[PATCH v12 09/16] iommu: Make iommu_queue_iopf() more generic

Lu Baolu
2024-02-07T01:39:52Z

Make iommu_queue_iopf() more generic by making the iopf_group a minimal
set of iopf's that an iopf handler of domain should handle and respond
to. Add domain parameter to struct iopf_group so that the handler can
retrieve and use it directly.

Change iommu_queue_iopf() to forward groups of iopf's to the domain's
iopf handler. This is also a necessary step to decouple the sva iopf
handling code from this interface.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Longfang Liu <liulongfang@huawei.com>
---
include/linux/iommu.h | 4 +--
drivers/iommu/iommu-sva.h | 6 ++--
drivers/iommu/io-pgfault.c | 68 +++++++++++++++++++++++++++++++-------
drivers/iommu/iommu-sva.c | 3 +-
4 files changed, 61 insertions(+), 20 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index c9d4f175f121..791f183a988e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -130,6 +130,7 @@ struct iopf_group {
struct list_head faults;
struct work_struct work;
struct device *dev;
+ struct iommu_domain *domain;
};

/**
@@ -209,8 +210,7 @@ struct iommu_domain {
unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */
struct iommu_domain_geometry geometry;
struct iommu_dma_cookie *iova_cookie;
- enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
- void *data);
+ int (*iopf_handler)(struct iopf_group *group);
void *fault_data;
union {
struct {
diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
index de7819c796ce..27c8da115b41 100644
--- a/drivers/iommu/iommu-sva.h
+++ b/drivers/iommu/iommu-sva.h
@@ -22,8 +22,7 @@ int iopf_queue_flush_dev(struct device *dev);
struct iopf_queue *iopf_queue_alloc(const char *name);
void iopf_queue_free(struct iopf_queue *queue);
int iopf_queue_discard_partial(struct iopf_queue *queue);
-enum iommu_page_response_code
-iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
+int iommu_sva_handle_iopf(struct iopf_group *group);

#else /* CONFIG_IOMMU_SVA */
static inline int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
@@ -62,8 +61,7 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
return -ENODEV;
}

-static inline enum iommu_page_response_code
-iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
+static inline int iommu_sva_handle_iopf(struct iopf_group *group)
{
return IOMMU_PAGE_RESP_INVALID;
}
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index c7e6bbed5c05..13cd0929e766 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -13,6 +13,9 @@

#include "iommu-sva.h"

+enum iommu_page_response_code
+iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm);
+
static void iopf_free_group(struct iopf_group *group)
{
struct iopf_fault *iopf, *next;
@@ -45,29 +48,48 @@ static void iopf_handler(struct work_struct *work)
{
struct iopf_fault *iopf;
struct iopf_group *group;
- struct iommu_domain *domain;
enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;

group = container_of(work, struct iopf_group, work);
- domain = iommu_get_domain_for_dev_pasid(group->dev,
- group->last_fault.fault.prm.pasid, 0);
- if (!domain || !domain->iopf_handler)
- status = IOMMU_PAGE_RESP_INVALID;
-
list_for_each_entry(iopf, &group->faults, list) {
/*
* For the moment, errors are sticky: don't handle subsequent
* faults in the group if there is an error.
*/
- if (status == IOMMU_PAGE_RESP_SUCCESS)
- status = domain->iopf_handler(&iopf->fault,
- domain->fault_data);
+ if (status != IOMMU_PAGE_RESP_SUCCESS)
+ break;
+
+ status = iommu_sva_handle_mm(&iopf->fault, group->domain->mm);
}

iopf_complete_group(group->dev, &group->last_fault, status);
iopf_free_group(group);
}

+static struct iommu_domain *get_domain_for_iopf(struct device *dev,
+ struct iommu_fault *fault)
+{
+ struct iommu_domain *domain;
+
+ if (fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) {
+ domain = iommu_get_domain_for_dev_pasid(dev, fault->prm.pasid, 0);
+ if (IS_ERR(domain))
+ domain = NULL;
+ } else {
+ domain = iommu_get_domain_for_dev(dev);
+ }
+
+ if (!domain || !domain->iopf_handler) {
+ dev_warn_ratelimited(dev,
+ "iopf (pasid %d) without domain attached or handler installed\n",
+ fault->prm.pasid);
+
+ return NULL;
+ }
+
+ return domain;
+}
+
/**
* iommu_queue_iopf - IO Page Fault handler
* @fault: fault event
@@ -112,6 +134,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
{
int ret;
struct iopf_group *group;
+ struct iommu_domain *domain;
struct iopf_fault *iopf, *next;
struct iommu_fault_param *iopf_param;
struct dev_iommu *param = dev->iommu;
@@ -143,6 +166,12 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
return 0;
}

+ domain = get_domain_for_iopf(dev, fault);
+ if (!domain) {
+ ret = -EINVAL;
+ goto cleanup_partial;
+ }
+
group = kzalloc(sizeof(*group), GFP_KERNEL);
if (!group) {
/*
@@ -157,8 +186,8 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
group->dev = dev;
group->last_fault.fault = *fault;
INIT_LIST_HEAD(&group->faults);
+ group->domain = domain;
list_add(&group->last_fault.list, &group->faults);
- INIT_WORK(&group->work, iopf_handler);

/* See if we have partial faults for this group */
list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
@@ -167,9 +196,13 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
list_move(&iopf->list, &group->faults);
}

- queue_work(iopf_param->queue->wq, &group->work);
- return 0;
+ mutex_unlock(&iopf_param->lock);
+ ret = domain->iopf_handler(group);
+ mutex_lock(&iopf_param->lock);
+ if (ret)
+ iopf_free_group(group);

+ return ret;
cleanup_partial:
list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
if (iopf->fault.prm.grpid == fault->prm.grpid) {
@@ -181,6 +214,17 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
}
EXPORT_SYMBOL_GPL(iommu_queue_iopf);

+int iommu_sva_handle_iopf(struct iopf_group *group)
+{
+ struct iommu_fault_param *fault_param = group->dev->iommu->fault_param;
+
+ INIT_WORK(&group->work, iopf_handler);
+ if (!queue_work(fault_param->queue->wq, &group->work))
+ return -EBUSY;
+
+ return 0;
+}
+
/**
* iopf_queue_flush_dev - Ensure that all queued faults have been processed
* @dev: the endpoint whose faults need to be flushed.
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index c3fc9201d0be..fcae7308fcb7 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -163,11 +163,10 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
* I/O page fault handler for SVA
*/
enum iommu_page_response_code
-iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
+iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm)
{
vm_fault_t ret;
struct vm_area_struct *vma;
- struct mm_struct *mm = data;
unsigned int access_flags = 0;
unsigned int fault_flags = FAULT_FLAG_REMOTE;
struct iommu_fault_page_request *prm = &fault->prm;
--
2.34.1