linux-kernel - RE: [PATCH 1/4] iommu/vt-d: Implement set device pasid op for default domain

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]

Date:   Fri, 3 Mar 2023 05:35:58 +0000
From:   "Tian, Kevin" <kevin.tian@...el.com>
To:     Baolu Lu <baolu.lu@...ux.intel.com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        LKML <linux-kernel@...r.kernel.org>,
        "iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
        Jason Gunthorpe <jgg@...dia.com>,
        Joerg Roedel <joro@...tes.org>,
        "dmaengine@...r.kernel.org" <dmaengine@...r.kernel.org>,
        "vkoul@...nel.org" <vkoul@...nel.org>
CC:     Robin Murphy <robin.murphy@....com>, Will Deacon <will@...nel.org>,
        "David Woodhouse" <dwmw2@...radead.org>,
        "Raj, Ashok" <ashok.raj@...el.com>,
        "Liu, Yi L" <yi.l.liu@...el.com>,
        "Yu, Fenghua" <fenghua.yu@...el.com>,
        "Jiang, Dave" <dave.jiang@...el.com>,
        "Luck, Tony" <tony.luck@...el.com>,
        "Zanussi, Tom" <tom.zanussi@...el.com>
Subject: RE: [PATCH 1/4] iommu/vt-d: Implement set device pasid op for default
 domain

> From: Baolu Lu <baolu.lu@...ux.intel.com>
> Sent: Friday, March 3, 2023 12:38 PM
> 
> On 3/3/23 11:02 AM, Tian, Kevin wrote:
> >> From: Baolu Lu <baolu.lu@...ux.intel.com>
> >> Sent: Friday, March 3, 2023 10:49 AM
> >>
> >> On 3/3/23 10:36 AM, Tian, Kevin wrote:
> >>>> From: Baolu Lu <baolu.lu@...ux.intel.com>
> >>>> Sent: Thursday, March 2, 2023 10:07 PM
> >>>>> +
> >>>>> +	if (!sm_supported(iommu) || !info)
> >>>>
> >>>> @info has been referenced. !info check makes no sense.
> >>>>
> >>>> Add pasid_supported(iommu).
> >>>>
> >>>> Do you need to check whether the domain is compatible for this rid
> >>>> pasid?
> >>>
> >>> what kind of compatibility is concerned here? In concept a pasid
> >>> can be attached to any domain if it has been successfully attached
> >>> to rid. Probably we can add a check here that RID2PASID must
> >>> point to the domain already.
> >>
> >> "...if it has been successfully attached to rid..."
> >>
> >> We should not have this assumption in iommu driver's callback. The
> iommu
> >> driver has no (and should not have) knowledge about the history of any
> >> domain.
> >
> > but this is an op for default domain which must have been attached
> > to RID2PASID and any compatibility check between this domain and device
> > should be passed.
> 
> This is an op for DMA, DMA-FQ and UNMANAGED domain. The IOMMU
> driver
> doesn't need to interpret the default domain concept. :-)
> 

yes if we target a general callback for all those domain types.

and probably this is the right thing to do as in the end DMA type will
be removed with Jason's cleanup