[coreboot] VT-d support

[ron minnich]

The reason I ask about what you need is that on chromebooks the main
coreboot support came down to 'don't disable anything'.

The DMAR requirements are not met on all platforms. But even after boot you
can insert DMAR tables into kernels.

So there is a key distinction between required support and desired support,
and I wonder if you could figure out what is required and let us know what
it is.



On Mon, Jun 5, 2017 at 9:39 AM Zoran Stojsavljevic <
zoran.stojsavljevic at gmail.com> wrote:

> > what support does it need?
>
> Intel Virtualization Technology for Directed I/O" (VT-d). VT-d is a
> virtualized IOMMU, so by using HYP type 1 there should be a VT-d driver
> supporting VT-d HW extension (?), as my best understanding is
>
> The practical implications are Graphics and Network Connectivity in
> Guests. DMA Remapping is the feature of VT-d.
>
> Good net pointer to read:
> https://unix.stackexchange.com/questions/34428/do-virtualbox-or-vmware-use-the-intel-vt-d-feature
>
> > Is anybody working on this?
>
> Don't think so... If anything is done, I guess, it is done by simplistic
> implementation of the feature called: pass-through (so guest by its own
> drivers is using directly platform devices' HW bypassing HYP1, my best
> guess).
>
> Zoran
> On Mon, Jun 5, 2017 at 6:11 PM, ron minnich <rminnich at gmail.com> wrote:
>
>>
>>
>> On Mon, Jun 5, 2017 at 9:00 AM Himanshu Chauhan <hschauhan at nulltrace.org>
>> wrote:
>>
>>> Hi,
>>>
>>> VT-d requires support from BIOS. Does coreboot support VT-d?
>>>
>>>
>>>
>> what support does it need?
>>
>> --
>> coreboot mailing list: coreboot at coreboot.org
>> https://mail.coreboot.org/mailman/listinfo/coreboot
>>
>
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