linux-kernel - Re: [PATCH 2/2] iommu/vt-d: Remove caching mode check before devtlb flush

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: <20240410091955.5c00e411@jacob-builder>
Date: Wed, 10 Apr 2024 09:19:55 -0700
From: Jacob Pan <jacob.jun.pan@...ux.intel.com>
To: "Tian, Kevin" <kevin.tian@...el.com>
Cc: Baolu Lu <baolu.lu@...ux.intel.com>, "iommu@...ts.linux.dev"
 <iommu@...ts.linux.dev>, "Liu, Yi L" <yi.l.liu@...el.com>, Joerg Roedel
 <joro@...tes.org>, Will Deacon <will@...nel.org>, Robin Murphy
 <robin.murphy@....com>, "linux-kernel@...r.kernel.org"
 <linux-kernel@...r.kernel.org>, jacob.jun.pan@...ux.intel.com
Subject: Re: [PATCH 2/2] iommu/vt-d: Remove caching mode check before devtlb
 flush

Hi Kevin,

On Wed, 10 Apr 2024 00:32:06 +0000, "Tian, Kevin" <kevin.tian@...el.com>
wrote:

> > From: Jacob Pan <jacob.jun.pan@...ux.intel.com>
> > Sent: Wednesday, April 10, 2024 1:32 AM
> > 
> > If the guest uses SL page tables in vIOMMU, we don;t expose ATS to the
> > guest. So ATS is not relevant here, does't matter map or unmap.
> >   
> 
> ATS is orthogonal to SL vs. FL. Where is this restriction coming from?
For practical purposes, what would be the usage to have SL in the guest and
ATS enabled. i.e. shadowing SL but directly expose ATS? 

Thanks,

Jacob