[PATCH v3 0/7] Re-enable IDXD kernel workqueue under DMA API

[PATCH v3 0/7] Re-enable IDXD kernel workqueue under DMA API

[Jacob Pan]

Hi all,

IDXD kernel work queues were disabled due to the flawed use of kernel VA
and SVA API.
Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/

The solution is to enable it under DMA API where IDXD shared workqueue users
can use ENQCMDS to submit work on buffers mapped by DMA API.

This patchset adds support for attaching PASID to the device's default
domain and the ability to reserve global PASIDs from SVA APIs. We can then
re-enable the kernel work queues and use them under DMA API.

This depends on the IOASID removal series.
https://lore.kernel.org/all/ZCaUBJvUMsJyD7EW@8bytes.org/


Thanks,

Jacob

---
Changelog:
v3:
	- moved global PASID allocation API from SVA to IOMMU (Kevin)
	- remove #ifdef around global PASID reservation during boot (Baolu)
	- remove restriction on PASID 0 allocation (Baolu)
	- fix a bug in sysfs domain change when attaching devices
	- clear idxd user interrupt enable bit after disabling device( Fenghua)
v2:
	- refactored device PASID attach domain ops based on Baolu's early patch
	- addressed TLB flush gap
	- explicitly reserve RID_PASID from SVA PASID number space
	- get dma domain directly, avoid checking domain types



Jacob Pan (7):
  iommu/vt-d: Use non-privileged mode for all PASIDs
  iommu/vt-d: Remove PASID supervisor request support
  iommu/sva: Support allocation of global PASIDs outside SVA
  iommu/vt-d: Reserve RID_PASID from global PASID space
  iommu/vt-d: Make device pasid attachment explicit
  iommu/vt-d: Implement set_dev_pasid domain op
  dmaengine/idxd: Re-enable kernel workqueue under DMA API

 drivers/dma/idxd/device.c   |  30 +-----
 drivers/dma/idxd/init.c     |  56 ++++++++++-
 drivers/dma/idxd/sysfs.c    |   7 --
 drivers/iommu/intel/iommu.c | 180 +++++++++++++++++++++++++++++-------
 drivers/iommu/intel/iommu.h |   8 ++
 drivers/iommu/intel/pasid.c |  43 ---------
 drivers/iommu/intel/pasid.h |   7 --
 drivers/iommu/iommu-sva.c   |  10 +-
 drivers/iommu/iommu.c       |  33 +++++++
 include/linux/iommu.h       |  10 ++
 10 files changed, 257 insertions(+), 127 deletions(-)

-- 
2.25.1

[PATCH v3 1/7] iommu/vt-d: Use non-privileged mode for all PASIDs

[Jacob Pan]

Supervisor Request Enable (SRE) bit in a PASID entry is for permission
checking on DMA requests. When SRE = 0, DMA with supervisor privilege
will be blocked. However, for in-kernel DMA this is not necessary in that
we are targeting kernel memory anyway. There's no need to differentiate
user and kernel for in-kernel DMA.

Let's use non-privileged (user) permission for all PASIDs used in kernel,
it will be consistent with DMA without PASID (RID_PASID) as well.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 0768dcae90fd..9f737ef55463 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2338,8 +2338,6 @@ static int domain_setup_first_level(struct intel_iommu *iommu,
 	if (level != 4 && level != 5)
 		return -EINVAL;
 
-	if (pasid != PASID_RID2PASID)
-		flags |= PASID_FLAG_SUPERVISOR_MODE;
 	if (level == 5)
 		flags |= PASID_FLAG_FL5LP;
 
-- 
2.25.1

Re: [PATCH v3 1/7] iommu/vt-d: Use non-privileged mode for all PASIDs

[Baolu Lu]

On 2023/4/1 7:11, Jacob Pan wrote:
> Supervisor Request Enable (SRE) bit in a PASID entry is for permission
> checking on DMA requests. When SRE = 0, DMA with supervisor privilege
> will be blocked. However, for in-kernel DMA this is not necessary in that
> we are targeting kernel memory anyway. There's no need to differentiate
> user and kernel for in-kernel DMA.
> 
> Let's use non-privileged (user) permission for all PASIDs used in kernel,
> it will be consistent with DMA without PASID (RID_PASID) as well.
> 
> Signed-off-by: Jacob Pan<jacob.jun.pan@linux.intel.com>

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu

[PATCH v3 2/7] iommu/vt-d: Remove PASID supervisor request support

[Jacob Pan]

There's no more usage,  remove PASID supervisor support.

Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/intel/pasid.c | 43 -------------------------------------
 drivers/iommu/intel/pasid.h |  7 ------
 2 files changed, 50 deletions(-)

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 633e0a4a01e7..c5d479770e12 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -335,15 +335,6 @@ static inline void pasid_set_fault_enable(struct pasid_entry *pe)
 	pasid_set_bits(&pe->val[0], 1 << 1, 0);
 }
 
-/*
- * Setup the SRE(Supervisor Request Enable) field (Bit 128) of a
- * scalable mode PASID entry.
- */
-static inline void pasid_set_sre(struct pasid_entry *pe)
-{
-	pasid_set_bits(&pe->val[2], 1 << 0, 1);
-}
-
 /*
  * Setup the WPE(Write Protect Enable) field (Bit 132) of a
  * scalable mode PASID entry.
@@ -521,23 +512,6 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 		return -EINVAL;
 	}
 
-	if (flags & PASID_FLAG_SUPERVISOR_MODE) {
-#ifdef CONFIG_X86
-		unsigned long cr0 = read_cr0();
-
-		/* CR0.WP is normally set but just to be sure */
-		if (unlikely(!(cr0 & X86_CR0_WP))) {
-			pr_err("No CPU write protect!\n");
-			return -EINVAL;
-		}
-#endif
-		if (!ecap_srs(iommu->ecap)) {
-			pr_err("No supervisor request support on %s\n",
-			       iommu->name);
-			return -EINVAL;
-		}
-	}
-
 	if ((flags & PASID_FLAG_FL5LP) && !cap_fl5lp_support(iommu->cap)) {
 		pr_err("No 5-level paging support for first-level on %s\n",
 		       iommu->name);
@@ -560,10 +534,6 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 
 	/* Setup the first level page table pointer: */
 	pasid_set_flptr(pte, (u64)__pa(pgd));
-	if (flags & PASID_FLAG_SUPERVISOR_MODE) {
-		pasid_set_sre(pte);
-		pasid_set_wpe(pte);
-	}
 
 	if (flags & PASID_FLAG_FL5LP)
 		pasid_set_flpm(pte, 1);
@@ -658,12 +628,6 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 	pasid_set_fault_enable(pte);
 	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
 
-	/*
-	 * Since it is a second level only translation setup, we should
-	 * set SRE bit as well (addresses are expected to be GPAs).
-	 */
-	if (pasid != PASID_RID2PASID && ecap_srs(iommu->ecap))
-		pasid_set_sre(pte);
 	pasid_set_present(pte);
 	spin_unlock(&iommu->lock);
 
@@ -700,13 +664,6 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
 	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_PT);
 	pasid_set_fault_enable(pte);
 	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
-
-	/*
-	 * We should set SRE bit as well since the addresses are expected
-	 * to be GPAs.
-	 */
-	if (ecap_srs(iommu->ecap))
-		pasid_set_sre(pte);
 	pasid_set_present(pte);
 	spin_unlock(&iommu->lock);
 
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index 20c54e50f533..d6b7d21244b1 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -41,13 +41,6 @@
 #define FLPT_DEFAULT_DID		1
 #define NUM_RESERVED_DID		2
 
-/*
- * The SUPERVISOR_MODE flag indicates a first level translation which
- * can be used for access to kernel addresses. It is valid only for
- * access to the kernel's static 1:1 mapping of physical memory — not
- * to vmalloc or even module mappings.
- */
-#define PASID_FLAG_SUPERVISOR_MODE	BIT(0)
 #define PASID_FLAG_NESTED		BIT(1)
 #define PASID_FLAG_PAGE_SNOOP		BIT(2)
 
-- 
2.25.1

[PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs outside SVA

[Jacob Pan]

Devices that use Intel ENQCMD to submit work must use global PASIDs in
that the PASID are stored in a per CPU MSR. When such device need to
submit work for in-kernel DMA with PASID, it must allocate PASIDs from
the same global number space to avoid conflict.

