Re: [PATCH v7 1/7] iommu/vt-d: Don't switch off swiotlb if use direct dma

From: Joerg Roedel
Date: Fri Aug 30 2019 - 06:31:54 EST


On Sat, Aug 24, 2019 at 10:17:30AM +0800, Lu Baolu wrote:
> If a system has any external port, through which an untrusted device
> might be connected, the external port itself should be marked as an
> untrusted device, and all devices beneath it just inherit this
> attribution.

Okay, makes sense.

> So during iommu driver initialization, we can easily know whether the
> system has (or potentially has) untrusted devices by iterating the
> device tree. I will add such check in the next version if no objections.

Sounds good, thanks Baolu.


Joerg