Hi all: This series implements packed virtqueues. The code were tested with Tiwei's RFC V6 at https://lkml.org/lkml/2018/6/5/120. Pktgen test for both RX and TX does not show obvious difference with split virtqueues. The main bottleneck is the guest Linux driver, since it can not stress vhost for a 100% CPU utilization. A full TCP benchmark is ongoing. Will test virtio-net pmd as well when it was ready. This version were tested with: - Zerocopy (Out of Order) support - vIOMMU support - mergeable buffer on/off - busy polling on/off Changes from RFC V5: - save unnecessary barriers during vhost_add_used_packed_n() - more compact math for event idx - fix failure of SET_VRING_BASE when avail_wrap_counter is true - fix not copy avail_wrap_counter during GET_VRING_BASE - introduce SET_VRING_USED_BASE/GET_VRING_USED_BASE for syncing last_used_idx - rename used_wrap_counter to last_used_wrap_counter - rebase to net-next Changes from RFC V4: - fix signalled_used index recording - track avail index correctly - various minor fixes Changes from RFC V3: - Fix math on event idx checking - Sync last avail wrap counter through GET/SET_VRING_BASE - remove desc_event prefix in the driver/device structure Changes from RFC V2: - do not use & in checking desc_event_flags - off should be most significant bit - remove the workaround of mergeable buffer for dpdk prototype - id should be in the last descriptor in the chain - keep _F_WRITE for write descriptor when adding used - device flags updating should use ADDR_USED type - return error on unexpected unavail descriptor in a chain - return false in vhost_ve_avail_empty is descriptor is available - track last seen avail_wrap_counter - correctly examine available descriptor in get_indirect_packed() - vhost_idx_diff should return u16 instead of bool Changes from RFC V1: - Refactor vhost used elem code to avoid open coding on used elem - Event suppression support (compile test only). - Indirect descriptor support (compile test only). - Zerocopy support. - vIOMMU support. - SCSI/VSOCK support (compile test only). - Fix several bugs Jason Wang (8): vhost: move get_rx_bufs to vhost.c vhost: hide used ring layout from device vhost: do not use vring_used_elem vhost_net: do not explicitly manipulate vhost_used_elem vhost: vhost_put_user() can accept metadata type virtio: introduce packed ring defines vhost: packed ring support vhost: event suppression for packed ring drivers/vhost/net.c | 144 ++---- drivers/vhost/scsi.c | 62 +-- drivers/vhost/vhost.c | 996 +++++++++++++++++++++++++++++++++---- drivers/vhost/vhost.h | 52 +- drivers/vhost/vsock.c | 42 +- include/uapi/linux/vhost.h | 7 + include/uapi/linux/virtio_config.h | 2 + include/uapi/linux/virtio_ring.h | 32 ++ 8 files changed, 1070 insertions(+), 267 deletions(-) -- 2.7.4
Move get_rx_bufs() to vhost.c and rename it to
vhost_get_bufs(). This helps to hide vring internal layout from
specific device implementation. Packed ring implementation will
benefit from this.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 77 --------------------------------------------------
drivers/vhost/vhost.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/vhost/vhost.h | 7 +++++
3 files changed, 85 insertions(+), 77 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 29756d8..712b134 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -685,83 +685,6 @@ static int vhost_net_rx_peek_head_len(struct vhost_net
*net, struct sock *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
- * @datalen - data length we'll be reading
- * @iovcount - returned count of io vectors we fill
- * @log - vhost log
- * @log_num - log offset
- * @quota - headcount quota, 1 for big buffer
- * returns number of buffer heads allocated, negative on error
- */
-static int get_rx_bufs(struct vhost_virtqueue *vq,
- struct vring_used_elem *heads,
- int datalen,
- unsigned *iovcount,
- struct vhost_log *log,
- unsigned *log_num,
- unsigned int quota)
-{
- unsigned int out, in;
- int seg = 0;
- int headcount = 0;
- unsigned d;
- int r, nlogs = 0;
- /* len is always initialized before use since we are always called with
- * datalen > 0.
- */
- u32 uninitialized_var(len);
-
- while (datalen > 0 && headcount < quota) {
- if (unlikely(seg >= UIO_MAXIOV)) {
- r = -ENOBUFS;
- goto err;
- }
- r = vhost_get_vq_desc(vq, vq->iov + seg,
- ARRAY_SIZE(vq->iov) - seg, &out,
- &in, log, log_num);
- if (unlikely(r < 0))
- goto err;
-
- d = r;
- if (d == vq->num) {
- r = 0;
- goto err;
- }
- if (unlikely(out || in <= 0)) {
- vq_err(vq, "unexpected descriptor format for RX: "
- "out %d, in %d\n", out, in);
- r = -EINVAL;
- goto err;
- }
- if (unlikely(log)) {
- nlogs += *log_num;
- log += *log_num;
- }
- heads[headcount].id = cpu_to_vhost32(vq, d);
- len = iov_length(vq->iov + seg, in);
- heads[headcount].len = cpu_to_vhost32(vq, len);
- datalen -= len;
- ++headcount;
- seg += in;
- }
- heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
- *iovcount = seg;
- if (unlikely(log))
- *log_num = nlogs;
-
- /* Detect overrun */
- if (unlikely(datalen > 0)) {
- r = UIO_MAXIOV + 1;
- goto err;
- }
- return headcount;
-err:
- vhost_discard_vq_desc(vq, headcount);
- return r;
-}
-
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
static void handle_rx(struct vhost_net *net)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a502f1a..8814e5b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2104,6 +2104,84 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
}
EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
+/* This is a multi-buffer version of vhost_get_desc, that works if
+ * vq has read descriptors only.
+ * @vq - the relevant virtqueue
+ * @datalen - data length we'll be reading
+ * @iovcount - returned count of io vectors we fill
+ * @log - vhost log
+ * @log_num - log offset
+ * @quota - headcount quota, 1 for big buffer
+ * returns number of buffer heads allocated, negative on error
+ */
+int vhost_get_bufs(struct vhost_virtqueue *vq,
+ struct vring_used_elem *heads,
+ int datalen,
+ unsigned *iovcount,
+ struct vhost_log *log,
+ unsigned *log_num,
+ unsigned int quota)
+{
+ unsigned int out, in;
+ int seg = 0;
+ int headcount = 0;
+ unsigned d;
+ int r, nlogs = 0;
+ /* len is always initialized before use since we are always called with
+ * datalen > 0.
+ */
+ u32 uninitialized_var(len);
+
+ while (datalen > 0 && headcount < quota) {
+ if (unlikely(seg >= UIO_MAXIOV)) {
+ r = -ENOBUFS;
+ goto err;
+ }
+ r = vhost_get_vq_desc(vq, vq->iov + seg,
+ ARRAY_SIZE(vq->iov) - seg, &out,
+ &in, log, log_num);
+ if (unlikely(r < 0))
+ goto err;
+
+ d = r;
+ if (d == vq->num) {
+ r = 0;
+ goto err;
+ }
+ if (unlikely(out || in <= 0)) {
+ vq_err(vq, "unexpected descriptor format for RX: "
+ "out %d, in %d\n", out, in);
+ r = -EINVAL;
+ goto err;
+ }
+ if (unlikely(log)) {
+ nlogs += *log_num;
+ log += *log_num;
+ }
+ heads[headcount].id = cpu_to_vhost32(vq, d);
+ len = iov_length(vq->iov + seg, in);
+ heads[headcount].len = cpu_to_vhost32(vq, len);
+ datalen -= len;
+ ++headcount;
+ seg += in;
+ }
+ heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
+ *iovcount = seg;
+ if (unlikely(log))
+ *log_num = nlogs;
+
+ /* Detect overrun */
+ if (unlikely(datalen > 0)) {
+ r = UIO_MAXIOV + 1;
+ goto err;
+ }
+ return headcount;
+err:
+ vhost_discard_vq_desc(vq, headcount);
+ return r;
+}
+EXPORT_SYMBOL_GPL(vhost_get_bufs);
+
/* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
{
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 6c844b9..52edd242 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -185,6 +185,13 @@ int vhost_get_vq_desc(struct vhost_virtqueue *,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num);
+int vhost_get_bufs(struct vhost_virtqueue *vq,
+ struct vring_used_elem *heads,
+ int datalen,
+ unsigned *iovcount,
+ struct vhost_log *log,
+ unsigned *log_num,
+ unsigned int quota);
void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
int vhost_vq_init_access(struct vhost_virtqueue *);
--
2.7.4
Jason Wang
2018-Jul-03 05:37 UTC
[PATCH net-next 2/8] vhost: hide used ring layout from device
We used to return descriptor head by vhost_get_vq_desc() to device and
pass it back to vhost_add_used() and its friends. This exposes the
internal used ring layout to device which makes it hard to be extended for
e.g packed ring layout.
So this patch tries to hide the used ring layout by
- letting vhost_get_vq_desc() return pointer to struct vring_used_elem
- accepting pointer to struct vring_used_elem in vhost_add_used() and
vhost_add_used_and_signal()
This could help to hide used ring layout and make it easier to
implement packed ring on top.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 46 +++++++++++++++++++++-----------------
drivers/vhost/scsi.c | 62 +++++++++++++++++++++++++++------------------------
drivers/vhost/vhost.c | 52 +++++++++++++++++++++---------------------
drivers/vhost/vhost.h | 9 +++++---
drivers/vhost/vsock.c | 42 +++++++++++++++++-----------------
5 files changed, 112 insertions(+), 99 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 712b134..449f793 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -433,22 +433,24 @@ static int vhost_net_enable_vq(struct vhost_net *n,
static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
struct vhost_virtqueue *vq,
+ struct vring_used_elem *used_elem,
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),
+ int r = vhost_get_vq_desc(vq, used_elem, vq->iov, ARRAY_SIZE(vq->iov),
out_num, in_num, NULL, NULL);
- if (r == vq->num && vq->busyloop_timeout) {
+ if (r == -ENOSPC && 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();
preempt_enable();
- r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
- out_num, in_num, NULL, NULL);
+ r = vhost_get_vq_desc(vq, used_elem, vq->iov,
+ ARRAY_SIZE(vq->iov), out_num, in_num,
+ NULL, NULL);
}
return r;
@@ -470,7 +472,6 @@ static void handle_tx(struct vhost_net *net)
struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
struct vhost_virtqueue *vq = &nvq->vq;
unsigned out, in;
- int head;
struct msghdr msg = {
.msg_name = NULL,
.msg_namelen = 0,
@@ -483,6 +484,7 @@ static void handle_tx(struct vhost_net *net)
size_t hdr_size;
struct socket *sock;
struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
+ struct vring_used_elem used;
bool zcopy, zcopy_used;
int sent_pkts = 0;
@@ -506,20 +508,20 @@ static void handle_tx(struct vhost_net *net)
vhost_zerocopy_signal_used(net, vq);
- 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;
+ err = vhost_net_tx_get_vq_desc(net, vq, &used, vq->iov,
+ ARRAY_SIZE(vq->iov),
+ &out, &in);
/* Nothing new? Wait for eventfd to tell us they refilled. */
- if (head == vq->num) {
+ if (err == -ENOSPC) {
if (unlikely(vhost_enable_notify(&net->dev, vq))) {
vhost_disable_notify(&net->dev, vq);
continue;
}
break;
}
+ /* On error, stop handling until the next kick. */
+ if (unlikely(err < 0))
+ break;
if (in) {
vq_err(vq, "Unexpected descriptor format for TX: "
"out %d, int %d\n", out, in);
@@ -547,7 +549,8 @@ static void handle_tx(struct vhost_net *net)
struct ubuf_info *ubuf;
ubuf = nvq->ubuf_info + nvq->upend_idx;
- vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
+ vq->heads[nvq->upend_idx].id + cpu_to_vhost32(vq, used.id);
vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = nvq->ubufs;
@@ -588,7 +591,7 @@ static void handle_tx(struct vhost_net *net)
pr_debug("Truncated TX packet: "
" len %d != %zd\n", err, len);
if (!zcopy_used)
- vhost_add_used_and_signal(&net->dev, vq, head, 0);
+ vhost_add_used_and_signal(&net->dev, vq, &used, 0);
else
vhost_zerocopy_signal_used(net, vq);
vhost_net_tx_packet(net);
@@ -735,14 +738,12 @@ static void handle_rx(struct vhost_net *net)
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 + nvq->done_idx,
- vhost_len, &in, vq_log, &log,
- likely(mergeable) ? UIO_MAXIOV : 1);
- /* On error, stop handling until the next kick. */
- if (unlikely(headcount < 0))
- goto out;
+ err = vhost_get_bufs(vq, vq->heads + nvq->done_idx,
+ vhost_len, &in, vq_log, &log,
+ likely(mergeable) ? UIO_MAXIOV : 1,
+ &headcount);
/* OK, now we need to know about added descriptors. */
- if (!headcount) {
+ if (err == -ENOSPC) {
if (unlikely(vhost_enable_notify(&net->dev, vq))) {
/* They have slipped one in as we were
* doing that: check again. */
@@ -753,6 +754,9 @@ static void handle_rx(struct vhost_net *net)
* they refilled. */
goto out;
}
+ /* On error, stop handling until the next kick. */
+ if (unlikely(err < 0))
+ goto out;
if (nvq->rx_ring)
msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
/* On overrun, truncate and discard */
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 17fcd3b..013464c 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -67,7 +67,7 @@ struct vhost_scsi_inflight {
struct vhost_scsi_cmd {
/* Descriptor from vhost_get_vq_desc() for virt_queue segment */
- int tvc_vq_desc;
+ struct vring_used_elem tvc_vq_used;
/* virtio-scsi initiator task attribute */
int tvc_task_attr;
/* virtio-scsi response incoming iovecs */
@@ -441,8 +441,9 @@ vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct
vhost_scsi_evt *evt)
struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
struct virtio_scsi_event *event = &evt->event;
struct virtio_scsi_event __user *eventp;
+ struct vring_used_elem used;
unsigned out, in;
- int head, ret;
+ int ret;
if (!vq->private_data) {
vs->vs_events_missed = true;
@@ -451,16 +452,16 @@ vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct
vhost_scsi_evt *evt)
again:
vhost_disable_notify(&vs->dev, vq);
- head = vhost_get_vq_desc(vq, vq->iov,
+ ret = vhost_get_vq_desc(vq, &used, vq->iov,
ARRAY_SIZE(vq->iov), &out, &in,
NULL, NULL);
- if (head < 0) {
+ if (ret == -ENOSPC) {
+ if (vhost_enable_notify(&vs->dev, vq))
+ goto again;
vs->vs_events_missed = true;
return;
}
- if (head == vq->num) {
- if (vhost_enable_notify(&vs->dev, vq))
- goto again;
+ if (ret < 0) {
vs->vs_events_missed = true;
return;
}
@@ -480,7 +481,7 @@ vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct
vhost_scsi_evt *evt)
eventp = vq->iov[out].iov_base;
ret = __copy_to_user(eventp, event, sizeof(*event));
if (!ret)
- vhost_add_used_and_signal(&vs->dev, vq, head, 0);
+ vhost_add_used_and_signal(&vs->dev, vq, &used, 0);
else
vq_err(vq, "Faulted on vhost_scsi_send_event\n");
}
@@ -541,7 +542,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work
*work)
ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
if (likely(ret == sizeof(v_rsp))) {
struct vhost_scsi_virtqueue *q;
- vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
+ vhost_add_used(cmd->tvc_vq, &cmd->tvc_vq_used, 0);
q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
vq = q - vs->vqs;
__set_bit(vq, signal);
@@ -784,7 +785,7 @@ static void vhost_scsi_submission_work(struct work_struct
*work)
static void
vhost_scsi_send_bad_target(struct vhost_scsi *vs,
struct vhost_virtqueue *vq,
- int head, unsigned out)
+ struct vring_used_elem *used, unsigned out)
{
struct virtio_scsi_cmd_resp __user *resp;
struct virtio_scsi_cmd_resp rsp;
@@ -795,7 +796,7 @@ vhost_scsi_send_bad_target(struct vhost_scsi *vs,
resp = vq->iov[out].iov_base;
ret = __copy_to_user(resp, &rsp, sizeof(rsp));
if (!ret)
- vhost_add_used_and_signal(&vs->dev, vq, head, 0);
+ vhost_add_used_and_signal(&vs->dev, vq, used, 0);
else
pr_err("Faulted on virtio_scsi_cmd_resp\n");
}
@@ -807,11 +808,12 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
struct virtio_scsi_cmd_req v_req;
struct virtio_scsi_cmd_req_pi v_req_pi;
struct vhost_scsi_cmd *cmd;
+ struct vring_used_elem used;
struct iov_iter out_iter, in_iter, prot_iter, data_iter;
u64 tag;
u32 exp_data_len, data_direction;
unsigned int out = 0, in = 0;
- int head, ret, prot_bytes;
+ int ret, prot_bytes;
size_t req_size, rsp_size = sizeof(struct virtio_scsi_cmd_resp);
size_t out_size, in_size;
u16 lun;
@@ -831,22 +833,22 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
vhost_disable_notify(&vs->dev, vq);
for (;;) {
- head = vhost_get_vq_desc(vq, vq->iov,
- ARRAY_SIZE(vq->iov), &out, &in,
- NULL, NULL);
+ ret = vhost_get_vq_desc(vq, &used, vq->iov,
+ ARRAY_SIZE(vq->iov), &out, &in,
+ NULL, NULL);
pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
- head, out, in);
- /* On error, stop handling until the next kick. */
- if (unlikely(head < 0))
- break;
+ used.id, out, in);
/* Nothing new? Wait for eventfd to tell us they refilled. */
- if (head == vq->num) {
+ if (ret == -ENOSPC) {
if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
vhost_disable_notify(&vs->dev, vq);
continue;
}
break;
}
+ /* On error, stop handling until the next kick. */
+ if (unlikely(ret < 0))
+ break;
/*
* Check for a sane response buffer so we can report early
* errors back to the guest.
