starving others. */
@@ -42,6 +43,21 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
#define VHOST_MAX_PEND 128
#define VHOST_GOODCOPY_LEN 256
+/*
+ * For transmit, used buffer len is unused; we override it to track buffer
+ * status internally; used for zerocopy tx only.
+ */
+/* Lower device DMA failed */
+#define VHOST_DMA_FAILED_LEN 3
+/* Lower device DMA done */
+#define VHOST_DMA_DONE_LEN 2
+/* Lower device DMA in progress */
+#define VHOST_DMA_IN_PROGRESS 1
+/* Buffer unused */
+#define VHOST_DMA_CLEAR_LEN 0
+
+#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
+
enum {
VHOST_NET_VQ_RX = 0,
VHOST_NET_VQ_TX = 1,
@@ -62,8 +78,39 @@ struct vhost_net {
* We only do this when socket buffer fills up.
* Protected by tx vq lock. */
enum vhost_net_poll_state tx_poll_state;
+ /* Number of TX recently submitted.
+ * Protected by tx vq lock. */
+ unsigned tx_packets;
+ /* Number of times zerocopy TX recently failed.
+ * Protected by tx vq lock. */
+ unsigned tx_zcopy_err;
+ /* Flush in progress. Protected by tx vq lock. */
+ bool tx_flush;
};
+static void vhost_net_tx_packet(struct vhost_net *net)
+{
+ ++net->tx_packets;
+ if (net->tx_packets < 1024)
+ return;
+ net->tx_packets = 0;
+ net->tx_zcopy_err = 0;
+}
+
+static void vhost_net_tx_err(struct vhost_net *net)
+{
+ ++net->tx_zcopy_err;
+}
+
+static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
+{
+ /* TX flush waits for outstanding DMAs to be done.
+ * Don't start new DMAs.
+ */
+ return !net->tx_flush &&
+ net->tx_packets / 64 >= net->tx_zcopy_err;
+}
+
static bool vhost_sock_zcopy(struct socket *sock)
{
return unlikely(experimental_zcopytx) &&
@@ -126,6 +173,55 @@ static void tx_poll_start(struct vhost_net *net, struct socket *sock)
net->tx_poll_state = VHOST_NET_POLL_STARTED;
}
+/* In case of DMA done not in order in lower device driver for some reason.
+ * upend_idx is used to track end of used idx, done_idx is used to track head
+ * of used idx. Once lower device DMA done contiguously, we will signal KVM
+ * guest used idx.
+ */
+static int vhost_zerocopy_signal_used(struct vhost_net *net,
+ struct vhost_virtqueue *vq)
+{
+ int i;
+ int j = 0;
+
+ for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
+ if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
+ vhost_net_tx_err(net);
+ if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
+ vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
+ vhost_add_used_and_signal(vq->dev, vq,
+ vq->heads[i].id, 0);
+ ++j;
+ } else
+ break;
+ }
+ if (j)
+ vq->done_idx = i;
+ return j;
+}
+
+static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
+{
+ struct vhost_ubuf_ref *ubufs = ubuf->ctx;
+ struct vhost_virtqueue *vq = ubufs->vq;
+ int cnt = atomic_read(&ubufs->kref.refcount);
+
+ /*
+ * Trigger polling thread if guest stopped submitting new buffers:
+ * in this case, the refcount after decrement will eventually reach 1
+ * so here it is 2.
+ * We also trigger polling periodically after each 16 packets
+ * (the value 16 here is more or less arbitrary, it's tuned to trigger
+ * less than 10% of times).
+ */
+ if (cnt <= 2 || !(cnt % 16))
+ vhost_poll_queue(&vq->poll);
+ /* set len to mark this desc buffers done DMA */
+ vq->heads[ubuf->desc].len = success ?
+ VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
+ vhost_ubuf_put(ubufs);
+}
+
/* 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)
@@ -146,7 +242,7 @@ static void handle_tx(struct vhost_net *net)
size_t hdr_size;
struct socket *sock;
struct vhost_ubuf_ref *uninitialized_var(ubufs);
- bool zcopy;
+ bool zcopy, zcopy_used;
/* TODO: check that we are running from vhost_worker? */
sock = rcu_dereference_check(vq->private_data, 1);
@@ -172,7 +268,7 @@ static void handle_tx(struct vhost_net *net)
for (;;) {
/* Release DMAs done buffers first */
if (zcopy)
- vhost_zerocopy_signal_used(vq);
+ vhost_zerocopy_signal_used(net, vq);
head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
ARRAY_SIZE(vq->iov),
@@ -224,10 +320,14 @@ static void handle_tx(struct vhost_net *net)
iov_length(vq->hdr, s), hdr_size);
break;
}
+ zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
+ vq->upend_idx != vq->done_idx);
+
/* use msg_control to pass vhost zerocopy ubuf info to skb */
- if (zcopy) {
+ if (zcopy_used) {
vq->heads[vq->upend_idx].id = head;
- if (len < VHOST_GOODCOPY_LEN) {
+ if (!vhost_net_tx_select_zcopy(net) ||
+ len < VHOST_GOODCOPY_LEN) {
/* copy don't need to wait for DMA done */
vq->heads[vq->upend_idx].len =
VHOST_DMA_DONE_LEN;
@@ -237,7 +337,8 @@ static void handle_tx(struct vhost_net *net)
} else {
struct ubuf_info *ubuf = &vq->ubuf_info[head];
- vq->heads[vq->upend_idx].len = len;
+ vq->heads[vq->upend_idx].len =
+ VHOST_DMA_IN_PROGRESS;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = vq->ubufs;
ubuf->desc = vq->upend_idx;
@@ -251,7 +352,7 @@ static void handle_tx(struct vhost_net *net)
/* TODO: Check specific error and bomb out unless ENOBUFS? */
err = sock->ops->sendmsg(NULL, sock, &msg, len);
if (unlikely(err < 0)) {
- if (zcopy) {
+ if (zcopy_used) {
if (ubufs)
vhost_ubuf_put(ubufs);
vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
@@ -265,11 +366,12 @@ static void handle_tx(struct vhost_net *net)
if (err != len)
pr_debug("Truncated TX packet: "
" len %d != %zd\n", err, len);
- if (!zcopy)
+ if (!zcopy_used)
vhost_add_used_and_signal(&net->dev, vq, head, 0);
else
- vhost_zerocopy_signal_used(vq);
+ vhost_zerocopy_signal_used(net, vq);
total_len += len;
+ vhost_net_tx_packet(net);
if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
vhost_poll_queue(&vq->poll);
break;
@@ -587,6 +689,17 @@ static void vhost_net_flush(struct vhost_net *n)
{
vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
+ if (n->dev.vqs[VHOST_NET_VQ_TX].ubufs) {
+ mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ n->tx_flush = true;
+ mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ /* Wait for all lower device DMAs done. */
+ vhost_ubuf_put_and_wait(n->dev.vqs[VHOST_NET_VQ_TX].ubufs);
+ mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ n->tx_flush = false;
+ kref_init(&n->dev.vqs[VHOST_NET_VQ_TX].ubufs->kref);
+ mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ }
}
static int vhost_net_release(struct inode *inode, struct file *f)
@@ -597,6 +710,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
+ vhost_dev_stop(&n->dev);
vhost_dev_cleanup(&n->dev, false);
if (tx_sock)
fput(tx_sock->file);
