2020-03-25 17:50:50

by Jacob Pan

[permalink] [raw]
Subject: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

The current ioasid_alloc function takes a token/ioasid_set then record it
on the IOASID being allocated. There is no alloc/free on the ioasid_set.

With the IOASID set APIs, callers must allocate an ioasid_set before
allocate IOASIDs within the set. Quota and other ioasid_set level
activities can then be enforced.

This patch converts existing API to the new ioasid_set model.

Signed-off-by: Liu Yi L <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
---
drivers/iommu/intel-iommu.c | 10 +++---
drivers/iommu/intel-svm.c | 10 +++---
drivers/iommu/ioasid.c | 78 +++++++++++++++++++++++++++++++++------------
include/linux/ioasid.h | 11 +++----
4 files changed, 72 insertions(+), 37 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index af7a1ef7b31e..c571cc8d9e57 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3323,11 +3323,11 @@ static void intel_ioasid_free(ioasid_t ioasid, void *data)
if (!iommu)
return;
/*
- * Sanity check the ioasid owner is done at upper layer, e.g. VFIO
- * We can only free the PASID when all the devices are unbound.
+ * In the guest, all IOASIDs belong to the system_ioasid set.
+ * Sanity check against the system set.
*/
- if (ioasid_find(NULL, ioasid, NULL)) {
- pr_alert("Cannot free active IOASID %d\n", ioasid);
+ if (IS_ERR(ioasid_find(system_ioasid_sid, ioasid, NULL))) {
+ pr_err("Cannot free IOASID %d, not in system set\n", ioasid);
return;
}
vcmd_free_pasid(iommu, ioasid);
@@ -5541,7 +5541,7 @@ static int aux_domain_add_dev(struct dmar_domain *domain,
int pasid;

/* No private data needed for the default pasid */
- pasid = ioasid_alloc(NULL, PASID_MIN,
+ pasid = ioasid_alloc(system_ioasid_sid, PASID_MIN,
pci_max_pasids(to_pci_dev(dev)) - 1,
NULL);
if (pasid == INVALID_IOASID) {
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 1991587fd3fd..f511855d187b 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -268,7 +268,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain,
}

mutex_lock(&pasid_mutex);
- svm = ioasid_find(NULL, data->hpasid, NULL);
+ svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
if (IS_ERR(svm)) {
ret = PTR_ERR(svm);
goto out;
@@ -401,7 +401,7 @@ int intel_svm_unbind_gpasid(struct device *dev, int pasid)
return -EINVAL;

mutex_lock(&pasid_mutex);
- svm = ioasid_find(NULL, pasid, NULL);
+ svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
if (!svm) {
ret = -EINVAL;
goto out;
@@ -559,7 +559,7 @@ static int intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *
pasid_max = intel_pasid_max_id;

/* Do not use PASID 0, reserved for RID to PASID */
- svm->pasid = ioasid_alloc(NULL, PASID_MIN,
+ svm->pasid = ioasid_alloc(system_ioasid_sid, PASID_MIN,
pasid_max - 1, svm);
if (svm->pasid == INVALID_IOASID) {
kfree(svm);
@@ -642,7 +642,7 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
if (!iommu)
goto out;

- svm = ioasid_find(NULL, pasid, NULL);
+ svm = ioasid_find(system_ioasid_sid, pasid, NULL);
if (!svm)
goto out;

@@ -778,7 +778,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)

if (!svm || svm->pasid != req->pasid) {
rcu_read_lock();
- svm = ioasid_find(NULL, req->pasid, NULL);
+ svm = ioasid_find(INVALID_IOASID_SET, req->pasid, NULL);
/* It *can't* go away, because the driver is not permitted
* to unbind the mm while any page faults are outstanding.
* So we only need RCU to protect the internal idr code. */
diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
index 9135af171a7c..f89a595f6978 100644
--- a/drivers/iommu/ioasid.c
+++ b/drivers/iommu/ioasid.c
@@ -31,7 +31,7 @@ struct ioasid_set_data {

struct ioasid_data {
ioasid_t id;
- struct ioasid_set *set;
+ struct ioasid_set_data *sdata;
void *private;
struct rcu_head rcu;
};
@@ -334,7 +334,7 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);

/**
* ioasid_alloc - Allocate an IOASID
- * @set: the IOASID set
+ * @sid: the IOASID set ID
* @min: the minimum ID (inclusive)
* @max: the maximum ID (inclusive)
* @private: data private to the caller
@@ -344,18 +344,30 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
*
* Return: the allocated ID on success, or %INVALID_IOASID on failure.
*/
-ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
- void *private)
+ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max, void *private)
{
+ struct ioasid_set_data *sdata;
struct ioasid_data *data;
void *adata;
ioasid_t id;

- data = kzalloc(sizeof(*data), GFP_ATOMIC);
+ /* Check if the IOASID set has been allocated and initialized */
+ sdata = xa_load(&ioasid_sets, sid);
+ if (!sdata) {
+ pr_err("Invalid IOASID set %d to allocate from\n", sid);
+ return INVALID_IOASID;
+ }
+
+ if (sdata->size <= sdata->nr_ioasids) {
+ pr_err("IOASID set %d out of quota\n", sid);
+ return INVALID_IOASID;
+ }
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return INVALID_IOASID;

- data->set = set;
+ data->sdata = sdata;
data->private = private;

/*
@@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
}
data->id = id;

+ /* Store IOASID in the per set data */
+ xa_store(&sdata->xa, id, data, GFP_KERNEL);
+ sdata->nr_ioasids++;
spin_unlock(&ioasid_allocator_lock);
return id;
exit_free:
@@ -388,19 +403,15 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
}
EXPORT_SYMBOL_GPL(ioasid_alloc);

-/**
- * ioasid_free - Free an IOASID
- * @ioasid: the ID to remove
- */
-void ioasid_free(ioasid_t ioasid)
+static void ioasid_free_locked(ioasid_t ioasid)
{
struct ioasid_data *ioasid_data;
+ struct ioasid_set_data *sdata;

- spin_lock(&ioasid_allocator_lock);
ioasid_data = xa_load(&active_allocator->xa, ioasid);
if (!ioasid_data) {
pr_err("Trying to free unknown IOASID %u\n", ioasid);
- goto exit_unlock;
+ return;
}

active_allocator->ops->free(ioasid, active_allocator->ops->pdata);
@@ -410,7 +421,27 @@ void ioasid_free(ioasid_t ioasid)
kfree_rcu(ioasid_data, rcu);
}

-exit_unlock:
+ sdata = xa_load(&ioasid_sets, ioasid_data->sdata->sid);
+ if (!sdata) {
+ pr_err("No set %d for IOASID %d\n", ioasid_data->sdata->sid,
+ ioasid);
+ return;
+ }
+ xa_erase(&sdata->xa, ioasid);
+ sdata->nr_ioasids--;
+}
+
+/**
+ * ioasid_free - Free an IOASID and notify users who registered a notifier
+ * on the IOASID set.
+ * IOASID can be re-allocated upon return
+ *
+ * @ioasid: the ID to remove
+ */
+void ioasid_free(ioasid_t ioasid)
+{
+ spin_lock(&ioasid_allocator_lock);
+ ioasid_free_locked(ioasid);
spin_unlock(&ioasid_allocator_lock);
}
EXPORT_SYMBOL_GPL(ioasid_free);
@@ -499,8 +530,12 @@ void ioasid_free_set(int sid, bool destroy_set)
goto done_destroy;
}

- /* Just a place holder for now */
xa_for_each(&sdata->xa, index, entry) {
+ /*
+ * Free from system-wide IOASID pool, all subscribers gets
+ * notified and do cleanup.
+ */
+ ioasid_free_locked(index);
/* Free from per sub-set pool */
xa_erase(&sdata->xa, index);
}
@@ -508,7 +543,6 @@ void ioasid_free_set(int sid, bool destroy_set)
done_destroy:
if (destroy_set) {
xa_erase(&ioasid_sets, sid);
-
/* Return the quota back to system pool */
ioasid_capacity_avail += sdata->size;
kfree_rcu(sdata, rcu);
@@ -522,7 +556,7 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);

/**
* ioasid_find - Find IOASID data
- * @set: the IOASID set
+ * @sid: the IOASID set ID
* @ioasid: the IOASID to find
* @getter: function to call on the found object
*
@@ -532,10 +566,12 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
*
* If the IOASID exists, return the private pointer passed to ioasid_alloc.
* Private data can be NULL if not set. Return an error if the IOASID is not
- * found, or if @set is not NULL and the IOASID does not belong to the set.
+ * found.
+ *
+ * If sid is INVALID_IOASID_SET, it will skip set ownership checking. Otherwise,
+ * error is returned even if the IOASID is found but does not belong the set.
*/
-void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
- bool (*getter)(void *))
+void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *))
{
void *priv;
struct ioasid_data *ioasid_data;
@@ -548,7 +584,7 @@ void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
priv = ERR_PTR(-ENOENT);
goto unlock;
}
- if (set && ioasid_data->set != set) {
+ if (sid != INVALID_IOASID_SET && ioasid_data->sdata->sid != sid) {
/* data found but does not belong to the set */
priv = ERR_PTR(-EACCES);
goto unlock;
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index 097b1cc043a3..e19c0ad93bd7 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -6,6 +6,7 @@
#include <linux/errno.h>

