From cfc65dd57967f2e0c7b3a8b73e6d12470b1cf1c1 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 30 Jul 2009 16:15:18 -0600 Subject: iommu=pt is a valid early param This avoids a "Malformed early option 'iommu'" warning on boot when trying to use pass-through mode. Signed-off-by: Alex Williamson Signed-off-by: David Woodhouse --- arch/x86/kernel/pci-dma.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 1a041bcf506b..ae13e34f7248 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -212,10 +212,8 @@ static __init int iommu_setup(char *p) if (!strncmp(p, "soft", 4)) swiotlb = 1; #endif - if (!strncmp(p, "pt", 2)) { + if (!strncmp(p, "pt", 2)) iommu_pass_through = 1; - return 1; - } gart_parse_options(p); -- cgit v1.2.3 From 19943b0e30b05d42e494ae6fef78156ebc8c637e Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 4 Aug 2009 16:19:20 +0100 Subject: intel-iommu: Unify hardware and software passthrough support This makes the hardware passthrough mode work a lot more like the software version, so that the behaviour of a kernel with 'iommu=pt' is the same whether the hardware supports passthrough or not. In particular: - We use a single si_domain for the pass-through devices. - 32-bit devices can be taken out of the pass-through domain so that they don't have to use swiotlb. - Devices will work again after being removed from a KVM guest. - A potential oops on OOM (in init_context_pass_through()) is fixed. Signed-off-by: David Woodhouse --- arch/x86/kernel/pci-swiotlb.c | 5 +- drivers/pci/intel-iommu.c | 174 ++++++++++++++++++------------------------ 2 files changed, 76 insertions(+), 103 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c index 6af96ee44200..1e66b18f45cb 100644 --- a/arch/x86/kernel/pci-swiotlb.c +++ b/arch/x86/kernel/pci-swiotlb.c @@ -71,9 +71,8 @@ void __init pci_swiotlb_init(void) { /* don't initialize swiotlb if iommu=off (no_iommu=1) */ #ifdef CONFIG_X86_64 - if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN) || - iommu_pass_through) - swiotlb = 1; + if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)) + swiotlb = 1; #endif if (swiotlb_force) swiotlb = 1; diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 097d5da2fae1..147b3b960b61 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -251,7 +251,8 @@ static inline int first_pte_in_page(struct dma_pte *pte) * 2. It maps to each iommu if successful. * 3. Each iommu mapps to this domain if successful. */ -struct dmar_domain *si_domain; +static struct dmar_domain *si_domain; +static int hw_pass_through = 1; /* devices under the same p2p bridge are owned in one domain */ #define DOMAIN_FLAG_P2P_MULTIPLE_DEVICES (1 << 0) @@ -1948,14 +1949,24 @@ static int iommu_prepare_identity_map(struct pci_dev *pdev, struct dmar_domain *domain; int ret; - printk(KERN_INFO - "IOMMU: Setting identity map for device %s [0x%Lx - 0x%Lx]\n", - pci_name(pdev), start, end); - domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH); if (!domain) return -ENOMEM; + /* For _hardware_ passthrough, don't bother. But for software + passthrough, we do it anyway -- it may indicate a memory + range which is reserved in E820, so which didn't get set + up to start with in si_domain */ + if (domain == si_domain && hw_pass_through) { + printk("Ignoring identity map for HW passthrough device %s [0x%Lx - 0x%Lx]\n", + pci_name(pdev), start, end); + return 0; + } + + printk(KERN_INFO + "IOMMU: Setting identity map for device %s [0x%Lx - 0x%Lx]\n", + pci_name(pdev), start, end); + ret = iommu_domain_identity_map(domain, start, end); if (ret) goto error; @@ -2006,23 +2017,6 @@ static inline void iommu_prepare_isa(void) } #endif /* !CONFIG_DMAR_FLPY_WA */ -/* Initialize each context entry as pass through.