On Sat, Nov 12, 2011 at 12:12:01AM +0200, Sasha Levin wrote:
> This is a patch based on Krishna Kumar's patch series which implements
> multiple VQ support for virtio-net.
>
> The patch was tested with ver3 of the patch.
>
> Cc: Krishna Kumar <krkumar2@xxxxxxxxxx>
> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
Any performance numbers?
> ---
> tools/kvm/include/kvm/virtio-pci.h | 2 +-
> tools/kvm/virtio/net.c | 94 +++++++++++++++++++----------------
> 2 files changed, 52 insertions(+), 44 deletions(-)
>
> diff --git a/tools/kvm/include/kvm/virtio-pci.h b/tools/kvm/include/kvm/virtio-pci.h
> index 2bbb271..94d20ee 100644
> --- a/tools/kvm/include/kvm/virtio-pci.h
> +++ b/tools/kvm/include/kvm/virtio-pci.h
> @@ -6,7 +6,7 @@
>
> #include <linux/types.h>
>
> -#define VIRTIO_PCI_MAX_VQ 3
> +#define VIRTIO_PCI_MAX_VQ 16
> #define VIRTIO_PCI_MAX_CONFIG 1
>
> struct kvm;
> diff --git a/tools/kvm/virtio/net.c b/tools/kvm/virtio/net.c
> index cee2b5b..0754795 100644
> --- a/tools/kvm/virtio/net.c
> +++ b/tools/kvm/virtio/net.c
> @@ -27,9 +27,8 @@
> #include <sys/wait.h>
>
> #define VIRTIO_NET_QUEUE_SIZE 128
> -#define VIRTIO_NET_NUM_QUEUES 2
> -#define VIRTIO_NET_RX_QUEUE 0
> -#define VIRTIO_NET_TX_QUEUE 1
> +#define VIRTIO_NET_NUM_QUEUES 16
> +#define VIRTIO_NET_IS_RX_QUEUE(x) (((x) % 2) == 0)
>
> struct net_dev;
>
> @@ -49,14 +48,13 @@ struct net_dev {
> struct virtio_net_config config;
> u32 features;
>
> - pthread_t io_rx_thread;
> - pthread_mutex_t io_rx_lock;
> - pthread_cond_t io_rx_cond;
> -
> - pthread_t io_tx_thread;
> - pthread_mutex_t io_tx_lock;
> - pthread_cond_t io_tx_cond;
> + pthread_t io_thread[VIRTIO_NET_NUM_QUEUES];
> + pthread_mutex_t io_lock[VIRTIO_NET_NUM_QUEUES];
> + pthread_cond_t io_cond[VIRTIO_NET_NUM_QUEUES];
>
> + int rx_vq_num;
> + int tx_vq_num;
> + int vq_num;
> int tap_fd;
> char tap_name[IFNAMSIZ];
>
> @@ -78,17 +76,22 @@ static void *virtio_net_rx_thread(void *p)
> struct net_dev *ndev = p;
> u16 out, in;
> u16 head;
> - int len;
> + int len, queue_num;
> +
> + mutex_lock(&ndev->mutex);
> + queue_num = ndev->rx_vq_num * 2;
> + ndev->tx_vq_num++;
> + mutex_unlock(&ndev->mutex);
>
> kvm = ndev->kvm;
> - vq = &ndev->vqs[VIRTIO_NET_RX_QUEUE];
> + vq = &ndev->vqs[queue_num];
>
> while (1) {
>
> - mutex_lock(&ndev->io_rx_lock);
> + mutex_lock(&ndev->io_lock[queue_num]);
> if (!virt_queue__available(vq))
> - pthread_cond_wait(&ndev->io_rx_cond, &ndev->io_rx_lock);
> - mutex_unlock(&ndev->io_rx_lock);
> + pthread_cond_wait(&ndev->io_cond[queue_num], &ndev->io_lock[queue_num]);
> + mutex_unlock(&ndev->io_lock[queue_num]);
>
> while (virt_queue__available(vq)) {
>
> @@ -99,7 +102,7 @@ static void *virtio_net_rx_thread(void *p)
> virt_queue__set_used_elem(vq, head, len);
>
> /* We should interrupt guest right now, otherwise latency is huge. */
> - ndev->vtrans.trans_ops->signal_vq(kvm, &ndev->vtrans, VIRTIO_NET_RX_QUEUE);
> + ndev->vtrans.trans_ops->signal_vq(kvm, &ndev->vtrans, queue_num);
> }
>
> }
> @@ -117,16 +120,21 @@ static void *virtio_net_tx_thread(void *p)
> struct net_dev *ndev = p;
> u16 out, in;
> u16 head;
> - int len;
> + int len, queue_num;
> +
> + mutex_lock(&ndev->mutex);
> + queue_num = ndev->tx_vq_num * 2 + 1;
> + ndev->tx_vq_num++;
> + mutex_unlock(&ndev->mutex);
>
> kvm = ndev->kvm;
> - vq = &ndev->vqs[VIRTIO_NET_TX_QUEUE];
