linux-kernel - Re: [RFC] /dev/ioasid uAPI proposal

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <9dc6c573-94df-a7c1-b4df-7f60fc3cf336@redhat.com>
Date:   Mon, 7 Jun 2021 08:51:42 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     "Tian, Kevin" <kevin.tian@...el.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Jason Gunthorpe <jgg@...dia.com>
Cc:     Jean-Philippe Brucker <jean-philippe@...aro.org>,
        "Jiang, Dave" <dave.jiang@...el.com>,
        "Raj, Ashok" <ashok.raj@...el.com>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        Jonathan Corbet <corbet@....net>,
        Robin Murphy <robin.murphy@....com>,
        LKML <linux-kernel@...r.kernel.org>,
        "iommu@...ts.linux-foundation.org" <iommu@...ts.linux-foundation.org>,
        David Gibson <david@...son.dropbear.id.au>,
        Kirti Wankhede <kwankhede@...dia.com>,
        David Woodhouse <dwmw2@...radead.org>,
        Jason Wang <jasowang@...hat.com>
Subject: Re: [RFC] /dev/ioasid uAPI proposal

On 07/06/21 05:25, Tian, Kevin wrote:
> Per Intel SDM wbinvd is a privileged instruction. A process on the
> host has no privilege to execute it.

(Half of) the point of the kernel is to do privileged tasks on the 
processes' behalf.  There are good reasons why a process that uses VFIO 
(without KVM) could want to use wbinvd, so VFIO lets them do it with a 
ioctl and adequate checks around the operation.

Paolo