@@ -891,20 +893,20 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
if (unlikely(!copy_from_iter_full(req, req_size, &out_iter))) {
vq_err(vq, "Faulted on copy_from_iter\n");
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq, &used, out);
continue;
}
/* virtio-scsi spec requires byte 0 of the lun to be 1 */
if (unlikely(*lunp != 1)) {
vq_err(vq, "Illegal virtio-scsi lun: %u\n", *lunp);
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq, &used, out);
continue;
}
tpg = READ_ONCE(vs_tpg[*target]);
if (unlikely(!tpg)) {
/* Target does not exist, fail the request */
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq, &used, out);
continue;
}
/*
@@ -950,7 +952,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
if (data_direction != DMA_TO_DEVICE) {
vq_err(vq, "Received non zero pi_bytesout,"
" but wrong data_direction\n");
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq,
+ &used, out);
continue;
}
prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
@@ -958,7 +961,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
if (data_direction != DMA_FROM_DEVICE) {
vq_err(vq, "Received non zero pi_bytesin,"
" but wrong data_direction\n");
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq,
+ &used, out);
continue;
}
prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
@@ -996,7 +1000,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
vq_err(vq, "Received SCSI CDB with command_size: %d that"
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq, &used, out);
continue;
}
cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
@@ -1005,7 +1009,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
if (IS_ERR(cmd)) {
vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
PTR_ERR(cmd));
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq, &used, out);
continue;
}
cmd->tvc_vhost = vs;
@@ -1025,7 +1029,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
if (unlikely(ret)) {
vq_err(vq, "Failed to map iov to sgl\n");
vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
- vhost_scsi_send_bad_target(vs, vq, head, out);
+ vhost_scsi_send_bad_target(vs, vq, &used, out);
continue;
}
}
@@ -1034,7 +1038,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
* complete the virtio-scsi request in TCM callback context via
* vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
*/
- cmd->tvc_vq_desc = head;
+ cmd->tvc_vq_used = used;
/*
* Dispatch cmd descriptor for cmwq execution in process
* context provided by vhost_scsi_workqueue. This also ensures
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 8814e5b..9572c4f 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1962,6 +1962,7 @@ static int get_indirect(struct vhost_virtqueue *vq,
* never a valid descriptor number) if none was found. A negative code is
* returned on error. */
int vhost_get_vq_desc(struct vhost_virtqueue *vq,
+ struct vring_used_elem *used,
struct iovec iov[], unsigned int iov_size,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num)
@@ -1994,7 +1995,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
* invalid.
*/
if (vq->avail_idx == last_avail_idx)
- return vq->num;
+ return -ENOSPC;
/* Only get avail ring entries after they have been
* exposed by guest.
@@ -2012,6 +2013,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
return -EFAULT;
}
+ used->id = ring_head;
head = vhost16_to_cpu(vq, ring_head);
/* If their number is silly, that's an error. */
@@ -2100,10 +2102,16 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
/* Assume notifications from guest are disabled at this point,
* if they aren't we would need to update avail_event index. */
BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
- return head;
+ return 0;
}
EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
+static void vhost_set_used_len(struct vhost_virtqueue *vq,
+ struct vring_used_elem *used, int len)
+{
+ used->len = cpu_to_vhost32(vq, len);
+}
+
/* This is a multi-buffer version of vhost_get_desc, that works if
* vq has read descriptors only.
* @vq - the relevant virtqueue
@@ -2120,13 +2128,13 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
unsigned *iovcount,
struct vhost_log *log,
unsigned *log_num,
- unsigned int quota)
+ unsigned int quota,
+ s16 *count)
{
unsigned int out, in;
int seg = 0;
int headcount = 0;
- unsigned d;
- int r, nlogs = 0;
+ int r = 0, nlogs = 0;
/* len is always initialized before use since we are always called with
* datalen > 0.
*/
@@ -2137,17 +2145,12 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
r = -ENOBUFS;
goto err;
}
- r = vhost_get_vq_desc(vq, vq->iov + seg,
+ r = vhost_get_vq_desc(vq, &heads[headcount], vq->iov + seg,
ARRAY_SIZE(vq->iov) - seg, &out,
&in, log, log_num);
if (unlikely(r < 0))
goto err;
- d = r;
- if (d == vq->num) {
- r = 0;
- goto err;
- }
if (unlikely(out || in <= 0)) {
vq_err(vq, "unexpected descriptor format for RX: "
"out %d, in %d\n", out, in);
@@ -2158,24 +2161,26 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
nlogs += *log_num;
log += *log_num;
}
- heads[headcount].id = cpu_to_vhost32(vq, d);
+
len = iov_length(vq->iov + seg, in);
- heads[headcount].len = cpu_to_vhost32(vq, len);
+ vhost_set_used_len(vq, &heads[headcount], len);
datalen -= len;
++headcount;
seg += in;
}
- heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
+ vhost_set_used_len(vq, &heads[headcount - 1], len + datalen);
*iovcount = seg;
if (unlikely(log))
*log_num = nlogs;
/* Detect overrun */
if (unlikely(datalen > 0)) {
- r = UIO_MAXIOV + 1;
+ headcount = UIO_MAXIOV + 1;
goto err;
}
- return headcount;
+
+ *count = headcount;
+ return 0;
err:
vhost_discard_vq_desc(vq, headcount);
return r;
@@ -2191,14 +2196,11 @@ EXPORT_SYMBOL_GPL(vhost_discard_vq_desc);
/* After we've used one of their buffers, we tell them about it. We'll
then
* want to notify the guest, using eventfd. */
-int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
+int vhost_add_used(struct vhost_virtqueue *vq, struct vring_used_elem *used,
+ int len)
{
- struct vring_used_elem heads = {
- cpu_to_vhost32(vq, head),
- cpu_to_vhost32(vq, len)
- };
-
- return vhost_add_used_n(vq, &heads, 1);
+ vhost_set_used_len(vq, used, len);
+ return vhost_add_used_n(vq, used, 1);
}
EXPORT_SYMBOL_GPL(vhost_add_used);
@@ -2331,9 +2333,9 @@ EXPORT_SYMBOL_GPL(vhost_signal);
/* And here's the combo meal deal. Supersize me! */
void vhost_add_used_and_signal(struct vhost_dev *dev,
struct vhost_virtqueue *vq,
- unsigned int head, int len)
+ struct vring_used_elem *used, int len)
{
- vhost_add_used(vq, head, len);
+ vhost_add_used(vq, used, len);
vhost_signal(dev, vq);
}
EXPORT_SYMBOL_GPL(vhost_add_used_and_signal);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 52edd242..a7cc7e7 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -182,6 +182,7 @@ bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
bool vhost_log_access_ok(struct vhost_dev *);
int vhost_get_vq_desc(struct vhost_virtqueue *,
+ struct vring_used_elem *used_elem,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num);
@@ -191,15 +192,17 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
unsigned *iovcount,
struct vhost_log *log,
unsigned *log_num,
- unsigned int quota);
+ unsigned int quota,
+ s16 *count);
void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
int vhost_vq_init_access(struct vhost_virtqueue *);
-int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
+int vhost_add_used(struct vhost_virtqueue *vq,
+ struct vring_used_elem *elem, int len);
int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
unsigned count);
void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
- unsigned int id, int len);
+ struct vring_used_elem *, int len);
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 *);
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 34bc3ab..59a01cd 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -98,11 +98,12 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
for (;;) {
struct virtio_vsock_pkt *pkt;
+ struct vring_used_elem used;
struct iov_iter iov_iter;
unsigned out, in;
size_t nbytes;
size_t len;
- int head;
+ int ret;
spin_lock_bh(&vsock->send_pkt_list_lock);
if (list_empty(&vsock->send_pkt_list)) {
@@ -116,16 +117,9 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
list_del_init(&pkt->list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
- head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
- &out, &in, NULL, NULL);
- if (head < 0) {
- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
- break;
- }
-
- if (head == vq->num) {
+ ret = vhost_get_vq_desc(vq, &used, vq->iov, ARRAY_SIZE(vq->iov),
+ &out, &in, NULL, NULL);
+ if (ret == -ENOSPC) {
spin_lock_bh(&vsock->send_pkt_list_lock);
list_add(&pkt->list, &vsock->send_pkt_list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
@@ -139,6 +133,12 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
}
break;
}
+ if (ret < 0) {
+ spin_lock_bh(&vsock->send_pkt_list_lock);
+ list_add(&pkt->list, &vsock->send_pkt_list);
+ spin_unlock_bh(&vsock->send_pkt_list_lock);
+ break;
+ }
if (out) {
virtio_transport_free_pkt(pkt);
@@ -146,7 +146,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
break;
}
- len = iov_length(&vq->iov[out], in);
+ len = vhost32_to_cpu(vq, used.len);
iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
@@ -163,7 +163,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
break;
}
- vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
+ vhost_add_used(vq, &used, sizeof(pkt->hdr) + pkt->len);
added = true;
if (pkt->reply) {
@@ -346,7 +346,8 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work
*work)
struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
dev);
struct virtio_vsock_pkt *pkt;
- int head;
+ struct vring_used_elem used;
+ int ret;
unsigned int out, in;
bool added = false;
@@ -367,18 +368,17 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work
*work)
goto no_more_replies;
}
- head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
- &out, &in, NULL, NULL);
- if (head < 0)
- break;
-
- if (head == vq->num) {
+ ret = vhost_get_vq_desc(vq, &used, vq->iov, ARRAY_SIZE(vq->iov),
+ &out, &in, NULL, NULL);
+ if (ret == -ENOSPC) {
if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
vhost_disable_notify(&vsock->dev, vq);
continue;
}
break;
}
+ if (ret < 0)
+ break;
pkt = vhost_vsock_alloc_pkt(vq, out, in);
if (!pkt) {
@@ -397,7 +397,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work
*work)
else
virtio_transport_free_pkt(pkt);
- vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
+ vhost_add_used(vq, &used, sizeof(pkt->hdr) + len);
added = true;
}
--
2.7.4
Instead of depending on the exported vring_used_elem, this patch
switches to use a new internal structure vhost_used_elem which embed
vring_used_elem in itself. This could be used to let vhost to record
extra metadata for the incoming packed ring layout.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 19 +++++++-------
drivers/vhost/scsi.c | 10 ++++----
drivers/vhost/vhost.c | 68 ++++++++++++---------------------------------------
drivers/vhost/vhost.h | 18 ++++++++------
drivers/vhost/vsock.c | 6 ++---
5 files changed, 45 insertions(+), 76 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 449f793..d109649 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -348,10 +348,10 @@ static void vhost_zerocopy_signal_used(struct vhost_net
*net,
int j = 0;
for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
- if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
+ if (vq->heads[i].elem.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;
+ if (VHOST_DMA_IS_DONE(vq->heads[i].elem.len)) {
+ vq->heads[i].elem.len = VHOST_DMA_CLEAR_LEN;
++j;
} else
break;
@@ -374,7 +374,7 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf,
bool success)
rcu_read_lock_bh();
/* set len to mark this desc buffers done DMA */
- vq->heads[ubuf->desc].len = success ?
+ vq->heads[ubuf->desc].elem.len = success ?
VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
cnt = vhost_net_ubuf_put(ubufs);
@@ -433,7 +433,7 @@ static int vhost_net_enable_vq(struct vhost_net *n,
static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
struct vhost_virtqueue *vq,
- struct vring_used_elem *used_elem,
+ struct vhost_used_elem *used_elem,
struct iovec iov[], unsigned int iov_size,
unsigned int *out_num, unsigned int *in_num)
{
@@ -484,7 +484,7 @@ static void handle_tx(struct vhost_net *net)
size_t hdr_size;
struct socket *sock;
struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
- struct vring_used_elem used;
+ struct vhost_used_elem used;
bool zcopy, zcopy_used;
int sent_pkts = 0;
@@ -549,9 +549,10 @@ static void handle_tx(struct vhost_net *net)
struct ubuf_info *ubuf;
ubuf = nvq->ubuf_info + nvq->upend_idx;
- vq->heads[nvq->upend_idx].id - cpu_to_vhost32(vq, used.id);
- vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
+ vq->heads[nvq->upend_idx].elem.id + cpu_to_vhost32(vq,
used.elem.id);
+ vq->heads[nvq->upend_idx].elem.len + VHOST_DMA_IN_PROGRESS;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = nvq->ubufs;
ubuf->desc = nvq->upend_idx;
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 013464c..149c38c 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -67,7 +67,7 @@ struct vhost_scsi_inflight {
struct vhost_scsi_cmd {
/* Descriptor from vhost_get_vq_desc() for virt_queue segment */
- struct vring_used_elem tvc_vq_used;
+ struct vhost_used_elem tvc_vq_used;
/* virtio-scsi initiator task attribute */
int tvc_task_attr;
/* virtio-scsi response incoming iovecs */
@@ -441,7 +441,7 @@ vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct
vhost_scsi_evt *evt)
struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
struct virtio_scsi_event *event = &evt->event;
struct virtio_scsi_event __user *eventp;
- struct vring_used_elem used;
+ struct vhost_used_elem used;
unsigned out, in;
int ret;
@@ -785,7 +785,7 @@ static void vhost_scsi_submission_work(struct work_struct
*work)
static void
vhost_scsi_send_bad_target(struct vhost_scsi *vs,
struct vhost_virtqueue *vq,
- struct vring_used_elem *used, unsigned out)
+ struct vhost_used_elem *used, unsigned out)
{
struct virtio_scsi_cmd_resp __user *resp;
struct virtio_scsi_cmd_resp rsp;
@@ -808,7 +808,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
struct virtio_scsi_cmd_req v_req;
struct virtio_scsi_cmd_req_pi v_req_pi;
struct vhost_scsi_cmd *cmd;
- struct vring_used_elem used;
+ struct vhost_used_elem used;
struct iov_iter out_iter, in_iter, prot_iter, data_iter;
u64 tag;
u32 exp_data_len, data_direction;
@@ -837,7 +837,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct
vhost_virtqueue *vq)
ARRAY_SIZE(vq->iov), &out, &in,
NULL, NULL);
pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
- used.id, out, in);
+ used.elem.id, out, in);
/* Nothing new? Wait for eventfd to tell us they refilled. */
if (ret == -ENOSPC) {
if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 9572c4f..641f4c6 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -731,41 +731,6 @@ static bool memory_access_ok(struct vhost_dev *d, struct
vhost_umem *umem,
static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
struct iovec iov[], int iov_size, int access);
-static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to,
- const void *from, unsigned size)
-{
- int ret;
-
- if (!vq->iotlb)
- return __copy_to_user(to, from, size);
- else {
- /* This function should be called after iotlb
- * prefetch, which means we're sure that all vq
- * could be access through iotlb. So -EAGAIN should
- * not happen in this case.
- */
- struct iov_iter t;
- void __user *uaddr = vhost_vq_meta_fetch(vq,
- (u64)(uintptr_t)to, size,
- VHOST_ADDR_USED);
-
- if (uaddr)
- return __copy_to_user(uaddr, from, size);
-
- ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov,
- ARRAY_SIZE(vq->iotlb_iov),
- VHOST_ACCESS_WO);
- if (ret < 0)
- goto out;
- iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size);
- ret = copy_to_iter(from, size, &t);
- if (ret == size)
- ret = 0;
- }
-out:
- return ret;
-}
-
static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,
void __user *from, unsigned size)
{
@@ -1962,7 +1927,7 @@ static int get_indirect(struct vhost_virtqueue *vq,
* never a valid descriptor number) if none was found. A negative code is
* returned on error. */
int vhost_get_vq_desc(struct vhost_virtqueue *vq,
- struct vring_used_elem *used,
+ struct vhost_used_elem *used,
struct iovec iov[], unsigned int iov_size,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num)
@@ -2013,7 +1978,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
return -EFAULT;
}
- used->id = ring_head;
+ used->elem.id = ring_head;
head = vhost16_to_cpu(vq, ring_head);
/* If their number is silly, that's an error. */
@@ -2107,9 +2072,9 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
static void vhost_set_used_len(struct vhost_virtqueue *vq,
- struct vring_used_elem *used, int len)
+ struct vhost_used_elem *used, int len)
{
- used->len = cpu_to_vhost32(vq, len);
+ used->elem.len = cpu_to_vhost32(vq, len);
}
/* This is a multi-buffer version of vhost_get_desc, that works if
@@ -2123,7 +2088,7 @@ static void vhost_set_used_len(struct vhost_virtqueue *vq,
* returns number of buffer heads allocated, negative on error
*/
int vhost_get_bufs(struct vhost_virtqueue *vq,
- struct vring_used_elem *heads,
+ struct vhost_used_elem *heads,
int datalen,
unsigned *iovcount,
struct vhost_log *log,
@@ -2196,7 +2161,7 @@ EXPORT_SYMBOL_GPL(vhost_discard_vq_desc);
/* After we've used one of their buffers, we tell them about it. We'll
then
* want to notify the guest, using eventfd. */
-int vhost_add_used(struct vhost_virtqueue *vq, struct vring_used_elem *used,
+int vhost_add_used(struct vhost_virtqueue *vq, struct vhost_used_elem *used,
int len)
{
vhost_set_used_len(vq, used, len);
@@ -2205,27 +2170,26 @@ int vhost_add_used(struct vhost_virtqueue *vq, struct
vring_used_elem *used,
EXPORT_SYMBOL_GPL(vhost_add_used);
static int __vhost_add_used_n(struct vhost_virtqueue *vq,
- struct vring_used_elem *heads,
+ struct vhost_used_elem *heads,
unsigned count)
{
struct vring_used_elem __user *used;
u16 old, new;
- int start;
+ int start, i;
start = vq->last_used_idx & (vq->num - 1);
used = vq->used->ring + start;
- if (count == 1) {
- if (vhost_put_user(vq, heads[0].id, &used->id)) {
+ for (i = 0; i < count; i++) {
+ if (unlikely(vhost_put_user(vq, heads[i].elem.id,
+ &used[i].id))) {
vq_err(vq, "Failed to write used id");
return -EFAULT;
}
- if (vhost_put_user(vq, heads[0].len, &used->len)) {
+ if (unlikely(vhost_put_user(vq, heads[i].elem.len,
+ &used[i].len))) {
vq_err(vq, "Failed to write used len");
return -EFAULT;
}
- } else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) {
- vq_err(vq, "Failed to write used");
- return -EFAULT;
}
if (unlikely(vq->log_used)) {
/* Make sure data is seen before log. */
@@ -2249,7 +2213,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq,
/* After we've used one of their buffers, we tell them about it. We'll
then
* want to notify the guest, using eventfd. */
-int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
+int vhost_add_used_n(struct vhost_virtqueue *vq, struct vhost_used_elem *heads,
unsigned count)
{
int start, n, r;
@@ -2333,7 +2297,7 @@ EXPORT_SYMBOL_GPL(vhost_signal);
/* And here's the combo meal deal. Supersize me! */
void vhost_add_used_and_signal(struct vhost_dev *dev,
struct vhost_virtqueue *vq,
- struct vring_used_elem *used, int len)
+ struct vhost_used_elem *used, int len)
{
vhost_add_used(vq, used, len);
vhost_signal(dev, vq);
@@ -2343,7 +2307,7 @@ EXPORT_SYMBOL_GPL(vhost_add_used_and_signal);
/* multi-buffer version of vhost_add_used_and_signal */
void vhost_add_used_and_signal_n(struct vhost_dev *dev,
struct vhost_virtqueue *vq,
- struct vring_used_elem *heads, unsigned count)
+ struct vhost_used_elem *heads, unsigned count)
{
vhost_add_used_n(vq, heads, count);
vhost_signal(dev, vq);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index a7cc7e7..8dea44b 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -34,6 +34,10 @@ struct vhost_poll {
struct vhost_dev *dev;
};
+struct vhost_used_elem {
+ struct vring_used_elem elem;
+};
+
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);
@@ -126,7 +130,7 @@ struct vhost_virtqueue {
struct iovec iov[UIO_MAXIOV];
struct iovec iotlb_iov[64];
struct iovec *indirect;
- struct vring_used_elem *heads;
+ struct vhost_used_elem *heads;
/* Protected by virtqueue mutex. */
struct vhost_umem *umem;
struct vhost_umem *iotlb;
@@ -182,12 +186,12 @@ bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
bool vhost_log_access_ok(struct vhost_dev *);
int vhost_get_vq_desc(struct vhost_virtqueue *,
- struct vring_used_elem *used_elem,
+ struct vhost_used_elem *used_elem,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num);
int vhost_get_bufs(struct vhost_virtqueue *vq,
- struct vring_used_elem *heads,
+ struct vhost_used_elem *heads,
int datalen,
unsigned *iovcount,
struct vhost_log *log,
@@ -198,13 +202,13 @@ void vhost_discard_vq_desc(struct vhost_virtqueue *, int
n);
int vhost_vq_init_access(struct vhost_virtqueue *);
int vhost_add_used(struct vhost_virtqueue *vq,
- struct vring_used_elem *elem, int len);
-int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
+ struct vhost_used_elem *elem, int len);
+int vhost_add_used_n(struct vhost_virtqueue *vq, struct vhost_used_elem *heads,
unsigned count);
void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
- struct vring_used_elem *, int len);
+ struct vhost_used_elem *, int len);
void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
- struct vring_used_elem *heads, unsigned count);
+ struct vhost_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 *);
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 59a01cd..695694f 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -98,7 +98,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
for (;;) {
struct virtio_vsock_pkt *pkt;
- struct vring_used_elem used;
+ struct vhost_used_elem used;
struct iov_iter iov_iter;
unsigned out, in;
size_t nbytes;
@@ -146,7 +146,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
break;
}
- len = vhost32_to_cpu(vq, used.len);
+ len = vhost32_to_cpu(vq, used.elem.len);
iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
@@ -346,7 +346,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work
*work)
struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
dev);
struct virtio_vsock_pkt *pkt;
- struct vring_used_elem used;
+ struct vhost_used_elem used;
int ret;
unsigned int out, in;
bool added = false;
--
2.7.4
Jason Wang
2018-Jul-03 05:38 UTC
[PATCH net-next 4/8] vhost_net: do not explicitly manipulate vhost_used_elem
Two helpers of setting/getting used len were introduced to avoid
explicitly manipulating vhost_used_elem in zerocopy code. This will be
used to hide used_elem internals and simplify packed ring
implementation.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 11 +++++------
drivers/vhost/vhost.c | 12 ++++++++++--
drivers/vhost/vhost.h | 5 +++++
3 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index d109649..eada5a6 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -348,9 +348,10 @@ static void vhost_zerocopy_signal_used(struct vhost_net
*net,
int j = 0;
for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
- if (vq->heads[i].elem.len == VHOST_DMA_FAILED_LEN)
+ if (vhost_get_used_len(vq, &vq->heads[i]) =+
VHOST_DMA_FAILED_LEN)
vhost_net_tx_err(net);
- if (VHOST_DMA_IS_DONE(vq->heads[i].elem.len)) {
+ if (VHOST_DMA_IS_DONE(vhost_get_used_len(vq, &vq->heads[i]))) {
vq->heads[i].elem.len = VHOST_DMA_CLEAR_LEN;
++j;
} else
@@ -549,10 +550,8 @@ static void handle_tx(struct vhost_net *net)
struct ubuf_info *ubuf;
ubuf = nvq->ubuf_info + nvq->upend_idx;
- vq->heads[nvq->upend_idx].elem.id - cpu_to_vhost32(vq,
used.elem.id);
- vq->heads[nvq->upend_idx].elem.len - VHOST_DMA_IN_PROGRESS;
+ vhost_set_used_len(vq, &used, VHOST_DMA_IN_PROGRESS);
+ vq->heads[nvq->upend_idx] = used;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = nvq->ubufs;
ubuf->desc = nvq->upend_idx;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 641f4c6..af15bec 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2071,11 +2071,19 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
}
EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
-static void vhost_set_used_len(struct vhost_virtqueue *vq,
- struct vhost_used_elem *used, int len)
+void vhost_set_used_len(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used, int len)
{
used->elem.len = cpu_to_vhost32(vq, len);
}
+EXPORT_SYMBOL_GPL(vhost_set_used_len);
+
+int vhost_get_used_len(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used)
+{
+ return vhost32_to_cpu(vq, used->elem.len);
+}
+EXPORT_SYMBOL_GPL(vhost_get_used_len);
/* This is a multi-buffer version of vhost_get_desc, that works if
* vq has read descriptors only.