This patch moves global PASID allocation APIs from SVA to IOMMU APIs.
It is expected that device drivers will use the allocated PASIDs to attach
to appropriate IOMMU domains for use.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/iommu-sva.c | 10 ++++------
 drivers/iommu/iommu.c     | 33 +++++++++++++++++++++++++++++++++
 include/linux/iommu.h     | 10 ++++++++++
 3 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index c434b95dc8eb..222544587582 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -9,15 +9,13 @@
 #include "iommu-sva.h"
 
 static DEFINE_MUTEX(iommu_sva_lock);
-static DEFINE_IDA(iommu_global_pasid_ida);
 
 /* Allocate a PASID for the mm within range (inclusive) */
 static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 {
 	int ret = 0;
 
-	if (!pasid_valid(min) || !pasid_valid(max) ||
-	    min == 0 || max < min)
+	if (!pasid_valid(min) || !pasid_valid(max) || max < min)
 		return -EINVAL;
 
 	mutex_lock(&iommu_sva_lock);
@@ -28,8 +26,8 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma
 		goto out;
 	}
 
-	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
-	if (ret < min)
+	ret = iommu_alloc_global_pasid(min, max);
+	if (!pasid_valid(ret))
 		goto out;
 	mm->pasid = ret;
 	ret = 0;
@@ -211,5 +209,5 @@ void mm_pasid_drop(struct mm_struct *mm)
 	if (likely(!pasid_valid(mm->pasid)))
 		return;
 
-	ida_free(&iommu_global_pasid_ida, mm->pasid);
+	iommu_free_global_pasid(mm->pasid);
 }
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 10db680acaed..5a8ffdc3063d 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -38,6 +38,7 @@
 
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
+static DEFINE_IDA(iommu_global_pasid_ida);
 
 static unsigned int iommu_def_domain_type __read_mostly;
 static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT);
@@ -3450,3 +3451,35 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
 
 	return domain;
 }
+
+/**
+ * @brief
+ *	Reserve a PASID from the SVA global number space.
+ *
+ * @param min starting range, inclusive
+ * @param max ending range, inclusive
+ * @return The reserved PASID on success or IOMMU_PASID_INVALID on failure.
+ */
+ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max)
+{
+	int ret;
+
+	if (!pasid_valid(min) || !pasid_valid(max) || max < min)
+		return IOMMU_PASID_INVALID;
+
+	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
+	if (ret < 0)
+		return IOMMU_PASID_INVALID;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid);
+
+void iommu_free_global_pasid(ioasid_t pasid)
+{
+	if (WARN_ON(!pasid_valid(pasid)))
+		return;
+
+	ida_free(&iommu_global_pasid_ida, pasid);
+}
+EXPORT_SYMBOL_GPL(iommu_free_global_pasid);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 54f535ff9868..f70478a11a5f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1187,6 +1187,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev,
 					struct mm_struct *mm);
 void iommu_sva_unbind_device(struct iommu_sva *handle);
 u32 iommu_sva_get_pasid(struct iommu_sva *handle);
+ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max);
+void iommu_free_global_pasid(ioasid_t pasid);
+
 #else
 static inline struct iommu_sva *
 iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
@@ -1202,6 +1205,13 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 {
 	return IOMMU_PASID_INVALID;
 }
+
+static inline ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max)
+{
+	return IOMMU_PASID_INVALID;
+}
+
+static inline void iommu_free_global_pasid(ioasid_t pasid) {}
 static inline void mm_pasid_init(struct mm_struct *mm) {}
 static inline void mm_pasid_drop(struct mm_struct *mm) {}
 #endif /* CONFIG_IOMMU_SVA */
-- 
2.25.1

Re: [PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs outside SVA

[Baolu Lu]

On 2023/4/1 7:11, Jacob Pan wrote:
> Devices that use Intel ENQCMD to submit work must use global PASIDs in
> that the PASID are stored in a per CPU MSR. When such device need to
> submit work for in-kernel DMA with PASID, it must allocate PASIDs from
> the same global number space to avoid conflict.
> 
> This patch moves global PASID allocation APIs from SVA to IOMMU APIs.
> It is expected that device drivers will use the allocated PASIDs to attach
> to appropriate IOMMU domains for use.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>   drivers/iommu/iommu-sva.c | 10 ++++------
>   drivers/iommu/iommu.c     | 33 +++++++++++++++++++++++++++++++++
>   include/linux/iommu.h     | 10 ++++++++++
>   3 files changed, 47 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
> index c434b95dc8eb..222544587582 100644
> --- a/drivers/iommu/iommu-sva.c
> +++ b/drivers/iommu/iommu-sva.c
> @@ -9,15 +9,13 @@
>   #include "iommu-sva.h"
>   
>   static DEFINE_MUTEX(iommu_sva_lock);
> -static DEFINE_IDA(iommu_global_pasid_ida);
>   
>   /* Allocate a PASID for the mm within range (inclusive) */
>   static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
>   {
>   	int ret = 0;
>   
> -	if (!pasid_valid(min) || !pasid_valid(max) ||
> -	    min == 0 || max < min)
> +	if (!pasid_valid(min) || !pasid_valid(max) || max < min)
>   		return -EINVAL;
>   
>   	mutex_lock(&iommu_sva_lock);
> @@ -28,8 +26,8 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma
>   		goto out;
>   	}
>   
> -	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
> -	if (ret < min)
> +	ret = iommu_alloc_global_pasid(min, max);
> +	if (!pasid_valid(ret))
>   		goto out;
>   	mm->pasid = ret;
>   	ret = 0;
> @@ -211,5 +209,5 @@ void mm_pasid_drop(struct mm_struct *mm)
>   	if (likely(!pasid_valid(mm->pasid)))
>   		return;
>   
> -	ida_free(&iommu_global_pasid_ida, mm->pasid);
> +	iommu_free_global_pasid(mm->pasid);
>   }
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 10db680acaed..5a8ffdc3063d 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -38,6 +38,7 @@
>   
>   static struct kset *iommu_group_kset;
>   static DEFINE_IDA(iommu_group_ida);
> +static DEFINE_IDA(iommu_global_pasid_ida);
>   
>   static unsigned int iommu_def_domain_type __read_mostly;
>   static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT);
> @@ -3450,3 +3451,35 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
>   
>   	return domain;
>   }
> +
> +/**
> + * @brief
> + *	Reserve a PASID from the SVA global number space.
> + *
> + * @param min starting range, inclusive
> + * @param max ending range, inclusive
> + * @return The reserved PASID on success or IOMMU_PASID_INVALID on failure.
> + */

Nit: the comments here also need to be changed accordingly.