*/ -static int __init init_context_pass_through(void) -{ - struct pci_dev *pdev = NULL; - struct dmar_domain *domain; - int ret; - - for_each_pci_dev(pdev) { - domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH); - ret = domain_context_mapping(domain, pdev, - CONTEXT_TT_PASS_THROUGH); - if (ret) - return ret; - } - return 0; -} - static int md_domain_init(struct dmar_domain *domain, int guest_width); static int __init si_domain_work_fn(unsigned long start_pfn, @@ -2037,7 +2031,7 @@ static int __init si_domain_work_fn(unsigned long start_pfn, } -static int si_domain_init(void) +static int si_domain_init(int hw) { struct dmar_drhd_unit *drhd; struct intel_iommu *iommu; @@ -2064,6 +2058,9 @@ static int si_domain_init(void) si_domain->flags = DOMAIN_FLAG_STATIC_IDENTITY; + if (hw) + return 0; + for_each_online_node(nid) { work_with_active_regions(nid, si_domain_work_fn, &ret); if (ret) @@ -2155,24 +2152,26 @@ static int iommu_should_identity_map(struct pci_dev *pdev, int startup) return 1; } -static int iommu_prepare_static_identity_mapping(void) +static int iommu_prepare_static_identity_mapping(int hw) { struct pci_dev *pdev = NULL; int ret; - ret = si_domain_init(); + ret = si_domain_init(hw); if (ret) return -EFAULT; for_each_pci_dev(pdev) { if (iommu_should_identity_map(pdev, 1)) { - printk(KERN_INFO "IOMMU: identity mapping for device %s\n", - pci_name(pdev)); + printk(KERN_INFO "IOMMU: %s identity mapping for device %s\n", + hw ? "hardware" : "software", pci_name(pdev)); ret = domain_context_mapping(si_domain, pdev, + hw ? CONTEXT_TT_PASS_THROUGH : CONTEXT_TT_MULTI_LEVEL); if (ret) return ret; + ret = domain_add_dev_info(si_domain, pdev); if (ret) return ret; @@ -2189,14 +2188,6 @@ int __init init_dmars(void) struct pci_dev *pdev; struct intel_iommu *iommu; int i, ret; - int pass_through = 1; - - /* - * In case pass through can not be enabled, iommu tries to use identity - * mapping. - */ - if (iommu_pass_through) - iommu_identity_mapping = 1; /* * for each drhd @@ -2250,14 +2241,8 @@ int __init init_dmars(void) goto error; } if (!ecap_pass_through(iommu->ecap)) - pass_through = 0; + hw_pass_through = 0; } - if (iommu_pass_through) - if (!pass_through) { - printk(KERN_INFO - "Pass Through is not supported by hardware.\n"); - iommu_pass_through = 0; - } /* * Start from the sane iommu hardware state. @@ -2312,64 +2297,57 @@ int __init init_dmars(void) } } + if (iommu_pass_through) + iommu_identity_mapping = 1; +#ifdef CONFIG_DMAR_BROKEN_GFX_WA + else + iommu_identity_mapping = 2; +#endif /* - * If pass through is set and enabled, context entries of all pci - * devices are intialized by pass through translation type. + * If pass through is not set or not enabled, setup context entries for + * identity mappings for rmrr, gfx, and isa and may fall back to static + * identity mapping if iommu_identity_mapping is set. */ - if (iommu_pass_through) { - ret = init_context_pass_through(); + if (iommu_identity_mapping) { + ret = iommu_prepare_static_identity_mapping(hw_pass_through); if (ret) { - printk(KERN_ERR "IOMMU: Pass through init failed.\n"); - iommu_pass_through = 0; + printk(KERN_CRIT "Failed to setup IOMMU pass-through\n"); + goto error; } } - /* - * If pass through is not set or not enabled, setup context entries for - * identity mappings for rmrr, gfx, and isa and may fall back to static - * identity mapping if iommu_identity_mapping is set. + * For each rmrr + * for each dev attached to rmrr + * do + * locate drhd for dev, alloc domain for dev + * allocate free domain + * allocate page table entries for rmrr + * if context not allocated for bus + * allocate and init context + * set present in root table for this bus + * init context with domain, translation etc + * endfor + * endfor */ - if (!iommu_pass_through) { -#ifdef CONFIG_DMAR_BROKEN_GFX_WA - if (!iommu_identity_mapping) - iommu_identity_mapping = 2; -#endif - if (iommu_identity_mapping) - iommu_prepare_static_identity_mapping(); - /* - * For each rmrr - * for each dev attached to rmrr - * do - * locate drhd for dev, alloc domain for dev - * allocate free domain - * allocate page table entries for rmrr - * if context not allocated