[v3,13/28] vhost: add helper for IOTLB misses

  This patch adds a helper for sending IOTLB misses as VDUSE
will use an ioctl while Vhost-user use a dedicated
Vhost-user backend request.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost.c      | 13 ++++++++++++-
 lib/vhost/vhost.h      |  4 ++++
 lib/vhost/vhost_user.c |  6 ++++--
 lib/vhost/vhost_user.h |  1 -
 4 files changed, 20 insertions(+), 4 deletions(-)
  

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Friday, May 26, 2023 12:26 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>;
> david.marchand@redhat.com; mkp@redhat.com; fbl@redhat.com;
> jasowang@redhat.com; Liang, Cunming <cunming.liang@intel.com>; Xie, Yongji
> <xieyongji@bytedance.com>; echaudro@redhat.com; eperezma@redhat.com;
> amorenoz@redhat.com; lulu@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v3 13/28] vhost: add helper for IOTLB misses
> 
> This patch adds a helper for sending IOTLB misses as VDUSE
> will use an ioctl while Vhost-user use a dedicated
> Vhost-user backend request.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/vhost.c      | 13 ++++++++++++-
>  lib/vhost/vhost.h      |  4 ++++
>  lib/vhost/vhost_user.c |  6 ++++--
>  lib/vhost/vhost_user.h |  1 -
>  4 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> index 41f212315e..790eb06b28 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -52,6 +52,12 @@ static const struct vhost_vq_stats_name_off
> vhost_vq_stat_strings[] = {
> 
>  #define VHOST_NB_VQ_STATS RTE_DIM(vhost_vq_stat_strings)
> 
> +static int
> +vhost_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm)
> +{
> +	return dev->backend_ops->iotlb_miss(dev, iova, perm);
> +}
> +
>  uint64_t
>  __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
>  		    uint64_t iova, uint64_t *size, uint8_t perm)
> @@ -86,7 +92,7 @@ __vhost_iova_to_vva(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
>  		vhost_user_iotlb_rd_unlock(vq);
> 
>  		vhost_user_iotlb_pending_insert(dev, iova, perm);
> -		if (vhost_user_iotlb_miss(dev, iova, perm)) {
> +		if (vhost_iotlb_miss(dev, iova, perm)) {
>  			VHOST_LOG_DATA(dev->ifname, ERR,
>  				"IOTLB miss req failed for IOVA 0x%" PRIx64 "\n",
>  				iova);
> @@ -686,6 +692,11 @@ vhost_new_device(struct vhost_backend_ops *ops)
>  		return -1;
>  	}
> 
> +	if (ops->iotlb_miss == NULL) {
> +		VHOST_LOG_CONFIG("device", ERR, "missing IOTLB miss backend
> op.\n");
> +		return -1;
> +	}
> +
>  	pthread_mutex_lock(&vhost_dev_lock);
>  	for (i = 0; i < RTE_MAX_VHOST_DEVICE; i++) {
>  		if (vhost_devices[i] == NULL)
> diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> index f37e0b83b8..ee7640e901 100644
> --- a/lib/vhost/vhost.h
> +++ b/lib/vhost/vhost.h
> @@ -89,13 +89,17 @@
>  	for (iter = val; iter < num; iter++)
>  #endif
> 
> +struct virtio_net;
>  typedef void (*vhost_iotlb_remove_notify)(uint64_t addr, uint64_t off,
> uint64_t size);
> 
> +typedef int (*vhost_iotlb_miss_cb)(struct virtio_net *dev, uint64_t iova,
> uint8_t perm);
> +
>  /**
>   * Structure that contains backend-specific ops.
>   */
>  struct vhost_backend_ops {
>  	vhost_iotlb_remove_notify iotlb_remove_notify;
> +	vhost_iotlb_miss_cb iotlb_miss;
>  };
> 
>  /**
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 7655082c4b..972559a2b5 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -3305,7 +3305,7 @@ vhost_user_msg_handler(int vid, int fd)
>  	return ret;
>  }
> 
> -int
> +static int
>  vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm)
>  {
>  	int ret;
> @@ -3465,7 +3465,9 @@ int rte_vhost_host_notifier_ctrl(int vid, uint16_t
> qid, bool enable)
>  	return ret;
>  }
> 
> -static struct vhost_backend_ops vhost_user_backend_ops;
> +static struct vhost_backend_ops vhost_user_backend_ops = {
> +	.iotlb_miss = vhost_user_iotlb_miss,
> +};
> 
>  int
>  vhost_user_new_device(void)
> diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h
> index 61456049c8..1ffeca92f3 100644
> --- a/lib/vhost/vhost_user.h
> +++ b/lib/vhost/vhost_user.h
> @@ -179,7 +179,6 @@ struct __rte_packed vhu_msg_context {
> 
>  /* vhost_user.c */
>  int vhost_user_msg_handler(int vid, int fd);
> -int vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t
> perm);
> 
>  /* socket.c */
>  int read_fd_message(char *ifname, int sockfd, char *buf, int buflen, int
> *fds, int max_fds,
> --
> 2.40.1

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>