Best regards,
baolu

> +ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max)
> +{
> +	int ret;
> +
> +	if (!pasid_valid(min) || !pasid_valid(max) || max < min)
> +		return IOMMU_PASID_INVALID;
> +
> +	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
> +	if (ret < 0)
> +		return IOMMU_PASID_INVALID;
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid);
> +
> +void iommu_free_global_pasid(ioasid_t pasid)
> +{
> +	if (WARN_ON(!pasid_valid(pasid)))
> +		return;
> +
> +	ida_free(&iommu_global_pasid_ida, pasid);
> +}
> +EXPORT_SYMBOL_GPL(iommu_free_global_pasid);
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 54f535ff9868..f70478a11a5f 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -1187,6 +1187,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev,
>   					struct mm_struct *mm);
>   void iommu_sva_unbind_device(struct iommu_sva *handle);
>   u32 iommu_sva_get_pasid(struct iommu_sva *handle);
> +ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max);
> +void iommu_free_global_pasid(ioasid_t pasid);
> +
>   #else
>   static inline struct iommu_sva *
>   iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
> @@ -1202,6 +1205,13 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
>   {
>   	return IOMMU_PASID_INVALID;
>   }
> +
> +static inline ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max)
> +{
> +	return IOMMU_PASID_INVALID;
> +}
> +
> +static inline void iommu_free_global_pasid(ioasid_t pasid) {}
>   static inline void mm_pasid_init(struct mm_struct *mm) {}
>   static inline void mm_pasid_drop(struct mm_struct *mm) {}
>   #endif /* CONFIG_IOMMU_SVA */

Re: [PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs outside SVA

[Jacob Pan]

Hi Baolu,

On Sat, 1 Apr 2023 21:16:39 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> > +/**
> > + * @brief
> > + *	Reserve a PASID from the SVA global number space.
> > + *
> > + * @param min starting range, inclusive
> > + * @param max ending range, inclusive
> > + * @return The reserved PASID on success or IOMMU_PASID_INVALID on
> > failure.
> > + */  
> 
> Nit: the comments here also need to be changed accordingly.
good catch! will fix.

Thanks,

Jacob

Re: [PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs outside SVA

[Baolu Lu]

On 2023/4/1 7:11, Jacob Pan wrote:
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 54f535ff9868..f70478a11a5f 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -1187,6 +1187,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev,
>   					struct mm_struct *mm);
>   void iommu_sva_unbind_device(struct iommu_sva *handle);
>   u32 iommu_sva_get_pasid(struct iommu_sva *handle);
> +ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max);
> +void iommu_free_global_pasid(ioasid_t pasid);
> +
>   #else
>   static inline struct iommu_sva *
>   iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
> @@ -1202,6 +1205,13 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
>   {
>   	return IOMMU_PASID_INVALID;
>   }
> +
> +static inline ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max)
> +{
> +	return IOMMU_PASID_INVALID;
> +}
> +
> +static inline void iommu_free_global_pasid(ioasid_t pasid) {}
>   static inline void mm_pasid_init(struct mm_struct *mm) {}
>   static inline void mm_pasid_drop(struct mm_struct *mm) {}
>   #endif /* CONFIG_IOMMU_SVA */

I don't think the function prototypes of
iommu_[alloc|free]_global_pasid() should be impacted by
CONFIG_IOMMU_SVA. Or I may overlooked something?

Best regards,
baolu

Re: [PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs outside SVA

[Jacob Pan]

Hi Baolu,

On Sat, 1 Apr 2023 21:28:02 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index 54f535ff9868..f70478a11a5f 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -1187,6 +1187,9 @@ struct iommu_sva *iommu_sva_bind_device(struct
> > device *dev, struct mm_struct *mm);
> >   void iommu_sva_unbind_device(struct iommu_sva *handle);
> >   u32 iommu_sva_get_pasid(struct iommu_sva *handle);
> > +ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max);
> > +void iommu_free_global_pasid(ioasid_t pasid);
> > +
> >   #else
> >   static inline struct iommu_sva *
> >   iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
> > @@ -1202,6 +1205,13 @@ static inline u32 iommu_sva_get_pasid(struct
> > iommu_sva *handle) {
> >   	return IOMMU_PASID_INVALID;
> >   }
> > +
> > +static inline ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t
> > max) +{
> > +	return IOMMU_PASID_INVALID;
> > +}
> > +
> > +static inline void iommu_free_global_pasid(ioasid_t pasid) {}
> >   static inline void mm_pasid_init(struct mm_struct *mm) {}
> >   static inline void mm_pasid_drop(struct mm_struct *mm) {}
> >   #endif /* CONFIG_IOMMU_SVA */  
> 
> I don't think the function prototypes of
> iommu_[alloc|free]_global_pasid() should be impacted by
> CONFIG_IOMMU_SVA. Or I may overlooked something?
you're right, the scope is beyond SVA now. It should be under
CONFIG_IOMMU_API, i think.

Thanks,

Jacob

[PATCH v3 4/7] iommu/vt-d: Reserve RID_PASID from global PASID space

[Jacob Pan]

On VT-d platforms, RID_PASID is used for DMA request without PASID. We
should not treat RID_PASID special instead let it be allocated from the
global PASID number space. Non-zero value can be used in RID_PASID on
Intel VT-d.

For ARM, AMD and others that _always_ use 0 as RID_PASID, there is no
impact in that SVA PASID allocation base is 1.

With this change, devices do both DMA with PASID and SVA will not worry
about conflicts when it comes to allocating PASIDs for in-kernel DMA.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9f737ef55463..cbb2670f88ca 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3956,6 +3956,10 @@ int __init intel_iommu_init(void)
 
 	intel_iommu_enabled = 1;
 
+	/* Reserved RID_PASID from the global namespace for legacy DMA */
+	WARN_ON(iommu_alloc_global_pasid(PASID_RID2PASID, PASID_RID2PASID) !=
+		PASID_RID2PASID);
+
 	return 0;
 
 out_free_dmar:
-- 
2.25.1

Re: [PATCH v3 4/7] iommu/vt-d: Reserve RID_PASID from global PASID space

[Baolu Lu]

On 2023/4/1 7:11, Jacob Pan wrote:
> On VT-d platforms, RID_PASID is used for DMA request without PASID. We
> should not treat RID_PASID special instead let it be allocated from the
> global PASID number space. Non-zero value can be used in RID_PASID on
> Intel VT-d.
> 
> For ARM, AMD and others that _always_ use 0 as RID_PASID, there is no
> impact in that SVA PASID allocation base is 1.
> 
> With this change, devices do both DMA with PASID and SVA will not worry
> about conflicts when it comes to allocating PASIDs for in-kernel DMA.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>   drivers/iommu/intel/iommu.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 9f737ef55463..cbb2670f88ca 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -3956,6 +3956,10 @@ int __init intel_iommu_init(void)
>   
>   	intel_iommu_enabled = 1;
>   
> +	/* Reserved RID_PASID from the global namespace for legacy DMA */
> +	WARN_ON(iommu_alloc_global_pasid(PASID_RID2PASID, PASID_RID2PASID) !=
> +		PASID_RID2PASID);

This looks odd. With the previous patch unchanged,
iommu_alloc_global_pasid() will always return IOMMU_PASID_INVALID if
CONFIG_IOMMU_SVA is not set.

