linux-kernel - Re: [PATCH v1 0/8] Add IO page table replacement support

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: <Y+D/9j8Yc444k8QE@nvidia.com>
Date:   Mon, 6 Feb 2023 09:26:14 -0400
From:   Jason Gunthorpe <jgg@...dia.com>
To:     "Tian, Kevin" <kevin.tian@...el.com>
Cc:     Nicolin Chen <nicolinc@...dia.com>,
        "joro@...tes.org" <joro@...tes.org>,
        "will@...nel.org" <will@...nel.org>,
        "robin.murphy@....com" <robin.murphy@....com>,
        "alex.williamson@...hat.com" <alex.williamson@...hat.com>,
        "shuah@...nel.org" <shuah@...nel.org>,
        "Liu, Yi L" <yi.l.liu@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
        "baolu.lu@...ux.intel.com" <baolu.lu@...ux.intel.com>
Subject: Re: [PATCH v1 0/8] Add IO page table replacement support

On Mon, Feb 06, 2023 at 06:39:29AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@...dia.com>
> > Sent: Friday, February 3, 2023 11:04 PM
> > 
> > On Fri, Feb 03, 2023 at 08:09:30AM +0000, Tian, Kevin wrote:
> > > > From: Nicolin Chen <nicolinc@...dia.com>
> > > > Sent: Thursday, February 2, 2023 3:05 PM
> > > >
> > > > QEMU with this feature should have the vIOMMU maintain a cache of the
> > > > guest io page table addresses and assign a unique IOAS to each unique
> > > > guest page table.
> > >
> > > I didn't get why we impose such requirement to userspace.
> > 
> > I read this as implementation guidance for qemu. qemu can do what it
> > wants of course
> > 
> 
> sure but I still didn't get why this is a guidance specific to the
> new replace cmd...

I think the guidance is about the change to VFIO uAPI where it is now
possible to change the domain attached, previously that was not
possible

Jason