This patch lets vhost support multiqueue. The idea is simple, just launching
multiple threads of vhost and let each of vhost thread processing a subset of
the virtqueues of the device. After this change each emulated device can have
multiple vhost threads as its backend.
To do this, a virtqueue index were introduced to record to first virtqueue that
will be handled by this vhost_net device. Based on this and nvqs, vhost could
calculate its relative index to setup vhost_net device.
Since we may have many vhost/net devices for a virtio-net device. The setting of
guest notifiers were moved out of the starting/stopping of a specific vhost
thread. The vhost_net_{start|stop}() were renamed to
vhost_net_{start|stop}_one(), and a new vhost_net_{start|stop}() were introduced
to configure the guest notifiers and start/stop all vhost/vhost_net devices.
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
hw/vhost.c | 82 +++++++++++++++++++++++-----------------------------
hw/vhost.h | 2 +
hw/vhost_net.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++-----
hw/vhost_net.h | 4 +-
hw/virtio-net.c | 4 +-
5 files changed, 120 insertions(+), 58 deletions(-)
diff --git a/hw/vhost.c b/hw/vhost.c
index cee8aad..38257b9 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -619,14 +619,17 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
{
hwaddr s, l, a;
int r;
+ int vhost_vq_index = idx - dev->vq_index;
struct vhost_vring_file file = {
- .index = idx,
+ .index = vhost_vq_index
};
struct vhost_vring_state state = {
- .index = idx,
+ .index = vhost_vq_index
};
struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
+ assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
+
vq->num = state.num = virtio_queue_get_num(vdev, idx);
r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
if (r) {
@@ -669,11 +672,12 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
goto fail_alloc_ring;
}
- r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
+ r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
if (r < 0) {
r = -errno;
goto fail_alloc;
}
+
file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
if (r) {
@@ -709,9 +713,10 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev,
unsigned idx)
{
struct vhost_vring_state state = {
- .index = idx,
+ .index = idx - dev->vq_index
};
int r;
+ assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
if (r < 0) {
fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
@@ -867,7 +872,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
}
for (i = 0; i < hdev->nvqs; ++i) {
- r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, true);
+ r = vdev->binding->set_host_notifier(vdev->binding_opaque,
+ hdev->vq_index + i,
+ true);
if (r < 0) {
fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
goto fail_vq;
@@ -877,7 +884,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
return 0;
fail_vq:
while (--i >= 0) {
- r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
+ r = vdev->binding->set_host_notifier(vdev->binding_opaque,
+ hdev->vq_index + i,
+ false);
if (r < 0) {
fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
fflush(stderr);
@@ -898,7 +907,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
int i, r;
for (i = 0; i < hdev->nvqs; ++i) {
- r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
+ r = vdev->binding->set_host_notifier(vdev->binding_opaque,
+ hdev->vq_index + i,
+ false);
if (r < 0) {
fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
fflush(stderr);
@@ -912,8 +923,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
*/
bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n)
{
- struct vhost_virtqueue *vq = hdev->vqs + n;
+ struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index;
assert(hdev->started);
+ assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs);
return event_notifier_test_and_clear(&vq->masked_notifier);
}
@@ -922,15 +934,16 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n,
bool mask)
{
struct VirtQueue *vvq = virtio_get_queue(vdev, n);
- int r;
+ int r, index = n - hdev->vq_index;
assert(hdev->started);
+ assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs);
struct vhost_vring_file file = {
- .index = n,
+ .index = index
};
if (mask) {
- file.fd = event_notifier_get_fd(&hdev->vqs[n].masked_notifier);
+ file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier);
} else {
file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
}
@@ -945,20 +958,6 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
hdev->started = true;
- if (!vdev->binding->set_guest_notifiers) {
- fprintf(stderr, "binding does not support guest notifiers\n");
- r = -ENOSYS;
- goto fail;
- }
-
- r = vdev->binding->set_guest_notifiers(vdev->binding_opaque,
- hdev->nvqs,
- true);
- if (r < 0) {
- fprintf(stderr, "Error binding guest notifier: %d\n", -r);
- goto fail_notifiers;
- }
-
r = vhost_dev_set_features(hdev, hdev->log_enabled);
if (r < 0) {
goto fail_features;
@@ -970,9 +969,9 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
}
for (i = 0; i < hdev->nvqs; ++i) {
r = vhost_virtqueue_start(hdev,
- vdev,
- hdev->vqs + i,
- i);
+ vdev,
+ hdev->vqs + i,
+ hdev->vq_index + i);
if (r < 0) {
goto fail_vq;
}
@@ -995,15 +994,13 @@ fail_log:
fail_vq:
while (--i >= 0) {
vhost_virtqueue_stop(hdev,
- vdev,
- hdev->vqs + i,
