The original debugfs only dumps all IOMMU page tables without pasid
supported. It traverses all devices on the pci bus, then dumps all
page tables based on device domains. This traversal is from software
perspective.
This series dumps page tables whose mappings are created and destroyed
by the iommu_map/unmap() interfaces, by traversing root tables,
context tables, pasid directories and pasid tables from hardware
perspective. It supports dumping a specified page table in legacy mode
or scalable mode with or without a specified pasid.
It adds a debugfs directory per pair of {device, pasid} when attaching
device with pasid, i.e.
/sys/kernel/debug/iommu/intel/<device source id>/<pasid>.
And 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/0000:00:02.0/1/domain_translation_struct.
For the default domain without pasid, it creates a debugfs file in the
debugfs device directory for users to dump its page table. e.g.
/sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct.
Remove the corresponding debugfs directory and file when detaching or
releasing a device.
For legacy mode, according to bus number and DEVFN, traverse the root
table and context table to get the pointer of page table in the
context table entry, then dump the specified page table.
For scalable mode, according to bus number, DEVFN and pasid, traverse
the root table, context table, pasid directory and pasid table to get
the pointer of page table in the pasid table entry, then dump the
specified page table.
Examples are as follows:
1) Dump the page table of device "0000:00:01.0" that only supports
legacy mode.
$ sudo cat
/sys/kernel/debug/iommu/intel/0000:00:01.0/domain_translation_struct
2) Dump the page table of device "0000:00:02.0" with PASID "1" that
supports scalable mode.
$ sudo cat
/sys/kernel/debug/iommu/intel/0000:00:0a.0/1/domain_translation_struct
Change log:
v4:
- Save the debugfs dentry in 'device_domain_info' and 'dev_pasid_info'
structures to simplify debugfs operations per Baolu's review.
- Use 'dev_pasid_info' to get the infomation of {device, pasid} pair
when dumping the page table per Baolu's review.
v3: https://lore.kernel.org/linux-iommu/[email protected]
- Add domain as a parameter for creating debugfs pasid directory
per Baolu's review.
- dput() the dentry after debugfs_lookup() per Baolu's review.
- debugfs device and pasid directory are managed separately per
Baolu's review.
v2: https://lore.kernel.org/linux-iommu/[email protected]
- Add a debugfs directory per {dev, pasid} as suggested by Kevin.
- Create the debugfs directory when attaching device as suggested by Baolu.
- Only dump the page tables whose mappings are created and destroyed
by the iommu_map/unmap() interfaces per Baolu's review.
- Rename the helpers for creating/removing debugfs directory/file and
merge patch 2,3,4,5 to one patch per Baolu's review.
v1: https://lore.kernel.org/linux-iommu/[email protected]
Jingqi Liu (3):
iommu/vt-d: debugfs: Dump entry pointing to huge page
iommu/vt-d: debugfs: Create/remove debugfs file per {device, pasid}
iommu/vt-d: debugfs: Support dumping a specified page table
drivers/iommu/intel/debugfs.c | 300 ++++++++++++++++++++++++++++------
drivers/iommu/intel/iommu.c | 11 ++
drivers/iommu/intel/iommu.h | 18 ++
3 files changed, 283 insertions(+), 46 deletions(-)
--
2.21.3
The original debugfs only dumps all page tables without pasid. With
pasid supported, the page table with pasid also needs to be dumped.
This patch supports dumping a specified page table in legacy mode or
scalable mode with or without a specified pasid.
For legacy mode, according to bus number and DEVFN, traverse the root
table and context table to get the pointer of page table in the
context table entry, then dump the specified page table.
For scalable mode, according to bus number, DEVFN and pasid, traverse
the root table, context table, pasid directory and pasid table to get
the pointer of page table in the pasid table entry, then dump the
specified page table..
Examples are as follows:
1) Dump the page table of device "0000:00:1f.0" that only supports
legacy mode.
$ sudo cat
/sys/kernel/debug/iommu/intel/0000:00:1f.0/domain_translation_struct
2) Dump the page table of device "0000:00:0a.0" with PASID "1" that
supports scalable mode.
