On Mon, Apr 15, 2024 at 10:55:12AM +0800, Honggang LI wrote: > Subject: Question about extra 40 bytes needed for UD receive buffer > From: Honggang LI <honggangli@xxxxxxx> > Date: Mon, 15 Apr 2024 10:55:12 +0800 > > However, I'm confused by the dump of `mckey` receive buffer. The flag > `IBV_WC_GRH` is set in `ibv_wc.wc_flags`, but there is no GRH in > the receive buffer. Received data starts from the *first* byte of > receive buffer. As multicast over UD QP only, can someone please explian > why there is no GRH in receive buffer and the data starts from the first > bytes of receive buffer with `IBV_WC_GRH` was set? Please ignore this. I made a mistake with the offset of the grh. There is a valid IP header in the receive buffer of 'mckey'.
