WIP: enabling-iommu-in-coreboot-for-pcengines-apu2: initial commit

_posts/04-05-2018-enabling-iommu-in-coreboot-for-pcengines-apu2.md

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+---
+author: Piotr Król
+layout: post
+published: true
+post_date: 2018-05-22 15:00:00
+
+tags:
+	- coreboot
+	- apu2
+	- iommu
+	- virtualization
+categories:
+	- Firmware
+---
+
+In [last post](TBD) I introduced latest version of `pxe-server` project which
+contain all necessary components to boot Xen on PC Engines apu2 over PXE. In
+this post I would like to present IOMMU enabling process that I get through.
+
+Base components of this work are [Kyösti Mälkki patches](http://xen.1045712.n5.nabble.com/Enabling-AMD-Vi-IOMMU-panics-Xen-td5731305.html)
+and Timothy Pearson patches
+[1](https://review.coreboot.org/#/c/coreboot/+/15186/),
+[2](https://review.coreboot.org/#/c/coreboot/+/15165/) and
+[3](https://review.coreboot.org/#/c/coreboot/+/15164/).
+
+# Kyösti patches
+
+Using first patches I was able to enable IOMMU with some features. `xl dmesg`
+give me:
+
+```
+(XEN) AMD-Vi: IOMMU Extended Features:
+(XEN)  - Peripheral Page Service Request
+(XEN)  - Guest Translation
+(XEN)  - Invalidate All Command
+(XEN)  - Guest APIC supported
+(XEN)  - Performance Counters
+(XEN) AMD-Vi: IOMMU 0 Enabled.
+(XEN) I/O virtualisation enabled
+(XEN)  - Dom0 mode: Relaxed
+```
+
+It looks like FACS address in FADT is incorrect:
+
+```
+(XEN) ACPI: 32/64X FACS address mismatch in FADT - cffae240/0000000000000000, using 32
+(XEN) ACPI:             wakeup_vec[cffae24c], vec_size[20]
+```
+
+There is also some complain about missing ACPI table for IOMMU:
+
+```
+(XEN) 0000:00:00.2 not found in ACPI tables; using same IOMMU as function 0
+```
+
+This patch series takes IVRS ACPI table from AGESA. What seems to be completely
+different approach from patches published by Timothy where whole table is
+created from scratch.
+