> From: Paul Durrant <p...@xen.org>
> Sent: Friday, November 20, 2020 9:25 PM
>
> From: Paul Durrant <pdurr...@amazon.com>
>
> This makes the code a little easier to read and also makes it more consistent
> with iremap_entry.
>
> Also take the opportunity to tidy up the implementation of
> device_in_domain().
>
> Signed-off-by: Paul Durrant <pdurr...@amazon.com>
Reviewed-by: <kevin.t...@intel.com>
> ---
> Cc: Kevin Tian <kevin.t...@intel.com>
>
> v10:
> - Small tweaks requested by Jan
> - Remove macros in favour of direct field access
> - Add missing barrier
>
> v4:
> - New in v4
> ---
> xen/drivers/passthrough/vtd/iommu.c | 9 +++++----
> xen/drivers/passthrough/vtd/iommu.h | 25 ++++++++++++-------------
> xen/drivers/passthrough/vtd/utils.c | 6 +++---
> xen/drivers/passthrough/vtd/x86/ats.c | 27 +++++++++++++++------------
> 4 files changed, 35 insertions(+), 32 deletions(-)
>
> diff --git a/xen/drivers/passthrough/vtd/iommu.c
> b/xen/drivers/passthrough/vtd/iommu.c
> index d136fe36883b..1a038541f0a3 100644
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -237,7 +237,7 @@ static u64 bus_to_context_maddr(struct vtd_iommu
> *iommu, u8 bus)
> ASSERT(spin_is_locked(&iommu->lock));
> root_entries = (struct root_entry *)map_vtd_domain_page(iommu-
> >root_maddr);
> root = &root_entries[bus];
> - if ( !root_present(*root) )
> + if ( !root->p )
> {
> maddr = alloc_pgtable_maddr(1, iommu->node);
> if ( maddr == 0 )
> @@ -245,11 +245,12 @@ static u64 bus_to_context_maddr(struct
> vtd_iommu *iommu, u8 bus)
> unmap_vtd_domain_page(root_entries);
> return 0;
> }
> - set_root_value(*root, maddr);
> - set_root_present(*root);
> + root->ctp = paddr_to_pfn(maddr);
> + smp_wmb();
> + root->p = true;
> iommu_sync_cache(root, sizeof(struct root_entry));
> }
> - maddr = (u64) get_context_addr(*root);
> + maddr = pfn_to_paddr(root->ctp);
> unmap_vtd_domain_page(root_entries);
> return maddr;
> }
> diff --git a/xen/drivers/passthrough/vtd/iommu.h
> b/xen/drivers/passthrough/vtd/iommu.h
> index 216791b3d634..b14628eec260 100644
> --- a/xen/drivers/passthrough/vtd/iommu.h
> +++ b/xen/drivers/passthrough/vtd/iommu.h
> @@ -184,21 +184,20 @@
> #define dma_frcd_source_id(c) (c & 0xffff)
> #define dma_frcd_page_addr(d) (d & (((u64)-1) << 12)) /* low 64 bit */
>
> -/*
> - * 0: Present
> - * 1-11: Reserved
> - * 12-63: Context Ptr (12 - (haw-1))
> - * 64-127: Reserved
> - */
> struct root_entry {
> - u64 val;
> - u64 rsvd1;
> + union {
> + struct { uint64_t lo, hi; };
> + struct {
> + /* 0 - 63 */
> + bool p:1;
> + unsigned int reserved0:11;
> + uint64_t ctp:52;
> +
> + /* 64 - 127 */
> + uint64_t reserved1;
> + };
> + };
> };
> -#define root_present(root) ((root).val & 1)
> -#define set_root_present(root) do {(root).val |= 1;} while(0)
> -#define get_context_addr(root) ((root).val & PAGE_MASK_4K)
> -#define set_root_value(root, value) \
> - do {(root).val |= ((value) & PAGE_MASK_4K);} while(0)
>
> struct context_entry {
> u64 lo;
> diff --git a/xen/drivers/passthrough/vtd/utils.c
> b/xen/drivers/passthrough/vtd/utils.c
> index 4febcf506d8a..5f25a86a535c 100644
> --- a/xen/drivers/passthrough/vtd/utils.c
> +++ b/xen/drivers/passthrough/vtd/utils.c
> @@ -112,15 +112,15 @@ void print_vtd_entries(struct vtd_iommu *iommu,
> int bus, int devfn, u64 gmfn)
> return;
> }
>
> - printk(" root_entry[%02x] = %"PRIx64"\n", bus, root_entry[bus].val);
> - if ( !root_present(root_entry[bus]) )
> + printk(" root_entry[%02x] = %"PRIx64"\n", bus, root_entry[bus].lo);
> + if ( !root_entry[bus].p )
> {
> unmap_vtd_domain_page(root_entry);
> printk(" root_entry[%02x] not present\n", bus);
> return;
> }
>
> - val = root_entry[bus].val;
> + val = pfn_to_paddr(root_entry[bus].ctp);
> unmap_vtd_domain_page(root_entry);
> ctxt_entry = map_vtd_domain_page(val);
> if ( ctxt_entry == NULL )
> diff --git a/xen/drivers/passthrough/vtd/x86/ats.c
> b/xen/drivers/passthrough/vtd/x86/ats.c
> index 04d702b1d6b1..fec969ef75bb 100644
> --- a/xen/drivers/passthrough/vtd/x86/ats.c
> +++ b/xen/drivers/passthrough/vtd/x86/ats.c
> @@ -74,8 +74,8 @@ int ats_device(const struct pci_dev *pdev, const struct
> acpi_drhd_unit *drhd)
> static bool device_in_domain(const struct vtd_iommu *iommu,
> const struct pci_dev *pdev, uint16_t did)
> {
> - struct root_entry *root_entry;
> - struct context_entry *ctxt_entry = NULL;
> + struct root_entry *root_entry, *root_entries;
> + struct context_entry *context_entry, *context_entries = NULL;
> unsigned int tt;
> bool found = false;
>
> @@ -85,25 +85,28 @@ static bool device_in_domain(const struct
> vtd_iommu *iommu,
> return false;
> }
>
> - root_entry = map_vtd_domain_page(iommu->root_maddr);
> - if ( !root_present(root_entry[pdev->bus]) )
> + root_entries = (struct root_entry *)map_vtd_domain_page(iommu-
> >root_maddr);
> + root_entry = &root_entries[pdev->bus];
> + if ( !root_entry->p )
> goto out;
>
> - ctxt_entry = map_vtd_domain_page(root_entry[pdev->bus].val);
> - if ( context_domain_id(ctxt_entry[pdev->devfn]) != did )
> + context_entries = map_vtd_domain_page(root_entry->ctp);
> + context_entry = &context_entries[pdev->devfn];
> + if ( context_domain_id(*context_entry) != did )
> goto out;
>
> - tt = context_translation_type(ctxt_entry[pdev->devfn]);
> + tt = context_translation_type(*context_entry);
> if ( tt != CONTEXT_TT_DEV_IOTLB )
> goto out;
>
> found = true;
> -out:
> - if ( root_entry )
> - unmap_vtd_domain_page(root_entry);
>
> - if ( ctxt_entry )
> - unmap_vtd_domain_page(ctxt_entry);
> + out:
> + if ( root_entries )
> + unmap_vtd_domain_page(root_entries);
> +
> + if ( context_entries )
> + unmap_vtd_domain_page(context_entries);
>
> return found;
> }
> --
> 2.20.1