@@ -722,6 +836,10 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
r = vhost_init_used(vq);
if (r)
goto err_vq;
+
+ n->tx_packets = 0;
+ n->tx_zcopy_err = 0;
+ n->tx_flush = false;
}
mutex_unlock(&vq->mutex);
@@ -729,7 +847,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
if (oldubufs) {
vhost_ubuf_put_and_wait(oldubufs);
mutex_lock(&vq->mutex);
- vhost_zerocopy_signal_used(vq);
+ vhost_zerocopy_signal_used(n, vq);
mutex_unlock(&vq->mutex);
}
@@ -838,8 +956,11 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
return vhost_net_reset_owner(n);
default:
mutex_lock(&n->dev.mutex);
- r = vhost_dev_ioctl(&n->dev, ioctl, arg);
- vhost_net_flush(n);
+ r = vhost_dev_ioctl(&n->dev, ioctl, argp);
+ if (r == -ENOIOCTLCMD)
+ r = vhost_vring_ioctl(&n->dev, ioctl, argp);
+ else
+ vhost_net_flush(n);
mutex_unlock(&n->dev.mutex);
return r;
}
diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index 6a69bf55aea..b20df5c829f 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -34,7 +34,6 @@
#include <linux/ctype.h>
#include <linux/compat.h>
#include <linux/eventfd.h>
-#include <linux/vhost.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <asm/unaligned.h>
@@ -231,7 +230,7 @@ static struct se_node_acl *tcm_vhost_alloc_fabric_acl(
nacl = kzalloc(sizeof(struct tcm_vhost_nacl), GFP_KERNEL);
if (!nacl) {
- pr_err("Unable to alocate struct tcm_vhost_nacl\n");
+ pr_err("Unable to allocate struct tcm_vhost_nacl\n");
return NULL;
}
@@ -415,14 +414,12 @@ static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd(
{
struct tcm_vhost_cmd *tv_cmd;
struct tcm_vhost_nexus *tv_nexus;
- struct se_session *se_sess;
tv_nexus = tv_tpg->tpg_nexus;
if (!tv_nexus) {
pr_err("Unable to locate active struct tcm_vhost_nexus\n");
return ERR_PTR(-EIO);
}
- se_sess = tv_nexus->tvn_se_sess;
tv_cmd = kzalloc(sizeof(struct tcm_vhost_cmd), GFP_ATOMIC);
if (!tv_cmd) {
@@ -891,6 +888,7 @@ static int vhost_scsi_release(struct inode *inode, struct file *f)
vhost_scsi_clear_endpoint(s, &backend);
}
+ vhost_dev_stop(&s->dev);
vhost_dev_cleanup(&s->dev, false);
kfree(s);
return 0;
@@ -966,7 +964,10 @@ static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
return vhost_scsi_set_features(vs, features);
default:
mutex_lock(&vs->dev.mutex);
- r = vhost_dev_ioctl(&vs->dev, ioctl, arg);
+ r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
+ /* TODO: flush backend after dev ioctl. */
+ if (r == -ENOIOCTLCMD)
+ r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
mutex_unlock(&vs->dev.mutex);
return r;
}
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 99ac2cb08b4..34389f75fe6 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -26,10 +26,6 @@
#include <linux/kthread.h>
#include <linux/cgroup.h>
-#include <linux/net.h>
-#include <linux/if_packet.h>
-#include <linux/if_arp.h>
-
#include "vhost.h"
enum {
@@ -414,28 +410,16 @@ long vhost_dev_reset_owner(struct vhost_dev *dev)
return 0;
}
-/* In case of DMA done not in order in lower device driver for some reason.
- * upend_idx is used to track end of used idx, done_idx is used to track head
- * of used idx. Once lower device DMA done contiguously, we will signal KVM
- * guest used idx.