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 8dea44b..604821b 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -198,6 +198,11 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
unsigned *log_num,
unsigned int quota,
s16 *count);
+void vhost_set_used_len(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used,
+ int len);
+int vhost_get_used_len(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used);
void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
int vhost_vq_init_access(struct vhost_virtqueue *);
--
2.7.4
Jason Wang
2018-Jul-03 05:38 UTC
[PATCH net-next 5/8] vhost: vhost_put_user() can accept metadata type
We assumes used ring update is the only user for vhost_put_user() in
the past. This may not be the case for the incoming packed ring which
may update the descriptor ring for used. So introduce a new type
parameter.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/vhost.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index af15bec..060a431 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -814,7 +814,7 @@ static inline void __user *__vhost_get_user(struct
vhost_virtqueue *vq,
return __vhost_get_user_slow(vq, addr, size, type);
}
-#define vhost_put_user(vq, x, ptr) \
+#define vhost_put_user(vq, x, ptr, type) \
({ \
int ret = -EFAULT; \
if (!vq->iotlb) { \
@@ -822,7 +822,7 @@ static inline void __user *__vhost_get_user(struct
vhost_virtqueue *vq,
} else { \
__typeof__(ptr) to = \
(__typeof__(ptr)) __vhost_get_user(vq, ptr, \
- sizeof(*ptr), VHOST_ADDR_USED); \
+ sizeof(*ptr), type); \
if (to != NULL) \
ret = __put_user(x, to); \
else \
@@ -1687,7 +1687,7 @@ static int vhost_update_used_flags(struct vhost_virtqueue
*vq)
{
void __user *used;
if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags),
- &vq->used->flags) < 0)
+ &vq->used->flags, VHOST_ADDR_USED) < 0)
return -EFAULT;
if (unlikely(vq->log_used)) {
/* Make sure the flag is seen before log. */
@@ -1706,7 +1706,7 @@ static int vhost_update_used_flags(struct vhost_virtqueue
*vq)
static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16
avail_event)
{
if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx),
- vhost_avail_event(vq)))
+ vhost_avail_event(vq), VHOST_ADDR_USED))
return -EFAULT;
if (unlikely(vq->log_used)) {
void __user *used;
@@ -2189,12 +2189,12 @@ static int __vhost_add_used_n(struct vhost_virtqueue
*vq,
used = vq->used->ring + start;
for (i = 0; i < count; i++) {
if (unlikely(vhost_put_user(vq, heads[i].elem.id,
- &used[i].id))) {
+ &used[i].id, VHOST_ADDR_USED))) {
vq_err(vq, "Failed to write used id");
return -EFAULT;
}
if (unlikely(vhost_put_user(vq, heads[i].elem.len,
- &used[i].len))) {
+ &used[i].len, VHOST_ADDR_USED))) {
vq_err(vq, "Failed to write used len");
return -EFAULT;
}
@@ -2240,7 +2240,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct
vhost_used_elem *heads,
/* Make sure buffer is written before we update index. */
smp_wmb();
if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx),
- &vq->used->idx)) {
+ &vq->used->idx, VHOST_ADDR_USED)) {
vq_err(vq, "Failed to increment used idx");
return -EFAULT;
}
--
2.7.4
Jason Wang
2018-Jul-03 05:38 UTC
[PATCH net-next 6/8] virtio: introduce packed ring defines
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
include/uapi/linux/virtio_config.h | 2 ++
include/uapi/linux/virtio_ring.h | 32 ++++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/include/uapi/linux/virtio_config.h
b/include/uapi/linux/virtio_config.h
index 449132c..947f6a3 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -75,6 +75,8 @@
*/
#define VIRTIO_F_IOMMU_PLATFORM 33
+#define VIRTIO_F_RING_PACKED 34
+
/*
* Does the device support Single Root I/O Virtualization?
*/
diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 6d5d5fa..71c7a46 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -43,6 +43,8 @@
#define VRING_DESC_F_WRITE 2
/* This means the buffer contains a list of buffer descriptors. */
#define VRING_DESC_F_INDIRECT 4
+#define VRING_DESC_F_AVAIL 7
+#define VRING_DESC_F_USED 15
/* The Host uses this in used->flags to advise the Guest: don't kick me
when
* you add a buffer. It's unreliable, so it's simply an optimization.
Guest
@@ -62,6 +64,36 @@
* at the end of the used ring. Guest should ignore the used->flags field.
*/
#define VIRTIO_RING_F_EVENT_IDX 29
+struct vring_desc_packed {
+ /* Buffer Address. */
+ __virtio64 addr;
+ /* Buffer Length. */
+ __virtio32 len;
+ /* Buffer ID. */
+ __virtio16 id;
+ /* The flags depending on descriptor type. */
+ __virtio16 flags;
+};
+
+/* Enable events */
+#define RING_EVENT_FLAGS_ENABLE 0x0
+/* Disable events */
+#define RING_EVENT_FLAGS_DISABLE 0x1
+/*
+ * Enable events for a specific descriptor
+ * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
+ * Only valid if VIRTIO_F_RING_EVENT_IDX has been negotiated.
+ */
+#define RING_EVENT_FLAGS_DESC 0x2
+/* The value 0x3 is reserved */
+
+struct vring_packed_desc_event {
+ /* Descriptor Ring Change Event Offset and Wrap Counter */
+ __virtio16 off_wrap;
+ /* Descriptor Ring Change Event Flags */
+ __virtio16 flags;
+};
+
/* Virtio ring descriptors: 16 bytes. These can chain together via
"next". */
struct vring_desc {
/* Address (guest-physical). */
--
2.7.4
This patch introduces basic support for packed ring. The idea behinds
packed ring is to use a single descriptor ring instead of three
different rings (avail, used and descriptor). This could help to
reduce the cache contention and PCI transactions. So it was designed
to help for the performance for both software implementation and
hardware implementation.
The implementation was straightforward, packed version of vhost core
(whose name has a packed suffix) helpers were introduced and previous
helpers were renamed with a split suffix. Then the exported helpers
can just do a switch to go to the correct internal helpers.
The event suppression (device area and driver area) were not
implemented. It will be done on top with another patch.
For more information of packed ring, please refer Virtio spec.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 15 +-
drivers/vhost/vhost.c | 655 ++++++++++++++++++++++++++++++++++++++++++---
drivers/vhost/vhost.h | 13 +-
include/uapi/linux/vhost.h | 7 +
4 files changed, 644 insertions(+), 46 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index eada5a6..90d9efb 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -74,7 +74,8 @@ enum {
VHOST_NET_FEATURES = VHOST_FEATURES |
(1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
(1ULL << VIRTIO_NET_F_MRG_RXBUF) |
- (1ULL << VIRTIO_F_IOMMU_PLATFORM)
+ (1ULL << VIRTIO_F_IOMMU_PLATFORM) |
+ (1ULL << VIRTIO_F_RING_PACKED)
};
enum {
@@ -583,7 +584,7 @@ static void handle_tx(struct vhost_net *net)
nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
% UIO_MAXIOV;
}
- vhost_discard_vq_desc(vq, 1);
+ vhost_discard_vq_desc(vq, &used, 1);
vhost_net_enable_vq(net, vq);
break;
}
@@ -736,10 +737,12 @@ static void handle_rx(struct vhost_net *net)
mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
+ struct vhost_used_elem *used = vq->heads + nvq->done_idx;
+
sock_len += sock_hlen;
vhost_len = sock_len + vhost_hlen;
- err = vhost_get_bufs(vq, vq->heads + nvq->done_idx,
- vhost_len, &in, vq_log, &log,
+ err = vhost_get_bufs(vq, used, vhost_len,
+ &in, vq_log, &log,
likely(mergeable) ? UIO_MAXIOV : 1,
&headcount);
/* OK, now we need to know about added descriptors. */
@@ -784,7 +787,7 @@ static void handle_rx(struct vhost_net *net)
if (unlikely(err != sock_len)) {
pr_debug("Discarded rx packet: "
" len %d, expected %zd\n", err, sock_len);
- vhost_discard_vq_desc(vq, headcount);
+ vhost_discard_vq_desc(vq, used, 1);
continue;
}
/* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
@@ -808,7 +811,7 @@ static void handle_rx(struct vhost_net *net)
copy_to_iter(&num_buffers, sizeof num_buffers,
&fixup) != sizeof num_buffers) {
vq_err(vq, "Failed num_buffers write");
- vhost_discard_vq_desc(vq, headcount);
+ vhost_discard_vq_desc(vq, used, 1);
goto out;
}
nvq->done_idx += headcount;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 060a431..0f3f07c 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -323,6 +323,9 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vhost_reset_is_le(vq);
vhost_disable_cross_endian(vq);
vq->busyloop_timeout = 0;
+ vq->last_used_wrap_counter = true;
+ vq->last_avail_wrap_counter = true;
+ vq->avail_wrap_counter = true;
vq->umem = NULL;
vq->iotlb = NULL;
__vhost_vq_meta_reset(vq);
@@ -1106,11 +1109,22 @@ static int vhost_iotlb_miss(struct vhost_virtqueue *vq,
u64 iova, int access)
return 0;
}
-static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
- struct vring_desc __user *desc,
- struct vring_avail __user *avail,
- struct vring_used __user *used)
+static int vq_access_ok_packed(struct vhost_virtqueue *vq, unsigned int num,
+ struct vring_desc __user *desc,
+ struct vring_avail __user *avail,
+ struct vring_used __user *used)
+{
+ struct vring_desc_packed *packed = (struct vring_desc_packed *)desc;
+
+ /* TODO: check device area and driver area */
+ return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) &&
+ access_ok(VERIFY_WRITE, packed, num * sizeof(*packed));
+}
+static int vq_access_ok_split(struct vhost_virtqueue *vq, unsigned int num,
+ struct vring_desc __user *desc,
+ struct vring_avail __user *avail,
+ struct vring_used __user *used)
{
size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
@@ -1121,6 +1135,17 @@ static bool vq_access_ok(struct vhost_virtqueue *vq,
unsigned int num,
sizeof *used + num * sizeof *used->ring + s);
}
+static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
+ struct vring_desc __user *desc,
+ struct vring_avail __user *avail,
+ struct vring_used __user *used)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vq_access_ok_packed(vq, num, desc, avail, used);
+ else
+ return vq_access_ok_split(vq, num, desc, avail, used);
+}
+
static void vhost_vq_meta_update(struct vhost_virtqueue *vq,
const struct vhost_umem_node *node,
int type)
@@ -1318,6 +1343,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int
ioctl, void __user *arg
struct vhost_vring_state s;
struct vhost_vring_file f;
struct vhost_vring_addr a;
+ bool wrap_counter;
u32 idx;
long r;
@@ -1360,6 +1386,10 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int
ioctl, void __user *arg
r = -EFAULT;
break;
}
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ wrap_counter = s.num >> 31;
+ s.num &= ~(1 << 31);
+ }
if (s.num > 0xffff) {
r = -EINVAL;
break;
@@ -1367,10 +1397,48 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int
ioctl, void __user *arg
vq->last_avail_idx = s.num;
/* Forget the cached index value. */
vq->avail_idx = vq->last_avail_idx;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ vq->last_avail_wrap_counter = wrap_counter;
+ vq->avail_wrap_counter = vq->last_avail_wrap_counter;
+ }
break;
case VHOST_GET_VRING_BASE:
s.index = idx;
s.num = vq->last_avail_idx;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ s.num |= vq->last_avail_wrap_counter << 31;
+ if (copy_to_user(argp, &s, sizeof(s)))
+ r = -EFAULT;
+ break;
+ case VHOST_SET_VRING_USED_BASE:
+ /* Moving base with an active backend?
+ * You don't want to do that.
+ */
+ if (vq->private_data) {
+ r = -EBUSY;
+ break;
+ }
+ if (copy_from_user(&s, argp, sizeof(s))) {
+ r = -EFAULT;
+ break;
+ }
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ wrap_counter = s.num >> 31;
+ s.num &= ~(1 << 31);
+ }
+ if (s.num > 0xffff) {
+ r = -EINVAL;
+ break;
+ }
+ vq->last_used_idx = s.num;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ vq->last_used_wrap_counter = wrap_counter;
+ break;
+ case VHOST_GET_VRING_USED_BASE:
+ s.index = idx;
+ s.num = vq->last_used_idx;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ s.num |= vq->last_used_wrap_counter << 31;
if (copy_to_user(argp, &s, sizeof s))
r = -EFAULT;
break;
@@ -1734,6 +1802,9 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq)
vhost_init_is_le(vq);
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return 0;
+
r = vhost_update_used_flags(vq);
if (r)
goto err;
@@ -1807,7 +1878,8 @@ static int translate_desc(struct vhost_virtqueue *vq, u64
addr, u32 len,
/* Each buffer in the virtqueues is actually a chain of descriptors. This
* function returns the next descriptor in the chain,
* or -1U if we're at the end. */
-static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)
+static unsigned next_desc_split(struct vhost_virtqueue *vq,
+ struct vring_desc *desc)
{
unsigned int next;
@@ -1820,11 +1892,17 @@ static unsigned next_desc(struct vhost_virtqueue *vq,
struct vring_desc *desc)
return next;
}
-static int get_indirect(struct vhost_virtqueue *vq,
- struct iovec iov[], unsigned int iov_size,
- unsigned int *out_num, unsigned int *in_num,
- struct vhost_log *log, unsigned int *log_num,
- struct vring_desc *indirect)
+static unsigned next_desc_packed(struct vhost_virtqueue *vq,
+ struct vring_desc_packed *desc)
+{
+ return desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT);
+}
+
+static int get_indirect_split(struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num,
+ struct vring_desc *indirect)
{
struct vring_desc desc;
unsigned int i = 0, count, found = 0;
@@ -1914,23 +1992,300 @@ static int get_indirect(struct vhost_virtqueue *vq,
}
*out_num += ret;
}
- } while ((i = next_desc(vq, &desc)) != -1);
+ } while ((i = next_desc_split(vq, &desc)) != -1);
return 0;
}
-/* This looks in the virtqueue and for the first available buffer, and converts
- * it to an iovec for convenient access. Since descriptors consist of some
- * number of output then some number of input descriptors, it's actually
two
- * iovecs, but we pack them into one and note how many of each there were.
- *
- * This function returns the descriptor number found, or vq->num (which is
- * never a valid descriptor number) if none was found. A negative code is
- * returned on error. */
-int vhost_get_vq_desc(struct vhost_virtqueue *vq,
- struct vhost_used_elem *used,
- struct iovec iov[], unsigned int iov_size,
- unsigned int *out_num, unsigned int *in_num,
- struct vhost_log *log, unsigned int *log_num)
+static int get_indirect_packed(struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num,
+ struct vring_desc_packed *indirect)
+{
+ struct vring_desc_packed desc;
+ unsigned int i = 0, count, found = 0;
+ u32 len = vhost32_to_cpu(vq, indirect->len);
+ struct iov_iter from;
+ int ret, access;
+
+ /* Sanity check */
+ if (unlikely(len % sizeof(desc))) {
+ vq_err(vq, "Invalid length in indirect descriptor: len 0x%llx not
multiple of 0x%zx\n",
+ (unsigned long long)len,
+ sizeof(desc));
+ return -EINVAL;
+ }
+
+ ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr),
+ len, vq->indirect,
+ UIO_MAXIOV, VHOST_ACCESS_RO);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Translation failure %d in indirect.\n",
+ ret);
+ return ret;
+ }
+ iov_iter_init(&from, READ, vq->indirect, ret, len);
+
+ /* We will use the result as an address to read from, so most
+ * architectures only need a compiler barrier here.
+ */
+ read_barrier_depends();
+
+ count = len / sizeof(desc);
+ /* Buffers are chained via a 16 bit next field, so
+ * we can have at most 2^16 of these.