$ sudo cat
/sys/kernel/debug/iommu/intel/0000:00:0a.0/1/domain_translation_struct
Suggested-by: Kevin Tian <[email protected]>
Signed-off-by: Jingqi Liu <[email protected]>
---
drivers/iommu/intel/debugfs.c | 188 ++++++++++++++++++++++++++--------
1 file changed, 148 insertions(+), 40 deletions(-)
diff --git a/drivers/iommu/intel/debugfs.c b/drivers/iommu/intel/debugfs.c
index 30bc1e06abbc..5f0dbb1f7661 100644
--- a/drivers/iommu/intel/debugfs.c
+++ b/drivers/iommu/intel/debugfs.c
@@ -347,60 +347,165 @@ static void pgtable_walk_level(struct seq_file *m, struct dma_pte *pde,
}
}
-static int __show_device_domain_translation(struct device *dev, void *data)
+static int domain_translation_struct_show(struct seq_file *m,
+ struct device_domain_info *info,
+ ioasid_t pasid)
{
- struct dmar_domain *domain;
- struct seq_file *m = data;
- u64 path[6] = { 0 };
+ bool scalable, found = false;
+ struct dmar_drhd_unit *drhd;
+ struct intel_iommu *iommu;
+ u16 devfn, bus, seg;
- domain = to_dmar_domain(iommu_get_domain_for_dev(dev));
- if (!domain)
- return 0;
+ bus = info->bus;
+ devfn = info->devfn;
+ seg = info->segment;
- seq_printf(m, "Device %s @0x%llx\n", dev_name(dev),
- (u64)virt_to_phys(domain->pgd));
- seq_puts(m, "IOVA_PFN\t\tPML5E\t\t\tPML4E\t\t\tPDPE\t\t\tPDE\t\t\tPTE\n");
+ rcu_read_lock();
+ for_each_active_iommu(iommu, drhd) {
+ struct context_entry *context;
+ u64 pgd, path[6] = { 0 };
+ u32 sts, agaw;
- pgtable_walk_level(m, domain->pgd, domain->agaw + 2, 0, path);
- seq_putc(m, '\n');
+ if (seg != iommu->segment)
+ continue;
+
+ sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
+ if (!(sts & DMA_GSTS_TES)) {
+ seq_printf(m, "DMA Remapping is not enabled on %s\n",
+ iommu->name);
+ continue;
+ }
+ if (dmar_readq(iommu->reg + DMAR_RTADDR_REG) & DMA_RTADDR_SMT)
+ scalable = true;
+ else
+ scalable = false;
+
+ /*
+ * The iommu->lock is held across the callback, which will
+ * block calls to domain_attach/domain_detach. Hence,
+ * the domain of the device will not change during traversal.
+ *
+ * Traversing page table possibly races with the iommu_unmap()
+ * interface. This could be solved by RCU-freeing the page
+ * table pages in the iommu_unmap() path.
+ */
+ spin_lock(&iommu->lock);
+
+ context = iommu_context_addr(iommu, bus, devfn, 0);
+ if (!context || !context_present(context))
+ goto iommu_unlock;
+
+ if (scalable) { /* scalable mode */
+ struct pasid_dir_entry *dir_tbl, *dir_entry;
+ struct pasid_entry *pasid_tbl, *pasid_tbl_entry;
+ u16 pasid_dir_size, dir_idx, tbl_idx, pgtt;
+ u64 pasid_dir_ptr;
+
+ pasid_dir_ptr = context->lo & VTD_PAGE_MASK;
+ pasid_dir_size = get_pasid_dir_size(context);
+
+ /* Dump specified device domain mappings with PASID. */
+ dir_idx = pasid >> PASID_PDE_SHIFT;
+ tbl_idx = pasid & PASID_PTE_MASK;
+
+ dir_tbl = phys_to_virt(pasid_dir_ptr);
+ dir_entry = &dir_tbl[dir_idx];
+
+ pasid_tbl = get_pasid_table_from_pde(dir_entry);
+ if (!pasid_tbl)
+ goto iommu_unlock;
+
+ pasid_tbl_entry = &pasid_tbl[tbl_idx];
+ if (!pasid_pte_is_present(pasid_tbl_entry))
+ goto iommu_unlock;
+
+ /*
+ * According to PASID Granular Translation Type(PGTT),
+ * get the page table pointer.