> +
>   	return 0;
>   
>   out_free_dmar:

Best regards,
baolu

Re: [PATCH v3 4/7] iommu/vt-d: Reserve RID_PASID from global PASID space

[Jacob Pan]

Hi Baolu,

On Sat, 1 Apr 2023 21:43:13 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> > On VT-d platforms, RID_PASID is used for DMA request without PASID. We
> > should not treat RID_PASID special instead let it be allocated from the
> > global PASID number space. Non-zero value can be used in RID_PASID on
> > Intel VT-d.
> > 
> > For ARM, AMD and others that _always_ use 0 as RID_PASID, there is no
> > impact in that SVA PASID allocation base is 1.
> > 
> > With this change, devices do both DMA with PASID and SVA will not worry
> > about conflicts when it comes to allocating PASIDs for in-kernel DMA.
> > 
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > ---
> >   drivers/iommu/intel/iommu.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index 9f737ef55463..cbb2670f88ca 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -3956,6 +3956,10 @@ int __init intel_iommu_init(void)
> >   
> >   	intel_iommu_enabled = 1;
> >   
> > +	/* Reserved RID_PASID from the global namespace for legacy DMA
> > */
> > +	WARN_ON(iommu_alloc_global_pasid(PASID_RID2PASID,
> > PASID_RID2PASID) !=
> > +		PASID_RID2PASID);  
> 
> This looks odd. With the previous patch unchanged,
> iommu_alloc_global_pasid() will always return IOMMU_PASID_INVALID if
> CONFIG_IOMMU_SVA is not set.
right, will move out of CONFIG_IOMMU_SVA. good point!

Thanks,

Jacob

[PATCH v3 5/7] iommu/vt-d: Make device pasid attachment explicit

[Jacob Pan]

Currently, when a device is attached to its DMA domain, RID_PASID is
implicitly attached if VT-d is in scalable mode. To prepare for generic
PASID-device domain attachment, this patch parameterizes PASID such that
all PASIDs are attached explicitly.

It will allow code reuse for DMA API with PASID usage and makes no
assumptions of the ordering in which PASIDs and device are attached.
The same change applies to IOTLB invalidation and removing PASIDs.

Extracted common code based on Baolu's patch:

Link:https://lore.kernel.org/linux-iommu/20220614034411.1634238-1-baolu.lu@linux.intel.com/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 153 ++++++++++++++++++++++++++++--------
 drivers/iommu/intel/iommu.h |   8 ++
 2 files changed, 128 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cbb2670f88ca..52b9d0d3a02c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -278,6 +278,8 @@ static LIST_HEAD(dmar_satc_units);
 	list_for_each_entry(rmrr, &dmar_rmrr_units, list)
 
 static void device_block_translation(struct device *dev);
+static void intel_iommu_detach_device_pasid(struct iommu_domain *domain,
+					    struct device *dev, ioasid_t pasid);
 static void intel_iommu_domain_free(struct iommu_domain *domain);
 
 int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
@@ -1365,6 +1367,7 @@ domain_lookup_dev_info(struct dmar_domain *domain,
 
 static void domain_update_iotlb(struct dmar_domain *domain)
 {
+	struct device_pasid_info *dev_pasid;
 	struct device_domain_info *info;
 	bool has_iotlb_device = false;
 	unsigned long flags;
@@ -1376,6 +1379,14 @@ static void domain_update_iotlb(struct dmar_domain *domain)
 			break;
 		}
 	}
+
+	list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+		info = dev_iommu_priv_get(dev_pasid->dev);
+		if (info->ats_enabled) {
+			has_iotlb_device = true;
+			break;
+		}
+	}
 	domain->has_iotlb_device = has_iotlb_device;
 	spin_unlock_irqrestore(&domain->lock, flags);
 }
@@ -1486,6 +1497,7 @@ static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
 static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
 				  u64 addr, unsigned mask)
 {
+	struct device_pasid_info *dev_pasid;
 	struct device_domain_info *info;
 	unsigned long flags;
 
@@ -1495,6 +1507,39 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
 	spin_lock_irqsave(&domain->lock, flags);
 	list_for_each_entry(info, &domain->devices, link)
 		__iommu_flush_dev_iotlb(info, addr, mask);
+
+	list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+		/* device TLB is not aware of the use of RID PASID is for DMA w/o PASID */
+		if (dev_pasid->pasid == PASID_RID2PASID)
+			continue;
+
+		info = dev_iommu_priv_get(dev_pasid->dev);
+		qi_flush_dev_iotlb_pasid(info->iommu,
+					 PCI_DEVID(info->bus, info->devfn),
+					 info->pfsid, dev_pasid->pasid,
+					 info->ats_qdep, addr,
+					 mask);
+	}
+	spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+/*
+ * The VT-d spec requires to use PASID-based-IOTLB Invalidation to
+ * invalidate IOTLB and the paging-structure-caches for a first-stage
+ * page table.
+ */
+static void domain_flush_pasid_iotlb(struct intel_iommu *iommu,
+				     struct dmar_domain *domain, u64 addr,
+				     unsigned long npages, bool ih)
+{
+	u16 did = domain_id_iommu(domain, iommu);
+	struct device_pasid_info *dev_pasid;
+	unsigned long flags;
+
+	spin_lock_irqsave(&domain->lock, flags);
+	list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain)
+		qi_flush_piotlb(iommu, did, dev_pasid->pasid, addr, npages, ih);
+
 	spin_unlock_irqrestore(&domain->lock, flags);
 }
 
@@ -1514,7 +1559,7 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
 		ih = 1 << 6;
 
 	if (domain->use_first_level) {
-		qi_flush_piotlb(iommu, did, PASID_RID2PASID, addr, pages, ih);
+		domain_flush_pasid_iotlb(iommu, domain, addr, pages, ih);
 	} else {
 		unsigned long bitmask = aligned_pages - 1;
 
@@ -1584,7 +1629,7 @@ static void intel_flush_iotlb_all(struct iommu_domain *domain)
 		u16 did = domain_id_iommu(dmar_domain, iommu);
 
 		if (dmar_domain->use_first_level)
-			qi_flush_piotlb(iommu, did, PASID_RID2PASID, 0, -1, 0);
+			domain_flush_pasid_iotlb(iommu, dmar_domain, 0, -1, 0);
 		else
 			iommu->flush.flush_iotlb(iommu, did, 0, 0,
 						 DMA_TLB_DSI_FLUSH);
@@ -1756,6 +1801,7 @@ static struct dmar_domain *alloc_domain(unsigned int type)
 		domain->use_first_level = true;
 	domain->has_iotlb_device = false;
 	INIT_LIST_HEAD(&domain->devices);
+	INIT_LIST_HEAD(&domain->dev_pasids);
 	spin_lock_init(&domain->lock);
 	xa_init(&domain->iommu_array);
 
