Re: [PATCH v3 2/2] intel_iommu: Make PASID-cache and PIOTLB type invalid in legacy mode

[Yi Liu <yi.l.liu@intel.com>]

On 2024/8/14 10:26, Zhenzhong Duan wrote:
> In vtd_process_inv_desc(), VTD_INV_DESC_PC and VTD_INV_DESC_PIOTLB are
> bypassed without scalable mode check. These two types are not valid
> in legacy mode and we should report error.
> 
> Fixes: 4a4f219e8a1 ("intel_iommu: add scalable-mode option to make scalable mode work")

4a4f219e8a10 would be better. :)

> Suggested-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Reviewed-by: Clément Mathieu--Drif<clement.mathieu--drif@eviden.com>
> Reviewed-by: Yi Liu <yi.l.liu@intel.com>
> ---
>   hw/i386/intel_iommu.c | 22 +++++++++++-----------
>   1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 68cb72a481..90cd4e5044 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -2763,17 +2763,6 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
>           }
>           break;
>   
> -    /*
> -     * TODO: the entity of below two cases will be implemented in future series.
> -     * To make guest (which integrates scalable mode support patch set in
> -     * iommu driver) work, just return true is enough so far.
> -     */
> -    case VTD_INV_DESC_PC:
> -        break;
> -
> -    case VTD_INV_DESC_PIOTLB:
> -        break;
> -
>       case VTD_INV_DESC_WAIT:
>           trace_vtd_inv_desc("wait", inv_desc.hi, inv_desc.lo);
>           if (!vtd_process_wait_desc(s, &inv_desc)) {
> @@ -2795,6 +2784,17 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
>           }
>           break;
>   
> +    /*
> +     * TODO: the entity of below two cases will be implemented in future series.
> +     * To make guest (which integrates scalable mode support patch set in
> +     * iommu driver) work, just return true is enough so far.
> +     */
> +    case VTD_INV_DESC_PC:
> +    case VTD_INV_DESC_PIOTLB:
> +        if (s->scalable_mode) {
> +            break;
> +        }
> +    /* fallthrough */
>       default:
>           error_report_once("%s: invalid inv desc: hi=%"PRIx64", lo=%"PRIx64
>                             " (unknown type)", __func__, inv_desc.hi,

-- 
Regards,
Yi Liu