[PATH,v3,2/3] iommu/vt-d: debugfs: Create/remove debugfs file per {device, pasid}

Message ID 20230927151536.67319-3-Jingqi.liu@intel.com
State New
Headers
Series iommu/vt-d: debugfs: Enhancements to IOMMU debugfs |

Commit Message

Liu, Jingqi Sept. 27, 2023, 3:15 p.m. UTC
  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@intel.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(-)
  

Comments

Baolu Lu Sept. 28, 2023, 1:58 a.m. UTC | #1
On 9/27/23 11:15 PM, Jingqi Liu wrote:
> 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@intel.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);
> +}

Above could simply be like this:

void intel_iommu_debugfs_create_dev(struct device *dev)
{
	struct device_domain_info *info = dev_iommu_priv_get(dev);

	info->debugfs_entry = debugfs_create_dir(dev_name(dev),
			intel_iommu_debug);
}

Isn't it?

> +
> +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);
> +}

And this could simply be like this:

void intel_iommu_debugfs_remove_dev(struct device *dev)
{
	struct device_domain_info *info = dev_iommu_priv_get(dev);

	debugfs_remove(info->debugfs_entry);
}

> +
> +/*
> + * 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);
> +}

And here,

void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
					  struct device *dev, u32 pasid)
{
	sprintf(dir_name, "%x", pasid);
	dev_pasid->debugfs_entry = debugfs_create_dir(dir_name,
			info->debugfs_entry);

	debugfs_create_file("domain_translation_struct", 0444,
			    dev_pasid->debugfs_entry, dev_pasid,
			    &domain_translation_struct_fops);
}

> +
> +/*
> + * 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);
> +}

The same thing here:

	debugfs_remove(dev_pasid->debugfs_entry);

> 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);

The function name is self-explained. So no need to add comments. Ditto
to all other places.

> +
>   	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[];

Best regards,
baolu
  
Liu, Jingqi Sept. 28, 2023, 9:02 a.m. UTC | #2
On 9/28/2023 9:58 AM, Baolu Lu wrote:
> On 9/27/23 11:15 PM, Jingqi Liu wrote:
......
>> +
>> +/* 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);
>> +}
>
> Above could simply be like this:
>
> void intel_iommu_debugfs_create_dev(struct device *dev)
> {
>     struct device_domain_info *info = dev_iommu_priv_get(dev);
>
>     info->debugfs_entry = debugfs_create_dir(dev_name(dev),
>             intel_iommu_debug);
> }
>
> Isn't it?
Thanks. Good point.
If add an "info->debugfs_dentry" to the device "info" to save the dentry 
of device
debugfs directory, there's no need to lookup the dentry by debugfs_lookup().
Just simply get it from the device "info".

>
>> +
>> +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);
>> +}
>
> And this could simply be like this:
>
> void intel_iommu_debugfs_remove_dev(struct device *dev)
> {
>     struct device_domain_info *info = dev_iommu_priv_get(dev);
>
>     debugfs_remove(info->debugfs_entry);
> }
>
Yes.
Just get the debugfs dentry of device simply for removing.
This helper should be called before the "info" is freed
in intel_iommu_release_device(). Like this:

+      intel_iommu_debugfs_remove_dev(dev);
         kfree(info);

>> +
>> +/*
>> + * 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);
>> +}
>
> And here,
>
> void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
>                       struct device *dev, u32 pasid)
> {
>     sprintf(dir_name, "%x", pasid);
>     dev_pasid->debugfs_entry = debugfs_create_dir(dir_name,
>             info->debugfs_entry);
>
>     debugfs_create_file("domain_translation_struct", 0444,
>                 dev_pasid->debugfs_entry, dev_pasid,
>                 &domain_translation_struct_fops);
> }
>
Thanks.
You mean to add 'debugfs_entry' in below structure.
     struct dev_pasid_info *dev_pasid;
This structure is also allocated per pair of {dev, pasid}.
The debugfs dentry of  {dev, pasid} can be simply obtained from 
'dev_pasid_info'.

So the 'dev_pasid_info' can be passed as a parameter of this helper, right ?
Like this:
void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
                       struct dev_pasid_info *dev_pasid) ;
>> +
>> +/*
>> + * 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);
>> +}
>
> The same thing here:
>
>     debugfs_remove(dev_pasid->debugfs_entry);
>
Yes.
Just get the debugfs dentry from "dev_pasid" instead of 'debugfs_lookup()'.
And this helper should be called before the "struct dev_pasid_info" is freed
in intel_iommu_remove_dev_pasid().
Like this:

+        intel_iommu_debugfs_remove_dev_pasid(dev, pasid);
           kfree(dev_pasid);

>> 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);
>
> The function name is self-explained. So no need to add comments. Ditto
> to all other places.
>
Indeed.
I'll delete all related comments.

Thanks,
Jingqi
  
Baolu Lu Sept. 28, 2023, 9:17 a.m. UTC | #3
On 2023/9/28 17:02, Liu, Jingqi wrote:
>> And here,
>>
>> void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
>>                       struct device *dev, u32 pasid)
>> {
>>     sprintf(dir_name, "%x", pasid);
>>     dev_pasid->debugfs_entry = debugfs_create_dir(dir_name,
>>             info->debugfs_entry);
>>
>>     debugfs_create_file("domain_translation_struct", 0444,
>>                 dev_pasid->debugfs_entry, dev_pasid,
>>                 &domain_translation_struct_fops);
>> }
>>
> Thanks.
> You mean to add 'debugfs_entry' in below structure.
>      struct dev_pasid_info *dev_pasid;
> This structure is also allocated per pair of {dev, pasid}.
> The debugfs dentry of  {dev, pasid} can be simply obtained from 
> 'dev_pasid_info'.
> 
> So the 'dev_pasid_info' can be passed as a parameter of this helper, 
> right ?
> Like this:
> void intel_iommu_debugfs_create_dev_pasid(struct iommu_domain *domain,
>                        struct dev_pasid_info *dev_pasid) ;

Yes.

Best regards,
baolu
  

Patch

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[];