- */
-int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq)
+void vhost_dev_stop(struct vhost_dev *dev)
{
int i;
- int j = 0;
-
- for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
- if ((vq->heads[i].len == VHOST_DMA_DONE_LEN)) {
- vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
- vhost_add_used_and_signal(vq->dev, vq,
- vq->heads[i].id, 0);
- ++j;
- } else
- break;
+
+ for (i = 0; i < dev->nvqs; ++i) {
+ if (dev->vqs[i].kick && dev->vqs[i].handle_kick) {
+ vhost_poll_stop(&dev->vqs[i].poll);
+ vhost_poll_flush(&dev->vqs[i].poll);
+ }
}
- if (j)
- vq->done_idx = i;
- return j;
}
/* Caller should have device mutex if and only if locked is set */
@@ -444,17 +428,6 @@ void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
int i;
for (i = 0; i < dev->nvqs; ++i) {
- if (dev->vqs[i].kick && dev->vqs[i].handle_kick) {
- vhost_poll_stop(&dev->vqs[i].poll);
- vhost_poll_flush(&dev->vqs[i].poll);
- }
- /* Wait for all lower device DMAs done. */
- if (dev->vqs[i].ubufs)
- vhost_ubuf_put_and_wait(dev->vqs[i].ubufs);
-
- /* Signal guest as appropriate. */
- vhost_zerocopy_signal_used(&dev->vqs[i]);
-
if (dev->vqs[i].error_ctx)
eventfd_ctx_put(dev->vqs[i].error_ctx);
if (dev->vqs[i].error)
@@ -634,7 +607,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
return 0;
}
-static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
+long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
{
struct file *eventfp, *filep = NULL;
bool pollstart = false, pollstop = false;
@@ -829,9 +802,8 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
}
/* Caller must have device mutex */
-long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg)
+long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
{
- void __user *argp = (void __user *)arg;
struct file *eventfp, *filep = NULL;
struct eventfd_ctx *ctx = NULL;
u64 p;
@@ -902,7 +874,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg)
fput(filep);
break;
default:
- r = vhost_set_vring(d, ioctl, argp);
+ r = -ENOIOCTLCMD;
break;
}
done:
@@ -1076,7 +1048,7 @@ static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len,
}
_iov = iov + ret;
size = reg->memory_size - addr + reg->guest_phys_addr;
- _iov->iov_len = min((u64)len, size);
+ _iov->iov_len = min((u64)len - s, size);
_iov->iov_base = (void __user *)(unsigned long)
(reg->userspace_addr + addr - reg->guest_phys_addr);
s += size;
@@ -1599,14 +1571,3 @@ void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs)
wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
kfree(ubufs);
}
-
-void vhost_zerocopy_callback(struct ubuf_info *ubuf)
-{
- struct vhost_ubuf_ref *ubufs = ubuf->ctx;
- struct vhost_virtqueue *vq = ubufs->vq;
-
- vhost_poll_queue(&vq->poll);
- /* set len = 1 to mark this desc buffers done DMA */
- vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN;
- kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
-}
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 1125af3d27d..2639c58b23a 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -7,17 +7,11 @@
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/file.h>
-#include <linux/skbuff.h>
#include <linux/uio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/atomic.h>
-/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
- * done */
-#define VHOST_DMA_DONE_LEN 1
-#define VHOST_DMA_CLEAR_LEN 0
-
struct vhost_device;
struct vhost_work;
@@ -70,6 +64,8 @@ struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy);
void vhost_ubuf_put(struct vhost_ubuf_ref *);
void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);
+struct ubuf_info;
+
/* The virtqueue structure describes a queue attached to a device. */
struct vhost_virtqueue {
struct vhost_dev *dev;
@@ -167,7 +163,9 @@ long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
long vhost_dev_check_owner(struct vhost_dev *);
long vhost_dev_reset_owner(struct vhost_dev *);
void vhost_dev_cleanup(struct vhost_dev *, bool locked);
-long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
+void vhost_dev_stop(struct vhost_dev *);
+long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
+long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
int vhost_vq_access_ok(struct vhost_virtqueue *vq);
int vhost_log_access_ok(struct vhost_dev *);
@@ -191,8 +189,6 @@ bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
unsigned int log_num, u64 len);
-void vhost_zerocopy_callback(struct ubuf_info *);
-int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq);
#define vq_err(vq, fmt, ...) do { \
pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-22 07:32:42 +0000