> -----Original Message----- > From: Tian, Kevin [mailto:kevin.t...@intel.com] > Sent: 07 August 2018 04:25 > To: Paul Durrant <paul.durr...@citrix.com>; xen-devel@lists.xenproject.org > Cc: Jan Beulich <jbeul...@suse.com>; George Dunlap > <george.dun...@citrix.com> > Subject: RE: [PATCH v5 09/15] vtd: add lookup_page method to iommu_ops > > > From: Paul Durrant [mailto:paul.durr...@citrix.com] > > Sent: Saturday, August 4, 2018 1:22 AM > > > > 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 b10a37e5d7..9b7baca93f 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) > > Not looking at later patches yet... but in concept bfn address > space is per device instead of per domain.
Not in this case. Xen has always maintained a single IOMMU address per virtual machine. That is what BFN refers to. Paul > In default situation > (w/o pvIOMMU exposed), all devices assigned to dom0 share > the same address space (bfn=pfn) which is currently linked > from domain structure. Then with pvIOMMU exposed, dom0 > starts to manage individual pfn address space (called IOVA > address space within dom0) per assigned device. In that case > lookup should accept a bdf number and then find the right > page table... > No. That is over-complicating things and would probably involve re-writing most of the IOMMU code in Xen AFAICT. > > +{ > > + 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 cc0be81b4e..7c5d46df81 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 > > { > > @@ -198,6 +200,8 @@ 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