From: Peter Xu <peterx@redhat.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org, eric.auger@redhat.com, kwankhede@nvidia.com,
linux-kernel@vger.kernel.org, slp@redhat.com
Subject: Re: [PATCH v4 2/2] vfio/type1: Prune vfio_pin_page_external()
Date: Mon, 17 Apr 2017 14:54:21 +0800 [thread overview]
Message-ID: <20170417065420.GD16703@pxdev.xzpeter.org> (raw)
In-Reply-To: <20170417014239.25866.42333.stgit@gimli.home>
On Sun, Apr 16, 2017 at 07:42:39PM -0600, Alex Williamson wrote:
> With vfio_lock_acct() testing the locked memory limit under mmap_sem,
> it's redundant to do it here for a single page. We can also reorder
> our tests such that we can avoid testing for reserved pages if we're
> not doing accounting, and test the process CAP_IPC_LOCK only if we
> are doing accounting. Finally, this function oddly returns 1 on
> success. Update to return zero on success, -errno on error. Since
> the function only pins a single page, there's no need to return the
> number of pages pinned.
>
> N.B. vfio_pin_pages_remote() can pin a large contiguous range of pages
> before calling vfio_lock_acct(). If we were to similarly remove the
> extra test there, a user could temporarily pin far more pages than
> they're allowed.
>
> Suggested-by: Kirti Wankhede <kwankhede@nvidia.com>
> Suggested-by: Peter Xu <peterx@redhat.com>
Maybe this suggested-by honor should be for Kirti only? :)
For the patch, I think it's good to me as long as we have the
accounting check in vfio_lock_acct() which is just introduced in
previous patch, so:
Reviewed-by: Peter Xu <peterx@redhat.com>
Thanks!
--
Peter Xu
next prev parent reply other threads:[~2017-04-17 6:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-17 1:42 [PATCH v4 0/2] vfio/type1: Synchronous locked page accounting Alex Williamson
2017-04-17 1:42 ` [PATCH v4 1/2] vfio/type1: Remove locked page accounting workqueue Alex Williamson
2017-04-17 6:47 ` Peter Xu
2017-04-17 14:32 ` Alex Williamson
2017-04-17 19:05 ` Kirti Wankhede
2017-04-17 19:19 ` Alex Williamson
2017-04-17 19:32 ` Kirti Wankhede
2017-04-17 21:32 ` Alex Williamson
2017-04-18 2:54 ` Peter Xu
2017-04-18 18:21 ` Kirti Wankhede
2017-04-17 1:42 ` [PATCH v4 2/2] vfio/type1: Prune vfio_pin_page_external() Alex Williamson
2017-04-17 6:54 ` Peter Xu [this message]
2017-04-17 17:20 ` Alex Williamson
2017-04-17 19:16 ` Kirti Wankhede
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