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Message-Id: <20230927151536.67319-3-Jingqi.liu@intel.com>
Date: Wed, 27 Sep 2023 23:15:35 +0800
From: Jingqi Liu <Jingqi.liu@...el.com>
To: iommu@...ts.linux.dev, Lu Baolu <baolu.lu@...ux.intel.com>,
Tian Kevin <kevin.tian@...el.com>,
Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>,
Robin Murphy <robin.murphy@....com>
Cc: linux-kernel@...r.kernel.org, Jingqi Liu <Jingqi.liu@...el.com>
Subject: [PATH v3 2/3] iommu/vt-d: debugfs: Create/remove debugfs file per {device, pasid}
Add a debugfs directory per pair of {device, pasid} if the mappings of
its page table are created and destroyed by the iommu_map/unmap()
interfaces. i.e. /sys/kernel/debug/iommu/intel/<device source id>/<pasid>.
Create a debugfs file in the directory for users to dump the page
table corresponding to {device, pasid}. e.g.
/sys/kernel/debug/iommu/intel/0000:00:02.0/0/domain_translation_struct.
When attaching device without pasid, create a debugfs file with
PASID#0, i.e. RID_PASID. When attaching a domain to a pasid of device,
create a debugfs file with the specified pasid.
When detaching without pasid, remove the directory and file for
PASID#0. When detaching with pasid, remove the debugfs directory and
file of the specified pasid. Remove the entire debugfs directory of
the specified device for releasing device.
e.g. /sys/kernel/debug/iommu/intel/0000:00:01.0
Signed-off-by: Jingqi Liu <Jingqi.liu@...el.com>
---
drivers/iommu/intel/debugfs.c | 133 ++++++++++++++++++++++++++++++++--
drivers/iommu/intel/iommu.c | 29 ++++++++
drivers/iommu/intel/iommu.h | 12 +++
3 files changed, 169 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/intel/debugfs.c b/drivers/iommu/intel/debugfs.c
index e2a3c37943a0..50dea53ba87c 100644
--- a/drivers/iommu/intel/debugfs.c
+++ b/drivers/iommu/intel/debugfs.c
@@ -32,6 +32,11 @@ struct iommu_regset {
const char *regs;
};
+struct show_domain_info {
+ struct device *dev;
+ ioasid_t pasid;
+};
+
#define DEBUG_BUFFER_SIZE 1024
static char debug_buf[DEBUG_BUFFER_SIZE];
@@ -111,6 +116,8 @@ static const struct iommu_regset iommu_regs_64[] = {
IOMMU_REGSET_ENTRY(VCRSP),
};
+static struct dentry *intel_iommu_debug;
+
static int iommu_regset_show(struct seq_file *m, void *unused)
{
struct dmar_drhd_unit *drhd;
@@ -673,16 +680,12 @@ static const struct file_operations dmar_perf_latency_fops = {
void __init intel_iommu_debugfs_init(void)
{
- struct dentry *intel_iommu_debug = debugfs_create_dir("intel",
- iommu_debugfs_dir);
+ intel_iommu_debug = debugfs_create_dir("intel", iommu_debugfs_dir);
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);
- debugfs_create_file("domain_translation_struct", 0444,
- intel_iommu_debug, NULL,
- &domain_translation_struct_fops);
debugfs_create_file("invalidation_queue", 0444, intel_iommu_debug,
NULL, &invalidation_queue_fops);
#ifdef CONFIG_IRQ_REMAP
@@ -692,3 +695,123 @@ void __init intel_iommu_debugfs_init(void)
debugfs_create_file("dmar_perf_latency", 0644, intel_iommu_debug,
NULL, &dmar_perf_latency_fops);
}
+
+/* Create a debugfs directory for each device. */
+void intel_iommu_debugfs_create_dev(struct device *dev)
+{
+ struct dentry *dev_dir;
+
+ dev_dir = debugfs_lookup(dev_name(dev), intel_iommu_debug);
+ if (!dev_dir) {
+ dev_dir = debugfs_create_dir(dev_name(dev), intel_iommu_debug);
+ if (IS_ERR(dev_dir))
+ pr_info("%s: Failed to create debugfs directory.\n",
+ dev_name(dev));
+ } else
+ dput(dev_dir);
+}
+
+void intel_iommu_debugfs_remove_dev(struct device *dev)
+{
+ struct dentry *dev_dir, *sub_dir, *dentry;
+ struct list_head *plist;
+
+ dev_dir = debugfs_lookup(dev_name(dev), intel_iommu_debug);
+ if (!dev_dir)
+ return;
+
+ list_for_each(plist, &(dev_dir->d_subdirs)) {
+ sub_dir = list_entry(plist, struct dentry, d_child);
+ if(sub_dir) {
+ dentry = debugfs_lookup("domain_translation_struct",
+ sub_dir);
+ if (!dentry)
+ continue;
+
+ if (dentry->d_inode->i_private)
+ kfree(dentry->d_inode->i_private);
+
+ dput(dentry);
+ }
+ }
+
+ debugfs_remove_recursive(dev_dir);
+ dput(dev_dir);
+}
+
+/*
+ * Create a debugfs directory per pair of {device, pasid},
+ * then create the corresponding debugfs file in this directory
+ * for user to dump its page table. e.g.
