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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 12/13] [RFC] iommu: VT-d: Squash map_pages/unmap_pages with map_page/unmap_page
Hi, all.
Any comments?
On Tue, Jul 25, 2017 at 8:26 PM, Oleksandr Tyshchenko
<olekstysh@xxxxxxxxx> wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
>
> Reduce the scope of the TODO by squashing single-page stuff with
> multi-page one. Next target is to use large pages whenever possible
> in the case that hardware supports them.
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> CC: Jan Beulich <jbeulich@xxxxxxxx>
> CC: Kevin Tian <kevin.tian@xxxxxxxxx>
>
> ---
> Changes in v1:
> -
>
> Changes in v2:
> -
> ---
> xen/drivers/passthrough/vtd/iommu.c | 138
> +++++++++++++++++-------------------
> 1 file changed, 67 insertions(+), 71 deletions(-)
>
> diff --git a/xen/drivers/passthrough/vtd/iommu.c
> b/xen/drivers/passthrough/vtd/iommu.c
> index 45d1f36..d20b2f9 100644
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -1750,15 +1750,24 @@ static void iommu_domain_teardown(struct domain *d)
> spin_unlock(&hd->arch.mapping_lock);
> }
>
> -static int __must_check intel_iommu_map_page(struct domain *d,
> - unsigned long gfn,
> - unsigned long mfn,
> - unsigned int flags)
> +static int __must_check intel_iommu_unmap_pages(struct domain *d,
> + unsigned long gfn,
> + unsigned int order);
> +
> +/*
> + * TODO: Optimize by using large pages whenever possible in the case
> + * that hardware supports them.
> + */
> +static int __must_check intel_iommu_map_pages(struct domain *d,
> + unsigned long gfn,
> + unsigned long mfn,
> + unsigned int order,
> + unsigned int flags)
> {
> struct domain_iommu *hd = dom_iommu(d);
> - struct dma_pte *page = NULL, *pte = NULL, old, new = { 0 };
> - u64 pg_maddr;
> int rc = 0;
> + unsigned long orig_gfn = gfn;
> + unsigned long i;
>
> /* Do nothing if VT-d shares EPT page table */
> if ( iommu_use_hap_pt(d) )
> @@ -1768,78 +1777,60 @@ static int __must_check intel_iommu_map_page(struct
> domain *d,
> if ( iommu_passthrough && is_hardware_domain(d) )
> return 0;
>
> - spin_lock(&hd->arch.mapping_lock);
> -
> - pg_maddr = addr_to_dma_page_maddr(d, (paddr_t)gfn << PAGE_SHIFT_4K, 1);
> - if ( pg_maddr == 0 )
> + for ( i = 0; i < (1UL << order); i++, gfn++, mfn++ )
> {
> - spin_unlock(&hd->arch.mapping_lock);
> - return -ENOMEM;
> - }
> - page = (struct dma_pte *)map_vtd_domain_page(pg_maddr);
> - pte = page + (gfn & LEVEL_MASK);
> - old = *pte;
> - dma_set_pte_addr(new, (paddr_t)mfn << PAGE_SHIFT_4K);
> - dma_set_pte_prot(new,
> - ((flags & IOMMUF_readable) ? DMA_PTE_READ : 0) |
> - ((flags & IOMMUF_writable) ? DMA_PTE_WRITE : 0));
> + struct dma_pte *page = NULL, *pte = NULL, old, new = { 0 };
> + u64 pg_maddr;
>
> - /* Set the SNP on leaf page table if Snoop Control available */
> - if ( iommu_snoop )
> - dma_set_pte_snp(new);
> + spin_lock(&hd->arch.mapping_lock);
>
> - if ( old.val == new.val )
> - {
> + pg_maddr = addr_to_dma_page_maddr(d, (paddr_t)gfn << PAGE_SHIFT_4K,
