lkml.org 
[lkml]   [2011]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] intel-iommu: Default to non-coherent for domains unattached to iommus
    From
    Date
    On Fri, 2011-11-11 at 16:45 -0800, Chris Wright wrote:
    > > So if you were to ditch the whole idea of a per-domain runtime update,
    > > and instead calculate a global value for 'iommu_coherency' at boot time,
    > > by iterating over for_each_active_iommu()¹, I think that would be a
    > > better way to deal with the issue. And you *could* really call that a
    > > 'fix'.
    > >
    > > Make sense?
    >
    > Ideally, yes. Not sure we can practically do it though. Would have to
    > be sure we force incoherent access mode for the busted hw.

    Why's it not practical? You do the *same* loop we currently have in
    domain_update_iommu_coherency(), except that you do it just *once*, over
    all active IOMMUs, at boot time. And then you just use that result
    forever more.

    So if *any* IOMMU in the system is non-coherent, you run them all that
    way.

    --
    dwmw2
    [unhandled content-type:application/x-pkcs7-signature]
    \
     
     \ /
      Last update: 2011-11-12 01:55    [W:0.040 / U:0.400 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site