Re: [PATCH] iommu/amd: Set translation valid bit only when IO page tables are in used

From: Vasant Hegde
Date: Thu Apr 28 2022 - 03:34:43 EST


On 4/20/2022 4:59 PM, Suravee Suthikulpanit via iommu wrote:
> On AMD system with SNP enabled, IOMMU hardware checks the host translation
> valid (TV) and guest translation valid (GV) bits in the device
> table entry (DTE) before accessing the corresponded page tables.
>
> However, current IOMMU driver sets the TV bit for all devices
> regardless of whether the host page table is in used.
> This results in ILLEGAL_DEV_TABLE_ENTRY event for devices, which
> do not the host page table root pointer set up.
>
> Thefore, only set TV bit when host or guest page tables are in used.
>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>

Looks good to me.

Reviewed-by: Vasant Hegde <vasant.hegde@xxxxxxx>

-Vasant