Signed-off-by: Jason Wang <address@hidden>
---
hw/net/vhost_net.c | 2 +-
hw/scsi/vhost-scsi.c | 2 +-
hw/virtio/vhost-backend.c | 8 ++++++++
hw/virtio/vhost.c | 40 ++++++++++++++++++++++++++++++++++++++-
include/hw/virtio/vhost-backend.h | 3 +++
include/hw/virtio/vhost.h | 3 ++-
include/net/vhost_net.h | 1 +
net/tap.c | 10 ++++++++--
net/vhost-user.c | 1 +
qapi-schema.json | 6 +++++-
qemu-options.hx | 3 +++
11 files changed, 72 insertions(+), 7 deletions(-)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 6e1032f..1840c73 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -166,7 +166,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
}
r = vhost_dev_init(&net->dev, options->opaque,
- options->backend_type);
+ options->backend_type, options->busyloop_timeout);
if (r < 0) {
goto fail;
}
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 9261d51..2a00f2f 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -248,7 +248,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error
**errp)
s->dev.backend_features = 0;
ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
- VHOST_BACKEND_TYPE_KERNEL);
+ VHOST_BACKEND_TYPE_KERNEL, 0);
if (ret < 0) {
error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
strerror(-ret));
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index b358902..d62372e 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -138,6 +138,12 @@ static int vhost_kernel_set_vring_call(struct vhost_dev
*dev,
return vhost_kernel_call(dev, VHOST_SET_VRING_CALL, file);
}
+static int vhost_kernel_set_vring_busyloop_timeout(struct vhost_dev *dev,
+ struct vhost_vring_state *s)
+{
+ return vhost_kernel_call(dev, VHOST_SET_VRING_BUSYLOOP_TIMEOUT, s);
+}
+
static int vhost_kernel_set_features(struct vhost_dev *dev,
uint64_t features)
{
@@ -185,6 +191,8 @@ static const VhostOps kernel_ops = {
.vhost_get_vring_base = vhost_kernel_get_vring_base,
.vhost_set_vring_kick = vhost_kernel_set_vring_kick,
.vhost_set_vring_call = vhost_kernel_set_vring_call,
+ .vhost_set_vring_busyloop_timeout =
+ vhost_kernel_set_vring_busyloop_timeout,
.vhost_set_features = vhost_kernel_set_features,
.vhost_get_features = vhost_kernel_get_features,
.vhost_set_owner = vhost_kernel_set_owner,
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 4400718..ebf8b08 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -964,6 +964,28 @@ static void vhost_eventfd_del(MemoryListener *listener,
{
}
+static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev,
+ int n, uint32_t timeout)
+{
+ int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n);
+ struct vhost_vring_state state = {
+ .index = vhost_vq_index,
+ .num = timeout,
+ };
+ int r;
+
+ if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) {
+ return -EINVAL;
+ }
+
+ r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state);
+ if (r) {
+ return r;
+ }
+
+ return 0;
+}
+
static int vhost_virtqueue_init(struct vhost_dev *dev,
struct vhost_virtqueue *vq, int n)
{
@@ -994,7 +1016,7 @@ static void vhost_virtqueue_cleanup(struct vhost_virtqueue
*vq)
}
int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
- VhostBackendType backend_type)
+ VhostBackendType backend_type, uint32_t busyloop_timeout)
{
uint64_t features;
int i, r;
@@ -1035,6 +1057,17 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
goto fail_vq;
}
}
+
+ if (busyloop_timeout) {
+ for (i = 0; i < hdev->nvqs; ++i) {
+ r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i,
+ busyloop_timeout);
+ if (r < 0) {
+ goto fail_busyloop;
+ }
+ }
+ }
+
hdev->features = features;
hdev->memory_listener = (MemoryListener) {
@@ -1077,6 +1110,11 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
hdev->memory_changed = false;
memory_listener_register(&hdev->memory_listener, &address_space_memory);
return 0;
+fail_busyloop:
+ while (--i >= 0) {
+ vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
+ }
+ i = hdev->nvqs;
fail_vq:
while (--i >= 0) {
vhost_virtqueue_cleanup(hdev->vqs + i);
diff --git a/include/hw/virtio/vhost-backend.h
b/include/hw/virtio/vhost-backend.h
index 95fcc96..84e1cb7 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -57,6 +57,8 @@ typedef int (*vhost_set_vring_kick_op)(struct vhost_dev *dev,
struct vhost_vring_file *file);
typedef int (*vhost_set_vring_call_op)(struct vhost_dev *dev,
struct vhost_vring_file *file);