#define INVALID_IOASID ((ioasid_t)-1)
+#define INVALID_IOASID_SET (-1)
typedef unsigned int ioasid_t;
typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t max, void *data);
typedef void (*ioasid_free_fn_t)(ioasid_t ioasid, void *data);
@@ -35,11 +36,10 @@ extern int system_ioasid_sid;
#define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 }

#if IS_ENABLED(CONFIG_IOASID)
-ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
+ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max,
void *private);
void ioasid_free(ioasid_t ioasid);
-void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
- bool (*getter)(void *));
+void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *));
int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator);
int ioasid_attach_data(ioasid_t ioasid, void *data);
@@ -49,7 +49,7 @@ int ioasid_alloc_set(struct ioasid_set *token, ioasid_t quota, int *sid);
void ioasid_free_set(int sid, bool destroy_set);
int ioasid_find_sid(ioasid_t ioasid);
#else /* !CONFIG_IOASID */
-static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
+static inline ioasid_t ioasid_alloc(int sid, ioasid_t min,
ioasid_t max, void *private)
{
return INVALID_IOASID;
@@ -68,8 +68,7 @@ static inline void ioasid_free_set(int sid, bool destroy_set)
{
}

-static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
- bool (*getter)(void *))
+static inline void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *))
{
return NULL;
}
--
2.7.4


2020-03-27 09:55:09

by Tian, Kevin

[permalink] [raw]
Subject: RE: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

> From: Jacob Pan <[email protected]>
> Sent: Thursday, March 26, 2020 1:55 AM
>
> The current ioasid_alloc function takes a token/ioasid_set then record it
> on the IOASID being allocated. There is no alloc/free on the ioasid_set.
>
> With the IOASID set APIs, callers must allocate an ioasid_set before
> allocate IOASIDs within the set. Quota and other ioasid_set level
> activities can then be enforced.
>
> This patch converts existing API to the new ioasid_set model.
>
> Signed-off-by: Liu Yi L <[email protected]>
> Signed-off-by: Jacob Pan <[email protected]>
> ---
> drivers/iommu/intel-iommu.c | 10 +++---
> drivers/iommu/intel-svm.c | 10 +++---
> drivers/iommu/ioasid.c | 78 +++++++++++++++++++++++++++++++++-------
> -----
> include/linux/ioasid.h | 11 +++----
> 4 files changed, 72 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index af7a1ef7b31e..c571cc8d9e57 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3323,11 +3323,11 @@ static void intel_ioasid_free(ioasid_t ioasid, void
> *data)
> if (!iommu)
> return;
> /*
> - * Sanity check the ioasid owner is done at upper layer, e.g. VFIO
> - * We can only free the PASID when all the devices are unbound.
> + * In the guest, all IOASIDs belong to the system_ioasid set.
> + * Sanity check against the system set.

below code has nothing to deal with guest, then why putting the comment
specifically for guest?

> */
> - if (ioasid_find(NULL, ioasid, NULL)) {
> - pr_alert("Cannot free active IOASID %d\n", ioasid);
> + if (IS_ERR(ioasid_find(system_ioasid_sid, ioasid, NULL))) {
> + pr_err("Cannot free IOASID %d, not in system set\n", ioasid);
> return;
> }
> vcmd_free_pasid(iommu, ioasid);
> @@ -5541,7 +5541,7 @@ static int aux_domain_add_dev(struct
> dmar_domain *domain,
> int pasid;
>
> /* No private data needed for the default pasid */
> - pasid = ioasid_alloc(NULL, PASID_MIN,
> + pasid = ioasid_alloc(system_ioasid_sid, PASID_MIN,
> pci_max_pasids(to_pci_dev(dev)) - 1,
> NULL);
> if (pasid == INVALID_IOASID) {
> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> index 1991587fd3fd..f511855d187b 100644
> --- a/drivers/iommu/intel-svm.c
> +++ b/drivers/iommu/intel-svm.c
> @@ -268,7 +268,7 @@ int intel_svm_bind_gpasid(struct iommu_domain
> *domain,
> }
>
> mutex_lock(&pasid_mutex);
> - svm = ioasid_find(NULL, data->hpasid, NULL);
> + svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
> if (IS_ERR(svm)) {
> ret = PTR_ERR(svm);
> goto out;
> @@ -401,7 +401,7 @@ int intel_svm_unbind_gpasid(struct device *dev, int
> pasid)
> return -EINVAL;
>
> mutex_lock(&pasid_mutex);
> - svm = ioasid_find(NULL, pasid, NULL);
> + svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> if (!svm) {
> ret = -EINVAL;
> goto out;
> @@ -559,7 +559,7 @@ static int intel_svm_bind_mm(struct device *dev, int
> flags, struct svm_dev_ops *
> pasid_max = intel_pasid_max_id;
>
> /* Do not use PASID 0, reserved for RID to PASID */
> - svm->pasid = ioasid_alloc(NULL, PASID_MIN,
> + svm->pasid = ioasid_alloc(system_ioasid_sid, PASID_MIN,
> pasid_max - 1, svm);
> if (svm->pasid == INVALID_IOASID) {
> kfree(svm);
> @@ -642,7 +642,7 @@ int intel_svm_unbind_mm(struct device *dev, int
> pasid)
> if (!iommu)
> goto out;
>
> - svm = ioasid_find(NULL, pasid, NULL);
> + svm = ioasid_find(system_ioasid_sid, pasid, NULL);
> if (!svm)
> goto out;
>
> @@ -778,7 +778,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
>
> if (!svm || svm->pasid != req->pasid) {
> rcu_read_lock();
> - svm = ioasid_find(NULL, req->pasid, NULL);
> + svm = ioasid_find(INVALID_IOASID_SET, req->pasid,
> NULL);

is there a criteria when INVALID_IOASID_SET should be used?

> /* It *can't* go away, because the driver is not
> permitted
> * to unbind the mm while any page faults are
> outstanding.
> * So we only need RCU to protect the internal idr
> code. */
> diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> index 9135af171a7c..f89a595f6978 100644
> --- a/drivers/iommu/ioasid.c
> +++ b/drivers/iommu/ioasid.c
> @@ -31,7 +31,7 @@ struct ioasid_set_data {
>
> struct ioasid_data {
> ioasid_t id;
> - struct ioasid_set *set;
> + struct ioasid_set_data *sdata;
> void *private;
> struct rcu_head rcu;
> };
> @@ -334,7 +334,7 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
>
> /**
> * ioasid_alloc - Allocate an IOASID
> - * @set: the IOASID set
> + * @sid: the IOASID set ID
> * @min: the minimum ID (inclusive)
> * @max: the maximum ID (inclusive)
> * @private: data private to the caller
> @@ -344,18 +344,30 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> *
> * Return: the allocated ID on success, or %INVALID_IOASID on failure.
> */
> -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
> - void *private)
> +ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max, void *private)
> {
> + struct ioasid_set_data *sdata;
> struct ioasid_data *data;
> void *adata;
> ioasid_t id;
>
> - data = kzalloc(sizeof(*data), GFP_ATOMIC);
> + /* Check if the IOASID set has been allocated and initialized */
> + sdata = xa_load(&ioasid_sets, sid);

ok, this change answers my previous question in last patch. ????

> + if (!sdata) {
> + pr_err("Invalid IOASID set %d to allocate from\n", sid);
> + return INVALID_IOASID;
> + }
> +
> + if (sdata->size <= sdata->nr_ioasids) {
> + pr_err("IOASID set %d out of quota\n", sid);
> + return INVALID_IOASID;
> + }
> +
> + data = kzalloc(sizeof(*data), GFP_KERNEL);
> if (!data)
> return INVALID_IOASID;
>
> - data->set = set;
> + data->sdata = sdata;
> data->private = private;
>
> /*
> @@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t
> min, ioasid_t max,
> }
> data->id = id;
>
> + /* Store IOASID in the per set data */
> + xa_store(&sdata->xa, id, data, GFP_KERNEL);
> + sdata->nr_ioasids++;
> spin_unlock(&ioasid_allocator_lock);
> return id;
> exit_free:
> @@ -388,19 +403,15 @@ ioasid_t ioasid_alloc(struct ioasid_set *set,
> ioasid_t min, ioasid_t max,
> }
> EXPORT_SYMBOL_GPL(ioasid_alloc);
>
> -/**
> - * ioasid_free - Free an IOASID
> - * @ioasid: the ID to remove
> - */
> -void ioasid_free(ioasid_t ioasid)
> +static void ioasid_free_locked(ioasid_t ioasid)
> {
> struct ioasid_data *ioasid_data;
> + struct ioasid_set_data *sdata;
>
> - spin_lock(&ioasid_allocator_lock);
> ioasid_data = xa_load(&active_allocator->xa, ioasid);
> if (!ioasid_data) {
> pr_err("Trying to free unknown IOASID %u\n", ioasid);
> - goto exit_unlock;
> + return;
> }
>
> active_allocator->ops->free(ioasid, active_allocator->ops->pdata);
> @@ -410,7 +421,27 @@ void ioasid_free(ioasid_t ioasid)
> kfree_rcu(ioasid_data, rcu);
> }
>
> -exit_unlock:
> + sdata = xa_load(&ioasid_sets, ioasid_data->sdata->sid);
> + if (!sdata) {
> + pr_err("No set %d for IOASID %d\n", ioasid_data->sdata->sid,
> + ioasid);
> + return;
> + }
> + xa_erase(&sdata->xa, ioasid);
> + sdata->nr_ioasids--;
> +}
> +
> +/**
> + * ioasid_free - Free an IOASID and notify users who registered a notifier
> + * on the IOASID set.
> + * IOASID can be re-allocated upon return
> + *
> + * @ioasid: the ID to remove
> + */
> +void ioasid_free(ioasid_t ioasid)
> +{
> + spin_lock(&ioasid_allocator_lock);
> + ioasid_free_locked(ioasid);
> spin_unlock(&ioasid_allocator_lock);
> }
> EXPORT_SYMBOL_GPL(ioasid_free);
> @@ -499,8 +530,12 @@ void ioasid_free_set(int sid, bool destroy_set)
> goto done_destroy;
> }
>
> - /* Just a place holder for now */
> xa_for_each(&sdata->xa, index, entry) {
> + /*
> + * Free from system-wide IOASID pool, all subscribers gets
> + * notified and do cleanup.
> + */

this comment might be added too early...

