Messages in this thread | | | Date | Mon, 13 Jul 2020 10:01:15 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH v4 4/4] PCI/ACS: Enable PCI_ACS_TB for untrusted/external-facing devices |
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On Sat, Jul 11, 2020 at 09:58:38PM -0500, Bjorn Helgaas wrote: > If BIOS handed off with ATS enabled and we somehow relied on it being > already enabled, something might break if we start disabling ATS. > Just a theoretical possibility, doesn't seem likely to me.
I don't think this will be a problem. When the BIOS enables ATS for a device it also needs to enable the IOMMU already, an we are not handling an already enabled IOMMU (outside of kdump kernels) very well.
Regards,
Joerg
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