+ */
+ pgtt = (u16)(pasid_tbl_entry->val[0] & GENMASK_ULL(8, 6)) >> 6;
+ agaw = (u8)(pasid_tbl_entry->val[0] & GENMASK_ULL(4, 2)) >> 2;
+
+ switch (pgtt) {
+ case PASID_ENTRY_PGTT_FL_ONLY:
+ pgd = pasid_tbl_entry->val[2];
+ break;
+ case PASID_ENTRY_PGTT_SL_ONLY:
+ case PASID_ENTRY_PGTT_NESTED:
+ pgd = pasid_tbl_entry->val[0];
+ break;
+ default:
+ goto iommu_unlock;
+ }
+ pgd &= VTD_PAGE_MASK;
+ } else { /* legacy mode */
+ pgd = context->lo & VTD_PAGE_MASK;
+ agaw = context->hi & 7;
+ }
+
+ seq_printf(m, "Device %04x:%02x:%02x.%x ",
+ iommu->segment, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+ if (scalable)
+ seq_printf(m, "with pasid %x @0x%llx\n", pasid, pgd);
+ else
+ seq_printf(m, "@0x%llx\n", pgd);
- /* Don't iterate */
- return 1;
+ seq_printf(m, "%-17s\t%-18s\t%-18s\t%-18s\t%-18s\t%-s\n",
+ "IOVA_PFN", "PML5E", "PML4E", "PDPE", "PDE", "PTE");
+ pgtable_walk_level(m, phys_to_virt(pgd), agaw + 2, 0, path);
+
+ found = true;
+iommu_unlock:
+ spin_unlock(&iommu->lock);
+ if (found)
+ break;
+ }
+ rcu_read_unlock();
+
+ return 0;
}
-static int show_device_domain_translation(struct device *dev, void *data)
+static int dev_domain_translation_struct_show(struct seq_file *m, void *unused)
{
- struct iommu_group *group;
+ struct device_domain_info *info;
- device_lock(dev);
- group = iommu_group_get(dev);
- device_unlock(dev);
- if (!group)
- return 0;
+ if (!m || !m->private) {
+ seq_puts(m, "Invalid device or pasid!\n");
+ return -EINVAL;
+ }
- /*
- * The group->mutex is held across the callback, which will
- * block calls to iommu_attach/detach_group/device. Hence,
- * the domain of the device will not change during traversal.
- *
- * All devices in an iommu group share a single domain, hence
- * we only dump the domain of the first device. Even though,
- * this code still possibly races with the iommu_unmap()
- * interface. This could be solved by RCU-freeing the page
- * table pages in the iommu_unmap() path.
- */
- iommu_group_for_each_dev(group, data, __show_device_domain_translation);
- iommu_group_put(group);
+ info = (struct device_domain_info*)m->private;
+ domain_translation_struct_show(m, info, IOMMU_NO_PASID);
return 0;
}
+DEFINE_SHOW_ATTRIBUTE(dev_domain_translation_struct);
-static int domain_translation_struct_show(struct seq_file *m, void *unused)
+static int pasid_domain_translation_struct_show(struct seq_file *m, void *unused)
{
- return bus_for_each_dev(&pci_bus_type, NULL, m,
- show_device_domain_translation);
+ struct device_domain_info *info;
+ struct dev_pasid_info *dev_pasid;
+
+ if (!m || !m->private) {
+ seq_puts(m, "Invalid device or pasid!\n");
+ return -EINVAL;
+ }
+
+ dev_pasid = (struct dev_pasid_info*)m->private;
+ if (!dev_pasid->dev ||
+ !dev_iommu_priv_get(dev_pasid->dev) ||
+ (dev_pasid->pasid == IOMMU_PASID_INVALID)) {
+ seq_puts(m, "Please specify device or pasid!\n");
+ return -ENODEV;
+ }
+
+ info = dev_iommu_priv_get(dev_pasid->dev);
+ domain_translation_struct_show(m, info, dev_pasid->pasid);
+
+ return 0;
}
-DEFINE_SHOW_ATTRIBUTE(domain_translation_struct);
+DEFINE_SHOW_ATTRIBUTE(pasid_domain_translation_struct);
static void invalidation_queue_entry_show(struct seq_file *m,
struct intel_iommu *iommu)
@@ -724,6 +829,7 @@ void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
struct device_domain_info *info,
struct dev_pasid_info *dev_pasid)
{
+ const struct file_operations *fops;
struct dentry *parent;
void *data;
@@ -750,13 +856,15 @@ void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
data = dev_pasid;
parent = dev_pasid->debugfs_dentry;
+ fops = &pasid_domain_translation_struct_fops;
} else {
data = info;
parent = info->debugfs_dentry;
+ fops = &dev_domain_translation_struct_fops;
}
- debugfs_create_file("domain_translation_struct", 0444, parent,
- data, &domain_translation_struct_fops);
+ debugfs_create_file("domain_translation_struct", 0444,
+ parent, data, fops);
}
/*
--
2.21.3
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/0000:00:02.0/1/domain_translation_struct.
