Re: [PATCH 1/4] amd-vi: fix IVMD memory type checks

[oxjo@xxxxxxxxx]

On Thursday, February 1st, 2024 at 18:01, Roger Pau Monne 
<roger.pau@xxxxxxxxxx> wrote:

> The current code that parses the IVMD blocks is relaxed with regard to the
> restriction that such unity regions should always fall into memory ranges
> marked as reserved in the memory map.
>
> However the type checks for the IVMD addresses are inverted, and as a result
> IVMD ranges falling into RAM areas are accepted. Note that having such ranges
> in the first place is a firmware bug, as IVMD should always fall into reserved
> ranges.
>
> Fixes: ed6c77ebf0c1 ('AMD/IOMMU: check / convert IVMD ranges for being / to 
> be reserved')
> Signed-off-by: Roger Pau Monné roger.pau@xxxxxxxxxx
>
> ---
> Cc: oxjo@xxxxxxxxx
> ---
> xen/drivers/passthrough/amd/iommu_acpi.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/xen/drivers/passthrough/amd/iommu_acpi.c 
> b/xen/drivers/passthrough/amd/iommu_acpi.c
> index 2e3b83014beb..ca70f4f3ae2c 100644
> --- a/xen/drivers/passthrough/amd/iommu_acpi.c
> +++ b/xen/drivers/passthrough/amd/iommu_acpi.c
> @@ -426,9 +426,14 @@ static int __init parse_ivmd_block(const struct 
> acpi_ivrs_memory ivmd_block)
> return -EIO;
> }
>
> - / Types which won't be handed out are considered good enough. /
> - if ( !(type & (RAM_TYPE_RESERVED | RAM_TYPE_ACPI |
> - RAM_TYPE_UNUSABLE)) )
> + /
> + * Types which aren't RAM are considered good enough.
> + * Note that a page being partially RESERVED, ACPI or UNUSABLE will
> + * force Xen into assuming the whole page as having that type in
> + * practice.
> + */
> + if ( type & (RAM_TYPE_RESERVED | RAM_TYPE_ACPI |
> + RAM_TYPE_UNUSABLE) )
> continue;
>
> AMD_IOMMU_ERROR("IVMD: page at %lx can't be converted\n", addr);

I tested the patch and it resolves the issue.
It eliminates the boot IVMD error message.
AMD-Vi is enabled and pci passthrough works.


Tested-by: oxjo <oxjo@xxxxxxxxx>