@@ -2429,10 +2475,11 @@ static int __init si_domain_init(int hw)
 	return 0;
 }
 
-static int dmar_domain_attach_device(struct dmar_domain *domain,
-				     struct device *dev)
+static int dmar_domain_attach_device_pasid(struct dmar_domain *domain,
+				     struct device *dev, ioasid_t pasid)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct device_pasid_info *dev_pasid;
 	struct intel_iommu *iommu;
 	unsigned long flags;
 	u8 bus, devfn;
@@ -2442,43 +2489,57 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
 	if (!iommu)
 		return -ENODEV;
 
+	dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
+	if (!dev_pasid)
+		return -ENOMEM;
+
 	ret = domain_attach_iommu(domain, iommu);
 	if (ret)
-		return ret;
+		goto exit_free;
+
 	info->domain = domain;
+	dev_pasid->pasid = pasid;
+	dev_pasid->dev = dev;
 	spin_lock_irqsave(&domain->lock, flags);
-	list_add(&info->link, &domain->devices);
+	if (!info->dev_attached)
+		list_add(&info->link, &domain->devices);
+
+	list_add(&dev_pasid->link_domain, &domain->dev_pasids);
 	spin_unlock_irqrestore(&domain->lock, flags);
 
 	/* PASID table is mandatory for a PCI device in scalable mode. */
 	if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
 		/* Setup the PASID entry for requests without PASID: */
 		if (hw_pass_through && domain_type_is_si(domain))
-			ret = intel_pasid_setup_pass_through(iommu, domain,
-					dev, PASID_RID2PASID);
+			ret = intel_pasid_setup_pass_through(iommu, domain, dev, pasid);
 		else if (domain->use_first_level)
-			ret = domain_setup_first_level(iommu, domain, dev,
-					PASID_RID2PASID);
+			ret = domain_setup_first_level(iommu, domain, dev, pasid);
 		else
-			ret = intel_pasid_setup_second_level(iommu, domain,
-					dev, PASID_RID2PASID);
+			ret = intel_pasid_setup_second_level(iommu, domain, dev, pasid);
 		if (ret) {
-			dev_err(dev, "Setup RID2PASID failed\n");
+			dev_err(dev, "Setup PASID %d failed\n", pasid);
 			device_block_translation(dev);
-			return ret;
+			goto exit_free;
 		}
 	}
+	/* device context already activated,  we are done */
+	if (info->dev_attached)
+		goto exit;
 
 	ret = domain_context_mapping(domain, dev);
 	if (ret) {
 		dev_err(dev, "Domain context map failed\n");
 		device_block_translation(dev);
-		return ret;
+		goto exit_free;
 	}
 
 	iommu_enable_pci_caps(info);
-
+	info->dev_attached = 1;
+exit:
 	return 0;
+exit_free:
+	kfree(dev_pasid);
+	return ret;
 }
 
 static bool device_has_rmrr(struct device *dev)
@@ -4029,8 +4090,7 @@ static void device_block_translation(struct device *dev)
 	iommu_disable_pci_caps(info);
 	if (!dev_is_real_dma_subdevice(dev)) {
 		if (sm_supported(iommu))
-			intel_pasid_tear_down_entry(iommu, dev,
-						    PASID_RID2PASID, false);
+			intel_iommu_detach_device_pasid(&info->domain->domain, dev, PASID_RID2PASID);
 		else
 			domain_context_clear(info);
 	}
@@ -4040,6 +4100,7 @@ static void device_block_translation(struct device *dev)
 
 	spin_lock_irqsave(&info->domain->lock, flags);
 	list_del(&info->link);
+	info->dev_attached = 0;
 	spin_unlock_irqrestore(&info->domain->lock, flags);
 
 	domain_detach_iommu(info->domain, iommu);
@@ -4186,7 +4247,7 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
 	if (ret)
 		return ret;
 
-	return dmar_domain_attach_device(to_dmar_domain(domain), dev);
+	return dmar_domain_attach_device_pasid(to_dmar_domain(domain), dev, PASID_RID2PASID);
 }
 
 static int intel_iommu_map(struct iommu_domain *domain,
@@ -4675,26 +4736,52 @@ static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
 		__mapping_notify_one(info->iommu, dmar_domain, pfn, pages);
 }
 
-static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+static void intel_iommu_detach_device_pasid(struct iommu_domain *domain,
+					    struct device *dev, ioasid_t pasid)
 {
-	struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
-	struct iommu_domain *domain;
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct device_pasid_info *i, *dev_pasid = NULL;
+	struct intel_iommu *iommu = info->iommu;
+	unsigned long flags;
 
-	/* Domain type specific cleanup: */
-	domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
-	if (domain) {
-		switch (domain->type) {
-		case IOMMU_DOMAIN_SVA:
-			intel_svm_remove_dev_pasid(dev, pasid);
-			break;
-		default:
-			/* should never reach here */
-			WARN_ON(1);
+	spin_lock_irqsave(&dmar_domain->lock, flags);
+	list_for_each_entry(i, &dmar_domain->dev_pasids, link_domain) {
+		if (i->dev == dev && i->pasid == pasid) {
+			list_del(&i->link_domain);
+			dev_pasid = i;
 			break;
 		}
 	}
+	spin_unlock_irqrestore(&dmar_domain->lock, flags);
+	if (WARN_ON(!dev_pasid))
+		return;
+
+	/* PASID entry already cleared during SVA unbind */
+	if (domain->type != IOMMU_DOMAIN_SVA)
+		intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+
+	kfree(dev_pasid);
+}
+
+static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct dmar_domain *dmar_domain;
+	struct iommu_domain *domain;
+
+	domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
+	dmar_domain = to_dmar_domain(domain);
+
+	/*
+	 * SVA Domain type specific cleanup: Not ideal but not until we have
+	 * IOPF capable domain specific ops, we need this special case.
+	 */
+	if (domain->type == IOMMU_DOMAIN_SVA)
+		return intel_svm_remove_dev_pasid(dev, pasid);
 
-	intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+	intel_iommu_detach_device_pasid(domain, dev, pasid);
+	domain_detach_iommu(dmar_domain, info->iommu);
 }
 
 const struct iommu_ops intel_iommu_ops = {
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 65b15be72878..b6c26f25d1ba 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -595,6 +595,7 @@ struct dmar_domain {
 
 	spinlock_t lock;		/* Protect device tracking lists */
 	struct list_head devices;	/* all devices' list */
+	struct list_head dev_pasids;	/* all attached pasids */
 
 	struct dma_pte	*pgd;		/* virtual address */
 	int		gaw;		/* max guest address width */
@@ -708,6 +709,7 @@ struct device_domain_info {
 	u8 ats_supported:1;
 	u8 ats_enabled:1;
 	u8 dtlb_extra_inval:1;	/* Quirk for devices need extra flush */
+	u8 dev_attached:1;	/* Device context activated */
 	u8 ats_qdep;
 	struct device *dev; /* it's NULL for PCIe-to-PCI bridge */
 	struct intel_iommu *iommu; /* IOMMU used by this device */
@@ -715,6 +717,12 @@ struct device_domain_info {
 	struct pasid_table *pasid_table; /* pasid table */
 };
 
+struct device_pasid_info {
+	struct list_head link_domain;	/* link to domain siblings */
+	struct device *dev;		/* physical device derived from */
+	ioasid_t pasid;			/* PASID on physical device */
+};
+
 static inline void __iommu_flush_cache(
 	struct intel_iommu *iommu, void *addr, int size)
 {
-- 
2.25.1

[PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

[Jacob Pan]

Devices that use ENQCMDS to submit work on buffers mapped by DMA API
must attach a PASID to the default domain of the device. In preparation
for this use case, this patch implements set_dev_pasid() for the
default_domain_ops.

