Re: [PATCH rdma-next v4 07/10] RDMA/mana_ib: Poll RC completions using PSN and FSN progress

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] rdma/mana_ib: unsignaled SQ WQEs drop cross-queue FENCE flags
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commit f52d44bbe1b3dcdecb4068d26d5596db440b5069
Author: Konstantin Taranov <kotaranov@microsoft.com>
Subject: RDMA/mana_ib: Poll RC completions using PSN and FSN progress

This commit introduces decoding for RC receive completions, armed-PSN
notifications, and MMQ completions. It retires requester and MMQ shadow
entries using sequence numbers and enforces cross-queue fence dependencies.

> diff --git a/drivers/infiniband/hw/mana/wr.c b/drivers/infiniband/hw/mana/wr.c
> index 6cc67537c6557..9fff8622aee22 100644
> --- a/drivers/infiniband/hw/mana/wr.c
> +++ b/drivers/infiniband/hw/mana/wr.c
> @@ -408,6 +408,9 @@ static int mana_ib_post_sq(struct mana_ib_qp *qp, const struct ib_send_wr *wr)
>  	if (err)
>  		return err;
>  
> +	if (wr->opcode != IB_WR_RDMA_READ)
> +		shadow_wqe->wqe_size_in_bu = wqe_info.wqe_size_in_bu;
> +
>  	shadow_wqe->wr_id = wr->wr_id;
>  	shadow_wqe->send_opcode = convert_wr_to_wc(wr->opcode);
>  	if (!signaled)

[Severity: High]
Does the logic immediately following this diff permanently drop the
MANA_WQ_FENCE_WC flag for unsignaled WQEs?

Looking at mana_ib_post_sq():

	if (!signaled)
		shadow_wqe->flags |= MANA_WQ_NO_SIGNAL_WC;
	else if ((wr->send_flags & IB_SEND_FENCE) || qp->pending_mmq_fence)
		shadow_wqe->flags |= MANA_WQ_FENCE_WC;

If a work request is unsignaled and requires a fence, the first branch
is taken, bypassing the fence branch entirely.

This appears to break cross-queue retirement dependencies and could
potentially leak unsignaled MMQ WQEs in the shadow queue.

Should this be changed to two separate 'if' statements so that both
MANA_WQ_NO_SIGNAL_WC and MANA_WQ_FENCE_WC can be set on the same shadow WQE?

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Sashiko AI review · https://sashiko.dev/#/patchset/20261010065443.3554193-1-kotaranov@linux.microsoft.com?part=7