[Qemu-devel] Re: [RFC PATCH] AMD IOMMU emulation

[Joerg Roedel <joro@8bytes.org>]

Hi Eduard,

On Thu, May 20, 2010 at 04:50:07PM +0300, Eduard - Gabriel Munteanu wrote:
> +  --enable-amd-iommu-emul) amd_iommu="yes"
> +  ;;

A compile-time option is a good idea.

> +/* MMIO registers */
> +#define MMIO_DEVICE_TABLE       0x0000
> +#define MMIO_COMMAND_BASE       0x0008
> +#define MMIO_EVENT_BASE         0x0010
> +#define MMIO_CONTROL            0x0018
> +#define MMIO_EXCL_BASE          0x0020
> +#define MMIO_EXCL_LIMIT         0x0028
> +#define MMIO_COMMAND_HEAD       0x2000
> +#define MMIO_COMMAND_TAIL       0x2008
> +#define MMIO_EVENT_HEAD         0x2010
> +#define MMIO_EVENT_TAIL         0x2018
> +#define MMIO_STATUS             0x2020
> +
> +#define MMIO_SIZE               0x2028

This size should be a power-of-two value. In this case probably 0x4000.

> +#define MMIO_DEVTAB_SIZE_MASK   ((1UL << 12) - 1)
> +#define MMIO_DEVTAB_BASE_MASK   (((1UL << 52) - 1) & ~MMIO_DEVTAB_SIZE_MASK)

You must use ULL to be 32bit safe. This is also true for the defines
below.

[...]

Otherwise the code looks good so far. Seems like the next step should be
some work on a qemu dma-layer where you can hook the translation into.

	Joerg