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From: Leon Romanovsky <leon@kernel.org>
To: Cheng Xu <chengyou@linux.alibaba.com>
Cc: jgg@ziepe.ca, dledford@redhat.com, linux-rdma@vger.kernel.org,
	KaiShen@linux.alibaba.com, tonylu@linux.alibaba.com
Subject: Re: [PATCH rdma-next 00/11] Elastic RDMA Adapter (ERDMA) driver
Date: Thu, 23 Dec 2021 15:44:29 +0200	[thread overview]
Message-ID: <YcR9PVDS2jFsrJ4N@unreal> (raw)
In-Reply-To: <9496ca18-760c-f90e-8735-f7fb2982e7a4@linux.alibaba.com>

On Thu, Dec 23, 2021 at 08:59:14PM +0800, Cheng Xu wrote:
> 
> 
> On 12/23/21 6:23 PM, Leon Romanovsky wrote:
> > On Wed, Dec 22, 2021 at 11:35:44AM +0800, Cheng Xu wrote:
> > > 
> > 
> > <...>
> > 
> > > > > 
> > > > > For the ECS instance with RDMA enabled, there are two kinds of devices
> > > > > allocated, one for ERDMA, and one for the original netdev (virtio-net).
> > > > > They are different PCI deivces. ERDMA driver can get the information about
> > > > > which netdev attached to in its PCIe barspace (by MAC address matching).
> > > > 
> > > > This is very questionable. The netdev part should be kept in the
> > > > drivers/ethernet/... part of the kernel.
> > > > 
> > > > Thanks
> > > 
> > > The net device used in Alibaba ECS instance is virtio-net device, driven
> > > by virtio-pci/virtio-net drivers. ERDMA device does not need its own net
> > > device, and will be attached to an existed virtio-net device. The
> > > relationship between ibdev and netdev in erdma is similar to siw/rxe.
> > 
> > siw/rxe binds through RDMA_NLDEV_CMD_NEWLINK netlink command and not
> > through MAC's matching.
> > 
> > Thanks
> 
> Both siw/rxe/erdma don't need to implement netdev part, this is what I
> wanted to express when I said 'similar'.
> What you mentioned (the bind mechanism) is one major difference between
> erdma and siw/rxe. For siw/rxe, user can attach ibdev to every netdev if
> he/she wants, but it is not true for erdma. When user buys the erdma
> service, he/she must specify which ENI (elastic network interface) to be
> binded, it means that the attached erdma device can only be binded to
> the specific netdev. Due to the uniqueness of MAC address in our ECS
> instance, we use the MAC address as the identification, then the driver
> knows which netdev should be binded to.

Nothing prohibits from you to implement this MAC check in RDMA_NLDEV_CMD_NEWLINK.
I personally don't like the idea that bind logic is performed "magically".

BTW,
1. No module parameters
2. No driver versions

Thanks

> 
> Thanks,
> Cheng Xu

  reply	other threads:[~2021-12-23 13:44 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-21  2:48 [PATCH rdma-next 00/11] Elastic RDMA Adapter (ERDMA) driver Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 01/11] RDMA: Add ERDMA to rdma_driver_id definition Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 02/11] RDMA/erdma: Add the hardware related definitions Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 03/11] RDMA/erdma: Add main include file Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 04/11] RDMA/erdma: Add cmdq implementation Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 05/11] RDMA/erdma: Add event queue implementation Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 06/11] RDMA/erdma: Add verbs header file Cheng Xu
2021-12-21 13:28   ` Leon Romanovsky
2021-12-22  2:36     ` Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 07/11] RDMA/erdma: Add verbs implementation Cheng Xu
2021-12-21 13:32   ` Leon Romanovsky
2021-12-21 15:20     ` Bernard Metzler
2021-12-22  3:11       ` Cheng Xu
2021-12-22  4:18         ` Cheng Xu
2021-12-22 12:46         ` Bernard Metzler
2021-12-23  8:38           ` Cheng Xu
2021-12-22  2:50     ` Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 08/11] RDMA/erdma: Add connection management (CM) support Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 09/11] RDMA/erdma: Add the erdma module Cheng Xu
2021-12-21 13:26   ` Leon Romanovsky
2021-12-22  2:33     ` Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 10/11] RDMA/erdma: Add the ABI definitions Cheng Xu
2021-12-21 11:57   ` kernel test robot
2021-12-22 16:14   ` kernel test robot
2021-12-23 15:46   ` Yanjun Zhu
2021-12-23 18:45     ` Leon Romanovsky
2021-12-23 22:55       ` Yanjun Zhu
2021-12-24  6:04         ` Leon Romanovsky
2021-12-24  7:54           ` Yanjun Zhu
2021-12-24 18:11             ` Leon Romanovsky
2021-12-24  7:12         ` Cheng Xu
2021-12-24  8:02           ` Yanjun Zhu
2021-12-24 18:19           ` Leon Romanovsky
2021-12-25  0:03             ` Yanjun Zhu
2021-12-25  3:36             ` Cheng Xu
2021-12-21  2:48 ` [PATCH rdma-next 11/11] RDMA/erdma: Add driver to kernel build environment Cheng Xu
2021-12-22  0:58   ` kernel test robot
2021-12-21 13:09 ` [PATCH rdma-next 00/11] Elastic RDMA Adapter (ERDMA) driver Leon Romanovsky
2021-12-22  3:35   ` Cheng Xu
2021-12-23 10:23     ` Leon Romanovsky
2021-12-23 12:59       ` Cheng Xu
2021-12-23 13:44         ` Leon Romanovsky [this message]
2021-12-24  7:07           ` Cheng Xu
2021-12-24 18:26             ` Leon Romanovsky
2021-12-25  2:54               ` Cheng Xu
2021-12-25  2:57               ` Cheng Xu
2021-12-25  3:03               ` [Please ignore the two former responses]Re: " Cheng Xu
2022-01-07 14:24         ` Jason Gunthorpe
2022-01-10 10:07           ` Cheng Xu

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