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Date:   Thu, 15 Sep 2022 13:40:15 +0200
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Subject: Re: [PATCH] xen/privcmd: remove privcmd_ioctl_mmap()
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To:     Juergen Gross <jgross@suse.com>
Cc:     Stefano Stabellini <sstabellini@kernel.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
        xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org
References: <20220915083944.10097-1-jgross@suse.com>
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From:   Jan Beulich <jbeulich@suse.com>
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On 15.09.2022 12:20, Juergen Gross wrote:
> On 15.09.22 11:32, Jan Beulich wrote:
>> On 15.09.2022 10:39, Juergen Gross wrote:
>>> The IOCTL_PRIVCMD_MMAP isn't in use by Xen since at least Xen 4.0.
>>>
>>> Remove it from the privcmd driver.
>>>
>>> Signed-off-by: Juergen Gross <jgross@suse.com>
>>
>> Can we reasonably remove an IOCTL, without being entirely certain that
>> no users exist outside of xen.git?
> 
> This is a valid question. I'm not sure how probable it is that such a user
> is existing. Are there any Xen tool stacks not using the Xen libraries?
> 
> If so, why? Do we want to support those use cases?

I'm afraid I have no answers to these questions, and hence would generally
want to be conservative with removal of functionality.

Jan

>> Even if so, shouldn't there be a
>> staged deprecation process?
> 
> Depends on the answer to above questions.
> 
> 
> Juergen