For the default domain without pasid, it creates a debugfs file in the
debugfs device directory for users to dump its page table. e.g.
/sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct.
When attaching device without pasid, create a debugfs file in the
debugfs device directory for users to dump the page table of default
domain. When attaching a domain to a pasid of device, create a debugfs
file in the pasid debugfs directory for users to dump the page table
of the specified pasid.
When detaching without pasid, remove the debugfs file in the device
debugfs directory. When detaching with pasid, remove the specified
pasid debugfs directory and file. Remove the debugfs device directory
of the device when releasing a device.
e.g. /sys/kernel/debug/iommu/intel/0000:00:01.0
Signed-off-by: Jingqi Liu <[email protected]>
---
drivers/iommu/intel/debugfs.c | 105 ++++++++++++++++++++++++++++++++--
drivers/iommu/intel/iommu.c | 11 ++++
drivers/iommu/intel/iommu.h | 18 ++++++
3 files changed, 129 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/intel/debugfs.c b/drivers/iommu/intel/debugfs.c
index e2a3c37943a0..30bc1e06abbc 100644
--- a/drivers/iommu/intel/debugfs.c
+++ b/drivers/iommu/intel/debugfs.c
@@ -111,6 +111,8 @@ 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 +675,12 @@ 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 +690,100 @@ 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 device_domain_info *info = dev_iommu_priv_get(dev);
+
+ info->debugfs_dentry = debugfs_create_dir(dev_name(dev),
+ intel_iommu_debug);
+}
+
+/* Remove the device debugfs directory. */
+void intel_iommu_debugfs_remove_dev(struct device *dev)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+
+ if (!info || IS_ERR_OR_NULL(info->debugfs_dentry))
+ return;
+
+ debugfs_remove_recursive(info->debugfs_dentry);
+}
+
+/*
+ * Create a debugfs directory per pair of {device, pasid},
+ * then create the corresponding debugfs file in this directory
+ * for users to dump its page table. e.g.
+ * /sys/kernel/debug/iommu/intel/0000:00:01.0/1/domain_translation_struct
+ * For the default domain of the device, create a debugfs file in the
+ * debugfs device directory for users to dump its page table. e.g.
+ * /sys/kernel/debug/iommu/intel/0000:00:01.0/domain_translation_struct
+ */
+void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
+ struct device_domain_info *info,
+ struct dev_pasid_info *dev_pasid)
+{
+ struct dentry *parent;
+ void *data;
+
+ if (!info || IS_ERR_OR_NULL(info->debugfs_dentry))
+ return;
+
+ /*
+ * 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;
+
+ if (dev_pasid) {
+ char dir_name[10];
+
+ sprintf(dir_name, "%x", dev_pasid->pasid);
+ dev_pasid->debugfs_dentry = debugfs_create_dir(dir_name,
+ info->debugfs_dentry);
+ if (IS_ERR(dev_pasid->debugfs_dentry))
+ return;
+
+ data = dev_pasid;
+ parent = dev_pasid->debugfs_dentry;
+ } else {
+ data = info;
+ parent = info->debugfs_dentry;
+ }
+
+ debugfs_create_file("domain_translation_struct", 0444, parent,
+ data, &domain_translation_struct_fops);
+}
+
+/*
+ * Remove the corresponding debugfs directory and file.
+ * If a pair {device, pasid} is specified, remove the debugfs
+ * directory of the specified pasid.
+ * If they are not specified, remove the debugfs file of the
+ * default domain.
