From 18f99c9b9dec15bc088d9db239f68e5c80415304 Mon Sep 17 00:00:00 2001 From: Sohil Mehta Date: Tue, 11 Sep 2018 17:11:41 -0700 Subject: [PATCH] iommu/vt-d: Add debugfs support to show context internals Export Intel IOMMU DMA remapping internal states, such as root and context table entries in debugfs. Example of such dump in Kabylake: /sys/kernel/debug/iommu/intel/dmar_translation_struct IOMMU dmar0: Root Table Address:45699c000 Root Table Entries: Bus: 0 H: 0 L: 45699f001 Context Table Entries for Bus: 0 Entry B:D.F High Low 16 00:02.0 102 45699e005 IOMMU dmar1: Root Table Address:45699d000 Root Table Entries: Bus: 0 H: 0 L: 45644f001 Context Table Entries for Bus: 0 Entry B:D.F High Low 160 00:14.0 102 45644e001 184 00:17.0 302 456310001 248 00:1f.0 202 4564bf001 Cc: Lu Baolu Cc: Fenghua Yu Cc: Ashok Raj Cc: Jacob Pan Co-Developed-by: Gayatri Kammela Signed-off-by: Gayatri Kammela Reviewed-by: Andy Shevchenko Reviewed-by: Lu Baolu Signed-off-by: Sohil Mehta Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu-debugfs.c | 65 +++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-iommu-debugfs.c index 2becbd7..7fabf9b 100644 --- a/drivers/iommu/intel-iommu-debugfs.c +++ b/drivers/iommu/intel-iommu-debugfs.c @@ -131,6 +131,69 @@ out: } DEFINE_SHOW_ATTRIBUTE(iommu_regset); +static void ctx_tbl_entry_show(struct seq_file *m, struct intel_iommu *iommu, + int bus) +{ + struct context_entry *context; + int devfn; + + seq_printf(m, " Context Table Entries for Bus: %d\n", bus); + seq_puts(m, " Entry\tB:D.F\tHigh\tLow\n"); + + for (devfn = 0; devfn < 256; devfn++) { + context = iommu_context_addr(iommu, bus, devfn, 0); + if (!context) + return; + + if (!context_present(context)) + continue; + + seq_printf(m, " %-5d\t%02x:%02x.%x\t%-6llx\t%llx\n", devfn, + bus, PCI_SLOT(devfn), PCI_FUNC(devfn), + context[0].hi, context[0].lo); + } +} + +static void root_tbl_entry_show(struct seq_file *m, struct intel_iommu *iommu) +{ + unsigned long flags; + int bus; + + spin_lock_irqsave(&iommu->lock, flags); + seq_printf(m, "IOMMU %s: Root Table Address:%llx\n", iommu->name, + (u64)virt_to_phys(iommu->root_entry)); + seq_puts(m, "Root Table Entries:\n"); + + for (bus = 0; bus < 256; bus++) { + if (!(iommu->root_entry[bus].lo & 1)) + continue; + + seq_printf(m, " Bus: %d H: %llx L: %llx\n", bus, + iommu->root_entry[bus].hi, + iommu->root_entry[bus].lo); + + ctx_tbl_entry_show(m, iommu, bus); + seq_putc(m, '\n'); + } + spin_unlock_irqrestore(&iommu->lock, flags); +} + +static int dmar_translation_struct_show(struct seq_file *m, void *unused) +{ + struct dmar_drhd_unit *drhd; + struct intel_iommu *iommu; + + rcu_read_lock(); + for_each_active_iommu(iommu, drhd) { + root_tbl_entry_show(m, iommu); + seq_putc(m, '\n'); + } + rcu_read_unlock(); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(dmar_translation_struct); + #ifdef CONFIG_IRQ_REMAP static void ir_tbl_remap_entry_show(struct seq_file *m, struct intel_iommu *iommu) @@ -242,6 +305,8 @@ void __init intel_iommu_debugfs_init(void) debugfs_create_file("iommu_regset", 0444, intel_iommu_debug, NULL, &iommu_regset_fops); + debugfs_create_file("dmar_translation_struct", 0444, intel_iommu_debug, + NULL, &dmar_translation_struct_fops); #ifdef CONFIG_IRQ_REMAP debugfs_create_file("ir_translation_struct", 0444, intel_iommu_debug, NULL, &ir_translation_struct_fops); -- 2.7.4