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From 7ebb5f8e001037efbdf18afabbbebf71bd98825e Mon Sep 17 00:00:00 2001 |
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From: Lu Baolu <baolu.lu@linux.intel.com> |
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Date: Wed, 21 Sep 2022 10:40:53 +0800 |
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Subject: Revert "iommu/vt-d: Fix possible recursive locking in |
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intel_iommu_init()" |
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|
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This reverts commit 9cd4f1434479f1ac25c440c421fbf52069079914. |
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|
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Some issues were reported on the original commit. Some thunderbolt devices |
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don't work anymore due to the following DMA fault. |
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|
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DMAR: DRHD: handling fault status reg 2 |
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DMAR: [INTR-REMAP] Request device [09:00.0] fault index 0x8080 |
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[fault reason 0x25] |
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Blocked a compatibility format interrupt request |
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|
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Bring it back for now to avoid functional regression. |
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|
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Fixes: 9cd4f1434479f ("iommu/vt-d: Fix possible recursive locking in intel_iommu_init()") |
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Link: https://lore.kernel.org/linux-iommu/485A6EA5-6D58-42EA-B298-8571E97422DE@getmailspring.com/ |
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Link: https://bugzilla.kernel.org/show_bug.cgi?id=216497 |
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Cc: Mika Westerberg <mika.westerberg@linux.intel.com> |
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Cc: <stable@vger.kernel.org> # 5.19.x |
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Reported-and-tested-by: George Hilliard <thirtythreeforty@gmail.com> |
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Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> |
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Link: https://lore.kernel.org/r/20220920081701.3453504-1-baolu.lu@linux.intel.com |
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Signed-off-by: Joerg Roedel <jroedel@suse.de> |
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--- |
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drivers/iommu/intel/dmar.c | 7 ------- |
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drivers/iommu/intel/iommu.c | 27 +++++++++++++++++++++++++-- |
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include/linux/dmar.h | 4 +--- |
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3 files changed, 26 insertions(+), 12 deletions(-) |
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|
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diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c |
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index 497c912ad9e13..5a8f780e7ffd8 100644 |
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--- a/drivers/iommu/intel/dmar.c |
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+++ b/drivers/iommu/intel/dmar.c |
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@@ -2349,13 +2349,6 @@ static int dmar_device_hotplug(acpi_handle handle, bool insert) |
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if (!dmar_in_use()) |
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return 0; |
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|
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- /* |
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- * It's unlikely that any I/O board is hot added before the IOMMU |
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- * subsystem is initialized. |
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- */ |
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- if (IS_ENABLED(CONFIG_INTEL_IOMMU) && !intel_iommu_enabled) |
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- return -EOPNOTSUPP; |
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- |
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if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) { |
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tmp = handle; |
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} else { |
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diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c |
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index 1f2cd43cf9bcf..64d30895a4c8f 100644 |
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--- a/drivers/iommu/intel/iommu.c |
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+++ b/drivers/iommu/intel/iommu.c |
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@@ -3019,7 +3019,13 @@ static int __init init_dmars(void) |
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|
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#ifdef CONFIG_INTEL_IOMMU_SVM |
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if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) { |
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+ /* |
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+ * Call dmar_alloc_hwirq() with dmar_global_lock held, |
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+ * could cause possible lock race condition. |
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+ */ |
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+ up_write(&dmar_global_lock); |
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ret = intel_svm_enable_prq(iommu); |
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+ down_write(&dmar_global_lock); |
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if (ret) |
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goto free_iommu; |
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} |
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@@ -3932,6 +3938,7 @@ int __init intel_iommu_init(void) |
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force_on = (!intel_iommu_tboot_noforce && tboot_force_iommu()) || |
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platform_optin_force_iommu(); |
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|
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+ down_write(&dmar_global_lock); |
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if (dmar_table_init()) { |
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if (force_on) |
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panic("tboot: Failed to initialize DMAR table\n"); |
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@@ -3944,6 +3951,16 @@ int __init intel_iommu_init(void) |
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goto out_free_dmar; |
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} |
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|
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+ up_write(&dmar_global_lock); |
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+ |
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+ /* |
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+ * The bus notifier takes the dmar_global_lock, so lockdep will |
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+ * complain later when we register it under the lock. |
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+ */ |
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+ dmar_register_bus_notifier(); |
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+ |
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+ down_write(&dmar_global_lock); |
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+ |
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if (!no_iommu) |
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intel_iommu_debugfs_init(); |
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|
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@@ -3988,9 +4005,11 @@ int __init intel_iommu_init(void) |
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pr_err("Initialization failed\n"); |
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goto out_free_dmar; |
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} |
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+ up_write(&dmar_global_lock); |
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|
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init_iommu_pm_ops(); |
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|
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+ down_read(&dmar_global_lock); |
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for_each_active_iommu(iommu, drhd) { |
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/* |
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* The flush queue implementation does not perform |
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@@ -4008,11 +4027,13 @@ int __init intel_iommu_init(void) |
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"%s", iommu->name); |
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iommu_device_register(&iommu->iommu, &intel_iommu_ops, NULL); |
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} |
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+ up_read(&dmar_global_lock); |
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|
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bus_set_iommu(&pci_bus_type, &intel_iommu_ops); |
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if (si_domain && !hw_pass_through) |
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register_memory_notifier(&intel_iommu_memory_nb); |
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|
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+ down_read(&dmar_global_lock); |
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if (probe_acpi_namespace_devices()) |
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pr_warn("ACPI name space devices didn't probe correctly\n"); |
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|
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@@ -4023,15 +4044,17 @@ int __init intel_iommu_init(void) |
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|
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iommu_disable_protect_mem_regions(iommu); |
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} |
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+ up_read(&dmar_global_lock); |
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|
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- intel_iommu_enabled = 1; |
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- dmar_register_bus_notifier(); |
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pr_info("Intel(R) Virtualization Technology for Directed I/O\n"); |
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|
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+ intel_iommu_enabled = 1; |
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+ |
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return 0; |
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|
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out_free_dmar: |
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intel_iommu_free_dmars(); |
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+ up_write(&dmar_global_lock); |
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return ret; |
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} |
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|
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diff --git a/include/linux/dmar.h b/include/linux/dmar.h |
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index 8917a32173c4e..d81a51978d013 100644 |
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--- a/include/linux/dmar.h |
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+++ b/include/linux/dmar.h |
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@@ -65,7 +65,6 @@ struct dmar_pci_notify_info { |
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|
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extern struct rw_semaphore dmar_global_lock; |
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extern struct list_head dmar_drhd_units; |
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-extern int intel_iommu_enabled; |
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|
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#define for_each_drhd_unit(drhd) \ |
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list_for_each_entry_rcu(drhd, &dmar_drhd_units, list, \ |
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@@ -89,8 +88,7 @@ extern int intel_iommu_enabled; |
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static inline bool dmar_rcu_check(void) |
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{ |
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return rwsem_is_locked(&dmar_global_lock) || |
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- system_state == SYSTEM_BOOTING || |
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- (IS_ENABLED(CONFIG_INTEL_IOMMU) && !intel_iommu_enabled); |
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+ system_state == SYSTEM_BOOTING; |
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} |
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|
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#define dmar_rcu_dereference(p) rcu_dereference_check((p), dmar_rcu_check()) |
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-- |
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cgit |
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