+ */
+ if (unlikely(count > USHRT_MAX + 1)) {
+ vq_err(vq, "Indirect buffer length too big: %d\n",
+ indirect->len);
+ return -E2BIG;
+ }
+
+ do {
+ unsigned int iov_count = *in_num + *out_num;
+
+ if (unlikely(++found > count)) {
+ vq_err(vq, "Loop detected: last one at %u indirect size %u\n",
+ i, count);
+ return -EINVAL;
+ }
+ if (unlikely(!copy_from_iter_full(&desc, sizeof(desc),
+ &from))) {
+ vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
+ i, (size_t)vhost64_to_cpu(vq, indirect->addr)
+ + i * sizeof(desc));
+ return -EINVAL;
+ }
+ if (unlikely(desc.flags &
+ cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) {
+ vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",
+ i, (size_t)vhost64_to_cpu(vq, indirect->addr)
+ + i * sizeof(desc));
+ return -EINVAL;
+ }
+
+ if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE))
+ access = VHOST_ACCESS_WO;
+ else
+ access = VHOST_ACCESS_RO;
+
+ ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
+ vhost32_to_cpu(vq, desc.len),
+ iov + iov_count,
+ iov_size - iov_count, access);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Translation failure %d indirect idx %d\n",
+ ret, i);
+ return ret;
+ }
+ /* If this is an input descriptor, increment that count. */
+ if (access == VHOST_ACCESS_WO) {
+ *in_num += ret;
+ if (unlikely(log)) {
+ log[*log_num].addr + vhost64_to_cpu(vq, desc.addr);
+ log[*log_num].len + vhost32_to_cpu(vq, desc.len);
+ ++*log_num;
+ }
+ } else {
+ /* If it's an output descriptor, they're all supposed
+ * to come before any input descriptors.
+ */
+ if (unlikely(*in_num)) {
+ vq_err(vq, "Indirect descriptor has out after in: idx %d\n",
+ i);
+ return -EINVAL;
+ }
+ *out_num += ret;
+ }
+ i++;
+ } while (next_desc_packed(vq, &desc));
+ return 0;
+}
+
+#define DESC_AVAIL (1 << VRING_DESC_F_AVAIL)
+#define DESC_USED (1 << VRING_DESC_F_USED)
+static bool desc_is_avail(struct vhost_virtqueue *vq, bool wrap_counter,
+ __virtio16 flags)
+{
+ bool avail = flags & cpu_to_vhost16(vq, DESC_AVAIL);
+
+ return avail == wrap_counter;
+}
+
+static __virtio16 get_desc_flags(struct vhost_virtqueue *vq,
+ bool wrap_counter, bool write)
+{
+ __virtio16 flags = 0;
+
+ if (wrap_counter) {
+ flags |= cpu_to_vhost16(vq, DESC_AVAIL);
+ flags |= cpu_to_vhost16(vq, DESC_USED);
+ } else {
+ flags &= ~cpu_to_vhost16(vq, DESC_AVAIL);
+ flags &= ~cpu_to_vhost16(vq, DESC_USED);
+ }
+
+ if (write)
+ flags |= cpu_to_vhost16(vq, VRING_DESC_F_WRITE);
+
+ return flags;
+}
+
+static bool vhost_vring_packed_need_event(struct vhost_virtqueue *vq,
+ bool wrap, __u16 off_wrap, __u16 new,
+ __u16 old)
+{
+ int off = off_wrap & ~(1 << 15);
+
+ if (wrap != off_wrap >> 15)
+ off -= vq->num;
+
+ return vring_need_event(off, new, old);
+}
+
+static int vhost_get_vq_desc_packed(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log,
+ unsigned int *log_num)
+{
+ struct vring_desc_packed desc;
+ int ret, access, i;
+ u16 last_avail_idx = vq->last_avail_idx;
+ u16 off_wrap = vq->avail_idx | (vq->avail_wrap_counter << 15);
+
+ /* When we start there are none of either input nor output. */
+ *out_num = *in_num = 0;
+ if (unlikely(log))
+ *log_num = 0;
+
+ used->count = 0;
+
+ do {
+ struct vring_desc_packed *d = vq->desc_packed +
+ vq->last_avail_idx;
+ unsigned int iov_count = *in_num + *out_num;
+
+ ret = vhost_get_user(vq, desc.flags, &d->flags,
+ VHOST_ADDR_DESC);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to get flags: idx %d addr %p\n",
+ vq->last_avail_idx, &d->flags);
+ return -EFAULT;
+ }
+
+ if (!desc_is_avail(vq, vq->last_avail_wrap_counter,
+ desc.flags)) {
+ /* If there's nothing new since last we looked, return
+ * invalid.
+ */
+ if (!used->count)
+ return -ENOSPC;
+ vq_err(vq, "Unexpected unavail descriptor: idx %d\n",
+ vq->last_avail_idx);
+ return -EFAULT;
+ }
+
+ /* Read desc content after we're sure it was available. */
+ smp_rmb();
+
+ ret = vhost_copy_from_user(vq, &desc, d, sizeof(desc));
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
+ vq->last_avail_idx, d);
+ return -EFAULT;
+ }
+
+ used->elem.id = desc.id;
+
+ if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {
+ ret = get_indirect_packed(vq, iov, iov_size,
+ out_num, in_num, log,
+ log_num, &desc);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Failure detected in indirect descriptor at idx
%d\n",
+ i);
+ return ret;
+ }
+ goto next;
+ }
+
+ if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE))
+ access = VHOST_ACCESS_WO;
+ else
+ access = VHOST_ACCESS_RO;
+ ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
+ vhost32_to_cpu(vq, desc.len),
+ iov + iov_count, iov_size - iov_count,
+ access);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Translation failure %d idx %d\n",
+ ret, i);
+ return ret;
+ }
+
+ if (access == VHOST_ACCESS_WO) {
+ /* If this is an input descriptor,
+ * increment that count.
+ */
+ *in_num += ret;
+ if (unlikely(log)) {
+ log[*log_num].addr + vhost64_to_cpu(vq, desc.addr);
+ log[*log_num].len + vhost32_to_cpu(vq, desc.len);
+ ++*log_num;
+ }
+ } else {
+ /* If it's an output descriptor, they're all supposed
+ * to come before any input descriptors.
+ */
+ if (unlikely(*in_num)) {
+ vq_err(vq, "Desc out after in: idx %d\n", i);
+ return -EINVAL;
+ }
+ *out_num += ret;
+ }
+
+next:
+ if (unlikely(++used->count > vq->num)) {
+ vq_err(vq, "Loop detected: last one at %u vq size %u head %u\n",
+ i, vq->num, used->elem.id);
+ return -EINVAL;
+ }
+ if (++vq->last_avail_idx >= vq->num) {
+ vq->last_avail_idx = 0;
+ vq->last_avail_wrap_counter ^= 1;
+ }
+ /* If this descriptor says it doesn't chain, we're done. */
+ } while (next_desc_packed(vq, &desc));
+
+ /* Packed ring does not have avail idx which means we need to
+ * track it by our own. The check here is to make sure it
+ * grows monotonically.
+ */
+ if (vhost_vring_packed_need_event(vq, vq->last_avail_wrap_counter,
+ off_wrap, vq->last_avail_idx,
+ last_avail_idx)) {
+ vq->avail_idx = vq->last_avail_idx;
+ vq->avail_wrap_counter = vq->last_avail_wrap_counter;
+ }
+
+ return 0;
+}
+
+static int vhost_get_vq_desc_split(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num)
{
struct vring_desc desc;
unsigned int i, head, found = 0;
@@ -2015,9 +2370,9 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
return -EFAULT;
}
if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {
- ret = get_indirect(vq, iov, iov_size,
- out_num, in_num,
- log, log_num, &desc);
+ ret = get_indirect_split(vq, iov, iov_size,
+ out_num, in_num,
+ log, log_num, &desc);
if (unlikely(ret < 0)) {
if (ret != -EAGAIN)
vq_err(vq, "Failure detected "
@@ -2059,7 +2414,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
}
*out_num += ret;
}
- } while ((i = next_desc(vq, &desc)) != -1);
+ } while ((i = next_desc_split(vq, &desc)) != -1);
/* On success, increment avail index. */
vq->last_avail_idx++;
@@ -2069,6 +2424,31 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
return 0;
}
+
+/* This looks in the virtqueue and for the first available buffer, and converts
+ * it to an iovec for convenient access. Since descriptors consist of some
+ * number of output then some number of input descriptors, it's actually
two
+ * iovecs, but we pack them into one and note how many of each there were.
+ *
+ * This function returns the descriptor number found, or vq->num (which is
+ * never a valid descriptor number) if none was found. A negative code is
+ * returned on error.
+ */
+int vhost_get_vq_desc(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vhost_get_vq_desc_packed(vq, used, iov, iov_size,
+ out_num, in_num,
+ log, log_num);
+ else
+ return vhost_get_vq_desc_split(vq, used, iov, iov_size,
+ out_num, in_num,
+ log, log_num);
+}
EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
void vhost_set_used_len(struct vhost_virtqueue *vq,
@@ -2155,15 +2535,30 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
*count = headcount;
return 0;
err:
- vhost_discard_vq_desc(vq, headcount);
+ vhost_discard_vq_desc(vq, heads, headcount);
return r;
}
EXPORT_SYMBOL_GPL(vhost_get_bufs);
/* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
-void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
+void vhost_discard_vq_desc(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *heads,
+ int headcount)
{
- vq->last_avail_idx -= n;
+ int i;
+
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ for (i = 0; i < headcount; i++) {
+ vq->last_avail_idx -= heads[i].count;
+ if (vq->last_avail_idx >= vq->num) {
+ vq->last_avail_wrap_counter ^= 1;
+ vq->last_avail_idx += vq->num;
+ }
+ }
+ } else {
+ vq->last_avail_idx -= headcount;
+ }
+
}
EXPORT_SYMBOL_GPL(vhost_discard_vq_desc);
@@ -2219,10 +2614,102 @@ static int __vhost_add_used_n(struct vhost_virtqueue
*vq,
return 0;
}
+static int vhost_add_used_packed(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *used,
+ int idx, bool wrap_counter)
+{
+ struct vring_desc_packed __user *desc = vq->desc_packed + idx;
+ int ret;
+
+ ret = vhost_put_user(vq, used->elem.id, &desc->id, VHOST_ADDR_DESC);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to update id: idx %d addr %p\n",
+ vq->last_used_idx, desc);
+ return -EFAULT;
+ }
+ ret = vhost_put_user(vq, used->elem.len, &desc->len,
VHOST_ADDR_DESC);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to update len: idx %d addr %p\n",
+ vq->last_used_idx, desc);
+ return -EFAULT;
+ }
+
+ if (idx == vq->last_used_idx) {
+ /* Make sure descriptor id and len is written before
+ * flags for the first used buffer.
+ */
+ smp_wmb();
+ }
+
+ ret = vhost_put_user(vq,
+ get_desc_flags(vq, wrap_counter, used->elem.len),
+ &desc->flags, VHOST_ADDR_DESC);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to update flags: idx %d addr %p\n",
+ vq->last_used_idx, desc);
+ return -EFAULT;
+ }
+
+ if (unlikely(vq->log_used)) {
+ /* Make sure desc is written before update log. */
+ smp_wmb();
+ log_write(vq->log_base, vq->log_addr +
+ vq->last_used_idx * sizeof(*desc),
+ sizeof(*desc));
+ if (vq->log_ctx)
+ eventfd_signal(vq->log_ctx, 1);
+ }
+
+ return 0;
+}
+
+static int vhost_add_used_n_packed(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *heads,
+ unsigned int count)
+{
+ u16 last_used_idx = vq->last_used_idx + heads[0].count;
+ u16 wrap_counter = vq->last_used_wrap_counter;
+ int i, ret;
+
+ /* Update used elems other than first to save unnecessary
+ * memory barriers.
+ */
+ for (i = 1; i < count; i++) {
+ if (last_used_idx >= vq->num) {
+ last_used_idx -= vq->num;
+ wrap_counter ^= 1;
+ }
+
+ ret = vhost_add_used_packed(vq, &heads[i], last_used_idx,
+ wrap_counter);
+ if (unlikely(ret))
+ return ret;
+
+ last_used_idx += heads[i].count;
+ }
+
+ ret = vhost_add_used_packed(vq, &heads[0], vq->last_used_idx,
+ vq->last_used_wrap_counter);
+ if (unlikely(ret))
+ return ret;
+
+ if (last_used_idx >= vq->num) {
+ last_used_idx -= vq->num;
+ wrap_counter ^= 1;
+ }
+
+ vq->last_used_idx = last_used_idx;
+ vq->last_used_wrap_counter = wrap_counter;
+
+ return 0;
+}
+
/* After we've used one of their buffers, we tell them about it. We'll
then
* want to notify the guest, using eventfd. */
-int vhost_add_used_n(struct vhost_virtqueue *vq, struct vhost_used_elem *heads,
- unsigned count)
+static int vhost_add_used_n_split(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *heads,
+ unsigned count)
+
{
int start, n, r;
@@ -2254,6 +2741,19 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct
vhost_used_elem *heads,
}
return r;
}
+
+/* After we've used one of their buffers, we tell them about it. We'll
then
+ * want to notify the guest, using eventfd.
+ */
+int vhost_add_used_n(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *heads,
+ unsigned int count)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vhost_add_used_n_packed(vq, heads, count);
+ else
+ return vhost_add_used_n_split(vq, heads, count);
+}
EXPORT_SYMBOL_GPL(vhost_add_used_n);
static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
@@ -2261,6 +2761,11 @@ static bool vhost_notify(struct vhost_dev *dev, struct
vhost_virtqueue *vq)
__u16 old, new;
__virtio16 event;
bool v;
+
+ /* TODO: check driver area */
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return true;
+
/* Flush out used index updates. This is paired
* with the barrier that the Guest executes when enabling
* interrupts. */
@@ -2323,7 +2828,8 @@ 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)
+static bool vhost_vq_avail_empty_split(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
{
__virtio16 avail_idx;
int r;
@@ -2338,10 +2844,59 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct
vhost_virtqueue *vq)
return vq->avail_idx == vq->last_avail_idx;
}
+
+static bool vhost_vq_avail_empty_packed(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
+{
+ struct vring_desc_packed *d = vq->desc_packed + vq->avail_idx;
+ __virtio16 flags;
+ int ret;
+
+ ret = vhost_get_user(vq, flags, &d->flags, VHOST_ADDR_DESC);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to get flags: idx %d addr %p\n",
+ vq->last_avail_idx, d);
+ return -EFAULT;
+ }
+
+ return !desc_is_avail(vq, vq->avail_wrap_counter, flags);
+}
+
+bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vhost_vq_avail_empty_packed(dev, vq);
+ else
+ return vhost_vq_avail_empty_split(dev, vq);
+}
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)
+static bool vhost_enable_notify_packed(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
+{
+ struct vring_desc_packed *d = vq->desc_packed + vq->avail_idx;
+ __virtio16 flags;
+ int ret;
+
+ /* TODO: enable notification through device area */
+
+ /* They could have slipped one in as we were doing that: make
+ * sure it's written, then check again.
+ */
+ smp_mb();
+
+ ret = vhost_get_user(vq, flags, &d->flags, VHOST_ADDR_DESC);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
+ vq->last_avail_idx, &d->flags);
+ return -EFAULT;
+ }
+
+ return desc_is_avail(vq, vq->avail_wrap_counter, flags);
+}
+
+static bool vhost_enable_notify_split(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
{
__virtio16 avail_idx;
int r;
@@ -2376,10 +2931,25 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct
vhost_virtqueue *vq)
return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx;
}
+
+/* OK, now we need to know about added descriptors. */
+bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vhost_enable_notify_packed(dev, vq);
+ else
+ return vhost_enable_notify_split(dev, vq);
+}
EXPORT_SYMBOL_GPL(vhost_enable_notify);
-/* We don't need to be notified again. */
-void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+static void vhost_disable_notify_packed(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
+{
+ /* TODO: disable notification through device area */
+}
+
+static void vhost_disable_notify_split(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
{
int r;
@@ -2393,6 +2963,15 @@ void vhost_disable_notify(struct vhost_dev *dev, struct
vhost_virtqueue *vq)
&vq->used->flags, r);
}
}
+
+/* We don't need to be notified again. */
+void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vhost_disable_notify_packed(dev, vq);
+ else
+ return vhost_disable_notify_split(dev, vq);
+}
EXPORT_SYMBOL_GPL(vhost_disable_notify);
/* Create a new message. */
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 604821b..db09958 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -36,6 +36,7 @@ struct vhost_poll {
struct vhost_used_elem {
struct vring_used_elem elem;
+ int count;
};
void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
@@ -91,7 +92,10 @@ struct vhost_virtqueue {
/* The actual ring of buffers. */
struct mutex mutex;
unsigned int num;
- struct vring_desc __user *desc;
+ union {
+ struct vring_desc __user *desc;
+ struct vring_desc_packed __user *desc_packed;
+ };
struct vring_avail __user *avail;
struct vring_used __user *used;
const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
@@ -148,6 +152,9 @@ struct vhost_virtqueue {
bool user_be;
#endif
u32 busyloop_timeout;
+ bool last_used_wrap_counter;
+ bool avail_wrap_counter;
+ bool last_avail_wrap_counter;
};
struct vhost_msg_node {
@@ -203,7 +210,9 @@ void vhost_set_used_len(struct vhost_virtqueue *vq,
int len);
int vhost_get_used_len(struct vhost_virtqueue *vq,
struct vhost_used_elem *used);
-void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
+void vhost_discard_vq_desc(struct vhost_virtqueue *vq,
+ struct vhost_used_elem *elem,
+ int n);
int vhost_vq_init_access(struct vhost_virtqueue *);
int vhost_add_used(struct vhost_virtqueue *vq,
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index c51f8e5..839ae7e 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -160,6 +160,13 @@ struct vhost_memory {
#define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24, \
struct vhost_vring_state)
+/* Base value where queue looks for used descriptors */
+#define VHOST_SET_VRING_USED_BASE _IOW(VHOST_VIRTIO, 0x25, \
+ struct vhost_vring_state)
+/* Get accessor: reads index, writes value in num */
+#define VHOST_GET_VRING_USED_BASE _IOWR(VHOST_VIRTIO, 0x26, \
+ struct vhost_vring_state)
+
/* VHOST_NET specific defines */
/* Attach virtio net ring to a raw socket, or tap device.
--
2.7.4
Jason Wang
2018-Jul-03 05:38 UTC
[PATCH net-next 8/8] vhost: event suppression for packed ring
This patch introduces support for event suppression. This is done by
have a two areas: device area and driver area. One side could then try
to disable or enable (delayed) notification from other side by using a
boolean hint or event index interface in the areas.
For more information, please refer Virtio spec.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++++++++++++----
drivers/vhost/vhost.h | 10 ++-
2 files changed, 185 insertions(+), 16 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 0f3f07c..cccbc82 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1115,10 +1115,15 @@ static int vq_access_ok_packed(struct vhost_virtqueue
*vq, unsigned int num,
struct vring_used __user *used)
{
struct vring_desc_packed *packed = (struct vring_desc_packed *)desc;
+ struct vring_packed_desc_event *driver_event + (struct
vring_packed_desc_event *)avail;
+ struct vring_packed_desc_event *device_event + (struct
vring_packed_desc_event *)used;
- /* TODO: check device area and driver area */
return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) &&
- access_ok(VERIFY_WRITE, packed, num * sizeof(*packed));
+ access_ok(VERIFY_WRITE, packed, num * sizeof(*packed)) &&
+ access_ok(VERIFY_READ, driver_event, sizeof(*driver_event)) &&
+ access_ok(VERIFY_WRITE, device_event, sizeof(*device_event));
}
static int vq_access_ok_split(struct vhost_virtqueue *vq, unsigned int num,
@@ -1193,14 +1198,27 @@ static bool iotlb_access_ok(struct vhost_virtqueue *vq,
return true;
}
-int vq_iotlb_prefetch(struct vhost_virtqueue *vq)
+int vq_iotlb_prefetch_packed(struct vhost_virtqueue *vq)
+{
+ int num = vq->num;
+
+ return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc,
+ num * sizeof(*vq->desc), VHOST_ADDR_DESC) &&
+ iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->desc,
+ num * sizeof(*vq->desc), VHOST_ADDR_DESC) &&
+ iotlb_access_ok(vq, VHOST_ACCESS_RO,
+ (u64)(uintptr_t)vq->driver_event,
+ sizeof(*vq->driver_event), VHOST_ADDR_AVAIL) &&
+ iotlb_access_ok(vq, VHOST_ACCESS_WO,
+ (u64)(uintptr_t)vq->device_event,
+ sizeof(*vq->device_event), VHOST_ADDR_USED);
+}
+
+int vq_iotlb_prefetch_split(struct vhost_virtqueue *vq)
{
size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
unsigned int num = vq->num;
- if (!vq->iotlb)
- return 1;
-
return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc,
num * sizeof(*vq->desc), VHOST_ADDR_DESC) &&
iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail,
@@ -1212,6 +1230,17 @@ int vq_iotlb_prefetch(struct vhost_virtqueue *vq)
num * sizeof(*vq->used->ring) + s,
VHOST_ADDR_USED);
}
+
+int vq_iotlb_prefetch(struct vhost_virtqueue *vq)
+{
+ if (!vq->iotlb)
+ return 1;
+
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vq_iotlb_prefetch_packed(vq);
+ else
+ return vq_iotlb_prefetch_split(vq);
+}
EXPORT_SYMBOL_GPL(vq_iotlb_prefetch);
/* Can we log writes? */
@@ -1771,6 +1800,50 @@ static int vhost_update_used_flags(struct vhost_virtqueue
*vq)
return 0;
}
+static int vhost_update_device_flags(struct vhost_virtqueue *vq,
+ __virtio16 device_flags)
+{
+ void __user *flags;
+
+ if (vhost_put_user(vq, device_flags, &vq->device_event->flags,
+ VHOST_ADDR_USED) < 0)
+ return -EFAULT;
+ if (unlikely(vq->log_used)) {
+ /* Make sure the flag is seen before log. */
+ smp_wmb();
+ /* Log used flag write. */
+ flags = &vq->device_event->flags;
+ log_write(vq->log_base, vq->log_addr +
+ (flags - (void __user *)vq->device_event),
+ sizeof(vq->device_event->flags));
+ if (vq->log_ctx)
+ eventfd_signal(vq->log_ctx, 1);
+ }
+ return 0;
+}
+
+static int vhost_update_device_off_wrap(struct vhost_virtqueue *vq,
+ __virtio16 device_off_wrap)
+{
+ void __user *off_wrap;
+
+ if (vhost_put_user(vq, device_off_wrap, &vq->device_event->off_wrap,
+ VHOST_ADDR_USED) < 0)
+ return -EFAULT;
+ if (unlikely(vq->log_used)) {
+ /* Make sure the flag is seen before log. */
+ smp_wmb();
+ /* Log used flag write. */
+ off_wrap = &vq->device_event->off_wrap;
+ log_write(vq->log_base, vq->log_addr +
+ (off_wrap - (void __user *)vq->device_event),
+ sizeof(vq->device_event->off_wrap));
+ if (vq->log_ctx)
+ eventfd_signal(vq->log_ctx, 1);
+ }
+ return 0;
+}
+
static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16
avail_event)
{
if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx),
@@ -2756,16 +2829,13 @@ int vhost_add_used_n(struct vhost_virtqueue *vq,
}
EXPORT_SYMBOL_GPL(vhost_add_used_n);
-static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+static bool vhost_notify_split(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
{
__u16 old, new;
__virtio16 event;
bool v;
- /* TODO: check driver area */
- if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
- return true;
-
/* Flush out used index updates. This is paired
* with the barrier that the Guest executes when enabling
* interrupts. */
@@ -2798,6 +2868,64 @@ static bool vhost_notify(struct vhost_dev *dev, struct
vhost_virtqueue *vq)
return vring_need_event(vhost16_to_cpu(vq, event), new, old);
}
+static bool vhost_notify_packed(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq)
+{
+ __virtio16 event_off_wrap, event_flags;
+ __u16 old, new, off_wrap;
+ bool v;
+
+ /* Flush out used descriptors updates. This is paired
+ * with the barrier that the Guest executes when enabling
+ * interrupts.
+ */
+ smp_mb();
+
+ if (vhost_get_avail(vq, event_flags,
+ &vq->driver_event->flags) < 0) {
+ vq_err(vq, "Failed to get driver desc_event_flags");
+ return true;
+ }
+
+ if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX))
+ return event_flags !+ cpu_to_vhost16(vq, RING_EVENT_FLAGS_DISABLE);
+
+ old = vq->signalled_used;
+ v = vq->signalled_used_valid;
+ new = vq->signalled_used = vq->last_used_idx;
+ vq->signalled_used_valid = true;
+
+ if (event_flags != cpu_to_vhost16(vq, RING_EVENT_FLAGS_DESC))
+ return event_flags !+ cpu_to_vhost16(vq, RING_EVENT_FLAGS_DISABLE);
+
+ /* Read desc event flags before event_off and event_wrap */
+ smp_rmb();
+
+ if (vhost_get_avail(vq, event_off_wrap,
+ &vq->driver_event->off_wrap) < 0) {
+ vq_err(vq, "Failed to get driver desc_event_off/wrap");
+ return true;
+ }
+
+ off_wrap = vhost16_to_cpu(vq, event_off_wrap);
+
+ if (unlikely(!v))
+ return true;
+
+ return vhost_vring_packed_need_event(vq, vq->last_used_wrap_counter,
+ off_wrap, new, old);
+}
+
+static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
+{
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ return vhost_notify_packed(dev, vq);
+ else
+ return vhost_notify_split(dev, vq);
+}
+
/* This actually signals the guest, using eventfd. */
void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
{
@@ -2875,10 +3003,34 @@ static bool vhost_enable_notify_packed(struct vhost_dev
*dev,
struct vhost_virtqueue *vq)
{
struct vring_desc_packed *d = vq->desc_packed + vq->avail_idx;
- __virtio16 flags;
+ __virtio16 flags = cpu_to_vhost16(vq, RING_EVENT_FLAGS_ENABLE);
int ret;
- /* TODO: enable notification through device area */
+ if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))
+ return false;
+ vq->used_flags &= ~VRING_USED_F_NO_NOTIFY;
+
+ if (vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
+ __virtio16 off_wrap = cpu_to_vhost16(vq, vq->avail_idx |
+ vq->avail_wrap_counter << 15);
+
+ ret = vhost_update_device_off_wrap(vq, off_wrap);
+ if (ret) {
+ vq_err(vq, "Failed to write to off warp at %p: %d\n",
+ &vq->device_event->off_wrap, ret);
+ return false;
+ }
+ /* Make sure off_wrap is wrote before flags */
+ smp_wmb();
+ flags = cpu_to_vhost16(vq, RING_EVENT_FLAGS_DESC);
+ }
+
+ ret = vhost_update_device_flags(vq, flags);
+ if (ret) {
+ vq_err(vq, "Failed to enable notification at %p: %d\n",
+ &vq->device_event->flags, ret);
+ return false;
+ }
/* They could have slipped one in as we were doing that: make
* sure it's written, then check again.
@@ -2945,7 +3097,18 @@ EXPORT_SYMBOL_GPL(vhost_enable_notify);
static void vhost_disable_notify_packed(struct vhost_dev *dev,
struct vhost_virtqueue *vq)
{
- /* TODO: disable notification through device area */
+ __virtio16 flags;
+ int r;
+
+ if (vq->used_flags & VRING_USED_F_NO_NOTIFY)
+ return;
+ vq->used_flags |= VRING_USED_F_NO_NOTIFY;
+
+ flags = cpu_to_vhost16(vq, RING_EVENT_FLAGS_DISABLE);
+ r = vhost_update_device_flags(vq, flags);
+ if (r)
+ vq_err(vq, "Failed to enable notification at %p: %d\n",
+ &vq->device_event->flags, r);
}
static void vhost_disable_notify_split(struct vhost_dev *dev,
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index db09958..d071daf 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -96,8 +96,14 @@ struct vhost_virtqueue {
struct vring_desc __user *desc;
struct vring_desc_packed __user *desc_packed;
};
- struct vring_avail __user *avail;
- struct vring_used __user *used;
+ union {
+ struct vring_avail __user *avail;
+ struct vring_packed_desc_event __user *driver_event;
+ };
+ union {
+ struct vring_used __user *used;
+ struct vring_packed_desc_event __user *device_event;
+ };
const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
struct file *kick;
struct eventfd_ctx *call_ctx;
--
2.7.4
kbuild test robot
2018-Jul-04 01:01 UTC
[PATCH net-next 1/8] vhost: move get_rx_bufs to vhost.c
Hi Jason,
I love your patch! Yet something to improve:
[auto build test ERROR on net-next/master]
url:
https://github.com/0day-ci/linux/commits/Jason-Wang/Packed-virtqueue-for-vhost/20180703-154751
config: x86_64-randconfig-s0-07032254 (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
Note: the linux-review/Jason-Wang/Packed-virtqueue-for-vhost/20180703-154751
HEAD 01b902f1126212ea2597e6d09802bd9c4431bf82 builds fine.
It only hurts bisectibility.
