[PATCH v5 7/8] iommufd: Remove unnecessary IOMMU_DEV_FEAT_IOPF

Lu Baolu
2025-04-18T08:01:26Z

The iopf enablement has been moved to the iommu drivers. It is unnecessary
for iommufd to handle iopf enablement. Remove the iopf enablement logic to
avoid duplication.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
drivers/iommu/iommufd/device.c | 59 ++++++++++++-------------
drivers/iommu/iommufd/eventq.c | 48 +-------------------
drivers/iommu/iommufd/iommufd_private.h | 6 ---
3 files changed, 30 insertions(+), 83 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 2111bad72c72..86244403b532 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -221,7 +221,6 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
refcount_inc(&idev->obj.users);
/* igroup refcount moves into iommufd_device */
idev->igroup = igroup;
- mutex_init(&idev->iopf_lock);

/*
* If the caller fails after this success it must call
@@ -425,6 +424,25 @@ static int iommufd_hwpt_pasid_compat(struct iommufd_hw_pagetable *hwpt,
return 0;
}

+static bool iommufd_hwpt_compatible_device(struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_device *idev)
+{
+ struct pci_dev *pdev;
+
+ if (!hwpt->fault || !dev_is_pci(idev->dev))
+ return true;
+
+ /*
+ * Once we turn on PCI/PRI support for VF, the response failure code
+ * should not be forwarded to the hardware due to PRI being a shared
+ * resource between PF and VFs. There is no coordination for this
+ * shared capability. This waits for a vPRI reset to recover.
+ */
+ pdev = to_pci_dev(idev->dev);
+
+ return (!pdev->is_virtfn || !pci_pri_supported(pdev));
+}
+
static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
struct iommufd_device *idev,
ioasid_t pasid)
@@ -432,6 +450,9 @@ static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
struct iommufd_attach_handle *handle;
int rc;

+ if (!iommufd_hwpt_compatible_device(hwpt, idev))
+ return -EINVAL;
+
rc = iommufd_hwpt_pasid_compat(hwpt, idev, pasid);
if (rc)
return rc;
@@ -440,12 +461,6 @@ static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
if (!handle)
return -ENOMEM;

- if (hwpt->fault) {
- rc = iommufd_fault_iopf_enable(idev);
- if (rc)
- goto out_free_handle;
- }
-
handle->idev = idev;
if (pasid == IOMMU_NO_PASID)
rc = iommu_attach_group_handle(hwpt->domain, idev->igroup->group,
@@ -454,13 +469,10 @@ static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
rc = iommu_attach_device_pasid(hwpt->domain, idev->dev, pasid,
&handle->handle);
if (rc)
- goto out_disable_iopf;
+ goto out_free_handle;

return 0;

-out_disable_iopf:
- if (hwpt->fault)
- iommufd_fault_iopf_disable(idev);
out_free_handle:
kfree(handle);
return rc;
@@ -492,10 +504,7 @@ static void iommufd_hwpt_detach_device(struct iommufd_hw_pagetable *hwpt,
else
iommu_detach_device_pasid(hwpt->domain, idev->dev, pasid);

- if (hwpt->fault) {
- iommufd_auto_response_faults(hwpt, handle);
- iommufd_fault_iopf_disable(idev);
- }
+ iommufd_auto_response_faults(hwpt, handle);
kfree(handle);
}

@@ -507,6 +516,9 @@ static int iommufd_hwpt_replace_device(struct iommufd_device *idev,
struct iommufd_attach_handle *handle, *old_handle;
int rc;

+ if (!iommufd_hwpt_compatible_device(hwpt, idev))
+ return -EINVAL;
+
rc = iommufd_hwpt_pasid_compat(hwpt, idev, pasid);
if (rc)
return rc;
@@ -517,12 +529,6 @@ static int iommufd_hwpt_replace_device(struct iommufd_device *idev,
if (!handle)
return -ENOMEM;

- if (hwpt->fault && !old->fault) {
- rc = iommufd_fault_iopf_enable(idev);
- if (rc)
- goto out_free_handle;
- }
-
handle->idev = idev;
if (pasid == IOMMU_NO_PASID)
rc = iommu_replace_group_handle(idev->igroup->group,
@@ -531,20 +537,13 @@ static int iommufd_hwpt_replace_device(struct iommufd_device *idev,
rc = iommu_replace_device_pasid(hwpt->domain, idev->dev,
pasid, &handle->handle);
if (rc)
- goto out_disable_iopf;
+ goto out_free_handle;

