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| author | Wei Wang <wei.wang2@amd.com> | 2011-01-27 16:10:52 +0000 |
|---|---|---|
| committer | Wei Wang <wei.wang2@amd.com> | 2011-01-27 16:10:52 +0000 |
| commit | 24c3ed18af8a89d0066f5668ad91a0c38c98f7a2 (patch) | |
| tree | 019aa625921eaabb519019de23f64391364cd24a | |
| parent | 3bbbb0c96c03814cb208f6bf9167c95a94f0bbcb (diff) | |
| download | xen-24c3ed18af8a89d0066f5668ad91a0c38c98f7a2.tar.gz xen-24c3ed18af8a89d0066f5668ad91a0c38c98f7a2.tar.bz2 xen-24c3ed18af8a89d0066f5668ad91a0c38c98f7a2.zip | |
amd iommu: reduce io page level for hvm guest (1/3)
Since in most case, 2 or 3 - level IO page tables are sufficient, this
patch updates page table level for device assignment to reduces
overhead of dma translation
Signed-off-by: Wei Wang <wei.wang2@amd.com>
| -rw-r--r-- | xen/drivers/passthrough/amd/iommu_map.c | 8 | ||||
| -rw-r--r-- | xen/drivers/passthrough/amd/pci_amd_iommu.c | 9 |
2 files changed, 11 insertions, 6 deletions
diff --git a/xen/drivers/passthrough/amd/iommu_map.c b/xen/drivers/passthrough/amd/iommu_map.c index 536da0da84..d973a123ea 100644 --- a/xen/drivers/passthrough/amd/iommu_map.c +++ b/xen/drivers/passthrough/amd/iommu_map.c @@ -411,10 +411,14 @@ static u64 iommu_l2e_from_pfn(struct page_info *table, int level, void *pde = NULL; void *table_vaddr; u64 next_table_maddr = 0; + unsigned int lowest = 1; - BUG_ON( table == NULL || level == 0 ); + BUG_ON( table == NULL || level < lowest ); - while ( level > 1 ) + if ( level == lowest ) + return page_to_maddr(table); + + while ( level > lowest ) { offset = io_pfn >> ((PTE_PER_TABLE_SHIFT * (level - IOMMU_PAGING_MODE_LEVEL_1))); diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c index 2442027fac..6a79efedb8 100644 --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c @@ -190,10 +190,7 @@ static int get_paging_mode(unsigned long entries) { int level = 1; - BUG_ON(!max_page); - - if ( entries > max_page ) - entries = max_page; + BUG_ON( !entries ); while ( entries > PTE_PER_TABLE_SIZE ) { @@ -278,6 +275,7 @@ static int reassign_device( struct domain *source, struct domain *target, struct pci_dev *pdev; struct amd_iommu *iommu; int bdf; + struct hvm_iommu *t = domain_hvm_iommu(target); ASSERT(spin_is_locked(&pcidevs_lock)); pdev = pci_get_pdev_by_domain(source, bus, devfn); @@ -300,6 +298,9 @@ static int reassign_device( struct domain *source, struct domain *target, list_move(&pdev->domain_list, &target->arch.pdev_list); pdev->domain = target; + if ( target->max_pages > 0 ) + t->paging_mode = get_paging_mode(target->max_pages); + amd_iommu_setup_domain_device(target, iommu, bdf); AMD_IOMMU_DEBUG("Re-assign %02x:%02x.%x from domain %d to domain %d\n", bus, PCI_SLOT(devfn), PCI_FUNC(devfn), |