All errors (new ones prefixed by >>):
drivers//vhost/net.c: In function
'handle_rx':>> drivers//vhost/net.c:738:15: error: implicit declaration of function
'get_rx_bufs' [-Werror=implicit-function-declaration]
headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx,
^~~~~~~~~~~
cc1: some warnings being treated as errors
vim +/get_rx_bufs +738 drivers//vhost/net.c
030881372 Jason Wang 2016-03-04 687
3a4d5c94e Michael S. Tsirkin 2010-01-14 688 /* Expects to be always run from
workqueue - which acts as
3a4d5c94e Michael S. Tsirkin 2010-01-14 689 * read-size critical section for
our kind of RCU. */
94249369e Jason Wang 2011-01-17 690 static void handle_rx(struct
vhost_net *net)
3a4d5c94e Michael S. Tsirkin 2010-01-14 691 {
81f95a558 Michael S. Tsirkin 2013-04-28 692 struct vhost_net_virtqueue *nvq =
&net->vqs[VHOST_NET_VQ_RX];
81f95a558 Michael S. Tsirkin 2013-04-28 693 struct vhost_virtqueue *vq =
&nvq->vq;
8dd014adf David Stevens 2010-07-27 694 unsigned uninitialized_var(in),
log;
8dd014adf David Stevens 2010-07-27 695 struct vhost_log *vq_log;
8dd014adf David Stevens 2010-07-27 696 struct msghdr msg = {
8dd014adf David Stevens 2010-07-27 697 .msg_name = NULL,
8dd014adf David Stevens 2010-07-27 698 .msg_namelen = 0,
8dd014adf David Stevens 2010-07-27 699 .msg_control = NULL, /* FIXME:
get and handle RX aux data. */
8dd014adf David Stevens 2010-07-27 700 .msg_controllen = 0,
8dd014adf David Stevens 2010-07-27 701 .msg_flags = MSG_DONTWAIT,
8dd014adf David Stevens 2010-07-27 702 };
0960b6417 Jason Wang 2015-02-15 703 struct virtio_net_hdr hdr = {
0960b6417 Jason Wang 2015-02-15 704 .flags = 0,
0960b6417 Jason Wang 2015-02-15 705 .gso_type =
VIRTIO_NET_HDR_GSO_NONE
8dd014adf David Stevens 2010-07-27 706 };
8dd014adf David Stevens 2010-07-27 707 size_t total_len = 0;
910a578f7 Michael S. Tsirkin 2012-10-24 708 int err, mergeable;
f5a4941aa Jason Wang 2018-05-29 709 s16 headcount;
8dd014adf David Stevens 2010-07-27 710 size_t vhost_hlen, sock_hlen;
8dd014adf David Stevens 2010-07-27 711 size_t vhost_len, sock_len;
2e26af79b Asias He 2013-05-07 712 struct socket *sock;
ba7438aed Al Viro 2014-12-10 713 struct iov_iter fixup;
0960b6417 Jason Wang 2015-02-15 714 __virtio16 num_buffers;
db688c24e Paolo Abeni 2018-04-24 715 int recv_pkts = 0;
8dd014adf David Stevens 2010-07-27 716
aaa3149bb Jason Wang 2018-03-26 717
mutex_lock_nested(&vq->mutex, 0);
2e26af79b Asias He 2013-05-07 718 sock = vq->private_data;
2e26af79b Asias He 2013-05-07 719 if (!sock)
2e26af79b Asias He 2013-05-07 720 goto out;
6b1e6cc78 Jason Wang 2016-06-23 721
6b1e6cc78 Jason Wang 2016-06-23 722 if (!vq_iotlb_prefetch(vq))
6b1e6cc78 Jason Wang 2016-06-23 723 goto out;
6b1e6cc78 Jason Wang 2016-06-23 724
8ea8cf89e Michael S. Tsirkin 2011-05-20 725
vhost_disable_notify(&net->dev, vq);
8241a1e46 Jason Wang 2016-06-01 726 vhost_net_disable_vq(net, vq);
2e26af79b Asias He 2013-05-07 727
81f95a558 Michael S. Tsirkin 2013-04-28 728 vhost_hlen = nvq->vhost_hlen;
81f95a558 Michael S. Tsirkin 2013-04-28 729 sock_hlen = nvq->sock_hlen;
8dd014adf David Stevens 2010-07-27 730
ea16c5143 Michael S. Tsirkin 2014-06-05 731 vq_log =
unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
8dd014adf David Stevens 2010-07-27 732 vq->log : NULL;
ea16c5143 Michael S. Tsirkin 2014-06-05 733 mergeable = vhost_has_feature(vq,
VIRTIO_NET_F_MRG_RXBUF);
8dd014adf David Stevens 2010-07-27 734
030881372 Jason Wang 2016-03-04 735 while ((sock_len =
vhost_net_rx_peek_head_len(net, sock->sk))) {
8dd014adf David Stevens 2010-07-27 736 sock_len += sock_hlen;
8dd014adf David Stevens 2010-07-27 737 vhost_len = sock_len +
vhost_hlen;
f5a4941aa Jason Wang 2018-05-29 @738 headcount = get_rx_bufs(vq,
vq->heads + nvq->done_idx,
f5a4941aa Jason Wang 2018-05-29 739 vhost_len, &in, vq_log,
&log,
94249369e Jason Wang 2011-01-17 740 likely(mergeable) ?
UIO_MAXIOV : 1);
8dd014adf David Stevens 2010-07-27 741 /* On error, stop handling until
the next kick. */
8dd014adf David Stevens 2010-07-27 742 if (unlikely(headcount < 0))
8241a1e46 Jason Wang 2016-06-01 743 goto out;
8dd014adf David Stevens 2010-07-27 744 /* OK, now we need to know about
added descriptors. */
8dd014adf David Stevens 2010-07-27 745 if (!headcount) {
8ea8cf89e Michael S. Tsirkin 2011-05-20 746 if
(unlikely(vhost_enable_notify(&net->dev, vq))) {
8dd014adf David Stevens 2010-07-27 747 /* They have slipped one in as
we were
8dd014adf David Stevens 2010-07-27 748 * doing that: check again. */
8ea8cf89e Michael S. Tsirkin 2011-05-20 749
vhost_disable_notify(&net->dev, vq);
8dd014adf David Stevens 2010-07-27 750 continue;
8dd014adf David Stevens 2010-07-27 751 }
8dd014adf David Stevens 2010-07-27 752 /* Nothing new? Wait for
eventfd to tell us
8dd014adf David Stevens 2010-07-27 753 * they refilled. */
8241a1e46 Jason Wang 2016-06-01 754 goto out;
8dd014adf David Stevens 2010-07-27 755 }
5990a3051 Jason Wang 2018-01-04 756 if (nvq->rx_ring)
6e474083f Wei Xu 2017-12-01 757 msg.msg_control =
vhost_net_buf_consume(&nvq->rxq);
6e474083f Wei Xu 2017-12-01 758 /* On overrun, truncate and
discard */
6e474083f Wei Xu 2017-12-01 759 if (unlikely(headcount >
UIO_MAXIOV)) {
6e474083f Wei Xu 2017-12-01 760
iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
6e474083f Wei Xu 2017-12-01 761 err =
sock->ops->recvmsg(sock, &msg,
6e474083f Wei Xu 2017-12-01 762 1, MSG_DONTWAIT |
MSG_TRUNC);
6e474083f Wei Xu 2017-12-01 763 pr_debug("Discarded rx
packet: len %zd\n", sock_len);
6e474083f Wei Xu 2017-12-01 764 continue;
6e474083f Wei Xu 2017-12-01 765 }
8dd014adf David Stevens 2010-07-27 766 /* We don't need to be
notified again. */
ba7438aed Al Viro 2014-12-10 767 iov_iter_init(&msg.msg_iter,
READ, vq->iov, in, vhost_len);
ba7438aed Al Viro 2014-12-10 768 fixup = msg.msg_iter;
ba7438aed Al Viro 2014-12-10 769 if (unlikely((vhost_hlen))) {
ba7438aed Al Viro 2014-12-10 770 /* We will supply the header
ourselves
ba7438aed Al Viro 2014-12-10 771 * TODO: support TSO.
ba7438aed Al Viro 2014-12-10 772 */
ba7438aed Al Viro 2014-12-10 773
iov_iter_advance(&msg.msg_iter, vhost_hlen);
ba7438aed Al Viro 2014-12-10 774 }
1b7841404 Ying Xue 2015-03-02 775 err =
sock->ops->recvmsg(sock, &msg,
8dd014adf David Stevens 2010-07-27 776 sock_len, MSG_DONTWAIT |
MSG_TRUNC);
8dd014adf David Stevens 2010-07-27 777 /* Userspace might have consumed
the packet meanwhile:
8dd014adf David Stevens 2010-07-27 778 * it's not supposed to do
this usually, but might be hard
8dd014adf David Stevens 2010-07-27 779 * to prevent. Discard data we
got (if any) and keep going. */
8dd014adf David Stevens 2010-07-27 780 if (unlikely(err != sock_len)) {
8dd014adf David Stevens 2010-07-27 781 pr_debug("Discarded rx
packet: "
8dd014adf David Stevens 2010-07-27 782 " len %d, expected
%zd\n", err, sock_len);
8dd014adf David Stevens 2010-07-27 783 vhost_discard_vq_desc(vq,
headcount);
8dd014adf David Stevens 2010-07-27 784 continue;
8dd014adf David Stevens 2010-07-27 785 }
ba7438aed Al Viro 2014-12-10 786 /* Supply virtio_net_hdr if
VHOST_NET_F_VIRTIO_NET_HDR */
4c5a84421 Michael S. Tsirkin 2015-02-25 787 if (unlikely(vhost_hlen)) {
4c5a84421 Michael S. Tsirkin 2015-02-25 788 if (copy_to_iter(&hdr,
sizeof(hdr),
4c5a84421 Michael S. Tsirkin 2015-02-25 789 &fixup) != sizeof(hdr))
{
4c5a84421 Michael S. Tsirkin 2015-02-25 790 vq_err(vq, "Unable to
write vnet_hdr "
4c5a84421 Michael S. Tsirkin 2015-02-25 791 "at addr
%p\n", vq->iov->iov_base);
8241a1e46 Jason Wang 2016-06-01 792 goto out;
8dd014adf David Stevens 2010-07-27 793 }
4c5a84421 Michael S. Tsirkin 2015-02-25 794 } else {
4c5a84421 Michael S. Tsirkin 2015-02-25 795 /* Header came from socket;
we'll need to patch
4c5a84421 Michael S. Tsirkin 2015-02-25 796 * ->num_buffers over if
VIRTIO_NET_F_MRG_RXBUF
4c5a84421 Michael S. Tsirkin 2015-02-25 797 */
4c5a84421 Michael S. Tsirkin 2015-02-25 798 iov_iter_advance(&fixup,
sizeof(hdr));
4c5a84421 Michael S. Tsirkin 2015-02-25 799 }
8dd014adf David Stevens 2010-07-27 800 /* TODO: Should check and handle
checksum. */
5201aa49b Michael S. Tsirkin 2015-02-03 801
0960b6417 Jason Wang 2015-02-15 802 num_buffers = cpu_to_vhost16(vq,
headcount);
cfbdab951 Jason Wang 2011-01-17 803 if (likely(mergeable) &&
0d79a493e Michael S. Tsirkin 2015-02-25 804
copy_to_iter(&num_buffers, sizeof num_buffers,
0d79a493e Michael S. Tsirkin 2015-02-25 805 &fixup) != sizeof
num_buffers) {
8dd014adf David Stevens 2010-07-27 806 vq_err(vq, "Failed
num_buffers write");
8dd014adf David Stevens 2010-07-27 807 vhost_discard_vq_desc(vq,
headcount);
8241a1e46 Jason Wang 2016-06-01 808 goto out;
8dd014adf David Stevens 2010-07-27 809 }
f5a4941aa Jason Wang 2018-05-29 810 nvq->done_idx += headcount;
f5a4941aa Jason Wang 2018-05-29 811 if (nvq->done_idx >
VHOST_RX_BATCH)
f5a4941aa Jason Wang 2018-05-29 812 vhost_rx_signal_used(nvq);
8dd014adf David Stevens 2010-07-27 813 if (unlikely(vq_log))
8dd014adf David Stevens 2010-07-27 814 vhost_log_write(vq, vq_log,
log, vhost_len);
8dd014adf David Stevens 2010-07-27 815 total_len += vhost_len;
db688c24e Paolo Abeni 2018-04-24 816 if (unlikely(total_len >=
VHOST_NET_WEIGHT) ||
db688c24e Paolo Abeni 2018-04-24 817 unlikely(++recv_pkts >=
VHOST_NET_PKT_WEIGHT)) {
8dd014adf David Stevens 2010-07-27 818
vhost_poll_queue(&vq->poll);
8241a1e46 Jason Wang 2016-06-01 819 goto out;
8dd014adf David Stevens 2010-07-27 820 }
8dd014adf David Stevens 2010-07-27 821 }
8241a1e46 Jason Wang 2016-06-01 822 vhost_net_enable_vq(net, vq);
2e26af79b Asias He 2013-05-07 823 out:
f5a4941aa Jason Wang 2018-05-29 824 vhost_rx_signal_used(nvq);
8dd014adf David Stevens 2010-07-27 825 mutex_unlock(&vq->mutex);
8dd014adf David Stevens 2010-07-27 826 }
8dd014adf David Stevens 2010-07-27 827
:::::: The code at line 738 was first introduced by commit
:::::: f5a4941aa6d190e676065e8f4ed35999f52a01c3 vhost_net: flush batched heads
before trying to busy polling
:::::: TO: Jason Wang <jasowang at redhat.com>
:::::: CC: David S. Miller <davem at davemloft.net>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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Wei Xu
2018-Jul-04 04:13 UTC
[PATCH net-next 8/8] vhost: event suppression for packed ring
On Tue, Jul 03, 2018 at 01:38:04PM +0800, Jason Wang wrote:> This patch introduces support for event suppression. This is done by > have a two areas: device area and driver area. One side could then try > to disable or enable (delayed) notification from other side by using a > boolean hint or event index interface in the areas. > > For more information, please refer Virtio spec. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++++++++++++---- > drivers/vhost/vhost.h | 10 ++- > 2 files changed, 185 insertions(+), 16 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 0f3f07c..cccbc82 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -1115,10 +1115,15 @@ static int vq_access_ok_packed(struct vhost_virtqueue *vq, unsigned int num, > struct vring_used __user *used) > { > struct vring_desc_packed *packed = (struct vring_desc_packed *)desc; > + struct vring_packed_desc_event *driver_event > + (struct vring_packed_desc_event *)avail; > + struct vring_packed_desc_event *device_event > + (struct vring_packed_desc_event *)used; > > - /* TODO: check device area and driver area */ > return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) && > - access_ok(VERIFY_WRITE, packed, num * sizeof(*packed)); > + access_ok(VERIFY_WRITE, packed, num * sizeof(*packed)) &&R/W parameter doesn't make sense to most architectures and the comment in x86 says WRITE is a superset of READ, is it possible to converge them here? /** * access_ok: - Checks if a user space pointer is valid * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe * to write to a block, it is always safe to read from it. * @addr: User space pointer to start of block to check * @size: Size of block to check * * Context: User context only. This function may sleep if pagefaults are * enabled. * * Checks if a pointer to a block of memory in user space is valid. * * Returns true (nonzero) if the memory block may be valid, false (zero) * if it is definitely invalid. * * Note that, depending on architecture, this function probably just * checks that the pointer is in the user space range - after calling * this function, memory access functions may still return -EFAULT. */ #define access_ok(type, addr, size) ...... Thanks, Wei> + access_ok(VERIFY_READ, driver_event, sizeof(*driver_event)) && > + access_ok(VERIFY_WRITE, device_event, sizeof(*device_event)); > } > > static