> From: Jan Beulich
> Sent: Tuesday, January 11, 2022 12:32 AM
>
> ... depending on feature availability (and absence of quirks).
>
> Also make the page table dumping function aware of superpages.
>
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
> ---
> v3: Rename queue_free_pt()'s last parameter. Replace "level > 1" checks
> where possible. Tighten assertion.
>
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -826,18 +826,37 @@ static int __must_check iommu_flush_iotl
> return iommu_flush_iotlb(d, INVALID_DFN, 0, 0);
> }
>
> +static void queue_free_pt(struct domain *d, mfn_t mfn, unsigned int level)
> +{
> + if ( level > 1 )
> + {
> + struct dma_pte *pt = map_domain_page(mfn);
> + unsigned int i;
> +
> + for ( i = 0; i < PTE_NUM; ++i )
> + if ( dma_pte_present(pt[i]) && !dma_pte_superpage(pt[i]) )
> + queue_free_pt(d, maddr_to_mfn(dma_pte_addr(pt[i])),
> + level - 1);
> +
> + unmap_domain_page(pt);
> + }
> +
> + iommu_queue_free_pgtable(d, mfn_to_page(mfn));
> +}
> +
> /* clear one page's page table */
> static int dma_pte_clear_one(struct domain *domain, daddr_t addr,
> unsigned int order,
> unsigned int *flush_flags)
> {
> struct domain_iommu *hd = dom_iommu(domain);
> - struct dma_pte *page = NULL, *pte = NULL;
> + struct dma_pte *page = NULL, *pte = NULL, old;
> u64 pg_maddr;
> + unsigned int level = (order / LEVEL_STRIDE) + 1;
>
> spin_lock(&hd->arch.mapping_lock);
> - /* get last level pte */
> - pg_maddr = addr_to_dma_page_maddr(domain, addr, 1, flush_flags,
> false);
> + /* get target level pte */
> + pg_maddr = addr_to_dma_page_maddr(domain, addr, level, flush_flags,
> false);
> if ( pg_maddr < PAGE_SIZE )
> {
> spin_unlock(&hd->arch.mapping_lock);
> @@ -845,7 +864,7 @@ static int dma_pte_clear_one(struct doma
> }
>
> page = (struct dma_pte *)map_vtd_domain_page(pg_maddr);
> - pte = page + address_level_offset(addr, 1);
> + pte = &page[address_level_offset(addr, level)];
>
> if ( !dma_pte_present(*pte) )
> {
> @@ -854,14 +873,20 @@ static int dma_pte_clear_one(struct doma
> return 0;
> }
>
> + old = *pte;
> dma_clear_pte(*pte);
> - *flush_flags |= IOMMU_FLUSHF_modified;
>
> spin_unlock(&hd->arch.mapping_lock);
> iommu_sync_cache(pte, sizeof(struct dma_pte));
>
> unmap_vtd_domain_page(page);
>
> + *flush_flags |= IOMMU_FLUSHF_modified;
> +
> + if ( order && !dma_pte_superpage(old) )
> + queue_free_pt(domain, maddr_to_mfn(dma_pte_addr(old)),
> + order / LEVEL_STRIDE);
> +
> return 0;
> }
>
> @@ -1952,6 +1977,7 @@ static int __must_check intel_iommu_map_
> struct domain_iommu *hd = dom_iommu(d);
> struct dma_pte *page, *pte, old, new = {};
> u64 pg_maddr;
> + unsigned int level = (IOMMUF_order(flags) / LEVEL_STRIDE) + 1;
> int rc = 0;
>
> /* Do nothing if VT-d shares EPT page table */
> @@ -1976,7 +2002,7 @@ static int __must_check intel_iommu_map_
> return 0;
> }
>
> - pg_maddr = addr_to_dma_page_maddr(d, dfn_to_daddr(dfn), 1,
> flush_flags,
> + pg_maddr = addr_to_dma_page_maddr(d, dfn_to_daddr(dfn), level,
> flush_flags,
> true);
> if ( pg_maddr < PAGE_SIZE )
> {
> @@ -1985,13 +2011,15 @@ static int __must_check intel_iommu_map_
> }
>
> page = (struct dma_pte *)map_vtd_domain_page(pg_maddr);
> - pte = &page[dfn_x(dfn) & LEVEL_MASK];
> + pte = &page[address_level_offset(dfn_to_daddr(dfn), level)];
> old = *pte;
>
> dma_set_pte_addr(new, mfn_to_maddr(mfn));
> dma_set_pte_prot(new,
> ((flags & IOMMUF_readable) ? DMA_PTE_READ : 0) |
> ((flags & IOMMUF_writable) ? DMA_PTE_WRITE : 0));
> + if ( IOMMUF_order(flags) )
> + dma_set_pte_superpage(new);
>
> /* Set the SNP on leaf page table if Snoop Control available */
> if ( iommu_snoop )
> @@ -2012,8 +2040,14 @@ static int __must_check intel_iommu_map_
>
> *flush_flags |= IOMMU_FLUSHF_added;
> if ( dma_pte_present(old) )
> + {
> *flush_flags |= IOMMU_FLUSHF_modified;
>
> + if ( IOMMUF_order(flags) && !dma_pte_superpage(old) )
> + queue_free_pt(d, maddr_to_mfn(dma_pte_addr(old)),
> + IOMMUF_order(flags) / LEVEL_STRIDE);
> + }
> +
> return rc;
> }
>
> @@ -2370,6 +2404,7 @@ static int __init vtd_setup(void)
> {
> struct acpi_drhd_unit *drhd;
> struct vtd_iommu *iommu;
> + unsigned int large_sizes = PAGE_SIZE_2M | PAGE_SIZE_1G;
> int ret;
> bool reg_inval_supported = true;
>
> @@ -2412,6 +2447,11 @@ static int __init vtd_setup(void)
> cap_sps_2mb(iommu->cap) ? ", 2MB" : "",
> cap_sps_1gb(iommu->cap) ? ", 1GB" : "");
>
> + if ( !cap_sps_2mb(iommu->cap) )
> + large_sizes &= ~PAGE_SIZE_2M;
> + if ( !cap_sps_1gb(iommu->cap) )
> + large_sizes &= ~PAGE_SIZE_1G;
> +
> #ifndef iommu_snoop
> if ( iommu_snoop && !ecap_snp_ctl(iommu->ecap) )
> iommu_snoop = false;
> @@ -2483,6 +2523,9 @@ static int __init vtd_setup(void)
> if ( ret )
> goto error;
>
> + ASSERT(iommu_ops.page_sizes == PAGE_SIZE_4K);
> + iommu_ops.page_sizes |= large_sizes;
> +
> register_keyhandler('V', vtd_dump_iommu_info, "dump iommu info", 1);
>
> return 0;
> @@ -2797,7 +2840,7 @@ static void vtd_dump_page_table_level(pa
> continue;
>
> address = gpa + offset_level_address(i, level);
> - if ( next_level >= 1 )
> + if ( next_level && !dma_pte_superpage(*pte) )
> vtd_dump_page_table_level(dma_pte_addr(*pte), next_level,
> address, indent + 1);
> else
>
