linux-kernel - Re: [PATCH] vfio iommu type1: Bypass the vma permission check in vfio_pin_pages

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20201207144838.GG203660@stefanha-x1.localdomain>
Date:   Mon, 7 Dec 2020 14:48:38 +0000
From:   Stefan Hajnoczi <stefanha@...il.com>
To:     David Hildenbrand <david@...hat.com>
Cc:     Peter Xu <peterx@...hat.com>,
        Stefan Hajnoczi <stefanha@...hat.com>,
        Justin He <Justin.He@....com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Cornelia Huck <cohuck@...hat.com>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] vfio iommu type1: Bypass the vma permission check in
 vfio_pin_pages_remote()

On Thu, Dec 03, 2020 at 05:01:32PM +0100, David Hildenbrand wrote:
> The real question is: do we even *need* DMA from vfio devices to
> virtio-fs regions? If not (do guests rely on it? what does the spec
> state?), just don't care about vfio at all and don't map anything.

Can DMA to/from the virtio-fs DAX Window happen? Yes, the guest could do
it although it's rare.

Is it a great idea to combine VFIO and virtio-fs DAX? Maybe not. It
involves pinning host page cache pages O_o.

Stefan

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)