> + ioasid_free_locked(index);
> /* Free from per sub-set pool */
> xa_erase(&sdata->xa, index);
> }
> @@ -508,7 +543,6 @@ void ioasid_free_set(int sid, bool destroy_set)
> done_destroy:
> if (destroy_set) {
> xa_erase(&ioasid_sets, sid);
> -
> /* Return the quota back to system pool */
> ioasid_capacity_avail += sdata->size;
> kfree_rcu(sdata, rcu);
> @@ -522,7 +556,7 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
>
> /**
> * ioasid_find - Find IOASID data
> - * @set: the IOASID set
> + * @sid: the IOASID set ID
> * @ioasid: the IOASID to find
> * @getter: function to call on the found object
> *
> @@ -532,10 +566,12 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> *
> * If the IOASID exists, return the private pointer passed to ioasid_alloc.
> * Private data can be NULL if not set. Return an error if the IOASID is not
> - * found, or if @set is not NULL and the IOASID does not belong to the set.
> + * found.
> + *
> + * If sid is INVALID_IOASID_SET, it will skip set ownership checking.
> Otherwise,
> + * error is returned even if the IOASID is found but does not belong the set.
> */
> -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> - bool (*getter)(void *))
> +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *))
> {
> void *priv;
> struct ioasid_data *ioasid_data;
> @@ -548,7 +584,7 @@ void *ioasid_find(struct ioasid_set *set, ioasid_t
> ioasid,
> priv = ERR_PTR(-ENOENT);
> goto unlock;
> }
> - if (set && ioasid_data->set != set) {
> + if (sid != INVALID_IOASID_SET && ioasid_data->sdata->sid != sid) {
> /* data found but does not belong to the set */
> priv = ERR_PTR(-EACCES);
> goto unlock;
> diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> index 097b1cc043a3..e19c0ad93bd7 100644
> --- a/include/linux/ioasid.h
> +++ b/include/linux/ioasid.h
> @@ -6,6 +6,7 @@
> #include <linux/errno.h>
>
> #define INVALID_IOASID ((ioasid_t)-1)
> +#define INVALID_IOASID_SET (-1)
> typedef unsigned int ioasid_t;
> typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t max, void *data);
> typedef void (*ioasid_free_fn_t)(ioasid_t ioasid, void *data);
> @@ -35,11 +36,10 @@ extern int system_ioasid_sid;
> #define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 }
>
> #if IS_ENABLED(CONFIG_IOASID)
> -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
> +ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max,
> void *private);
> void ioasid_free(ioasid_t ioasid);
> -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> - bool (*getter)(void *));
> +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *));
> int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
> void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator);
> int ioasid_attach_data(ioasid_t ioasid, void *data);
> @@ -49,7 +49,7 @@ int ioasid_alloc_set(struct ioasid_set *token, ioasid_t
> quota, int *sid);
> void ioasid_free_set(int sid, bool destroy_set);
> int ioasid_find_sid(ioasid_t ioasid);
> #else /* !CONFIG_IOASID */
> -static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> +static inline ioasid_t ioasid_alloc(int sid, ioasid_t min,
> ioasid_t max, void *private)
> {
> return INVALID_IOASID;
> @@ -68,8 +68,7 @@ static inline void ioasid_free_set(int sid, bool
> destroy_set)
> {
> }
>
> -static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> - bool (*getter)(void *))
> +static inline void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *))
> {
> return NULL;
> }
> --
> 2.7.4

2020-03-27 17:37:55

by Jacob Pan

[permalink] [raw]
Subject: Re: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

On Fri, 27 Mar 2020 09:54:11 +0000
"Tian, Kevin" <[email protected]> wrote:

> > From: Jacob Pan <[email protected]>
> > Sent: Thursday, March 26, 2020 1:55 AM
> >
> > The current ioasid_alloc function takes a token/ioasid_set then
> > record it on the IOASID being allocated. There is no alloc/free on
> > the ioasid_set.
> >
> > With the IOASID set APIs, callers must allocate an ioasid_set before
> > allocate IOASIDs within the set. Quota and other ioasid_set level
> > activities can then be enforced.
> >
> > This patch converts existing API to the new ioasid_set model.
> >
> > Signed-off-by: Liu Yi L <[email protected]>
> > Signed-off-by: Jacob Pan <[email protected]>
> > ---
> > drivers/iommu/intel-iommu.c | 10 +++---
> > drivers/iommu/intel-svm.c | 10 +++---
> > drivers/iommu/ioasid.c | 78
> > +++++++++++++++++++++++++++++++++------- -----
> > include/linux/ioasid.h | 11 +++----
> > 4 files changed, 72 insertions(+), 37 deletions(-)
> >
> > diff --git a/drivers/iommu/intel-iommu.c
> > b/drivers/iommu/intel-iommu.c index af7a1ef7b31e..c571cc8d9e57
> > 100644 --- a/drivers/iommu/intel-iommu.c
> > +++ b/drivers/iommu/intel-iommu.c
> > @@ -3323,11 +3323,11 @@ static void intel_ioasid_free(ioasid_t
> > ioasid, void *data)
> > if (!iommu)
> > return;
> > /*
> > - * Sanity check the ioasid owner is done at upper layer,
> > e.g. VFIO
> > - * We can only free the PASID when all the devices are
> > unbound.
> > + * In the guest, all IOASIDs belong to the system_ioasid
> > set.
> > + * Sanity check against the system set.
>
> below code has nothing to deal with guest, then why putting the
> comment specifically for guest?
>
intel_ioasid_alloc/free() is the custom IOASID allocator only
registered when running in the guest.

The custom allocator calls virtual command. Since we don't support
nested guest, all IOASIDs belong to the system ioasid_set.

> > */
> > - if (ioasid_find(NULL, ioasid, NULL)) {
> > - pr_alert("Cannot free active IOASID %d\n", ioasid);
> > + if (IS_ERR(ioasid_find(system_ioasid_sid, ioasid, NULL))) {
> > + pr_err("Cannot free IOASID %d, not in system
> > set\n", ioasid); return;
> > }
> > vcmd_free_pasid(iommu, ioasid);
> > @@ -5541,7 +5541,7 @@ static int aux_domain_add_dev(struct
> > dmar_domain *domain,
> > int pasid;
> >
> > /* No private data needed for the default pasid */
> > - pasid = ioasid_alloc(NULL, PASID_MIN,
> > + pasid = ioasid_alloc(system_ioasid_sid, PASID_MIN,
> > pci_max_pasids(to_pci_dev(dev))
> > - 1, NULL);
> > if (pasid == INVALID_IOASID) {
> > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> > index 1991587fd3fd..f511855d187b 100644
> > --- a/drivers/iommu/intel-svm.c
> > +++ b/drivers/iommu/intel-svm.c
> > @@ -268,7 +268,7 @@ int intel_svm_bind_gpasid(struct iommu_domain
> > *domain,
> > }
> >
> > mutex_lock(&pasid_mutex);
> > - svm = ioasid_find(NULL, data->hpasid, NULL);
> > + svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
> > if (IS_ERR(svm)) {
> > ret = PTR_ERR(svm);
> > goto out;
> > @@ -401,7 +401,7 @@ int intel_svm_unbind_gpasid(struct device *dev,
> > int pasid)
> > return -EINVAL;
> >
> > mutex_lock(&pasid_mutex);
> > - svm = ioasid_find(NULL, pasid, NULL);
> > + svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> > if (!svm) {
> > ret = -EINVAL;
> > goto out;
> > @@ -559,7 +559,7 @@ static int intel_svm_bind_mm(struct device
> > *dev, int flags, struct svm_dev_ops *
> > pasid_max = intel_pasid_max_id;
> >
> > /* Do not use PASID 0, reserved for RID to PASID */
> > - svm->pasid = ioasid_alloc(NULL, PASID_MIN,
> > + svm->pasid = ioasid_alloc(system_ioasid_sid,
> > PASID_MIN, pasid_max - 1, svm);
> > if (svm->pasid == INVALID_IOASID) {
> > kfree(svm);
> > @@ -642,7 +642,7 @@ int intel_svm_unbind_mm(struct device *dev, int
> > pasid)
> > if (!iommu)
> > goto out;
> >
> > - svm = ioasid_find(NULL, pasid, NULL);
> > + svm = ioasid_find(system_ioasid_sid, pasid, NULL);
> > if (!svm)
> > goto out;
> >
> > @@ -778,7 +778,7 @@ static irqreturn_t prq_event_thread(int irq,
> > void *d)
> >
> > if (!svm || svm->pasid != req->pasid) {
> > rcu_read_lock();
> > - svm = ioasid_find(NULL, req->pasid, NULL);
> > + svm = ioasid_find(INVALID_IOASID_SET,
> > req->pasid, NULL);
>
> is there a criteria when INVALID_IOASID_SET should be used?
>
Two use cases for INVALID_IOASID_SET:
1. a hint to ioasid_find to do global search, ignore set ownership check
2. cannot find a set ID for a given ioasid_find_sid()

You brought up a good point, I missed the second use case.