If the device context has not been set up prior to this call, this will
set up the device context in addition to PASID attachment.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 52b9d0d3a02c..1ad9c5a4bd8f 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
 	domain_detach_iommu(dmar_domain, info->iommu);
 }
 
+static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
+					   struct device *dev, ioasid_t pasid)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct intel_iommu *iommu = info->iommu;
+	int ret;
+
+	if (!pasid_supported(iommu))
+		return -ENODEV;
+
+	ret = prepare_domain_attach_device(domain, dev);
+	if (ret)
+		return ret;
+
+	return dmar_domain_attach_device_pasid(dmar_domain, dev, pasid);
+}
+
+
+
 const struct iommu_ops intel_iommu_ops = {
 	.capable		= intel_iommu_capable,
 	.domain_alloc		= intel_iommu_domain_alloc,
@@ -4803,6 +4823,7 @@ const struct iommu_ops intel_iommu_ops = {
 #endif
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev		= intel_iommu_attach_device,
+		.set_dev_pasid          = intel_iommu_attach_device_pasid,
 		.map_pages		= intel_iommu_map_pages,
 		.unmap_pages		= intel_iommu_unmap_pages,
 		.iotlb_sync_map		= intel_iommu_iotlb_sync_map,
-- 
2.25.1

Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

[Baolu Lu]

On 2023/4/1 7:11, Jacob Pan wrote:
> Devices that use ENQCMDS to submit work on buffers mapped by DMA API
> must attach a PASID to the default domain of the device. In preparation
> for this use case, this patch implements set_dev_pasid() for the
> default_domain_ops.
> 
> If the device context has not been set up prior to this call, this will
> set up the device context in addition to PASID attachment.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>   drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 52b9d0d3a02c..1ad9c5a4bd8f 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
>   	domain_detach_iommu(dmar_domain, info->iommu);
>   }
>   
> +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
> +					   struct device *dev, ioasid_t pasid)
> +{
> +	struct device_domain_info *info = dev_iommu_priv_get(dev);
> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> +	struct intel_iommu *iommu = info->iommu;
> +	int ret;
> +
> +	if (!pasid_supported(iommu))
> +		return -ENODEV;

As the domain ID will be set to the pasid entry, need to get a refcount
of the domain ID. Call domain_attach_iommu() here, and release it after
the pasid entry is torn down.

> +	ret = prepare_domain_attach_device(domain, dev);
> +	if (ret)
> +		return ret;
> +
> +	return dmar_domain_attach_device_pasid(dmar_domain, dev, pasid);
> +}
> +
> +
> +
>   const struct iommu_ops intel_iommu_ops = {
>   	.capable		= intel_iommu_capable,
>   	.domain_alloc		= intel_iommu_domain_alloc,
> @@ -4803,6 +4823,7 @@ const struct iommu_ops intel_iommu_ops = {
>   #endif
>   	.default_domain_ops = &(const struct iommu_domain_ops) {
>   		.attach_dev		= intel_iommu_attach_device,
> +		.set_dev_pasid          = intel_iommu_attach_device_pasid,
>   		.map_pages		= intel_iommu_map_pages,
>   		.unmap_pages		= intel_iommu_unmap_pages,
>   		.iotlb_sync_map		= intel_iommu_iotlb_sync_map,

Best regards,
baolu

Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

[Jacob Pan]

Hi Baolu,

On Sat, 1 Apr 2023 21:48:36 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> > Devices that use ENQCMDS to submit work on buffers mapped by DMA API
> > must attach a PASID to the default domain of the device. In preparation
> > for this use case, this patch implements set_dev_pasid() for the
> > default_domain_ops.
> > 
> > If the device context has not been set up prior to this call, this will
> > set up the device context in addition to PASID attachment.
> > 
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > ---
> >   drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
> >   1 file changed, 21 insertions(+)
> > 
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index 52b9d0d3a02c..1ad9c5a4bd8f 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct
> > device *dev, ioasid_t pasid) domain_detach_iommu(dmar_domain,
> > info->iommu); }
> >   
> > +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
> > +					   struct device *dev,
> > ioasid_t pasid) +{
> > +	struct device_domain_info *info = dev_iommu_priv_get(dev);
> > +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> > +	struct intel_iommu *iommu = info->iommu;
> > +	int ret;
> > +
> > +	if (!pasid_supported(iommu))
> > +		return -ENODEV;  
> 
> As the domain ID will be set to the pasid entry, need to get a refcount
> of the domain ID. Call domain_attach_iommu() here, and release it after
> the pasid entry is torn down.
dmar_domain_attach_device_pasid() below will call domain_attach_iommu() and
release in intel_iommu_remove_dev_pasid(). The previous patch has
consolidated the code path with device attachment.
would it be sufficient?

> > +	ret = prepare_domain_attach_device(domain, dev);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return dmar_domain_attach_device_pasid(dmar_domain, dev,
> > pasid); +}
> > +
> > +
> > +
> >   const struct iommu_ops intel_iommu_ops = {
> >   	.capable		= intel_iommu_capable,
> >   	.domain_alloc		= intel_iommu_domain_alloc,
> > @@ -4803,6 +4823,7 @@ const struct iommu_ops intel_iommu_ops = {
> >   #endif
> >   	.default_domain_ops = &(const struct iommu_domain_ops) {
> >   		.attach_dev		=
> > intel_iommu_attach_device,
> > +		.set_dev_pasid          =
> > intel_iommu_attach_device_pasid, .map_pages		=
> > intel_iommu_map_pages, .unmap_pages		=
> > intel_iommu_unmap_pages, .iotlb_sync_map		=
> > intel_iommu_iotlb_sync_map,  
> 
> Best regards,
> baolu


Thanks,

Jacob

Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

[Baolu Lu]

On 4/4/23 5:48 AM, Jacob Pan wrote:
> On Sat, 1 Apr 2023 21:48:36 +0800, Baolu Lu<baolu.lu@linux.intel.com>
> wrote:
> 
>> On 2023/4/1 7:11, Jacob Pan wrote:
>>> Devices that use ENQCMDS to submit work on buffers mapped by DMA API
>>> must attach a PASID to the default domain of the device. In preparation
>>> for this use case, this patch implements set_dev_pasid() for the
>>> default_domain_ops.
>>>
>>> If the device context has not been set up prior to this call, this will
>>> set up the device context in addition to PASID attachment.
>>>
>>> Signed-off-by: Jacob Pan<jacob.jun.pan@linux.intel.com>
>>> ---
>>>    drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
>>>    1 file changed, 21 insertions(+)
>>>
>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>>> index 52b9d0d3a02c..1ad9c5a4bd8f 100644
>>> --- a/drivers/iommu/intel/iommu.c
>>> +++ b/drivers/iommu/intel/iommu.c
>>> @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct
>>> device *dev, ioasid_t pasid) domain_detach_iommu(dmar_domain,
>>> info->iommu); }
>>>    
>>> +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
>>> +					   struct device *dev,
>>> ioasid_t pasid) +{
>>> +	struct device_domain_info *info = dev_iommu_priv_get(dev);
>>> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
>>> +	struct intel_iommu *iommu = info->iommu;
>>> +	int ret;
>>> +
>>> +	if (!pasid_supported(iommu))
>>> +		return -ENODEV;
>> As the domain ID will be set to the pasid entry, need to get a refcount
>> of the domain ID. Call domain_attach_iommu() here, and release it after
>> the pasid entry is torn down.
> dmar_domain_attach_device_pasid() below will call domain_attach_iommu() and
> release in intel_iommu_remove_dev_pasid(). The previous patch has
> consolidated the code path with device attachment.
> would it be sufficient?