- i);
+ vdev,
+ hdev->vqs + i,
+ hdev->vq_index + i);
}
+ i = hdev->nvqs;
fail_mem:
fail_features:
- vdev->binding->set_guest_notifiers(vdev->binding_opaque, hdev->nvqs, false);
-fail_notifiers:
-fail:
hdev->started = false;
return r;
@@ -1012,29 +1009,22 @@ fail:
/* Host notifiers must be enabled at this point. */
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
{
- int i, r;
+ int i;
for (i = 0; i < hdev->nvqs; ++i) {
vhost_virtqueue_stop(hdev,
- vdev,
- hdev->vqs + i,
- i);
+ vdev,
+ hdev->vqs + i,
+ hdev->vq_index + i);
}
for (i = 0; i < hdev->n_mem_sections; ++i) {
vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i],
0, (hwaddr)~0x0ull);
}
- r = vdev->binding->set_guest_notifiers(vdev->binding_opaque,
- hdev->nvqs,
- false);
- if (r < 0) {
- fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
- fflush(stderr);
- }
- assert (r >= 0);
hdev->started = false;
g_free(hdev->log);
hdev->log = NULL;
hdev->log_size = 0;
}
+
diff --git a/hw/vhost.h b/hw/vhost.h
index 44c61a5..f062d48 100644
--- a/hw/vhost.h
+++ b/hw/vhost.h
@@ -35,6 +35,8 @@ struct vhost_dev {
MemoryRegionSection *mem_sections;
struct vhost_virtqueue *vqs;
int nvqs;
+ /* the first virtuque which would be used by this vhost dev */
+ int vq_index;
unsigned long long features;
unsigned long long acked_features;
unsigned long long backend_features;
diff --git a/hw/vhost_net.c b/hw/vhost_net.c
index d3a04ca..8693ac2 100644
--- a/hw/vhost_net.c
+++ b/hw/vhost_net.c
@@ -140,12 +140,21 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
return vhost_dev_query(&net->dev, dev);
}
-int vhost_net_start(struct vhost_net *net,
- VirtIODevice *dev)
+static int vhost_net_start_one(struct vhost_net *net,
+ VirtIODevice *dev,
+ int vq_index)
{
struct vhost_vring_file file = { };
int r;
+ if (net->dev.started) {
+ return 0;
+ }
+
+ net->dev.nvqs = 2;
+ net->dev.vqs = net->vqs;
+ net->dev.vq_index = vq_index;
+
r = vhost_dev_enable_notifiers(&net->dev, dev);
if (r < 0) {
goto fail_notifiers;
@@ -181,11 +190,15 @@ fail_notifiers:
return r;
}
-void vhost_net_stop(struct vhost_net *net,
- VirtIODevice *dev)
+static void vhost_net_stop_one(struct vhost_net *net,
+ VirtIODevice *dev)
{
struct vhost_vring_file file = { .fd = -1 };
+ if (!net->dev.started) {
+ return;
+ }
+
for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
assert(r >= 0);
@@ -195,6 +208,61 @@ void vhost_net_stop(struct vhost_net *net,
vhost_dev_disable_notifiers(&net->dev, dev);
}
+int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
+ int total_queues)
+{
+ int r, i = 0;
+
+ if (!dev->binding->set_guest_notifiers) {
+ error_report("binding does not support guest notifiers\n");
+ r = -ENOSYS;
+ goto err;
+ }
+
+ for (i = 0; i < total_queues; i++) {
+ r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);
+
+ if (r < 0) {
+ goto err;
+ }
+ }
+
+ r = dev->binding->set_guest_notifiers(dev->binding_opaque,
+ total_queues * 2,
+ true);
+ if (r < 0) {
+ error_report("Error binding guest notifier: %d\n", -r);
+ goto err;
+ }
+
+ return 0;
+
+err:
+ while (--i >= 0) {
+ vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
+ }
+ return r;
+}
+
+void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
+ int total_queues)
+{
+ int i, r;
+
+ r = dev->binding->set_guest_notifiers(dev->binding_opaque,
+ total_queues * 2,
+ false);
+ if (r < 0) {
+ fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
+ fflush(stderr);
+ }
+ assert(r >= 0);
+
+ for (i = 0; i < total_queues; i++) {
+ vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
+ }
+}
+
void vhost_net_cleanup(struct vhost_net *net)
{
vhost_dev_cleanup(&net->dev);
@@ -224,13 +292,15 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
return false;
}
-int vhost_net_start(struct vhost_net *net,
- VirtIODevice *dev)
+int vhost_net_start(VirtIODevice *dev,
+ NetClientState *ncs,
+ int total_queues)
{
return -ENOSYS;
}
-void vhost_net_stop(struct vhost_net *net,
- VirtIODevice *dev)
+void vhost_net_stop(VirtIODevice *dev,
+ NetClientState *ncs,
+ int total_queues)
{
}
diff --git a/hw/vhost_net.h b/hw/vhost_net.h
index 88912b8..2d936bb 100644
--- a/hw/vhost_net.h
+++ b/hw/vhost_net.h
@@ -9,8 +9,8 @@ typedef struct vhost_net VHostNetState;
VHostNetState *vhost_net_init(NetClientState *backend, int devfd, bool force);
bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
-int vhost_net_start(VHostNetState *net, VirtIODevice *dev);
-void vhost_net_stop(VHostNetState *net, VirtIODevice *dev);
+int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int total_queues);
+void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, int total_queues);
void vhost_net_cleanup(VHostNetState *net);
diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 47f4ab4..2dfcc4d 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -129,14 +129,14 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
return;
}
n->vhost_started = 1;
- r = vhost_net_start(tap_get_vhost_net(nc->peer), &n->vdev);
+ r = vhost_net_start(&n->vdev, nc, 1);
if (r < 0) {
error_report("unable to start vhost net: %d: "
"falling back on userspace virtio", -r);
n->vhost_started = 0;
}
} else {
- vhost_net_stop(tap_get_vhost_net(nc->peer), &n->vdev);
+ vhost_net_stop(&n->vdev, nc, 1);
n->vhost_started = 0;
}
}
--
1.7.1
--
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