linux-kernel - Re: [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <02593083-056e-cc62-22cf-d6bd6c9b18a8@talpey.com>
Date:   Wed, 14 Apr 2021 10:16:28 -0400
From:   Tom Talpey <tom@...pey.com>
To:     Jason Gunthorpe <jgg@...dia.com>
Cc:     Haakon Bugge <haakon.bugge@...cle.com>,
        David Laight <David.Laight@...lab.com>,
        Chuck Lever III <chuck.lever@...cle.com>,
        Christoph Hellwig <hch@....de>,
        Leon Romanovsky <leon@...nel.org>,
        Doug Ledford <dledford@...hat.com>,
        Leon Romanovsky <leonro@...dia.com>,
        Adit Ranadive <aditr@...are.com>,
        Anna Schumaker <anna.schumaker@...app.com>,
        Ariel Elior <aelior@...vell.com>,
        Avihai Horon <avihaih@...dia.com>,
        Bart Van Assche <bvanassche@....org>,
        Bernard Metzler <bmt@...ich.ibm.com>,
        "David S. Miller" <davem@...emloft.net>,
        Dennis Dalessandro <dennis.dalessandro@...nelisnetworks.com>,
        Devesh Sharma <devesh.sharma@...adcom.com>,
        Faisal Latif <faisal.latif@...el.com>,
        Jack Wang <jinpu.wang@...os.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Bruce Fields <bfields@...ldses.org>, Jens Axboe <axboe@...com>,
        Karsten Graul <kgraul@...ux.ibm.com>,
        Keith Busch <kbusch@...nel.org>, Lijun Ou <oulijun@...wei.com>,
        CIFS <linux-cifs@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux NFS Mailing List <linux-nfs@...r.kernel.org>,
        "linux-nvme@...ts.infradead.org" <linux-nvme@...ts.infradead.org>,
        OFED mailing list <linux-rdma@...r.kernel.org>,
        "linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
        Max Gurtovoy <maxg@...lanox.com>,
        Max Gurtovoy <mgurtovoy@...dia.com>,
        "Md. Haris Iqbal" <haris.iqbal@...os.com>,
        Michael Guralnik <michaelgur@...dia.com>,
        Michal Kalderon <mkalderon@...vell.com>,
        Mike Marciniszyn <mike.marciniszyn@...nelisnetworks.com>,
        Naresh Kumar PBS <nareshkumar.pbs@...adcom.com>,
        Linux-Net <netdev@...r.kernel.org>,
        Potnuri Bharat Teja <bharat@...lsio.com>,
        "rds-devel@....oracle.com" <rds-devel@....oracle.com>,
        Sagi Grimberg <sagi@...mberg.me>,
        "samba-technical@...ts.samba.org" <samba-technical@...ts.samba.org>,
        Santosh Shilimkar <santosh.shilimkar@...cle.com>,
        Selvin Xavier <selvin.xavier@...adcom.com>,
        Shiraz Saleem <shiraz.saleem@...el.com>,
        Somnath Kotur <somnath.kotur@...adcom.com>,
        Sriharsha Basavapatna <sriharsha.basavapatna@...adcom.com>,
        Steve French <sfrench@...ba.org>,
        Trond Myklebust <trond.myklebust@...merspace.com>,
        VMware PV-Drivers <pv-drivers@...are.com>,
        Weihang Li <liweihang@...wei.com>,
        Yishai Hadas <yishaih@...dia.com>,
        Zhu Yanjun <zyjzyj2000@...il.com>
Subject: Re: [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs

On 4/12/2021 6:48 PM, Jason Gunthorpe wrote:
> On Mon, Apr 12, 2021 at 04:20:47PM -0400, Tom Talpey wrote:
> 
>> So the issue is only in testing all the providers and platforms,
>> to be sure this new behavior isn't tickling anything that went
>> unnoticed all along, because no RDMA provider ever issued RO.
> 
> The mlx5 ethernet driver has run in RO mode for a long time, and it
> operates in basically the same way as RDMA. The issues with Haswell
> have been worked out there already.
> 
> The only open question is if the ULPs have errors in their
> implementation, which I don't think we can find out until we apply
> this series and people start running their tests aggressively.

I agree that the core RO support should go in. But turning it on
by default for a ULP should be the decision of each ULP maintainer.
It's a huge risk to shift all the storage drivers overnight. How
do you propose to ensure the aggressive testing happens?

One thing that worries me is the patch02 on-by-default for the dma_lkey.
There's no way for a ULP to prevent IB_ACCESS_RELAXED_ORDERING
from being set in __ib_alloc_pd().

Tom.