> > /* It *can't* go away, because the driver
> > is not permitted
> > * to unbind the mm while any page faults
> > are outstanding.
> > * So we only need RCU to protect the
> > internal idr code. */
> > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> > index 9135af171a7c..f89a595f6978 100644
> > --- a/drivers/iommu/ioasid.c
> > +++ b/drivers/iommu/ioasid.c
> > @@ -31,7 +31,7 @@ struct ioasid_set_data {
> >
> > struct ioasid_data {
> > ioasid_t id;
> > - struct ioasid_set *set;
> > + struct ioasid_set_data *sdata;
> > void *private;
> > struct rcu_head rcu;
> > };
> > @@ -334,7 +334,7 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> >
> > /**
> > * ioasid_alloc - Allocate an IOASID
> > - * @set: the IOASID set
> > + * @sid: the IOASID set ID
> > * @min: the minimum ID (inclusive)
> > * @max: the maximum ID (inclusive)
> > * @private: data private to the caller
> > @@ -344,18 +344,30 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> > *
> > * Return: the allocated ID on success, or %INVALID_IOASID on
> > failure. */
> > -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> > ioasid_t max,
> > - void *private)
> > +ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max, void
> > *private) {
> > + struct ioasid_set_data *sdata;
> > struct ioasid_data *data;
> > void *adata;
> > ioasid_t id;
> >
> > - data = kzalloc(sizeof(*data), GFP_ATOMIC);
> > + /* Check if the IOASID set has been allocated and
> > initialized */
> > + sdata = xa_load(&ioasid_sets, sid);
>
> ok, this change answers my previous question in last patch. ????
>
I guess you meant the NULL set question?

> > + if (!sdata) {
> > + pr_err("Invalid IOASID set %d to allocate from\n",
> > sid);
> > + return INVALID_IOASID;
> > + }
> > +
> > + if (sdata->size <= sdata->nr_ioasids) {
> > + pr_err("IOASID set %d out of quota\n", sid);
> > + return INVALID_IOASID;
> > + }
> > +
> > + data = kzalloc(sizeof(*data), GFP_KERNEL);
> > if (!data)
> > return INVALID_IOASID;
> >
> > - data->set = set;
> > + data->sdata = sdata;
> > data->private = private;
> >
> > /*
> > @@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set *set,
> > ioasid_t min, ioasid_t max,
> > }
> > data->id = id;
> >
> > + /* Store IOASID in the per set data */
> > + xa_store(&sdata->xa, id, data, GFP_KERNEL);
> > + sdata->nr_ioasids++;
> > spin_unlock(&ioasid_allocator_lock);
> > return id;
> > exit_free:
> > @@ -388,19 +403,15 @@ ioasid_t ioasid_alloc(struct ioasid_set *set,
> > ioasid_t min, ioasid_t max,
> > }
> > EXPORT_SYMBOL_GPL(ioasid_alloc);
> >
> > -/**
> > - * ioasid_free - Free an IOASID
> > - * @ioasid: the ID to remove
> > - */
> > -void ioasid_free(ioasid_t ioasid)
> > +static void ioasid_free_locked(ioasid_t ioasid)
> > {
> > struct ioasid_data *ioasid_data;
> > + struct ioasid_set_data *sdata;
> >
> > - spin_lock(&ioasid_allocator_lock);
> > ioasid_data = xa_load(&active_allocator->xa, ioasid);
> > if (!ioasid_data) {
> > pr_err("Trying to free unknown IOASID %u\n",
> > ioasid);
> > - goto exit_unlock;
> > + return;
> > }
> >
> > active_allocator->ops->free(ioasid,
> > active_allocator->ops->pdata); @@ -410,7 +421,27 @@ void
> > ioasid_free(ioasid_t ioasid) kfree_rcu(ioasid_data, rcu);
> > }
> >
> > -exit_unlock:
> > + sdata = xa_load(&ioasid_sets, ioasid_data->sdata->sid);
> > + if (!sdata) {
> > + pr_err("No set %d for IOASID %d\n",
> > ioasid_data->sdata->sid,
> > + ioasid);
> > + return;
> > + }
> > + xa_erase(&sdata->xa, ioasid);
> > + sdata->nr_ioasids--;
> > +}
> > +
> > +/**
> > + * ioasid_free - Free an IOASID and notify users who registered a
> > notifier
> > + * on the IOASID set.
> > + * IOASID can be re-allocated upon return
> > + *
> > + * @ioasid: the ID to remove
> > + */
> > +void ioasid_free(ioasid_t ioasid)
> > +{
> > + spin_lock(&ioasid_allocator_lock);
> > + ioasid_free_locked(ioasid);
> > spin_unlock(&ioasid_allocator_lock);
> > }
> > EXPORT_SYMBOL_GPL(ioasid_free);
> > @@ -499,8 +530,12 @@ void ioasid_free_set(int sid, bool destroy_set)
> > goto done_destroy;
> > }
> >
> > - /* Just a place holder for now */
> > xa_for_each(&sdata->xa, index, entry) {
> > + /*
> > + * Free from system-wide IOASID pool, all
> > subscribers gets
> > + * notified and do cleanup.
> > + */
>
> this comment might be added too early...
Yes, I should move it to notifier patch.

>
> > + ioasid_free_locked(index);
> > /* Free from per sub-set pool */
> > xa_erase(&sdata->xa, index);
> > }
> > @@ -508,7 +543,6 @@ void ioasid_free_set(int sid, bool destroy_set)
> > done_destroy:
> > if (destroy_set) {
> > xa_erase(&ioasid_sets, sid);
> > -
> > /* Return the quota back to system pool */
> > ioasid_capacity_avail += sdata->size;
> > kfree_rcu(sdata, rcu);
> > @@ -522,7 +556,7 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> >
> > /**
> > * ioasid_find - Find IOASID data
> > - * @set: the IOASID set
> > + * @sid: the IOASID set ID
> > * @ioasid: the IOASID to find
> > * @getter: function to call on the found object
> > *
> > @@ -532,10 +566,12 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> > *
> > * If the IOASID exists, return the private pointer passed to
> > ioasid_alloc.
> > * Private data can be NULL if not set. Return an error if the
> > IOASID is not
> > - * found, or if @set is not NULL and the IOASID does not belong to
> > the set.
> > + * found.
> > + *
> > + * If sid is INVALID_IOASID_SET, it will skip set ownership
> > checking. Otherwise,
> > + * error is returned even if the IOASID is found but does not
> > belong the set. */
> > -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> > - bool (*getter)(void *))
> > +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *))
> > {
> > void *priv;
> > struct ioasid_data *ioasid_data;
> > @@ -548,7 +584,7 @@ void *ioasid_find(struct ioasid_set *set,
> > ioasid_t ioasid,
> > priv = ERR_PTR(-ENOENT);
> > goto unlock;
> > }
> > - if (set && ioasid_data->set != set) {
> > + if (sid != INVALID_IOASID_SET &&
> > ioasid_data->sdata->sid != sid) { /* data found but does not belong
> > to the set */ priv = ERR_PTR(-EACCES);
> > goto unlock;
> > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> > index 097b1cc043a3..e19c0ad93bd7 100644
> > --- a/include/linux/ioasid.h
> > +++ b/include/linux/ioasid.h
> > @@ -6,6 +6,7 @@
> > #include <linux/errno.h>
> >
> > #define INVALID_IOASID ((ioasid_t)-1)
> > +#define INVALID_IOASID_SET (-1)
> > typedef unsigned int ioasid_t;
> > typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t max,
> > void *data); typedef void (*ioasid_free_fn_t)(ioasid_t ioasid, void
> > *data); @@ -35,11 +36,10 @@ extern int system_ioasid_sid;
> > #define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 }
> >
> > #if IS_ENABLED(CONFIG_IOASID)
> > -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> > ioasid_t max, +ioasid_t ioasid_alloc(int sid, ioasid_t min,
> > ioasid_t max, void *private);
> > void ioasid_free(ioasid_t ioasid);
> > -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> > - bool (*getter)(void *));
> > +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void
> > *)); int ioasid_register_allocator(struct ioasid_allocator_ops
> > *allocator); void ioasid_unregister_allocator(struct
> > ioasid_allocator_ops *allocator); int ioasid_attach_data(ioasid_t
> > ioasid, void *data); @@ -49,7 +49,7 @@ int ioasid_alloc_set(struct
> > ioasid_set *token, ioasid_t quota, int *sid);
> > void ioasid_free_set(int sid, bool destroy_set);
> > int ioasid_find_sid(ioasid_t ioasid);
> > #else /* !CONFIG_IOASID */
> > -static inline ioasid_t ioasid_alloc(struct ioasid_set *set,
> > ioasid_t min, +static inline ioasid_t ioasid_alloc(int sid,
> > ioasid_t min, ioasid_t max, void *private)
> > {
> > return INVALID_IOASID;
> > @@ -68,8 +68,7 @@ static inline void ioasid_free_set(int sid, bool
> > destroy_set)
> > {
> > }
> >
> > -static inline void *ioasid_find(struct ioasid_set *set, ioasid_t
> > ioasid,
> > - bool (*getter)(void *))
> > +static inline void *ioasid_find(int sid, ioasid_t ioasid, bool
> > (*getter)(void *)) {
> > return NULL;
> > }
> > --
> > 2.7.4
>

