Re: [PATCH v2 1/2] intel_iommu: split the resevred fields arrays into two ones

[Peter Xu <peterx@redhat.com>]

On Tue, Nov 19, 2019 at 08:28:13PM +0800, qi1.zhang@intel.com wrote:
> @@ -3547,15 +3548,17 @@ static void vtd_init(IntelIOMMUState *s)
>      /*
>       * Rsvd field masks for spte
>       */
> -    vtd_paging_entry_rsvd_field[0] = ~0ULL;
> -    vtd_paging_entry_rsvd_field[1] = VTD_SPTE_PAGE_L1_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[2] = VTD_SPTE_PAGE_L2_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[3] = VTD_SPTE_PAGE_L3_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[4] = VTD_SPTE_PAGE_L4_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[5] = VTD_SPTE_LPAGE_L1_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[6] = VTD_SPTE_LPAGE_L2_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[7] = VTD_SPTE_LPAGE_L3_RSVD_MASK(s->aw_bits);
> -    vtd_paging_entry_rsvd_field[8] = VTD_SPTE_LPAGE_L4_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd[0] = ~0ULL;
> +    vtd_spte_rsvd[1] = VTD_SPTE_PAGE_L1_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd[2] = VTD_SPTE_PAGE_L2_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd[3] = VTD_SPTE_PAGE_L3_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd[4] = VTD_SPTE_PAGE_L4_RSVD_MASK(s->aw_bits);
> +
> +    vtd_spte_rsvd_large[0] = ~0ULL;
> +    vtd_spte_rsvd_large[1] = VTD_SPTE_LPAGE_L1_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd_large[2] = VTD_SPTE_LPAGE_L2_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd_large[3] = VTD_SPTE_LPAGE_L3_RSVD_MASK(s->aw_bits);
> +    vtd_spte_rsvd_large[4] = VTD_SPTE_LPAGE_L4_RSVD_MASK(s->aw_bits);

This looks good to me in general, but... Since we're at it, do you
think we can directly drop VTD_SPTE_LPAGE_L1_RSVD_MASK and
VTD_SPTE_LPAGE_L4_RSVD_MASK?  Are they really useful?

I think I'm using the latest vt-d spec now (June, 2019) and it only
supports 2M/1G huge pages, corresponds to VTD_SPTE_LPAGE_L2_RSVD_MASK
and VTD_SPTE_LPAGE_L3_RSVD_MASK.

-- 
Peter Xu