On 09/18/2015 10:58 PM, Yuanhan Liu wrote:
> This is for querying how many queues the backend supports if it has mq
> support(when VHOST_USER_PROTOCOL_F_MQ flag is set from the quried
> protocol features).
>
> vhost_net_get_max_queues() is the interface to export that value, and
> to tell if the backend supports # of queues user requested, which is
> done in the following patch.
>
> Signed-off-by: Yuanhan Liu <yuanhan....@linux.intel.com>
> ---
> docs/specs/vhost-user.txt | 11 +++++++++++
> hw/net/vhost_net.c | 7 +++++++
> hw/virtio/vhost-user.c | 15 ++++++++++++++-
> include/hw/virtio/vhost.h | 1 +
> include/net/vhost_net.h | 1 +
> 5 files changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt
> index ccbbcbb..43db9b4 100644
> --- a/docs/specs/vhost-user.txt
> +++ b/docs/specs/vhost-user.txt
> @@ -301,3 +301,14 @@ Message types
> Bits (0-7) of the payload contain the vring index. Bit 8 is the
> invalid FD flag. This flag is set when there is no file descriptor
> in the ancillary data.
> +
> + * VHOST_USER_GET_QUEUE_NUM
> +
> + Id: 17
> + Equivalent ioctl: N/A
> + Master payload: N/A
> + Slave payload: u64
> +
> + Query how many queues the backend supports. This request should be
> + sent only when VHOST_USER_PROTOCOL_F_MQ is set in quried protocol
> + features by VHOST_USER_GET_PROTOCOL_FEATURES.
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index b7d29b7..bc88006 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -122,6 +122,11 @@ void vhost_net_ack_features(struct vhost_net *net,
> uint64_t features)
> vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
> }
>
> +uint64_t vhost_net_get_max_queues(VHostNetState *net)
> +{
> + return net->dev.max_queues;
> +}
Looks like need a dummy function for !CONFIG_VHOST_NET.
> +
> static int vhost_net_get_fd(NetClientState *backend)
> {
> switch (backend->info->type) {
> @@ -144,6 +149,8 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
> goto fail;
> }
>
> + net->dev.max_queues = 1;
> +
> if (backend_kernel) {
> r = vhost_net_get_fd(options->net_backend);
> if (r < 0) {
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 9cb2f52..694fde5 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -25,7 +25,9 @@
>
> #define VHOST_MEMORY_MAX_NREGIONS 8
> #define VHOST_USER_F_PROTOCOL_FEATURES 30
> -#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x0ULL
> +#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x1ULL
> +
> +#define VHOST_USER_PROTOCOL_F_MQ 0
>
> typedef enum VhostUserRequest {
> VHOST_USER_NONE = 0,
> @@ -45,6 +47,7 @@ typedef enum VhostUserRequest {
> VHOST_USER_SET_VRING_ERR = 14,
> VHOST_USER_GET_PROTOCOL_FEATURES = 15,
> VHOST_USER_SET_PROTOCOL_FEATURES = 16,
> + VHOST_USER_GET_QUEUE_NUM = 17,
> VHOST_USER_MAX
> } VhostUserRequest;
>
> @@ -211,6 +214,7 @@ static int vhost_user_call(struct vhost_dev *dev,
> unsigned long int request,
> switch (msg_request) {
> case VHOST_USER_GET_FEATURES:
> case VHOST_USER_GET_PROTOCOL_FEATURES:
> + case VHOST_USER_GET_QUEUE_NUM:
> need_reply = 1;
> break;
>
> @@ -315,6 +319,7 @@ static int vhost_user_call(struct vhost_dev *dev,
> unsigned long int request,
> switch (msg_request) {
> case VHOST_USER_GET_FEATURES:
> case VHOST_USER_GET_PROTOCOL_FEATURES:
> + case VHOST_USER_GET_QUEUE_NUM:
> if (msg.size != sizeof(m.u64)) {
> error_report("Received bad msg size.");
> return -1;
> @@ -366,6 +371,14 @@ static int vhost_user_init(struct vhost_dev *dev, void
> *opaque)
> if (err < 0) {
> return err;
> }
> +
> + /* query the max queues we support if backend supports Multiple
> Queue */
> + if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
> + err = vhost_user_call(dev, VHOST_USER_GET_QUEUE_NUM,
> &dev->max_queues);
> + if (err < 0) {
> + return err;
> + }
> + }
> }
>
> return 0;
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 6467c73..c3758f3 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -48,6 +48,7 @@ struct vhost_dev {
> unsigned long long acked_features;
> unsigned long long backend_features;
> unsigned long long protocol_features;
> + unsigned long long max_queues;
> bool started;
> bool log_enabled;
> unsigned long long log_size;
> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> index 840d4b1..8db723e 100644
> --- a/include/net/vhost_net.h
> +++ b/include/net/vhost_net.h
> @@ -13,6 +13,7 @@ typedef struct VhostNetOptions {
> void *opaque;
> } VhostNetOptions;
>
> +uint64_t vhost_net_get_max_queues(VHostNetState *net);
> struct vhost_net *vhost_net_init(VhostNetOptions *options);
>
> int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int
> total_queues);