for bus - * allocate and init context - * set present in root table for this bus - * init context with domain, translation etc - * endfor - * endfor - */ - printk(KERN_INFO "IOMMU: Setting RMRR:\n"); - for_each_rmrr_units(rmrr) { - for (i = 0; i < rmrr->devices_cnt; i++) { - pdev = rmrr->devices[i]; - /* - * some BIOS lists non-exist devices in DMAR - * table. - */ - if (!pdev) - continue; - ret = iommu_prepare_rmrr_dev(rmrr, pdev); - if (ret) - printk(KERN_ERR - "IOMMU: mapping reserved region failed\n"); - } + printk(KERN_INFO "IOMMU: Setting RMRR:\n"); + for_each_rmrr_units(rmrr) { + for (i = 0; i < rmrr->devices_cnt; i++) { + pdev = rmrr->devices[i]; + /* + * some BIOS lists non-exist devices in DMAR + * table. + */ + if (!pdev) + continue; + ret = iommu_prepare_rmrr_dev(rmrr, pdev); + if (ret) + printk(KERN_ERR + "IOMMU: mapping reserved region failed\n"); } - - iommu_prepare_isa(); } + iommu_prepare_isa(); + /* * for each drhd * enable fault log @@ -2536,7 +2514,10 @@ static int iommu_no_mapping(struct device *dev) ret = domain_add_dev_info(si_domain, pdev); if (ret) return 0; - ret = domain_context_mapping(si_domain, pdev, CONTEXT_TT_MULTI_LEVEL); + ret = domain_context_mapping(si_domain, pdev, + hw_pass_through ? + CONTEXT_TT_PASS_THROUGH : + CONTEXT_TT_MULTI_LEVEL); if (!ret) { printk(KERN_INFO "64bit %s uses identity mapping\n", pci_name(pdev)); @@ -3202,7 +3183,7 @@ int __init intel_iommu_init(void) * Check the need for DMA-remapping initialization now. * Above initialization will also be used by Interrupt-remapping. */ - if (no_iommu || (swiotlb && !iommu_pass_through) || dmar_disabled) + if (no_iommu || swiotlb || dmar_disabled) return -ENODEV; iommu_init_mempool(); @@ -3222,14 +3203,7 @@ int __init intel_iommu_init(void) init_timer(&unmap_timer); force_iommu = 1; - - if (!iommu_pass_through) { - printk(KERN_INFO - "Multi-level page-table translation for DMAR.\n"); - dma_ops = &intel_dma_ops; - } else - printk(KERN_INFO - "DMAR: Pass through translation for DMAR.\n"); + dma_ops = &intel_dma_ops; init_iommu_sysfs(); -- cgit v1.2.3 From 0c02a20ff7695f9c54cc7c013dda326270ccdac8 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sat, 19 Sep 2009 09:37:23 -0700 Subject: intel-iommu: Kill DMAR_BROKEN_GFX_WA option. Just make it depend on BROKEN for now, in case people scream really loud about it (and because we might want to keep some of this logic for an upcoming BIOS workaround, so I don't just want to rip it out entirely just yet). But for graphics devices, it really ought to be unnecessary. Signed-off-by: David Woodhouse --- Documentation/Intel-IOMMU.txt | 6 +----- arch/x86/Kconfig | 2 +- 2 files changed, 2 insertions(+), 6 deletions(-) (limited to 'arch/x86') diff --git a/Documentation/Intel-IOMMU.txt b/Documentation/Intel-IOMMU.txt index 21bc416d887e..cf9431db8731 100644 --- a/Documentation/Intel-IOMMU.txt +++ b/Documentation/Intel-IOMMU.txt @@ -56,11 +56,7 @@ Graphics Problems? ------------------ If you encounter issues with graphics devices, you can try adding option intel_iommu=igfx_off to turn off the integrated graphics engine. - -If it happens to be a PCI device included in the INCLUDE_ALL Engine, -then try enabling CONFIG_DMAR_GFX_WA to setup a 1-1 map. We hear -graphics drivers may be in process of using DMA api's in the near -future and at that time this option can be yanked out. +If this fixes anything, please ensure you file a bug reporting the problem. Some exceptions to IOVA ----------------------- diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 738bdc6b0f8b..22a0fd132112 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1916,7 +1916,7 @@ config DMAR_DEFAULT_ON config DMAR_BROKEN_GFX_WA def_bool n prompt "Workaround broken graphics drivers (going away soon)" - depends on DMAR + depends on DMAR && BROKEN ---help--- Current Graphics drivers tend to use physical address for DMA and avoid using DMA APIs. Setting this config -- cgit v1.2.3