- if (old->fault) {
- iommufd_auto_response_faults(hwpt, old_handle);
- if (!hwpt->fault)
- iommufd_fault_iopf_disable(idev);
- }
+ iommufd_auto_response_faults(hwpt, old_handle);
kfree(old_handle);

return 0;

-out_disable_iopf:
- if (hwpt->fault && !old->fault)
- iommufd_fault_iopf_disable(idev);
out_free_handle:
kfree(handle);
return rc;
diff --git a/drivers/iommu/iommufd/eventq.c b/drivers/iommu/iommufd/eventq.c
index f39cf0797347..e373b9eec7f5 100644
--- a/drivers/iommu/iommufd/eventq.c
+++ b/drivers/iommu/iommufd/eventq.c
@@ -9,8 +9,6 @@
#include <linux/iommufd.h>
#include <linux/module.h>
#include <linux/mutex.h>
-#include <linux/pci.h>
-#include <linux/pci-ats.h>
#include <linux/poll.h>
#include <uapi/linux/iommufd.h>

@@ -18,50 +16,6 @@
#include "iommufd_private.h"

/* IOMMUFD_OBJ_FAULT Functions */
-
-int iommufd_fault_iopf_enable(struct iommufd_device *idev)
-{
- struct device *dev = idev->dev;
- int ret;
-
- /*
- * Once we turn on PCI/PRI support for VF, the response failure code
- * should not be forwarded to the hardware due to PRI being a shared
- * resource between PF and VFs. There is no coordination for this
- * shared capability. This waits for a vPRI reset to recover.
- */
- if (dev_is_pci(dev)) {
- struct pci_dev *pdev = to_pci_dev(dev);
-
- if (pdev->is_virtfn && pci_pri_supported(pdev))
- return -EINVAL;
- }
-
- mutex_lock(&idev->iopf_lock);
- /* Device iopf has already been on. */
- if (++idev->iopf_enabled > 1) {
- mutex_unlock(&idev->iopf_lock);
- return 0;
- }
-
- ret = iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_IOPF);
- if (ret)
- --idev->iopf_enabled;
- mutex_unlock(&idev->iopf_lock);
-
- return ret;
-}
-
-void iommufd_fault_iopf_disable(struct iommufd_device *idev)
-{
- mutex_lock(&idev->iopf_lock);
- if (!WARN_ON(idev->iopf_enabled == 0)) {
- if (--idev->iopf_enabled == 0)
- iommu_dev_disable_feature(idev->dev, IOMMU_DEV_FEAT_IOPF);
- }
- mutex_unlock(&idev->iopf_lock);
-}
-
void iommufd_auto_response_faults(struct iommufd_hw_pagetable *hwpt,
struct iommufd_attach_handle *handle)
{
@@ -70,7 +24,7 @@ void iommufd_auto_response_faults(struct iommufd_hw_pagetable *hwpt,
struct list_head free_list;
unsigned long index;

- if (!fault)
+ if (!fault || !handle)
return;
INIT_LIST_HEAD(&free_list);

diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 80e8c76d25f2..9ccc83341f32 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -425,9 +425,6 @@ struct iommufd_device {
/* always the physical device */
struct device *dev;
bool enforce_cache_coherency;
- /* protect iopf_enabled counter */
- struct mutex iopf_lock;
- unsigned int iopf_enabled;
};

static inline struct iommufd_device *
@@ -506,9 +503,6 @@ iommufd_get_fault(struct iommufd_ucmd *ucmd, u32 id)
int iommufd_fault_alloc(struct iommufd_ucmd *ucmd);
void iommufd_fault_destroy(struct iommufd_object *obj);
int iommufd_fault_iopf_handler(struct iopf_group *group);
-
-int iommufd_fault_iopf_enable(struct iommufd_device *idev);
-void iommufd_fault_iopf_disable(struct iommufd_device *idev);
void iommufd_auto_response_faults(struct iommufd_hw_pagetable *hwpt,
struct iommufd_attach_handle *handle);

--
2.43.0