> 1);
> + if ( pg_maddr == 0 )
> + {
> + spin_unlock(&hd->arch.mapping_lock);
> + rc = -ENOMEM;
> + goto err;
> + }
> + page = (struct dma_pte *)map_vtd_domain_page(pg_maddr);
> + pte = page + (gfn & LEVEL_MASK);
> + old = *pte;
> + dma_set_pte_addr(new, (paddr_t)mfn << PAGE_SHIFT_4K);
> + dma_set_pte_prot(new,
> + ((flags & IOMMUF_readable) ? DMA_PTE_READ : 0) |
> + ((flags & IOMMUF_writable) ? DMA_PTE_WRITE : 0));
> +
> + /* Set the SNP on leaf page table if Snoop Control available */
> + if ( iommu_snoop )
> + dma_set_pte_snp(new);
> +
> + if ( old.val == new.val )
> + {
> + spin_unlock(&hd->arch.mapping_lock);
> + unmap_vtd_domain_page(page);
> + continue;
> + }
> + *pte = new;
> +
> + iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
> spin_unlock(&hd->arch.mapping_lock);
> unmap_vtd_domain_page(page);
> - return 0;
> - }
> - *pte = new;
> -
> - iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
> - spin_unlock(&hd->arch.mapping_lock);
> - unmap_vtd_domain_page(page);
>
> - if ( !this_cpu(iommu_dont_flush_iotlb) )
> - rc = iommu_flush_iotlb(d, gfn, dma_pte_present(old), 1);
> -
> - return rc;
> -}
> -
> -static int __must_check intel_iommu_unmap_page(struct domain *d,
> - unsigned long gfn)
> -{
> - /* Do nothing if hardware domain and iommu supports pass thru. */
> - if ( iommu_passthrough && is_hardware_domain(d) )
> - return 0;
> -
> - return dma_pte_clear_one(d, (paddr_t)gfn << PAGE_SHIFT_4K);
> -}
> -
> -/* TODO: Optimize by squashing map_pages/unmap_pages with
> map_page/unmap_page */
> -static int __must_check intel_iommu_map_pages(struct domain *d,
> - unsigned long gfn,
> - unsigned long mfn,
> - unsigned int order,
> - unsigned int flags)
> -{
> - unsigned long i;
> - int rc = 0;
> -
> - for ( i = 0; i < (1UL << order); i++ )
> - {
> - rc = intel_iommu_map_page(d, gfn + i, mfn + i, flags);
> - if ( unlikely(rc) )
> + if ( !this_cpu(iommu_dont_flush_iotlb) )
> {
> - while ( i-- )
> - /* If statement to satisfy __must_check. */
> - if ( intel_iommu_unmap_page(d, gfn + i) )
> - continue;
> -
> - break;
> + rc = iommu_flush_iotlb(d, gfn, dma_pte_present(old), 1);
> + if ( rc )
> + goto err;
> }
> }
>
> + return 0;
> +
> +err:
> + while ( i-- )
> + /* If statement to satisfy __must_check. */
> + if ( intel_iommu_unmap_pages(d, orig_gfn + i, 0) )
> + continue;
> +
> return rc;
> }
>
> @@ -1847,12 +1838,17 @@ static int __must_check
> intel_iommu_unmap_pages(struct domain *d,
> unsigned long gfn,
> unsigned int order)
> {
> - unsigned long i;
> int rc = 0;
> + unsigned long i;
> +
> + /* Do nothing if hardware domain and iommu supports pass thru. */
> + if ( iommu_passthrough && is_hardware_domain(d) )
> + return 0;
>
> - for ( i = 0; i < (1UL << order); i++ )
> + for ( i = 0; i < (1UL << order); i++, gfn++ )
> {
> - int ret = intel_iommu_unmap_page(d, gfn + i);
> + int ret = dma_pte_clear_one(d, (paddr_t)gfn << PAGE_SHIFT_4K);
> +
> if ( !rc )
> rc = ret;
> }
> --
> 2.7.4
>
--
Regards,
Oleksandr Tyshchenko
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