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Date:   Mon, 11 Feb 2019 02:01:18 -0500
From:   Kimberly Brown <kimbrownkd@gmail.com>
To:     Stephen Hemminger <stephen@networkplumber.org>
Cc:     Michael Kelley <mikelley@microsoft.com>,
        Long Li <longli@microsoft.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>,
        Dexuan Cui <decui@microsoft.com>, devel@linuxdriverproject.org,
        Haiyang Zhang <haiyangz@microsoft.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] Drivers: hv: vmbus: Display nothing in sysfs if
 monitor_allocated not set
Message-ID: <20190211070118.GA2977@ubu-Virtual-Machine>
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 <52d58fe5805f2ba2405c9091b4c86033d434d2b9.1549619051.git.kimbrownkd@gmail.com>
 <20190208143148.052c8d9c@hermes.lan>
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On Fri, Feb 08, 2019 at 02:32:09PM -0800, Stephen Hemminger wrote:
> On Fri, 8 Feb 2019 05:01:12 -0500
> Kimberly Brown <kimbrownkd@gmail.com> wrote:
> 
> You are right, the current behavior is broken.
> It would be good to add a description of under what conditions
> monitor is not used. Is this some part of a project emulating
> Hyper-V?
> 

I'm not sure which conditions determine whether the monitor mechanism is
used. I've searched the Hypervisor TLFS, and I couldn't find any
information. If you have any suggestions for where I can find this
information, please let me know.

No, I'm not working on a project emulating Hyper-V.


> 
> > +
> > +	if (!hv_dev->channel->offermsg.monitor_allocated)
> > +		return sprintf(buf, "\n");
> 
> If monitor is not used, why not return an error instead of empty
> data. Any program (or user) would have to handle that already.

I think that returning an error instead is fine. I'll make this change
in the next version of the patch.