+typedef int (*vhost_set_vring_busyloop_timeout_op)(struct vhost_dev *dev,
+ struct vhost_vring_state
*r);
typedef int (*vhost_set_features_op)(struct vhost_dev *dev,
uint64_t features);
typedef int (*vhost_get_features_op)(struct vhost_dev *dev,
@@ -91,6 +93,7 @@ typedef struct VhostOps {
vhost_get_vring_base_op vhost_get_vring_base;
vhost_set_vring_kick_op vhost_set_vring_kick;
vhost_set_vring_call_op vhost_set_vring_call;
+ vhost_set_vring_busyloop_timeout_op vhost_set_vring_busyloop_timeout;
vhost_set_features_op vhost_set_features;
vhost_get_features_op vhost_get_features;
vhost_set_owner_op vhost_set_owner;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index b60d758..2106ed8 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -64,7 +64,8 @@ struct vhost_dev {
};
int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
- VhostBackendType backend_type);
+ VhostBackendType backend_type,
+ uint32_t busyloop_timeout);
void vhost_dev_cleanup(struct vhost_dev *hdev);
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index 3389b41..8354b98 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -10,6 +10,7 @@ typedef struct vhost_net VHostNetState;
typedef struct VhostNetOptions {
VhostBackendType backend_type;
NetClientState *net_backend;
+ uint32_t busyloop_timeout;
void *opaque;
} VhostNetOptions;
diff --git a/net/tap.c b/net/tap.c
index 740e8a2..7e28102 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -663,6 +663,11 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
options.net_backend = &s->nc;
+ if (tap->has_vhost_poll_us) {
+ options.busyloop_timeout = tap->vhost_poll_us;
+ } else {
+ options.busyloop_timeout = 0;
+ }
if (vhostfdname) {
vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
@@ -686,8 +691,9 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
"vhost-net requested but could not be initialized");
return;
}
- } else if (vhostfdname) {
- error_setg(errp, "vhostfd= is not valid without vhost");
+ } else if (vhostfdname || tap->has_vhost_poll_us) {
+ error_setg(errp, "vhostfd(s)= or vhost_poll_us= is not valid"
+ " without vhost");
}
}
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 1b9e73a..b200182 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -80,6 +80,7 @@ static int vhost_user_start(int queues, NetClientState *ncs[])
options.net_backend = ncs[i];
options.opaque = s->chr;
+ options.busyloop_timeout = 0;
s->vhost_net = vhost_net_init(&options);
if (!s->vhost_net) {
error_report("failed to init vhost_net for queue %d", i);
diff --git a/qapi-schema.json b/qapi-schema.json
index 54634c4..8afdedf 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2531,6 +2531,9 @@
#
# @queues: #optional number of queues to be created for multiqueue capable tap
#
+# @vhost-poll-us: #optional maximum number of microseconds that could
+# be spent on busy polling for vhost net (since 2.7)
+#
# Since 1.2
##
{ 'struct': 'NetdevTapOptions',
@@ -2547,7 +2550,8 @@
'*vhostfd': 'str',
'*vhostfds': 'str',
'*vhostforce': 'bool',
- '*queues': 'uint32'} }
+ '*queues': 'uint32',
+ '*vhost-poll-us': 'uint32'} }
##
# @NetdevSocketOptions
diff --git a/qemu-options.hx b/qemu-options.hx
index 587de8f..22ddb82 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1569,6 +1569,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
"-netdev
tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
"
[,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
"
[,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
+ " [,vhost-poll-us=n]\n"
" configure a host TAP network backend with ID 'str'\n"
" use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT
")\n"
" to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT
")\n"
@@ -1588,6 +1589,8 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
" use 'vhostfd=h' to connect to an already opened vhost net
device\n"
" use 'vhostfds=x:y:...:z to connect to multiple already opened
vhost net devices\n"
" use 'queues=n' to specify the number of queues to be created
for multiqueue TAP\n"
+ " use 'vhost-poll-us=n' to speciy the maximum number of
microseconds that could be\n"
+ " spent on busy polling for vhost net\n"
"-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
" configure a host TAP network backend with ID 'str' that
is\n"
" connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE
")\n"
--
2.5.0