This patch adds a new method to the VT-d IOMMU implementation to find the MFN currently mapped by the specified BFN along with a wrapper function in generic IOMMU code to call the implementation if it exists.
This functionality will be used by a subsequent patch. Signed-off-by: Paul Durrant <paul.durr...@citrix.com> Reviewed-by: Wei Liu <wei.l...@citrix.com> --- Cc: Kevin Tian <kevin.t...@intel.com> Cc: Jan Beulich <jbeul...@suse.com> Cc: George Dunlap <george.dun...@citrix.com> v3: - Addressed comments from George. v2: - Addressed some comments from Jan. --- xen/drivers/passthrough/iommu.c | 11 +++++++++++ xen/drivers/passthrough/vtd/iommu.c | 34 ++++++++++++++++++++++++++++++++++ xen/drivers/passthrough/vtd/iommu.h | 3 +++ xen/include/xen/iommu.h | 4 ++++ 4 files changed, 52 insertions(+) diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c index 9b63e9efee..7808fa85d0 100644 --- a/xen/drivers/passthrough/iommu.c +++ b/xen/drivers/passthrough/iommu.c @@ -305,6 +305,17 @@ int iommu_unmap_page(struct domain *d, bfn_t bfn) return rc; } +int iommu_lookup_page(struct domain *d, bfn_t bfn, mfn_t *mfn, + unsigned int *flags) +{ + const struct domain_iommu *hd = dom_iommu(d); + + if ( !iommu_enabled || !hd->platform_ops ) + return -EOPNOTSUPP; + + return hd->platform_ops->lookup_page(d, bfn, mfn, flags); +} + static void iommu_free_pagetables(unsigned long unused) { do { diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 282e227414..8cd3b59aa0 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -1830,6 +1830,39 @@ static int __must_check intel_iommu_unmap_page(struct domain *d, return dma_pte_clear_one(d, bfn_to_baddr(bfn)); } +static int intel_iommu_lookup_page(struct domain *d, bfn_t bfn, mfn_t *mfn, + unsigned int *flags) +{ + struct domain_iommu *hd = dom_iommu(d); + struct dma_pte *page = NULL, *pte = NULL, val; + u64 pg_maddr; + + spin_lock(&hd->arch.mapping_lock); + + pg_maddr = addr_to_dma_page_maddr(d, bfn_to_baddr(bfn), 0); + if ( pg_maddr == 0 ) + { + spin_unlock(&hd->arch.mapping_lock); + return -ENOMEM; + } + + page = map_vtd_domain_page(pg_maddr); + pte = page + (bfn_x(bfn) & LEVEL_MASK); + val = *pte; + + unmap_vtd_domain_page(page); + spin_unlock(&hd->arch.mapping_lock); + + if ( !dma_pte_present(val) ) + return -ENOENT; + + *mfn = maddr_to_mfn(dma_pte_addr(val)); + *flags = dma_pte_read(val) ? IOMMUF_readable : 0; + *flags |= dma_pte_write(val) ? IOMMUF_writable : 0; + + return 0; +} + int iommu_pte_flush(struct domain *d, uint64_t bfn, uint64_t *pte, int order, int present) { @@ -2661,6 +2694,7 @@ const struct iommu_ops intel_iommu_ops = { .teardown = iommu_domain_teardown, .map_page = intel_iommu_map_page, .unmap_page = intel_iommu_unmap_page, + .lookup_page = intel_iommu_lookup_page, .free_page_table = iommu_free_page_table, .reassign_device = reassign_device_ownership, .get_device_group_id = intel_iommu_group_id, diff --git a/xen/drivers/passthrough/vtd/iommu.h b/xen/drivers/passthrough/vtd/iommu.h index 72c1a2e3cd..47bdfcb5ea 100644 --- a/xen/drivers/passthrough/vtd/iommu.h +++ b/xen/drivers/passthrough/vtd/iommu.h @@ -272,6 +272,9 @@ struct dma_pte { #define dma_set_pte_prot(p, prot) do { \ (p).val = ((p).val & ~DMA_PTE_PROT) | ((prot) & DMA_PTE_PROT); \ } while (0) +#define dma_pte_prot(p) ((p).val & DMA_PTE_PROT) +#define dma_pte_read(p) (dma_pte_prot(p) & DMA_PTE_READ) +#define dma_pte_write(p) (dma_pte_prot(p) & DMA_PTE_WRITE) #define dma_pte_addr(p) ((p).val & PADDR_MASK & PAGE_MASK_4K) #define dma_set_pte_addr(p, addr) do {\ (p).val |= ((addr) & PAGE_MASK_4K); } while (0) diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h index 8cdb530d49..cdd75acf62 100644 --- a/xen/include/xen/iommu.h +++ b/xen/include/xen/iommu.h @@ -100,6 +100,8 @@ void iommu_teardown(struct domain *d); int __must_check iommu_map_page(struct domain *d, bfn_t bfn, mfn_t mfn, unsigned int flags); int __must_check iommu_unmap_page(struct domain *d, bfn_t bfn); +int __must_check iommu_lookup_page(struct domain *d, bfn_t bfn, mfn_t *mfn, + unsigned int *flags); enum iommu_feature { @@ -196,6 +198,8 @@ struct iommu_ops { int __must_check (*map_page)(struct domain *d, bfn_t bfn, mfn_t mfn, unsigned int flags); int __must_check (*unmap_page)(struct domain *d, bfn_t bfn); + int __must_check (*lookup_page)(struct domain *d, bfn_t bfn, mfn_t *mfn, + unsigned int *flags); void (*free_page_table)(struct page_info *); #ifdef CONFIG_X86 void (*update_ire_from_apic)(unsigned int apic, unsigned int reg, unsigned int value); -- 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel