On: iMac Pro's T2 chip

[turblety]

Isn't that a feature of the CPU though?

*edit sorry I am wrong. DMA seems to bypass the CPU [1]

1. https://www.csoonline.com/article/2607924/security/stop-snea...

[godelmachine → turblety]

I was about to correct you when you edited your own comment !! :)

[j_coder → godelmachine]

Not having a central controller multiple subsystem vendors would have to cooperate using an agreed DMA communication protocol to monitor you and send the information back using the wifi/ethernet chip. Possible but unlikely.

[jnwatson → j_coder]

The DMA communication protocol is already defined. It is part of PCIExpress.

[walterbell → jnwatson]

On the iMac Pro, will PCI devices be able to DMA into both the Intel and ARM CPUs? Is there a single IOMMU which will arbitrate DMA for both CPUs?

[jnwatson → walterbell]

The IOMMU functionality is built into the Platform Controller Hub, which is between the baseboard management controller (the ARM) and the main processor.

Theoretically it would be possible to prevent DMA between the two, but it is highly doubtful Apple would program it that way.