[Jacob Pan]

2020-03-28 06:42:58

by Tian, Kevin

[permalink] [raw]
Subject: RE: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

> From: Jacob Pan <[email protected]>
> Sent: Saturday, March 28, 2020 1:42 AM
>
> On Fri, 27 Mar 2020 09:54:11 +0000
> "Tian, Kevin" <[email protected]> wrote:
>
> > > From: Jacob Pan <[email protected]>
> > > Sent: Thursday, March 26, 2020 1:55 AM
> > >
> > > The current ioasid_alloc function takes a token/ioasid_set then
> > > record it on the IOASID being allocated. There is no alloc/free on
> > > the ioasid_set.
> > >
> > > With the IOASID set APIs, callers must allocate an ioasid_set before
> > > allocate IOASIDs within the set. Quota and other ioasid_set level
> > > activities can then be enforced.
> > >
> > > This patch converts existing API to the new ioasid_set model.
> > >
> > > Signed-off-by: Liu Yi L <[email protected]>
> > > Signed-off-by: Jacob Pan <[email protected]>
> > > ---
> > > drivers/iommu/intel-iommu.c | 10 +++---
> > > drivers/iommu/intel-svm.c | 10 +++---
> > > drivers/iommu/ioasid.c | 78
> > > +++++++++++++++++++++++++++++++++------- -----
> > > include/linux/ioasid.h | 11 +++----
> > > 4 files changed, 72 insertions(+), 37 deletions(-)
> > >
> > > diff --git a/drivers/iommu/intel-iommu.c
> > > b/drivers/iommu/intel-iommu.c index af7a1ef7b31e..c571cc8d9e57
> > > 100644 --- a/drivers/iommu/intel-iommu.c
> > > +++ b/drivers/iommu/intel-iommu.c
> > > @@ -3323,11 +3323,11 @@ static void intel_ioasid_free(ioasid_t
> > > ioasid, void *data)
> > > if (!iommu)
> > > return;
> > > /*
> > > - * Sanity check the ioasid owner is done at upper layer,
> > > e.g. VFIO
> > > - * We can only free the PASID when all the devices are
> > > unbound.
> > > + * In the guest, all IOASIDs belong to the system_ioasid
> > > set.
> > > + * Sanity check against the system set.
> >
> > below code has nothing to deal with guest, then why putting the
> > comment specifically for guest?
> >
> intel_ioasid_alloc/free() is the custom IOASID allocator only
> registered when running in the guest.

in that case may be rename the functions to intel_guest_ioasid_alloc/free
would avoid similar confusion as I had?

>
> The custom allocator calls virtual command. Since we don't support
> nested guest, all IOASIDs belong to the system ioasid_set.

could you put no support of nested guest in the comment, so later
when people want to add nested support they will know some
additional work required here?

>
> > > */
> > > - if (ioasid_find(NULL, ioasid, NULL)) {
> > > - pr_alert("Cannot free active IOASID %d\n", ioasid);
> > > + if (IS_ERR(ioasid_find(system_ioasid_sid, ioasid, NULL))) {
> > > + pr_err("Cannot free IOASID %d, not in system
> > > set\n", ioasid); return;
> > > }
> > > vcmd_free_pasid(iommu, ioasid);
> > > @@ -5541,7 +5541,7 @@ static int aux_domain_add_dev(struct
> > > dmar_domain *domain,
> > > int pasid;
> > >
> > > /* No private data needed for the default pasid */
> > > - pasid = ioasid_alloc(NULL, PASID_MIN,
> > > + pasid = ioasid_alloc(system_ioasid_sid, PASID_MIN,
> > > pci_max_pasids(to_pci_dev(dev))
> > > - 1, NULL);
> > > if (pasid == INVALID_IOASID) {
> > > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> > > index 1991587fd3fd..f511855d187b 100644
> > > --- a/drivers/iommu/intel-svm.c
> > > +++ b/drivers/iommu/intel-svm.c
> > > @@ -268,7 +268,7 @@ int intel_svm_bind_gpasid(struct iommu_domain
> > > *domain,
> > > }
> > >
> > > mutex_lock(&pasid_mutex);
> > > - svm = ioasid_find(NULL, data->hpasid, NULL);
> > > + svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
> > > if (IS_ERR(svm)) {
> > > ret = PTR_ERR(svm);
> > > goto out;
> > > @@ -401,7 +401,7 @@ int intel_svm_unbind_gpasid(struct device *dev,
> > > int pasid)
> > > return -EINVAL;
> > >
> > > mutex_lock(&pasid_mutex);
> > > - svm = ioasid_find(NULL, pasid, NULL);
> > > + svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> > > if (!svm) {
> > > ret = -EINVAL;
> > > goto out;
> > > @@ -559,7 +559,7 @@ static int intel_svm_bind_mm(struct device
> > > *dev, int flags, struct svm_dev_ops *
> > > pasid_max = intel_pasid_max_id;
> > >
> > > /* Do not use PASID 0, reserved for RID to PASID */
> > > - svm->pasid = ioasid_alloc(NULL, PASID_MIN,
> > > + svm->pasid = ioasid_alloc(system_ioasid_sid,
> > > PASID_MIN, pasid_max - 1, svm);
> > > if (svm->pasid == INVALID_IOASID) {
> > > kfree(svm);
> > > @@ -642,7 +642,7 @@ int intel_svm_unbind_mm(struct device *dev, int
> > > pasid)
> > > if (!iommu)
> > > goto out;
> > >
> > > - svm = ioasid_find(NULL, pasid, NULL);
> > > + svm = ioasid_find(system_ioasid_sid, pasid, NULL);
> > > if (!svm)
> > > goto out;
> > >
> > > @@ -778,7 +778,7 @@ static irqreturn_t prq_event_thread(int irq,
> > > void *d)
> > >
> > > if (!svm || svm->pasid != req->pasid) {
> > > rcu_read_lock();
> > > - svm = ioasid_find(NULL, req->pasid, NULL);
> > > + svm = ioasid_find(INVALID_IOASID_SET,
> > > req->pasid, NULL);
> >
> > is there a criteria when INVALID_IOASID_SET should be used?
> >
> Two use cases for INVALID_IOASID_SET:
> 1. a hint to ioasid_find to do global search, ignore set ownership check
> 2. cannot find a set ID for a given ioasid_find_sid()
>
> You brought up a good point, I missed the second use case.
>
>
> > > /* It *can't* go away, because the driver
> > > is not permitted
> > > * to unbind the mm while any page faults
> > > are outstanding.
> > > * So we only need RCU to protect the
> > > internal idr code. */
> > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> > > index 9135af171a7c..f89a595f6978 100644
> > > --- a/drivers/iommu/ioasid.c
> > > +++ b/drivers/iommu/ioasid.c
> > > @@ -31,7 +31,7 @@ struct ioasid_set_data {
> > >
> > > struct ioasid_data {
> > > ioasid_t id;
> > > - struct ioasid_set *set;
> > > + struct ioasid_set_data *sdata;
> > > void *private;
> > > struct rcu_head rcu;
> > > };
> > > @@ -334,7 +334,7 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> > >
> > > /**
> > > * ioasid_alloc - Allocate an IOASID
> > > - * @set: the IOASID set
> > > + * @sid: the IOASID set ID
> > > * @min: the minimum ID (inclusive)
> > > * @max: the maximum ID (inclusive)
> > > * @private: data private to the caller
> > > @@ -344,18 +344,30 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> > > *
> > > * Return: the allocated ID on success, or %INVALID_IOASID on
> > > failure. */
> > > -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> > > ioasid_t max,
> > > - void *private)
> > > +ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max, void
> > > *private) {
> > > + struct ioasid_set_data *sdata;
> > > struct ioasid_data *data;
> > > void *adata;
> > > ioasid_t id;
> > >
> > > - data = kzalloc(sizeof(*data), GFP_ATOMIC);
> > > + /* Check if the IOASID set has been allocated and
> > > initialized */
> > > + sdata = xa_load(&ioasid_sets, sid);
> >
> > ok, this change answers my previous question in last patch. ????
> >
> I guess you meant the NULL set question?

