Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sinan Kaya <Okaya@kernel.org>
Subject: Re: [PATCH] PCI: Add link_change error handler and vfio-pci user
To:     Alex Williamson <alex.williamson@redhat.com>,
        Bjorn Helgaas <helgaas@kernel.org>
Cc:     mr.nuke.me@gmail.com, linux-pci@vger.kernel.org,
        austin_bolen@dell.com, alex_gagniuc@dellteam.com,
        keith.busch@intel.com, Shyam_Iyer@Dell.com, lukas@wunner.de,
        torvalds@linux-foundation.org, linux-kernel@vger.kernel.org
References: <155605909349.3575.13433421148215616375.stgit@gimli.home>
 <20190424175758.GC244134@google.com> <20190429085104.728aee75@x1.home>
Message-ID: <76169da9-36cd-6754-41e7-47c8ef668648@kernel.org>
Date:   Mon, 29 Apr 2019 09:45:28 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.6.1
MIME-Version: 1.0
In-Reply-To: <20190429085104.728aee75@x1.home>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 4/29/2019 10:51 AM, Alex Williamson wrote:
> So where do we go from here?  I agree that dmesg is not necessarily a
> great choice for these sorts of events and if they went somewhere else,
> maybe I wouldn't have the same concerns about them generating user
> confusion or contributing to DoS vectors from userspace drivers.  As it
> is though, we have known cases where benign events generate confusing
> logging messages, which seems like a regression.  Drivers didn't ask
> for a link_change handler, but nor did they ask that the link state to
> their device be monitored so closely.  Maybe this not only needs some
> sort of change to the logging mechanism, but also an opt-in by the
> driver if they don't expect runtime link changes.  Thanks,

Is there anyway to detect autonomous hardware management support and
not report link state changes in that situation?

I thought there were some capability bits for these.