int vq_access_ok_split(struct vhost_virtqueue *vq, unsigned int num, > @@ -1193,14 +1198,27 @@ static bool iotlb_access_ok(struct vhost_virtqueue *vq, > return true; > } > > -int vq_iotlb_prefetch(struct vhost_virtqueue *vq) > +int vq_iotlb_prefetch_packed(struct vhost_virtqueue *vq) > +{ > + int num = vq->num; > + > + return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc, > + num * sizeof(*vq->desc), VHOST_ADDR_DESC) && > + iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->desc, > + num * sizeof(*vq->desc), VHOST_ADDR_DESC) && > + iotlb_access_ok(vq, VHOST_ACCESS_RO, > + (u64)(uintptr_t)vq->driver_event, > + sizeof(*vq->driver_event), VHOST_ADDR_AVAIL) && > + iotlb_access_ok(vq, VHOST_ACCESS_WO, > + (u64)(uintptr_t)vq->device_event, > + sizeof(*vq->device_event), VHOST_ADDR_USED); > +} > + > +int vq_iotlb_prefetch_split(struct vhost_virtqueue *vq) > { > size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; > unsigned int num = vq->num; > > - if (!vq->iotlb) > - return 1; > - > return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc, > num * sizeof(*vq->desc), VHOST_ADDR_DESC) && > iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail, > @@ -1212,6 +1230,17 @@ int vq_iotlb_prefetch(struct vhost_virtqueue *vq) > num * sizeof(*vq->used->ring) + s, > VHOST_ADDR_USED); > } > + > +int vq_iotlb_prefetch(struct vhost_virtqueue *vq) > +{ > + if (!vq->iotlb) > + return 1; > + > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > + return vq_iotlb_prefetch_packed(vq); > + else > + return vq_iotlb_prefetch_split(vq); > +} > EXPORT_SYMBOL_GPL(vq_iotlb_prefetch); > > /* Can we log writes? */ > @@ -1771,6 +1800,50 @@ static int vhost_update_used_flags(struct vhost_virtqueue *vq) > return 0; > } > > +static int vhost_update_device_flags(struct vhost_virtqueue *vq, > + __virtio16 device_flags) > +{ > + void __user *flags; > + > + if (vhost_put_user(vq, device_flags, &vq->device_event->flags, > + VHOST_ADDR_USED) < 0) > + return -EFAULT; > + if (unlikely(vq->log_used)) { > + /* Make sure the flag is seen before log. */ > + smp_wmb(); > + /* Log used flag write. */ > + flags = &vq->device_event->flags; > + log_write(vq->log_base, vq->log_addr + > + (flags - (void __user *)vq->device_event), > + sizeof(vq->device_event->flags)); > + if (vq->log_ctx) > + eventfd_signal(vq->log_ctx, 1); > + } > + return 0; > +} > + > +static int vhost_update_device_off_wrap(struct vhost_virtqueue *vq, > + __virtio16 device_off_wrap) > +{ > + void __user *off_wrap; > + > + if (vhost_put_user(vq, device_off_wrap, &vq->device_event->off_wrap, > + VHOST_ADDR_USED) < 0) > + return -EFAULT; > + if (unlikely(vq->log_used)) { > + /* Make sure the flag is seen before log. */ > + smp_wmb(); > + /* Log used flag write. */ > + off_wrap = &vq->device_event->off_wrap; > + log_write(vq->log_base, vq->log_addr + > + (off_wrap - (void __user *)vq->device_event), > + sizeof(vq->device_event->off_wrap)); > + if (vq->log_ctx) > + eventfd_signal(vq->log_ctx, 1); > + } > + return 0; > +} > + > static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) > { > if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), > @@ -2756,16 +2829,13 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, > } > EXPORT_SYMBOL_GPL(vhost_add_used_n); > > -static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) > +static bool vhost_notify_split(struct vhost_dev *dev, > + struct vhost_virtqueue *vq) > { > __u16 old, new; > __virtio16 event; > bool v; > > - /* TODO: check driver area */ > - if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > - return true; > - > /* Flush out used index updates. This is paired > * with the barrier that the Guest executes when enabling > * interrupts. */ > @@ -2798,6 +2868,64 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) > return vring_need_event(vhost16_to_cpu(vq, event), new, old); > } > > +static bool vhost_notify_packed(struct vhost_dev *dev, > + struct vhost_virtqueue *vq) > +{ > + __virtio16 event_off_wrap, event_flags; > + __u16 old, new, off_wrap; > + bool v; > + > + /* Flush out used descriptors updates. This is paired > + * with the barrier that the Guest executes when enabling > + * interrupts. > + */ > + smp_mb(); > + > + if (vhost_get_avail(vq, event_flags, > + &vq->driver_event->flags) < 0) { > + vq_err(vq, "Failed to get driver desc_event_flags"); > + return true; > + } > + > + if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) > + return event_flags !> + cpu_to_vhost16(vq, RING_EVENT_FLAGS_DISABLE); > + > + old = vq->signalled_used; > + v = vq->signalled_used_valid; > + new = vq->signalled_used = vq->last_used_idx; > + vq->signalled_used_valid = true; > + > + if (event_flags != cpu_to_vhost16(vq, RING_EVENT_FLAGS_DESC)) > + return event_flags !> + cpu_to_vhost16(vq, RING_EVENT_FLAGS_DISABLE); > + > + /* Read desc event flags before event_off and event_wrap */ > + smp_rmb(); > + > + if (vhost_get_avail(vq, event_off_wrap, > + &vq->driver_event->off_wrap) < 0) { > + vq_err(vq, "Failed to get driver desc_event_off/wrap"); > + return true; > + } > + > + off_wrap = vhost16_to_cpu(vq, event_off_wrap); > + > + if (unlikely(!v)) > + return true; > + > + return vhost_vring_packed_need_event(vq, vq->last_used_wrap_counter, > + off_wrap, new, old); > +} > + > +static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) > +{ > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > + return vhost_notify_packed(dev, vq); > + else > + return vhost_notify_split(dev, vq); > +} > + > /* This actually signals the guest, using eventfd. */ > void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) > { > @@ -2875,10 +3003,34 @@ static bool vhost_enable_notify_packed(struct vhost_dev *dev, > struct vhost_virtqueue *vq) > { > struct vring_desc_packed *d = vq->desc_packed + vq->avail_idx; > - __virtio16 flags; > + __virtio16 flags = cpu_to_vhost16(vq, RING_EVENT_FLAGS_ENABLE); > int ret; > > - /* TODO: enable notification through device area */ > + if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) > + return false; > + vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; > + > + if (vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { > + __virtio16 off_wrap = cpu_to_vhost16(vq, vq->avail_idx | > + vq->avail_wrap_counter << 15); > + > + ret = vhost_update_device_off_wrap(vq, off_wrap); > + if (ret) { > + vq_err(vq, "Failed to write to off warp at %p: %d\n", > + &vq->device_event->off_wrap, ret); > + return false; > + } > + /* Make sure off_wrap is wrote before flags */ > + smp_wmb(); > + flags = cpu_to_vhost16(vq, RING_EVENT_FLAGS_DESC); > + } > + > + ret = vhost_update_device_flags(vq, flags); > + if (ret) { > + vq_err(vq, "Failed to enable notification at %p: %d\n", > + &vq->device_event->flags, ret); > + return false; > + } > > /* They could have slipped one in as we were doing that: make > * sure it's written, then check again. > @@ -2945,7 +3097,18 @@ EXPORT_SYMBOL_GPL(vhost_enable_notify); > static void vhost_disable_notify_packed(struct vhost_dev *dev, > struct vhost_virtqueue *vq) > { > - /* TODO: disable notification through device area */ > + __virtio16 flags; > + int r; > + > + if (vq->used_flags & VRING_USED_F_NO_NOTIFY) > + return; > + vq->used_flags |= VRING_USED_F_NO_NOTIFY; > + > + flags = cpu_to_vhost16(vq, RING_EVENT_FLAGS_DISABLE); > + r = vhost_update_device_flags(vq, flags); > + if (r) > + vq_err(vq, "Failed to enable notification at %p: %d\n", > + &vq->device_event->flags, r); > } > > static void vhost_disable_notify_split(struct vhost_dev *dev, > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index db09958..d071daf 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -96,8 +96,14 @@ struct vhost_virtqueue { > struct vring_desc __user *desc; > struct vring_desc_packed __user *desc_packed; > }; > - struct vring_avail __user *avail; > - struct vring_used __user *used; > + union { > + struct vring_avail __user *avail; > + struct vring_packed_desc_event __user *driver_event; > + }; > + union { > + struct vring_used __user *used; > + struct vring_packed_desc_event __user *device_event; > + }; > const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS]; > struct file *kick; > struct eventfd_ctx *call_ctx; > -- > 2.7.4 >
Tiwei Bie
2018-Jul-04 04:48 UTC
[PATCH net-next 6/8] virtio: introduce packed ring defines
On Tue, Jul 03, 2018 at 01:38:02PM +0800, Jason Wang wrote:> Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > include/uapi/linux/virtio_config.h | 2 ++ > include/uapi/linux/virtio_ring.h | 32 ++++++++++++++++++++++++++++++++ > 2 files changed, 34 insertions(+) > > diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h > index 449132c..947f6a3 100644 > --- a/include/uapi/linux/virtio_config.h > +++ b/include/uapi/linux/virtio_config.h > @@ -75,6 +75,8 @@ > */ > #define VIRTIO_F_IOMMU_PLATFORM 33 > > +#define VIRTIO_F_RING_PACKED 34It's better to add some comments for this macro.> + > /* > * Does the device support Single Root I/O Virtualization? > */ > diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h > index 6d5d5fa..71c7a46 100644 > --- a/include/uapi/linux/virtio_ring.h > +++ b/include/uapi/linux/virtio_ring.h > @@ -43,6 +43,8 @@ > #define VRING_DESC_F_WRITE 2 > /* This means the buffer contains a list of buffer descriptors. */ > #define VRING_DESC_F_INDIRECT 4 > +#define VRING_DESC_F_AVAIL 7It's better to use tab between VRING_DESC_F_AVAIL and 7.> +#define VRING_DESC_F_USED 15Maybe it's better to define VRING_DESC_F_AVAIL and VRING_DESC_F_USED as (1 << 7) and (1 << 15) or something similar to make them consistent with VRING_DESC_F_NEXT (1 << 0), VRING_DESC_F_WRITE (1 << 1) and VRING_DESC_F_INDIRECT (1 << 2). I plan to define below macros in virtio_ring.c: #define _VRING_DESC_F_AVAIL(b) ((__u16)(b) << 7) #define _VRING_DESC_F_USED(b) ((__u16)(b) << 15)> > /* The Host uses this in used->flags to advise the Guest: don't kick me when > * you add a buffer. It's unreliable, so it's simply an optimization. Guest > @@ -62,6 +64,36 @@ > * at the end of the used ring. Guest should ignore the used->flags field. */ > #define VIRTIO_RING_F_EVENT_IDX 29 > > +struct vring_desc_packed {We may have other related types named as: struct vring_packed; struct vring_packed_desc_event; So maybe it's better to name this type as: struct vring_packed_desc;> + /* Buffer Address. */ > + __virtio64 addr; > + /* Buffer Length. */ > + __virtio32 len; > + /* Buffer ID. */ > + __virtio16 id; > + /* The flags depending on descriptor type. */ > + __virtio16 flags; > +}; > + > +/* Enable events */ > +#define RING_EVENT_FLAGS_ENABLE 0x0 > +/* Disable events */ > +#define RING_EVENT_FLAGS_DISABLE 0x1 > +/* > + * Enable events for a specific descriptor > + * (as specified by Descriptor Ring Change Event Offset/Wrap Counter). > + * Only valid if VIRTIO_F_RING_EVENT_IDX has been negotiated. > + */ > +#define RING_EVENT_FLAGS_DESC 0x2For above three macros, maybe it's better to name them as: VRING_EVENT_FLAGS_ENABLE VRING_EVENT_FLAGS_DISABLE VRING_EVENT_FLAGS_DESC or VRING_EVENT_F_ENABLE VRING_EVENT_F_DISABLE VRING_EVENT_F_DESC VRING_EVENT_F_* will be more consistent with VIRTIO_F_*, VRING_DESC_F_*, etc> +/* The value 0x3 is reserved */ > + > +struct vring_packed_desc_event { > + /* Descriptor Ring Change Event Offset and Wrap Counter */ > + __virtio16 off_wrap; > + /* Descriptor Ring Change Event Flags */ > + __virtio16 flags; > +}; > + > /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ > struct vring_desc { > /* Address (guest-physical). */ > -- > 2.7.4 >
Jason Wang
2018-Jul-05 11:30 UTC
[PATCH net-next 6/8] virtio: introduce packed ring defines
On 2018?07?05? 04:15, Maxime Coquelin wrote:> > > On 07/03/2018 07:38 AM, Jason Wang wrote: >> diff --git a/include/uapi/linux/virtio_ring.h >> b/include/uapi/linux/virtio_ring.h >> index 6d5d5fa..71c7a46 100644 >> --- a/include/uapi/linux/virtio_ring.h >> +++ b/include/uapi/linux/virtio_ring.h >> @@ -43,6 +43,8 @@ >> ? #define VRING_DESC_F_WRITE??? 2 >> ? /* This means the buffer contains a list of buffer descriptors. */ >> ? #define VRING_DESC_F_INDIRECT??? 4 >> +#define VRING_DESC_F_AVAIL????? 7 >> +#define VRING_DESC_F_USED??? 15 > > For consistency, you may want to make VRING_DESC_F_AVAIL and > VRING_DESC_F_USED to represent the bit mask and not the bit position, > as done for VRING_DESC_F_WRITE and VRING_DESC_F_INDIRECT. > > Regards, > MaximeYes, Tiwei has the same comment. Will fix this. Thanks
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