yes

>
> > > + if (!sdata) {
> > > + pr_err("Invalid IOASID set %d to allocate from\n",
> > > sid);
> > > + return INVALID_IOASID;
> > > + }
> > > +
> > > + if (sdata->size <= sdata->nr_ioasids) {
> > > + pr_err("IOASID set %d out of quota\n", sid);
> > > + return INVALID_IOASID;
> > > + }
> > > +
> > > + data = kzalloc(sizeof(*data), GFP_KERNEL);
> > > if (!data)
> > > return INVALID_IOASID;
> > >
> > > - data->set = set;
> > > + data->sdata = sdata;
> > > data->private = private;
> > >
> > > /*
> > > @@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set *set,
> > > ioasid_t min, ioasid_t max,
> > > }
> > > data->id = id;
> > >
> > > + /* Store IOASID in the per set data */
> > > + xa_store(&sdata->xa, id, data, GFP_KERNEL);
> > > + sdata->nr_ioasids++;
> > > spin_unlock(&ioasid_allocator_lock);
> > > return id;
> > > exit_free:
> > > @@ -388,19 +403,15 @@ ioasid_t ioasid_alloc(struct ioasid_set *set,
> > > ioasid_t min, ioasid_t max,
> > > }
> > > EXPORT_SYMBOL_GPL(ioasid_alloc);
> > >
> > > -/**
> > > - * ioasid_free - Free an IOASID
> > > - * @ioasid: the ID to remove
> > > - */
> > > -void ioasid_free(ioasid_t ioasid)
> > > +static void ioasid_free_locked(ioasid_t ioasid)
> > > {
> > > struct ioasid_data *ioasid_data;
> > > + struct ioasid_set_data *sdata;
> > >
> > > - spin_lock(&ioasid_allocator_lock);
> > > ioasid_data = xa_load(&active_allocator->xa, ioasid);
> > > if (!ioasid_data) {
> > > pr_err("Trying to free unknown IOASID %u\n",
> > > ioasid);
> > > - goto exit_unlock;
> > > + return;
> > > }
> > >
> > > active_allocator->ops->free(ioasid,
> > > active_allocator->ops->pdata); @@ -410,7 +421,27 @@ void
> > > ioasid_free(ioasid_t ioasid) kfree_rcu(ioasid_data, rcu);
> > > }
> > >
> > > -exit_unlock:
> > > + sdata = xa_load(&ioasid_sets, ioasid_data->sdata->sid);
> > > + if (!sdata) {
> > > + pr_err("No set %d for IOASID %d\n",
> > > ioasid_data->sdata->sid,
> > > + ioasid);
> > > + return;
> > > + }
> > > + xa_erase(&sdata->xa, ioasid);
> > > + sdata->nr_ioasids--;
> > > +}
> > > +
> > > +/**
> > > + * ioasid_free - Free an IOASID and notify users who registered a
> > > notifier
> > > + * on the IOASID set.
> > > + * IOASID can be re-allocated upon return
> > > + *
> > > + * @ioasid: the ID to remove
> > > + */
> > > +void ioasid_free(ioasid_t ioasid)
> > > +{
> > > + spin_lock(&ioasid_allocator_lock);
> > > + ioasid_free_locked(ioasid);
> > > spin_unlock(&ioasid_allocator_lock);
> > > }
> > > EXPORT_SYMBOL_GPL(ioasid_free);
> > > @@ -499,8 +530,12 @@ void ioasid_free_set(int sid, bool destroy_set)
> > > goto done_destroy;
> > > }
> > >
> > > - /* Just a place holder for now */
> > > xa_for_each(&sdata->xa, index, entry) {
> > > + /*
> > > + * Free from system-wide IOASID pool, all
> > > subscribers gets
> > > + * notified and do cleanup.
> > > + */
> >
> > this comment might be added too early...
> Yes, I should move it to notifier patch.
>
> >
> > > + ioasid_free_locked(index);
> > > /* Free from per sub-set pool */
> > > xa_erase(&sdata->xa, index);
> > > }
> > > @@ -508,7 +543,6 @@ void ioasid_free_set(int sid, bool destroy_set)
> > > done_destroy:
> > > if (destroy_set) {
> > > xa_erase(&ioasid_sets, sid);
> > > -
> > > /* Return the quota back to system pool */
> > > ioasid_capacity_avail += sdata->size;
> > > kfree_rcu(sdata, rcu);
> > > @@ -522,7 +556,7 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> > >
> > > /**
> > > * ioasid_find - Find IOASID data
> > > - * @set: the IOASID set
> > > + * @sid: the IOASID set ID
> > > * @ioasid: the IOASID to find
> > > * @getter: function to call on the found object
> > > *
> > > @@ -532,10 +566,12 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> > > *
> > > * If the IOASID exists, return the private pointer passed to
> > > ioasid_alloc.
> > > * Private data can be NULL if not set. Return an error if the
> > > IOASID is not
> > > - * found, or if @set is not NULL and the IOASID does not belong to
> > > the set.
> > > + * found.
> > > + *
> > > + * If sid is INVALID_IOASID_SET, it will skip set ownership
> > > checking. Otherwise,
> > > + * error is returned even if the IOASID is found but does not
> > > belong the set. */
> > > -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> > > - bool (*getter)(void *))
> > > +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void *))
> > > {
> > > void *priv;
> > > struct ioasid_data *ioasid_data;
> > > @@ -548,7 +584,7 @@ void *ioasid_find(struct ioasid_set *set,
> > > ioasid_t ioasid,
> > > priv = ERR_PTR(-ENOENT);
> > > goto unlock;
> > > }
> > > - if (set && ioasid_data->set != set) {
> > > + if (sid != INVALID_IOASID_SET &&
> > > ioasid_data->sdata->sid != sid) { /* data found but does not belong
> > > to the set */ priv = ERR_PTR(-EACCES);
> > > goto unlock;
> > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> > > index 097b1cc043a3..e19c0ad93bd7 100644
> > > --- a/include/linux/ioasid.h
> > > +++ b/include/linux/ioasid.h
> > > @@ -6,6 +6,7 @@
> > > #include <linux/errno.h>
> > >
> > > #define INVALID_IOASID ((ioasid_t)-1)
> > > +#define INVALID_IOASID_SET (-1)
> > > typedef unsigned int ioasid_t;
> > > typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t max,
> > > void *data); typedef void (*ioasid_free_fn_t)(ioasid_t ioasid, void
> > > *data); @@ -35,11 +36,10 @@ extern int system_ioasid_sid;
> > > #define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 }
> > >
> > > #if IS_ENABLED(CONFIG_IOASID)
> > > -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> > > ioasid_t max, +ioasid_t ioasid_alloc(int sid, ioasid_t min,
> > > ioasid_t max, void *private);
> > > void ioasid_free(ioasid_t ioasid);
> > > -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> > > - bool (*getter)(void *));
> > > +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void
> > > *)); int ioasid_register_allocator(struct ioasid_allocator_ops
> > > *allocator); void ioasid_unregister_allocator(struct
> > > ioasid_allocator_ops *allocator); int ioasid_attach_data(ioasid_t
> > > ioasid, void *data); @@ -49,7 +49,7 @@ int ioasid_alloc_set(struct
> > > ioasid_set *token, ioasid_t quota, int *sid);
> > > void ioasid_free_set(int sid, bool destroy_set);
> > > int ioasid_find_sid(ioasid_t ioasid);
> > > #else /* !CONFIG_IOASID */
> > > -static inline ioasid_t ioasid_alloc(struct ioasid_set *set,
> > > ioasid_t min, +static inline ioasid_t ioasid_alloc(int sid,
> > > ioasid_t min, ioasid_t max, void *private)
> > > {
> > > return INVALID_IOASID;
> > > @@ -68,8 +68,7 @@ static inline void ioasid_free_set(int sid, bool
> > > destroy_set)
> > > {
> > > }
> > >
> > > -static inline void *ioasid_find(struct ioasid_set *set, ioasid_t
> > > ioasid,
> > > - bool (*getter)(void *))
> > > +static inline void *ioasid_find(int sid, ioasid_t ioasid, bool
> > > (*getter)(void *)) {
> > > return NULL;
> > > }
> > > --
> > > 2.7.4
> >
>
> [Jacob Pan]

2020-04-01 15:07:58

by Jean-Philippe Brucker

[permalink] [raw]
Subject: Re: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

On Wed, Mar 25, 2020 at 10:55:27AM -0700, Jacob Pan wrote:
> The current ioasid_alloc function takes a token/ioasid_set then record it
> on the IOASID being allocated. There is no alloc/free on the ioasid_set.
>
> With the IOASID set APIs, callers must allocate an ioasid_set before
> allocate IOASIDs within the set. Quota and other ioasid_set level
> activities can then be enforced.
>
> This patch converts existing API to the new ioasid_set model.
>
> Signed-off-by: Liu Yi L <[email protected]>
> Signed-off-by: Jacob Pan <[email protected]>

[...]

> @@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
> }
> data->id = id;
>
> + /* Store IOASID in the per set data */
> + xa_store(&sdata->xa, id, data, GFP_KERNEL);

I couldn't figure out why you're maintaining an additional xarray for each
set. We're already storing that data in active_allocator->xa, why the
duplication? If it's for the gPASID -> hPASID translation mentioned by
the cover letter, maybe you could add this xa when introducing that
change?

Thanks,
Jean

2020-04-01 22:40:31

by Jacob Pan

[permalink] [raw]
Subject: Re: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

On Wed, 1 Apr 2020 15:55:25 +0200
Jean-Philippe Brucker <[email protected]> wrote:

> On Wed, Mar 25, 2020 at 10:55:27AM -0700, Jacob Pan wrote:
> > The current ioasid_alloc function takes a token/ioasid_set then
> > record it on the IOASID being allocated. There is no alloc/free on
> > the ioasid_set.
> >
> > With the IOASID set APIs, callers must allocate an ioasid_set before
> > allocate IOASIDs within the set. Quota and other ioasid_set level
> > activities can then be enforced.
> >
> > This patch converts existing API to the new ioasid_set model.
> >
> > Signed-off-by: Liu Yi L <[email protected]>
> > Signed-off-by: Jacob Pan <[email protected]>
>
> [...]
>
> > @@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set *set,
> > ioasid_t min, ioasid_t max, }
> > data->id = id;
> >
> > + /* Store IOASID in the per set data */
> > + xa_store(&sdata->xa, id, data, GFP_KERNEL);
>
> I couldn't figure out why you're maintaining an additional xarray for
> each set. We're already storing that data in active_allocator->xa,
> why the duplication? If it's for the gPASID -> hPASID translation
> mentioned by the cover letter, maybe you could add this xa when
> introducing that change?
>
Sounds good. I will add that later. I was hoping to get common code in
place.

