Messages in this thread Patch in this message | | | Subject | Re: [RFC PATCH 3/4] iommu/vt-d: Map/unmap domain with mmmap/mmunmap | From | Lu Baolu <> | Date | Wed, 25 Sep 2019 15:06:43 +0800 |
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Hi,
On 9/25/19 1:00 PM, Tian, Kevin wrote: >> From: Lu Baolu [mailto:baolu.lu@linux.intel.com] >> Sent: Monday, September 23, 2019 8:25 PM >> >> If a dmar domain has DOMAIN_FLAG_FIRST_LEVEL_TRANS bit set >> in its flags, IOMMU will use the first level page table for >> translation. Hence, we need to map or unmap addresses in the >> first level page table. >> >> Cc: Ashok Raj <ashok.raj@intel.com> >> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> >> Cc: Kevin Tian <kevin.tian@intel.com> >> Cc: Liu Yi L <yi.l.liu@intel.com> >> Cc: Yi Sun <yi.y.sun@linux.intel.com> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> --- >> drivers/iommu/intel-iommu.c | 94 ++++++++++++++++++++++++++++++++- >> ---- >> 1 file changed, 82 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> index 9cfe8098d993..103480016010 100644 >> --- a/drivers/iommu/intel-iommu.c >> +++ b/drivers/iommu/intel-iommu.c >> @@ -168,6 +168,11 @@ static inline unsigned long virt_to_dma_pfn(void >> *p) >> return page_to_dma_pfn(virt_to_page(p)); >> } >> >> +static inline unsigned long dma_pfn_to_addr(unsigned long pfn) >> +{ >> + return pfn << VTD_PAGE_SHIFT; >> +} >> + >> /* global iommu list, set NULL for ignored DMAR units */ >> static struct intel_iommu **g_iommus; >> >> @@ -307,6 +312,9 @@ static int hw_pass_through = 1; >> */ >> #define DOMAIN_FLAG_LOSE_CHILDREN BIT(1) >> >> +/* Domain uses first level translation for DMA remapping. */ >> +#define DOMAIN_FLAG_FIRST_LEVEL_TRANS BIT(2) >> + >> #define for_each_domain_iommu(idx, domain) \ >> for (idx = 0; idx < g_num_of_iommus; idx++) \ >> if (domain->iommu_refcnt[idx]) >> @@ -552,6 +560,11 @@ static inline int domain_type_is_si(struct >> dmar_domain *domain) >> return domain->flags & DOMAIN_FLAG_STATIC_IDENTITY; >> } >> >> +static inline int domain_type_is_flt(struct dmar_domain *domain) >> +{ >> + return domain->flags & DOMAIN_FLAG_FIRST_LEVEL_TRANS; >> +} >> + >> static inline int domain_pfn_supported(struct dmar_domain *domain, >> unsigned long pfn) >> { >> @@ -1147,8 +1160,15 @@ static struct page *domain_unmap(struct >> dmar_domain *domain, >> BUG_ON(start_pfn > last_pfn); >> >> /* we don't need lock here; nobody else touches the iova range */ >> - freelist = dma_pte_clear_level(domain, agaw_to_level(domain- >>> agaw), >> - domain->pgd, 0, start_pfn, last_pfn, >> NULL); >> + if (domain_type_is_flt(domain)) >> + freelist = intel_mmunmap_range(domain, >> + dma_pfn_to_addr(start_pfn), >> + dma_pfn_to_addr(last_pfn + 1)); >> + else >> + freelist = dma_pte_clear_level(domain, >> + agaw_to_level(domain->agaw), >> + domain->pgd, 0, start_pfn, >> + last_pfn, NULL); > > what about providing an unified interface at the caller side, then having > the level differentiated within the interface?
Good point! I ever thought about adding some ops in struct dmar_domain, something like:
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index ed11ef594378..1dd184f76bfb 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -489,7 +489,14 @@ struct dmar_domain { struct list_head auxd; /* link to device's auxiliary list */ struct iova_domain iovad; /* iova's that belong to this domain */
+ /* per domain page table and manipulation ops */ struct dma_pte *pgd; /* virtual address */ + int (*map)(struct dmar_domain *domain, + unsigned long addr, unsigned long end, + phys_addr_t phys_addr, int dma_prot); + struct page *(*unmap)(struct dmar_domain *domain, + unsigned long addr, unsigned long end); + int gaw; /* max guest address width */
/* adjusted guest address width, 0 is level 2 30-bit */ So that this code could be simply like this:
freelist = domain->unmap(...);
Best regards, Baolu
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