> + vq = &ndev->vqs[queue_num];
>
> while (1) {
> - mutex_lock(&ndev->io_tx_lock);
> + mutex_lock(&ndev->io_lock[queue_num]);
> if (!virt_queue__available(vq))
> - pthread_cond_wait(&ndev->io_tx_cond, &ndev->io_tx_lock);
> - mutex_unlock(&ndev->io_tx_lock);
> + pthread_cond_wait(&ndev->io_cond[queue_num], &ndev->io_lock[queue_num]);
> + mutex_unlock(&ndev->io_lock[queue_num]);
>
> while (virt_queue__available(vq)) {
>
> @@ -137,7 +145,7 @@ static void *virtio_net_tx_thread(void *p)
> virt_queue__set_used_elem(vq, head, len);
> }
>
> - ndev->vtrans.trans_ops->signal_vq(kvm, &ndev->vtrans, VIRTIO_NET_TX_QUEUE);
> + ndev->vtrans.trans_ops->signal_vq(kvm, &ndev->vtrans, queue_num);
> }
>
> pthread_exit(NULL);
> @@ -148,20 +156,9 @@ static void *virtio_net_tx_thread(void *p)
>
> static void virtio_net_handle_callback(struct kvm *kvm, struct net_dev *ndev, int queue)
> {
> - switch (queue) {
> - case VIRTIO_NET_TX_QUEUE:
> - mutex_lock(&ndev->io_tx_lock);
> - pthread_cond_signal(&ndev->io_tx_cond);
> - mutex_unlock(&ndev->io_tx_lock);
> - break;
> - case VIRTIO_NET_RX_QUEUE:
> - mutex_lock(&ndev->io_rx_lock);
> - pthread_cond_signal(&ndev->io_rx_cond);
> - mutex_unlock(&ndev->io_rx_lock);
> - break;
> - default:
> - pr_warning("Unknown queue index %u", queue);
> - }
> + mutex_lock(&ndev->io_lock[queue]);
> + pthread_cond_signal(&ndev->io_cond[queue]);
> + mutex_unlock(&ndev->io_lock[queue]);
> }
>
> static bool virtio_net__tap_init(const struct virtio_net_params *params,
> @@ -248,14 +245,17 @@ fail:
>
> static void virtio_net__io_thread_init(struct kvm *kvm, struct net_dev *ndev)
> {
> - pthread_mutex_init(&ndev->io_tx_lock, NULL);
> - pthread_mutex_init(&ndev->io_rx_lock, NULL);
> + int i;
>
> - pthread_cond_init(&ndev->io_tx_cond, NULL);
> - pthread_cond_init(&ndev->io_rx_cond, NULL);
> + for (i = 0; i < ndev->vq_num; i++) {
> + pthread_mutex_init(&ndev->io_lock[i], NULL);
> + pthread_cond_init(&ndev->io_cond[i], NULL);
> + }
>
> - pthread_create(&ndev->io_tx_thread, NULL, virtio_net_tx_thread, ndev);
> - pthread_create(&ndev->io_rx_thread, NULL, virtio_net_rx_thread, ndev);
> + for (i = 0; i < ndev->vq_num; i += 2) {
> + pthread_create(&ndev->io_thread[i], NULL, virtio_net_tx_thread, ndev);
> + pthread_create(&ndev->io_thread[i + 1], NULL, virtio_net_rx_thread, ndev);
> + }
> }
>
> static inline int tap_ops_tx(struct iovec *iov, u16 out, struct net_dev *ndev)
> @@ -311,13 +311,19 @@ static u32 get_host_features(struct kvm *kvm, void *dev)
> | 1UL << VIRTIO_NET_F_HOST_TSO6
> | 1UL << VIRTIO_NET_F_GUEST_UFO
> | 1UL << VIRTIO_NET_F_GUEST_TSO4
> - | 1UL << VIRTIO_NET_F_GUEST_TSO6;
> + | 1UL << VIRTIO_NET_F_GUEST_TSO6
> + | 1UL << VIRTIO_NET_F_MULTIQUEUE;
> }
>
> static void set_guest_features(struct kvm *kvm, void *dev, u32 features)
> {
> struct net_dev *ndev = dev;
>
> + if (features & (1UL << VIRTIO_NET_F_MULTIQUEUE))
> + ndev->vq_num = ndev->config.num_queues;
> + else
> + ndev->vq_num = 2;
> +
> ndev->features = features;
> }
>
> @@ -395,6 +401,8 @@ void virtio_net__init(const struct virtio_net_params *params)
> ndev->info.host_mac.addr[i] = params->host_mac[i];
> }
>
> + ndev->config.num_queues = VIRTIO_NET_NUM_QUEUES;
> +
> ndev->mode = params->mode;
> if (ndev->mode == NET_MODE_TAP) {
> if (!virtio_net__tap_init(params, ndev))
> --
> 1.7.7.2
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