This has been an issue since before AM2+, but AM2+ is when I first started to deal with it. For AMD IOMMU does not fully work behind the DMI. If you break out IOMMU from the CPU lanes You can generally get it working anyway you want. But if you try and break out DMI attached devices (PCIE, Onboard, other) the Groups are generally broken and do not work. Have tried this with many HyperVisors and some will just give up the ghost after a while due to sharing violations. So this is not exactly new and I wouldnt expect a proper fix.
Hi, Sir Squishy. AM2+ is 11 years old, perhaps IOMMU was not a mature technology at the time of AM2+ creation. IOMMU is better at the newer AMDs, but at 16h Jaguar it simply does not exist, even at desktops... Also, please make sure that you have the latest microcode installed: for example, if the latest microcode is not installed on G505S with its' A10-5750M, there are IOMMU-related freezes at Qubes OS. Recently we got the latest 15h / 16h microcodes merged to coreboot, so the people with 15h / 16h at older coreboot builds - have to update, and those with proprietary BIOSes could try to manually patch them by hand.
Best regards, Mike Banon
On Fri, Jun 21, 2019 at 11:22 AM Sirsquishy sirsquishy@gmail.com wrote:
This has been an issue since before AM2+, but AM2+ is when I first started to deal with it. For AMD IOMMU does not fully work behind the DMI. If you break out IOMMU from the CPU lanes You can generally get it working anyway you want. But if you try and break out DMI attached devices (PCIE, Onboard, other) the Groups are generally broken and do not work. Have tried this with many HyperVisors and some will just give up the ghost after a while due to sharing violations. So this is not exactly new and I wouldnt expect a proper fix. _______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-leave@coreboot.org
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Mike Banon -
Sirsquishy