2020-04-06 20:02:58

by Jacob Pan

[permalink] [raw]
Subject: Re: [PATCH 06/10] iommu/ioasid: Convert to set aware allocations

On Sat, 28 Mar 2020 06:40:58 +0000
"Tian, Kevin" <[email protected]> wrote:

> > From: Jacob Pan <[email protected]>
> > Sent: Saturday, March 28, 2020 1:42 AM
> >
> > On Fri, 27 Mar 2020 09:54:11 +0000
> > "Tian, Kevin" <[email protected]> wrote:
> >
> > > > From: Jacob Pan <[email protected]>
> > > > Sent: Thursday, March 26, 2020 1:55 AM
> > > >
> > > > The current ioasid_alloc function takes a token/ioasid_set then
> > > > record it on the IOASID being allocated. There is no alloc/free
> > > > on the ioasid_set.
> > > >
> > > > With the IOASID set APIs, callers must allocate an ioasid_set
> > > > before allocate IOASIDs within the set. Quota and other
> > > > ioasid_set level activities can then be enforced.
> > > >
> > > > This patch converts existing API to the new ioasid_set model.
> > > >
> > > > Signed-off-by: Liu Yi L <[email protected]>
> > > > Signed-off-by: Jacob Pan <[email protected]>
> > > > ---
> > > > drivers/iommu/intel-iommu.c | 10 +++---
> > > > drivers/iommu/intel-svm.c | 10 +++---
> > > > drivers/iommu/ioasid.c | 78
> > > > +++++++++++++++++++++++++++++++++------- -----
> > > > include/linux/ioasid.h | 11 +++----
> > > > 4 files changed, 72 insertions(+), 37 deletions(-)
> > > >
> > > > diff --git a/drivers/iommu/intel-iommu.c
> > > > b/drivers/iommu/intel-iommu.c index af7a1ef7b31e..c571cc8d9e57
> > > > 100644 --- a/drivers/iommu/intel-iommu.c
> > > > +++ b/drivers/iommu/intel-iommu.c
> > > > @@ -3323,11 +3323,11 @@ static void intel_ioasid_free(ioasid_t
> > > > ioasid, void *data)
> > > > if (!iommu)
> > > > return;
> > > > /*
> > > > - * Sanity check the ioasid owner is done at upper
> > > > layer, e.g. VFIO
> > > > - * We can only free the PASID when all the devices are
> > > > unbound.
> > > > + * In the guest, all IOASIDs belong to the
> > > > system_ioasid set.
> > > > + * Sanity check against the system set.
> > >
> > > below code has nothing to deal with guest, then why putting the
> > > comment specifically for guest?
> > >
> > intel_ioasid_alloc/free() is the custom IOASID allocator only
> > registered when running in the guest.
>
> in that case may be rename the functions to
> intel_guest_ioasid_alloc/free would avoid similar confusion as I had?
>
Sounds good.
> >
> > The custom allocator calls virtual command. Since we don't support
> > nested guest, all IOASIDs belong to the system ioasid_set.
>
> could you put no support of nested guest in the comment, so later
> when people want to add nested support they will know some
> additional work required here?
>
will do.

