Re: [Qemu-devel] [PATCH v2 02/22] hw/rdma: Add ability to force notification without re-arm

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

On 11/8/18 6:07 PM, Yuval Shaia wrote:
> Upon completion of incoming packet the device pushes CQE to driver's RX
> ring and notify the driver (msix).
> While for data-path incoming packets the driver needs the ability to
> control whether it wished to receive interrupts or not, for control-path
> packets such as incoming MAD the driver needs to be notified anyway, it
> even do not need to re-arm the notification bit.
>
> Enhance the notification field to support this.
>
> Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
> ---
>   hw/rdma/rdma_rm.c           | 12 ++++++++++--
>   hw/rdma/rdma_rm_defs.h      |  8 +++++++-
>   hw/rdma/vmw/pvrdma_qp_ops.c |  6 ++++--
>   3 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/hw/rdma/rdma_rm.c b/hw/rdma/rdma_rm.c
> index 8d59a42cd1..4f10fcabcc 100644
> --- a/hw/rdma/rdma_rm.c
> +++ b/hw/rdma/rdma_rm.c
> @@ -263,7 +263,7 @@ int rdma_rm_alloc_cq(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
>       }
>   
>       cq->opaque = opaque;
> -    cq->notify = false;
> +    cq->notify = CNT_CLEAR;
>   
>       rc = rdma_backend_create_cq(backend_dev, &cq->backend_cq, cqe);
>       if (rc) {
> @@ -291,7 +291,10 @@ void rdma_rm_req_notify_cq(RdmaDeviceResources *dev_res, uint32_t cq_handle,
>           return;
>       }
>   
> -    cq->notify = notify;
> +    if (cq->notify != CNT_SET) {
> +        cq->notify = notify ? CNT_ARM : CNT_CLEAR;
> +    }
> +
>       pr_dbg("notify=%d\n", cq->notify);
>   }
>   
> @@ -349,6 +352,11 @@ int rdma_rm_alloc_qp(RdmaDeviceResources *dev_res, uint32_t pd_handle,
>           return -EINVAL;
>       }
>   
> +    if (qp_type == IBV_QPT_GSI) {
> +        scq->notify = CNT_SET;
> +        rcq->notify = CNT_SET;
> +    }
> +
>       qp = res_tbl_alloc(&dev_res->qp_tbl, &rm_qpn);
>       if (!qp) {
>           return -ENOMEM;
> diff --git a/hw/rdma/rdma_rm_defs.h b/hw/rdma/rdma_rm_defs.h
> index 7228151239..9b399063d3 100644
> --- a/hw/rdma/rdma_rm_defs.h
> +++ b/hw/rdma/rdma_rm_defs.h
> @@ -49,10 +49,16 @@ typedef struct RdmaRmPD {
>       uint32_t ctx_handle;
>   } RdmaRmPD;
>   
> +typedef enum CQNotificationType {
> +    CNT_CLEAR,
> +    CNT_ARM,
> +    CNT_SET,
> +} CQNotificationType;
> +
>   typedef struct RdmaRmCQ {
>       RdmaBackendCQ backend_cq;
>       void *opaque;
> -    bool notify;
> +    CQNotificationType notify;
>   } RdmaRmCQ;
>   
>   /* MR (DMA region) */
> diff --git a/hw/rdma/vmw/pvrdma_qp_ops.c b/hw/rdma/vmw/pvrdma_qp_ops.c
> index c668afd0ed..762700a205 100644
> --- a/hw/rdma/vmw/pvrdma_qp_ops.c
> +++ b/hw/rdma/vmw/pvrdma_qp_ops.c
> @@ -89,8 +89,10 @@ static int pvrdma_post_cqe(PVRDMADev *dev, uint32_t cq_handle,
>       pvrdma_ring_write_inc(&dev->dsr_info.cq);
>   
>       pr_dbg("cq->notify=%d\n", cq->notify);
> -    if (cq->notify) {
> -        cq->notify = false;
> +    if (cq->notify != CNT_CLEAR) {
> +        if (cq->notify == CNT_ARM) {
> +            cq->notify = CNT_CLEAR;
> +        }
>           post_interrupt(dev, INTR_VEC_CMD_COMPLETION_Q);
>       }
>   

Reviewed-by: Marcel Apfelbaum<marcel.apfelbaum@gmail.com>

Thanks,
Marcel