It's fine. Sorry, I overlooked this.

Best regards,
baolu

[PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Jacob Pan]

Kernel workqueues were disabled due to flawed use of kernel VA and SVA
API. Now That we have the support for attaching PASID to the device's
default domain and the ability to reserve global PASIDs from SVA APIs,
we can re-enable the kernel work queues and use them under DMA API.

We also use non-privileged access for in-kernel DMA to be consistent
with the IOMMU settings. Consequently, interrupt for user privilege is
enabled for work completion IRQs.

Link:https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/dma/idxd/device.c | 30 ++++-----------------
 drivers/dma/idxd/init.c   | 56 ++++++++++++++++++++++++++++++++++++---
 drivers/dma/idxd/sysfs.c  |  7 -----
 3 files changed, 57 insertions(+), 36 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 6fca8fa8d3a8..f6b133d61a04 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -299,21 +299,6 @@ void idxd_wqs_unmap_portal(struct idxd_device *idxd)
 	}
 }
 
-static void __idxd_wq_set_priv_locked(struct idxd_wq *wq, int priv)
-{
-	struct idxd_device *idxd = wq->idxd;
-	union wqcfg wqcfg;
-	unsigned int offset;
-
-	offset = WQCFG_OFFSET(idxd, wq->id, WQCFG_PRIVL_IDX);
-	spin_lock(&idxd->dev_lock);
-	wqcfg.bits[WQCFG_PRIVL_IDX] = ioread32(idxd->reg_base + offset);
-	wqcfg.priv = priv;
-	wq->wqcfg->bits[WQCFG_PRIVL_IDX] = wqcfg.bits[WQCFG_PRIVL_IDX];
-	iowrite32(wqcfg.bits[WQCFG_PRIVL_IDX], idxd->reg_base + offset);
-	spin_unlock(&idxd->dev_lock);
-}
-
 static void __idxd_wq_set_pasid_locked(struct idxd_wq *wq, int pasid)
 {
 	struct idxd_device *idxd = wq->idxd;
@@ -1324,15 +1309,14 @@ int drv_enable_wq(struct idxd_wq *wq)
 	}
 
 	/*
-	 * In the event that the WQ is configurable for pasid and priv bits.
-	 * For kernel wq, the driver should setup the pasid, pasid_en, and priv bit.
-	 * However, for non-kernel wq, the driver should only set the pasid_en bit for
-	 * shared wq. A dedicated wq that is not 'kernel' type will configure pasid and
+	 * In the event that the WQ is configurable for pasid, the driver
+	 * should setup the pasid, pasid_en bit. This is true for both kernel
+	 * and user shared workqueues. There is no need to setup priv bit in
+	 * that in-kernel DMA will also do user privileged requests.
+	 * A dedicated wq that is not 'kernel' type will configure pasid and
 	 * pasid_en later on so there is no need to setup.
 	 */
 	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) {
-		int priv = 0;
-
 		if (wq_pasid_enabled(wq)) {
 			if (is_idxd_wq_kernel(wq) || wq_shared(wq)) {
 				u32 pasid = wq_dedicated(wq) ? idxd->pasid : 0;
@@ -1340,10 +1324,6 @@ int drv_enable_wq(struct idxd_wq *wq)
 				__idxd_wq_set_pasid_locked(wq, pasid);
 			}
 		}
-
-		if (is_idxd_wq_kernel(wq))
-			priv = 1;
-		__idxd_wq_set_priv_locked(wq, priv);
 	}
 
 	rc = 0;
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index e6ee267da0ff..6f7778e1e936 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -506,14 +506,61 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
 
 static int idxd_enable_system_pasid(struct idxd_device *idxd)
 {
-	return -EOPNOTSUPP;
+	struct pci_dev *pdev = idxd->pdev;
+	struct device *dev = &pdev->dev;
+	struct iommu_domain *domain;
+	union gencfg_reg gencfg;
+	ioasid_t pasid;
+	int ret;
+
+	/*
+	 * Attach a global PASID to the DMA domain so that we can use ENQCMDS
+	 * to submit work on buffers mapped by DMA API.
+	 */
+	domain = iommu_get_domain_for_dev(dev);
+	if (!domain)
+		return -EPERM;
+
+	pasid = iommu_alloc_global_pasid(0, dev->iommu->max_pasids);
+	if (!pasid_valid(pasid))
+		return -ENOSPC;
+
+	ret = iommu_attach_device_pasid(domain, dev, pasid);
+	if (ret) {
+		dev_err(dev, "failed to attach device pasid %d, domain type %d",
+			pasid, domain->type);
+		iommu_free_global_pasid(pasid);
+		return ret;
+	}
+
+	/* Since we set user privilege for kernel DMA, enable completion IRQ */
+	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
+	gencfg.user_int_en = 1;
+	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
+	idxd->pasid = pasid;
+
+	return ret;
 }
 
 static void idxd_disable_system_pasid(struct idxd_device *idxd)
 {
+	struct pci_dev *pdev = idxd->pdev;
+	struct device *dev = &pdev->dev;
+	struct iommu_domain *domain;
+	union gencfg_reg gencfg;
+
+	domain = iommu_get_domain_for_dev(dev);
+	if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
+		return;
+
+	iommu_detach_device_pasid(domain, dev, idxd->pasid);
+	iommu_free_global_pasid(idxd->pasid);
 
-	iommu_sva_unbind_device(idxd->sva);
+	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
+	gencfg.user_int_en = 0;
+	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
 	idxd->sva = NULL;
+	idxd->pasid = IOMMU_PASID_INVALID;
 }
 
 static int idxd_probe(struct idxd_device *idxd)
@@ -535,8 +582,9 @@ static int idxd_probe(struct idxd_device *idxd)
 		} else {
 			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
 
-			if (idxd_enable_system_pasid(idxd))
-				dev_warn(dev, "No in-kernel DMA with PASID.\n");
+			rc = idxd_enable_system_pasid(idxd);
+			if (rc)
+				dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
 			else
 				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 		}
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 18cd8151dee0..c5561c00a503 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -944,13 +944,6 @@ static ssize_t wq_name_store(struct device *dev,
 	if (strlen(buf) > WQ_NAME_SIZE || strlen(buf) == 0)
 		return -EINVAL;
 
-	/*
-	 * This is temporarily placed here until we have SVM support for
-	 * dmaengine.
-	 */
-	if (wq->type == IDXD_WQT_KERNEL && device_pasid_enabled(wq->idxd))
-		return -EOPNOTSUPP;
-
 	input = kstrndup(buf, count, GFP_KERNEL);
 	if (!input)
 		return -ENOMEM;
-- 
2.25.1

RE: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Yu, Fenghua]

Hi, Jacob,

> Kernel workqueues were disabled due to flawed use of kernel VA and SVA API.
> Now That we have the support for attaching PASID to the device's default

s/That/that/

> domain and the ability to reserve global PASIDs from SVA APIs, we can re-enable
> the kernel work queues and use them under DMA API.
> 
> We also use non-privileged access for in-kernel DMA to be consistent with the
> IOMMU settings. Consequently, interrupt for user privilege is enabled for work
> completion IRQs.
> 
> Link:https://lore.kernel.org/linux-
> iommu/20210511194726.GP1002214@nvidia.com/
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>

Other than the typo,

Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>

Thanks.