+ */
+void intel_iommu_debugfs_remove_dev_pasid(struct device *dev,
+ struct dev_pasid_info *dev_pasid)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+
+ if (!info || IS_ERR_OR_NULL(info->debugfs_dentry))
+ return;
+
+ if (dev_pasid)
+ debugfs_remove_recursive(dev_pasid->debugfs_dentry);
+ else {
+ struct dentry *dentry;
+
+ dentry = debugfs_lookup("domain_translation_struct",
+ info->debugfs_dentry);
+ if (dentry) {
+ debugfs_remove(dentry);
+ dput(dentry);
+ }
+ }
+}
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index dd8ff358867d..aef58217f253 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2488,6 +2488,8 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
iommu_enable_pci_caps(info);
+ intel_iommu_debugfs_create_dev_pasid(&domain->domain, info, NULL);
+
return 0;
}
@@ -3997,6 +3999,8 @@ static void device_block_translation(struct device *dev)
domain_detach_iommu(info->domain, iommu);
info->domain = NULL;
+
+ intel_iommu_debugfs_remove_dev_pasid(dev, NULL);
}
static int md_domain_init(struct dmar_domain *domain, int guest_width)
@@ -4424,6 +4428,8 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
}
}
+ intel_iommu_debugfs_create_dev(dev);
+
return &iommu->iommu;
}
@@ -4433,6 +4439,7 @@ static void intel_iommu_release_device(struct device *dev)
dmar_remove_one_dev_info(dev);
intel_pasid_free_table(dev);
+ intel_iommu_debugfs_remove_dev(dev);
dev_iommu_priv_set(dev, NULL);
kfree(info);
set_dma_ops(dev, NULL);
@@ -4725,6 +4732,8 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
spin_unlock_irqrestore(&dmar_domain->lock, flags);
domain_detach_iommu(dmar_domain, iommu);
+
+ intel_iommu_debugfs_remove_dev_pasid(dev, dev_pasid);
kfree(dev_pasid);
out_tear_down:
intel_pasid_tear_down_entry(iommu, dev, pasid, false);
@@ -4777,6 +4786,8 @@ 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);
+ intel_iommu_debugfs_create_dev_pasid(domain, info, 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..61113a76e23a 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -716,12 +716,14 @@ struct device_domain_info {
struct intel_iommu *iommu; /* IOMMU used by this device */
struct dmar_domain *domain; /* pointer to domain */
struct pasid_table *pasid_table; /* pasid table */
+ struct dentry *debugfs_dentry; /* pointer to device directory dentry */
};
struct dev_pasid_info {
struct list_head link_domain; /* link to domain siblings */
struct device *dev;
ioasid_t pasid;
+ struct dentry *debugfs_dentry; /* pointer to pasid directory dentry */
};
static inline void __iommu_flush_cache(
@@ -883,8 +885,24 @@ 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_remove_dev(struct device *dev);
+void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
+ struct device_domain_info *info,
+ struct dev_pasid_info *dev_pasid);
+void intel_iommu_debugfs_remove_dev_pasid(struct device *dev,
+ struct dev_pasid_info *dev_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_remove_dev(struct device *dev) {}
+static inline
+void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
+ struct device_domain_info *info,
+ struct dev_pasid_info *dev_pasid){}
+static inline
+void intel_iommu_debugfs_remove_dev_pasid(struct device *dev,
+ struct dev_pasid_info *dev_pasid){}
#endif /* CONFIG_INTEL_IOMMU_DEBUGFS */
extern const struct attribute_group *intel_iommu_groups[];
--
2.21.3
On 10/11/23 4:39 PM, Jingqi Liu wrote:
> The original debugfs only dumps all IOMMU page tables without pasid
> supported. It traverses all devices on the pci bus, then dumps all page
> tables based on device domains. This traversal is from software
> perspective. This series dumps page tables whose mappings are created
> and destroyed by the iommu_map/unmap() interfaces, by traversing root
> tables, context tables, pasid directories and pasid tables from hardware
> perspective. It supports dumping a specified page table in legacy mode
> or scalable mode with or without a specified pasid. It adds a debugfs
> directory per pair of {device, pasid} when attaching device with pasid,
> i.e. /sys/kernel/debug/iommu/intel/<device source id>/<pasid>. And
> 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/0000:00:02.0/1/domain_translation_struct.
> For the default domain without pasid, it creates a debugfs file in the
> debugfs device directory for users to dump its page table. e.g.
> /sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct.
> Remove the corresponding debugfs directory and file when detaching or
> releasing a device. For legacy mode, according to bus number and DEVFN,
> traverse the root table and context table to get the pointer of page
> table in the context table entry, then dump the specified page table.
> For scalable mode, according to bus number, DEVFN and pasid, traverse
> the root table, context table, pasid directory and pasid table to get
> the pointer of page table in the pasid table entry, then dump the
> specified page table. Examples are as follows: 1) Dump the page table of
> device "0000:00:01.0" that only supports legacy mode. $ sudo cat
> /sys/kernel/debug/iommu/intel/0000:00:01.0/domain_translation_struct 2)
> Dump the page table of device "0000:00:02.0" with PASID "1" that
> supports scalable mode. $ sudo cat
> /sys/kernel/debug/iommu/intel/0000:00:0a.0/1/domain_translation_struct
This series doesn't apply to v6.6-rc5. Can you please rebase and send a
new version?
Best regards,
baolu