From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
Baolu Lu <baolu.lu@linux.intel.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] iommu/vt-d: Add opt-in for ATS support on discrete devices
Date: Fri, 3 Mar 2023 09:18:00 -0400 [thread overview]
Message-ID: <ZAHziAcvAozFJ3Cq@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB5276F192BCECE567DBFE21C08CB39@BN9PR11MB5276.namprd11.prod.outlook.com>
On Fri, Mar 03, 2023 at 08:19:29AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Thursday, March 2, 2023 1:43 AM
> >
> > If Intel BIOS's have populated the "satcu" to say that ATS is not
> > supported by the HW when the HW supports ATS perfectly fine, then get
> > the BIOS fixed or patch the ACPI until it is fixed. The BIOS should
> > not be saying that the HW does not support ATS when it does, it is a
> > simple BIOS bug.
> >
>
> That is not the purpose of SATC.
>
> The ATS support in VT-d side is reported in two interfaces:
>
> 1) "Device-TLB support" in Extended Capability Register;
> 2) Root port ATS capability in ACPI ATSR structure;
>
> A device gets ATS enabled if 1/2 are true and !pdev->untrusted. Same
> as SMMU does.
>
> The main purpose of SATC is to describe which ATS-capable integrated
> device meets the requirements of securely using ATS as stated in VT-d
> spec 4.4.
Then it should be mapped to pdev->untrusted and possibly
pdev->untrusted to be enhanced to be more descriptive.
iommu driver and BIOS should have no role in security policy beyond
feeding in data to a common policy engine.
Jason
next prev parent reply other threads:[~2023-03-03 13:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-28 2:33 [PATCH 1/1] iommu/vt-d: Add opt-in for ATS support on discrete devices Lu Baolu
2023-02-28 12:23 ` Jason Gunthorpe
2023-03-01 4:22 ` Baolu Lu
2023-03-01 14:04 ` Jason Gunthorpe
2023-03-01 17:15 ` Robin Murphy
2023-03-01 17:42 ` Jason Gunthorpe
2023-03-01 18:19 ` Robin Murphy
2023-03-02 2:30 ` Baolu Lu
2023-03-03 8:19 ` Tian, Kevin
2023-03-03 9:51 ` Baolu Lu
2023-03-03 13:18 ` Jason Gunthorpe [this message]
2023-03-07 5:20 ` Tian, Kevin
2023-03-02 1:56 ` Baolu Lu
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