> >
> > > > */
> > > > - if (ioasid_find(NULL, ioasid, NULL)) {
> > > > - pr_alert("Cannot free active IOASID %d\n",
> > > > ioasid);
> > > > + if (IS_ERR(ioasid_find(system_ioasid_sid, ioasid,
> > > > NULL))) {
> > > > + pr_err("Cannot free IOASID %d, not in system
> > > > set\n", ioasid); return;
> > > > }
> > > > vcmd_free_pasid(iommu, ioasid);
> > > > @@ -5541,7 +5541,7 @@ static int aux_domain_add_dev(struct
> > > > dmar_domain *domain,
> > > > int pasid;
> > > >
> > > > /* No private data needed for the default
> > > > pasid */
> > > > - pasid = ioasid_alloc(NULL, PASID_MIN,
> > > > + pasid = ioasid_alloc(system_ioasid_sid,
> > > > PASID_MIN, pci_max_pasids(to_pci_dev(dev))
> > > > - 1, NULL);
> > > > if (pasid == INVALID_IOASID) {
> > > > diff --git a/drivers/iommu/intel-svm.c
> > > > b/drivers/iommu/intel-svm.c index 1991587fd3fd..f511855d187b
> > > > 100644 --- a/drivers/iommu/intel-svm.c
> > > > +++ b/drivers/iommu/intel-svm.c
> > > > @@ -268,7 +268,7 @@ int intel_svm_bind_gpasid(struct
> > > > iommu_domain *domain,
> > > > }
> > > >
> > > > mutex_lock(&pasid_mutex);
> > > > - svm = ioasid_find(NULL, data->hpasid, NULL);
> > > > + svm = ioasid_find(INVALID_IOASID_SET, data->hpasid,
> > > > NULL); if (IS_ERR(svm)) {
> > > > ret = PTR_ERR(svm);
> > > > goto out;
> > > > @@ -401,7 +401,7 @@ int intel_svm_unbind_gpasid(struct device
> > > > *dev, int pasid)
> > > > return -EINVAL;
> > > >
> > > > mutex_lock(&pasid_mutex);
> > > > - svm = ioasid_find(NULL, pasid, NULL);
> > > > + svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> > > > if (!svm) {
> > > > ret = -EINVAL;
> > > > goto out;
> > > > @@ -559,7 +559,7 @@ static int intel_svm_bind_mm(struct device
> > > > *dev, int flags, struct svm_dev_ops *
> > > > pasid_max = intel_pasid_max_id;
> > > >
> > > > /* Do not use PASID 0, reserved for RID to
> > > > PASID */
> > > > - svm->pasid = ioasid_alloc(NULL, PASID_MIN,
> > > > + svm->pasid = ioasid_alloc(system_ioasid_sid,
> > > > PASID_MIN, pasid_max - 1, svm);
> > > > if (svm->pasid == INVALID_IOASID) {
> > > > kfree(svm);
> > > > @@ -642,7 +642,7 @@ int intel_svm_unbind_mm(struct device *dev,
> > > > int pasid)
> > > > if (!iommu)
> > > > goto out;
> > > >
> > > > - svm = ioasid_find(NULL, pasid, NULL);
> > > > + svm = ioasid_find(system_ioasid_sid, pasid, NULL);
> > > > if (!svm)
> > > > goto out;
> > > >
> > > > @@ -778,7 +778,7 @@ static irqreturn_t prq_event_thread(int irq,
> > > > void *d)
> > > >
> > > > if (!svm || svm->pasid != req->pasid) {
> > > > rcu_read_lock();
> > > > - svm = ioasid_find(NULL, req->pasid,
> > > > NULL);
> > > > + svm = ioasid_find(INVALID_IOASID_SET,
> > > > req->pasid, NULL);
> > >
> > > is there a criteria when INVALID_IOASID_SET should be used?
> > >
> > Two use cases for INVALID_IOASID_SET:
> > 1. a hint to ioasid_find to do global search, ignore set ownership
> > check 2. cannot find a set ID for a given ioasid_find_sid()
> >
> > You brought up a good point, I missed the second use case.
> >
> >
> > > > /* It *can't* go away, because the
> > > > driver is not permitted
> > > > * to unbind the mm while any page
> > > > faults are outstanding.
> > > > * So we only need RCU to protect the
> > > > internal idr code. */
> > > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> > > > index 9135af171a7c..f89a595f6978 100644
> > > > --- a/drivers/iommu/ioasid.c
> > > > +++ b/drivers/iommu/ioasid.c
> > > > @@ -31,7 +31,7 @@ struct ioasid_set_data {
> > > >
> > > > struct ioasid_data {
> > > > ioasid_t id;
> > > > - struct ioasid_set *set;
> > > > + struct ioasid_set_data *sdata;
> > > > void *private;
> > > > struct rcu_head rcu;
> > > > };
> > > > @@ -334,7 +334,7 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> > > >
> > > > /**
> > > > * ioasid_alloc - Allocate an IOASID
> > > > - * @set: the IOASID set
> > > > + * @sid: the IOASID set ID
> > > > * @min: the minimum ID (inclusive)
> > > > * @max: the maximum ID (inclusive)
> > > > * @private: data private to the caller
> > > > @@ -344,18 +344,30 @@ EXPORT_SYMBOL_GPL(ioasid_attach_data);
> > > > *
> > > > * Return: the allocated ID on success, or %INVALID_IOASID on
> > > > failure. */
> > > > -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> > > > ioasid_t max,
> > > > - void *private)
> > > > +ioasid_t ioasid_alloc(int sid, ioasid_t min, ioasid_t max, void
> > > > *private) {
> > > > + struct ioasid_set_data *sdata;
> > > > struct ioasid_data *data;
> > > > void *adata;
> > > > ioasid_t id;
> > > >
> > > > - data = kzalloc(sizeof(*data), GFP_ATOMIC);
> > > > + /* Check if the IOASID set has been allocated and
> > > > initialized */
> > > > + sdata = xa_load(&ioasid_sets, sid);
> > >
> > > ok, this change answers my previous question in last patch. ????
> > >
> > I guess you meant the NULL set question?
>
> yes
>
> >
> > > > + if (!sdata) {
> > > > + pr_err("Invalid IOASID set %d to allocate
> > > > from\n", sid);
> > > > + return INVALID_IOASID;
> > > > + }
> > > > +
> > > > + if (sdata->size <= sdata->nr_ioasids) {
> > > > + pr_err("IOASID set %d out of quota\n", sid);
> > > > + return INVALID_IOASID;
> > > > + }
> > > > +
> > > > + data = kzalloc(sizeof(*data), GFP_KERNEL);
> > > > if (!data)
> > > > return INVALID_IOASID;
> > > >
> > > > - data->set = set;
> > > > + data->sdata = sdata;
> > > > data->private = private;
> > > >
> > > > /*
> > > > @@ -379,6 +391,9 @@ ioasid_t ioasid_alloc(struct ioasid_set
> > > > *set, ioasid_t min, ioasid_t max,
> > > > }
> > > > data->id = id;
> > > >
> > > > + /* Store IOASID in the per set data */
> > > > + xa_store(&sdata->xa, id, data, GFP_KERNEL);
> > > > + sdata->nr_ioasids++;
> > > > spin_unlock(&ioasid_allocator_lock);
> > > > return id;
> > > > exit_free:
> > > > @@ -388,19 +403,15 @@ ioasid_t ioasid_alloc(struct ioasid_set
> > > > *set, ioasid_t min, ioasid_t max,
> > > > }
> > > > EXPORT_SYMBOL_GPL(ioasid_alloc);
> > > >
> > > > -/**
> > > > - * ioasid_free - Free an IOASID
> > > > - * @ioasid: the ID to remove
> > > > - */
> > > > -void ioasid_free(ioasid_t ioasid)
> > > > +static void ioasid_free_locked(ioasid_t ioasid)
> > > > {
> > > > struct ioasid_data *ioasid_data;
> > > > + struct ioasid_set_data *sdata;
> > > >
> > > > - spin_lock(&ioasid_allocator_lock);
> > > > ioasid_data = xa_load(&active_allocator->xa, ioasid);
> > > > if (!ioasid_data) {
> > > > pr_err("Trying to free unknown IOASID %u\n",
> > > > ioasid);
> > > > - goto exit_unlock;
> > > > + return;
> > > > }
> > > >
> > > > active_allocator->ops->free(ioasid,
> > > > active_allocator->ops->pdata); @@ -410,7 +421,27 @@ void
> > > > ioasid_free(ioasid_t ioasid) kfree_rcu(ioasid_data, rcu);
> > > > }
> > > >
> > > > -exit_unlock:
> > > > + sdata = xa_load(&ioasid_sets, ioasid_data->sdata->sid);
> > > > + if (!sdata) {
> > > > + pr_err("No set %d for IOASID %d\n",
> > > > ioasid_data->sdata->sid,
> > > > + ioasid);
> > > > + return;
> > > > + }
> > > > + xa_erase(&sdata->xa, ioasid);
> > > > + sdata->nr_ioasids--;
> > > > +}
> > > > +
> > > > +/**
> > > > + * ioasid_free - Free an IOASID and notify users who
> > > > registered a notifier
> > > > + * on the IOASID set.
> > > > + * IOASID can be re-allocated upon return
> > > > + *
> > > > + * @ioasid: the ID to remove
> > > > + */
> > > > +void ioasid_free(ioasid_t ioasid)
> > > > +{
> > > > + spin_lock(&ioasid_allocator_lock);
> > > > + ioasid_free_locked(ioasid);
> > > > spin_unlock(&ioasid_allocator_lock);
> > > > }
> > > > EXPORT_SYMBOL_GPL(ioasid_free);
> > > > @@ -499,8 +530,12 @@ void ioasid_free_set(int sid, bool
> > > > destroy_set) goto done_destroy;
> > > > }
> > > >
> > > > - /* Just a place holder for now */
> > > > xa_for_each(&sdata->xa, index, entry) {
> > > > + /*
> > > > + * Free from system-wide IOASID pool, all
> > > > subscribers gets
> > > > + * notified and do cleanup.
> > > > + */
> > >
> > > this comment might be added too early...
> > Yes, I should move it to notifier patch.
> >
> > >
> > > > + ioasid_free_locked(index);
> > > > /* Free from per sub-set pool */
> > > > xa_erase(&sdata->xa, index);
> > > > }
> > > > @@ -508,7 +543,6 @@ void ioasid_free_set(int sid, bool
> > > > destroy_set) done_destroy:
> > > > if (destroy_set) {
> > > > xa_erase(&ioasid_sets, sid);
> > > > -
> > > > /* Return the quota back to system pool */
> > > > ioasid_capacity_avail += sdata->size;
> > > > kfree_rcu(sdata, rcu);
> > > > @@ -522,7 +556,7 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> > > >
> > > > /**
> > > > * ioasid_find - Find IOASID data
> > > > - * @set: the IOASID set
> > > > + * @sid: the IOASID set ID
> > > > * @ioasid: the IOASID to find
> > > > * @getter: function to call on the found object
> > > > *
> > > > @@ -532,10 +566,12 @@ EXPORT_SYMBOL_GPL(ioasid_free_set);
> > > > *
> > > > * If the IOASID exists, return the private pointer passed to
> > > > ioasid_alloc.
> > > > * Private data can be NULL if not set. Return an error if the
> > > > IOASID is not
> > > > - * found, or if @set is not NULL and the IOASID does not
> > > > belong to the set.
> > > > + * found.
> > > > + *
> > > > + * If sid is INVALID_IOASID_SET, it will skip set ownership
> > > > checking. Otherwise,
> > > > + * error is returned even if the IOASID is found but does not
> > > > belong the set. */
> > > > -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> > > > - bool (*getter)(void *))
> > > > +void *ioasid_find(int sid, ioasid_t ioasid, bool
> > > > (*getter)(void *)) {
> > > > void *priv;
> > > > struct ioasid_data *ioasid_data;
> > > > @@ -548,7 +584,7 @@ void *ioasid_find(struct ioasid_set *set,
> > > > ioasid_t ioasid,
> > > > priv = ERR_PTR(-ENOENT);
> > > > goto unlock;
> > > > }
> > > > - if (set && ioasid_data->set != set) {
> > > > + if (sid != INVALID_IOASID_SET &&
> > > > ioasid_data->sdata->sid != sid) { /* data found but does not
> > > > belong to the set */ priv = ERR_PTR(-EACCES);
> > > > goto unlock;
> > > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> > > > index 097b1cc043a3..e19c0ad93bd7 100644
> > > > --- a/include/linux/ioasid.h
> > > > +++ b/include/linux/ioasid.h
> > > > @@ -6,6 +6,7 @@
> > > > #include <linux/errno.h>
> > > >
> > > > #define INVALID_IOASID ((ioasid_t)-1)
> > > > +#define INVALID_IOASID_SET (-1)
> > > > typedef unsigned int ioasid_t;
> > > > typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t
> > > > max, void *data); typedef void (*ioasid_free_fn_t)(ioasid_t
> > > > ioasid, void *data); @@ -35,11 +36,10 @@ extern int
> > > > system_ioasid_sid; #define DECLARE_IOASID_SET(name) struct
> > > > ioasid_set name = { 0 }
> > > >
> > > > #if IS_ENABLED(CONFIG_IOASID)
> > > > -ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
> > > > ioasid_t max, +ioasid_t ioasid_alloc(int sid, ioasid_t min,
> > > > ioasid_t max, void *private);
> > > > void ioasid_free(ioasid_t ioasid);
> > > > -void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> > > > - bool (*getter)(void *));
> > > > +void *ioasid_find(int sid, ioasid_t ioasid, bool (*getter)(void
> > > > *)); int ioasid_register_allocator(struct ioasid_allocator_ops
> > > > *allocator); void ioasid_unregister_allocator(struct
> > > > ioasid_allocator_ops *allocator); int
> > > > ioasid_attach_data(ioasid_t ioasid, void *data); @@ -49,7 +49,7
> > > > @@ int ioasid_alloc_set(struct ioasid_set *token, ioasid_t
> > > > quota, int *sid); void ioasid_free_set(int sid, bool
> > > > destroy_set); int ioasid_find_sid(ioasid_t ioasid);
> > > > #else /* !CONFIG_IOASID */
> > > > -static inline ioasid_t ioasid_alloc(struct ioasid_set *set,
> > > > ioasid_t min, +static inline ioasid_t ioasid_alloc(int sid,
> > > > ioasid_t min, ioasid_t max, void *private)
> > > > {
> > > > return INVALID_IOASID;
> > > > @@ -68,8 +68,7 @@ static inline void ioasid_free_set(int sid,
> > > > bool destroy_set)
> > > > {
> > > > }
> > > >
> > > > -static inline void *ioasid_find(struct ioasid_set *set,
> > > > ioasid_t ioasid,
> > > > - bool (*getter)(void *))
> > > > +static inline void *ioasid_find(int sid, ioasid_t ioasid, bool
> > > > (*getter)(void *)) {
> > > > return NULL;
> > > > }
> > > > --
> > > > 2.7.4
> > >
> >
> > [Jacob Pan]

[Jacob Pan]