+ * /sys/kernel/debug/iommu/intel/0000:00:01.0/0/domain_translation_struct
+ */
+void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, u32 pasid)
+{
+ struct dentry *dev_dir, *pasid_dir;
+ struct show_domain_info *sinfo;
+ char dir_name[10];
+
+ /*
+ * The debugfs only dumps the page tables whose mappings are created
+ * and destroyed by the iommu_map/unmap() interfaces. Check the
+ * mapping type of the domain before creating debugfs directory.
+ */
+ if (!domain || !(domain->type & __IOMMU_DOMAIN_PAGING))
+ return;
+
+ dev_dir = debugfs_lookup(dev_name(dev), intel_iommu_debug);
+ if (!dev_dir)
+ return;
+
+ sprintf(dir_name, "%x", pasid);
+ pasid_dir = debugfs_create_dir(dir_name, dev_dir);
+ if (IS_ERR(pasid_dir))
+ goto dput_out;
+
+ sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
+ if (!sinfo)
+ goto dput_out;
+
+ sinfo->dev = dev;
+ sinfo->pasid = pasid;
+ debugfs_create_file("domain_translation_struct", 0444,
+ pasid_dir, sinfo,
+ &domain_translation_struct_fops);
+dput_out:
+ dput(dev_dir);
+}
+
+/*
+ * Remove the debugfs directory and file corresponding to each pair of
+ * {device, pasid}.
+ */
+void intel_iommu_debugfs_remove_dev_pasid(struct device *dev, u32 pasid)
+{
+ struct dentry *dev_dir, *pasid_dir, *dentry;
+ char dir_name[10];
+
+ dev_dir = debugfs_lookup(dev_name(dev), intel_iommu_debug);
+ if (!dev_dir)
+ return;
+
+ sprintf(dir_name, "%x", pasid);
+ pasid_dir = debugfs_lookup(dir_name, dev_dir);
+ if (!pasid_dir)
+ goto dput_dev;
+
+ dentry = debugfs_lookup("domain_translation_struct", pasid_dir);
+ if (!dentry)
+ goto dput_pasid;
+
+ if (dentry->d_inode->i_private)
+ kfree(dentry->d_inode->i_private);
+
+ debugfs_remove_recursive(pasid_dir);
+
+ dput(dentry);
+dput_pasid:
+ dput(pasid_dir);
+dput_dev:
+ dput(dev_dir);
+}
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index dd8ff358867d..af9c989035a2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2488,6 +2488,13 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
iommu_enable_pci_caps(info);
+ /*
+ * Create a debugfs directory specified by RID_PASID
+ * in the debugfs device directory.
+ */
+ intel_iommu_debugfs_create_dev_pasid(&info->domain->domain,
+ dev, IOMMU_NO_PASID);
+
return 0;
}
@@ -3997,6 +4004,12 @@ static void device_block_translation(struct device *dev)
domain_detach_iommu(info->domain, iommu);
info->domain = NULL;
+
+ /*
+ * Remove the debugfs directory specified by RID_PASID
+ * in the device debugfs directory.
+ */
+ intel_iommu_debugfs_remove_dev_pasid(dev, IOMMU_NO_PASID);
}
static int md_domain_init(struct dmar_domain *domain, int guest_width)
@@ -4424,6 +4437,9 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
}
}
+ /* Create a debugfs directory per device. */
+ intel_iommu_debugfs_create_dev(dev);
+
return &iommu->iommu;
}
@@ -4436,6 +4452,7 @@ static void intel_iommu_release_device(struct device *dev)
dev_iommu_priv_set(dev, NULL);
kfree(info);
set_dma_ops(dev, NULL);
+ intel_iommu_debugfs_remove_dev(dev);
}
static void intel_iommu_probe_finalize(struct device *dev)
@@ -4729,6 +4746,12 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
out_tear_down:
intel_pasid_tear_down_entry(iommu, dev, pasid, false);
intel_drain_pasid_prq(dev, pasid);
+
+ /*
+ * Remove the debugfs directory of the specified pasid
+ * in the device debugfs directory.
+ */
+ intel_iommu_debugfs_remove_dev_pasid(dev, pasid);
}
static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
@@ -4777,6 +4800,12 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
spin_unlock_irqrestore(&dmar_domain->lock, flags);
+ /*
+ * Create a debugfs directory with specified pasid
+ * in the debugfs device directory.
+ */
+ intel_iommu_debugfs_create_dev_pasid(domain, dev, pasid);
+
return 0;
out_detach_iommu:
domain_detach_iommu(dmar_domain, iommu);
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index c18fb699c87a..f1c27e928886 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -883,8 +883,20 @@ static inline void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid
#ifdef CONFIG_INTEL_IOMMU_DEBUGFS
void intel_iommu_debugfs_init(void);
+void intel_iommu_debugfs_create_dev(struct device *dev);
+void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, u32 pasid);
+void intel_iommu_debugfs_remove_dev(struct device *dev);
+void intel_iommu_debugfs_remove_dev_pasid(struct device *dev, u32 pasid);
#else
static inline void intel_iommu_debugfs_init(void) {}
+static inline void intel_iommu_debugfs_create_dev(struct device *dev) {}
+static inline
+void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, u32 pasid) {}
+static inline void intel_iommu_debugfs_remove_dev(struct device *dev) {}
+static inline
+void intel_iommu_debugfs_remove_dev_pasid(struct device *dev, u32 pasid) {}
#endif /* CONFIG_INTEL_IOMMU_DEBUGFS */
extern const struct attribute_group *intel_iommu_groups[];
--
2.21.3
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