-Fenghua

Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Jacob Pan]

Hi Fenghua,

On Fri, 31 Mar 2023 23:31:13 +0000, "Yu, Fenghua" <fenghua.yu@intel.com>
wrote:

> Hi, Jacob,
> 
> > Kernel workqueues were disabled due to flawed use of kernel VA and SVA
> > API. Now That we have the support for attaching PASID to the device's
> > default  
> 
> s/That/that/
will fix, for real this time :) you pointed it out before.

> > domain and the ability to reserve global PASIDs from SVA APIs, we can
> > re-enable the kernel work queues and use them under DMA API.
> > 
> > We also use non-privileged access for in-kernel DMA to be consistent
> > with the IOMMU settings. Consequently, interrupt for user privilege is
> > enabled for work completion IRQs.
> > 
> > Link:https://lore.kernel.org/linux-
> > iommu/20210511194726.GP1002214@nvidia.com/
> > Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>  
> 
> Other than the typo,
> 
> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
> 
> Thanks.
> 
> -Fenghua


Thanks,

Jacob

Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Baolu Lu]

On 2023/4/1 7:11, Jacob Pan wrote:
>   static void idxd_disable_system_pasid(struct idxd_device *idxd)
>   {
> +	struct pci_dev *pdev = idxd->pdev;
> +	struct device *dev = &pdev->dev;
> +	struct iommu_domain *domain;
> +	union gencfg_reg gencfg;
> +
> +	domain = iommu_get_domain_for_dev(dev);
> +	if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> +		return;

Out of curiosity, why do you need to check the domain type? And, in
which case could the domain for the device be changed to a blocking one?

Once a driver is bound to the device, the driver "owns" the DMA of the
device. No one else could change the domain except the driver itself.

> +
> +	iommu_detach_device_pasid(domain, dev, idxd->pasid);
> +	iommu_free_global_pasid(idxd->pasid);
>   
> -	iommu_sva_unbind_device(idxd->sva);
> +	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
> +	gencfg.user_int_en = 0;
> +	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
>   	idxd->sva = NULL;
> +	idxd->pasid = IOMMU_PASID_INVALID;
>   }

Best regards,
baolu

Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Jacob Pan]

Hi Baolu,

On Sat, 1 Apr 2023 21:39:32 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> >   static void idxd_disable_system_pasid(struct idxd_device *idxd)
> >   {
> > +	struct pci_dev *pdev = idxd->pdev;
> > +	struct device *dev = &pdev->dev;
> > +	struct iommu_domain *domain;
> > +	union gencfg_reg gencfg;
> > +
> > +	domain = iommu_get_domain_for_dev(dev);
> > +	if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> > +		return;  
> 
> Out of curiosity, why do you need to check the domain type? And, in
> which case could the domain for the device be changed to a blocking one?
> 
> Once a driver is bound to the device, the driver "owns" the DMA of the
> device. No one else could change the domain except the driver itself.
nothing particular just for precaution, I can drop the check or add a
warn_on.

> > +
> > +	iommu_detach_device_pasid(domain, dev, idxd->pasid);
> > +	iommu_free_global_pasid(idxd->pasid);
> >   
> > -	iommu_sva_unbind_device(idxd->sva);
> > +	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
> > +	gencfg.user_int_en = 0;
> > +	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
> >   	idxd->sva = NULL;
> > +	idxd->pasid = IOMMU_PASID_INVALID;
> >   }  
> 
> Best regards,
> baolu


Thanks,

Jacob

Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Jason Gunthorpe]

On Fri, Mar 31, 2023 at 04:11:37PM -0700, Jacob Pan wrote:
>  static void idxd_disable_system_pasid(struct idxd_device *idxd)
>  {
> +	struct pci_dev *pdev = idxd->pdev;
> +	struct device *dev = &pdev->dev;
> +	struct iommu_domain *domain;
> +	union gencfg_reg gencfg;
> +
> +	domain = iommu_get_domain_for_dev(dev);
> +	if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> +		return;
> +
> +	iommu_detach_device_pasid(domain, dev, idxd->pasid);

This sequence is kinda weird, we shouldn't pass in domain to
detach_device_pasid, IMHO. We already know the domain because we store
it in an xarray, it just creates weirdness if the user passes in the
wrong domain.

Jason

Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

[Baolu Lu]

On 4/5/23 8:15 PM, Jason Gunthorpe wrote:
> On Fri, Mar 31, 2023 at 04:11:37PM -0700, Jacob Pan wrote:
>>   static void idxd_disable_system_pasid(struct idxd_device *idxd)
>>   {
>> +	struct pci_dev *pdev = idxd->pdev;
>> +	struct device *dev = &pdev->dev;
>> +	struct iommu_domain *domain;
>> +	union gencfg_reg gencfg;
>> +
>> +	domain = iommu_get_domain_for_dev(dev);
>> +	if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
>> +		return;
>> +
>> +	iommu_detach_device_pasid(domain, dev, idxd->pasid);
> This sequence is kinda weird, we shouldn't pass in domain to
> detach_device_pasid, IMHO. We already know the domain because we store
> it in an xarray, it just creates weirdness if the user passes in the
> wrong domain.

The initial idea was that the driver has a domain and it wants to attach
the domain to a pasid of the device. During attaching, iommu core will
save the domain in its xarray.

After use, driver want to detach the domain from the pasid by calling
iommu_detach_device_pasid(). The iommu core will compare the input
domain and the one it saved. A warning will be triggered if they are
different.

	WARN_ON(xa_erase(&group->pasid_array, pasid) != domain);

Logically speaking, @domain for detach_device_pasid is unnecessary,
because the pasid array is essentially per-device (as we discussed
before. the pci_enable_pasid() ensures this), although it is currently
placed in the group structure. In that case, the driver can and should
own everything about the pasid and domain. The roles of the iommu core
and the individual driver are only to handle requests of installing or
withdrawing a domain on/from a device's pasid.

Best regards,
baolu

Re: [PATCH v3 0/7] Re-enable IDXD kernel workqueue under DMA API

[Baolu Lu]

Hi Jacob,

On 2023/4/1 7:11, Jacob Pan wrote:
> Jacob Pan (7):
>    iommu/vt-d: Use non-privileged mode for all PASIDs
>    iommu/vt-d: Remove PASID supervisor request support

Above two patches are vt-d cleanups after

942fd5435dcc iommu: Remove SVM_FLAG_SUPERVISOR_MODE support

I will queue them as vt-d updates for v6.4 if no objection.

Best regards,
baolu