Re: [Qemu-devel] [PATCH 0/4] AMD IOMMU v1

[Valentine Sinitsyn]

Hi David,

Thanks for your efforts.

On 09.10.2015 07:53, David Kiarie wrote:
> David (4):
>    hw/core: Add iommu to machine properties
>    hw/pci-host: Add AMD IOMMU to PIIX and Q35 pcs
>    hw/i386: Introduce AMD IOMMU
>    hw/acpi: ACPI table for AMD IOMMU
>
>   hw/core/machine.c           |   25 +
>   hw/i386/Makefile.objs       |    1 +
>   hw/i386/acpi-build.c        |   85 +++
>   hw/i386/amd_iommu.c         | 1266 +++++++++++++++++++++++++++++++++++++++++++
>   hw/i386/amd_iommu.h         |  363 +++++++++++++
>   hw/pci-host/piix.c          |   10 +
>   hw/pci-host/q35.c           |   10 +
>   include/hw/acpi/acpi-defs.h |   55 ++
>   include/hw/boards.h         |    2 +
>   9 files changed, 1817 insertions(+)
>   create mode 100644 hw/i386/amd_iommu.c
>   create mode 100644 hw/i386/amd_iommu.h
>
>
> AMD IOMMU v1
>
> Changes since RFC
>      -code cleanup around MMIO code
>      -compacted startup code - some of the 'init' and 'reset' code is similar 
> and can be reused
>      -Implemented basic IOTLB - it's just a hashtable of already requested 
> virtual address translations whereby if a device requests translation of the 
> same address we don't have to do a page walk, again.
>      -Implemented event logging - this version logs about all possible SW/HW 
> errors but most of them are very unlikely to occur.
>      -Changed GVA and HVA to go by the physical host bus implementations - 48 
> bits virtual and 40 bits physical address space.
I haven't looked into this closely yet, but shouldn't you support a 
whole 63 bits wide addresses (and 6-level page tables),  as per 
specification?

> TODO
>     -Implement MMIO reserving code
>     -Implement r/wc MMIO registers
>     -Implement interrupts related to r/wc registers
>
> IOMMU won't be able to implement PPR logging with the current Qemu 
> infrastructure - Qemu doesn't implement anything that's related to PASID. 
> Similary, guest translation won't be possible.
>
> Note: I have not tested this code and it might have a few bugs (silly bugs) of 
> course but the RFC version works so, if present, it's just minor bugs.

Regards,
Valentine Sinitsyn