diff mbox series

[v3,1/6] dmaengine: idxd: Add enable/disable device IOPF feature

Message ID 20230324120234.313643-2-baolu.lu@linux.intel.com
State New
Headers
Series iommu/vt-d: Refactor code for non-PRI IOPF |

Commit Message

Baolu Lu March 24, 2023, 12:02 p.m. UTC 
  The iommu subsystem requires IOMMU_DEV_FEAT_IOPF must be enabled before
and disabled after IOMMU_DEV_FEAT_SVA, if device's I/O page faults rely
on the IOMMU. Add explicit IOMMU_DEV_FEAT_IOPF enabling/disabling in this
driver.

At present, missing IOPF enabling/disabling doesn't cause any real issue,
because the IOMMU driver places the IOPF enabling/disabling in the path
of SVA feature handling. But this may change.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/dma/idxd/init.c | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

Comments

Baolu Lu April 3, 2023, 5:49 a.m. UTC | #1 
On 3/24/23 8:02 PM, Lu Baolu wrote:
> The iommu subsystem requires IOMMU_DEV_FEAT_IOPF must be enabled before
> and disabled after IOMMU_DEV_FEAT_SVA, if device's I/O page faults rely
> on the IOMMU. Add explicit IOMMU_DEV_FEAT_IOPF enabling/disabling in this
> driver.
> 
> At present, missing IOPF enabling/disabling doesn't cause any real issue,
> because the IOMMU driver places the IOPF enabling/disabling in the path
> of SVA feature handling. But this may change.
> 
> Reviewed-by: Dave Jiang<dave.jiang@intel.com>
> Reviewed-by: Fenghua Yu<fenghua.yu@intel.com>
> Reviewed-by: Kevin Tian<kevin.tian@intel.com>
> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>

Hi Dave and Fenghua,

The following iommu patches depends on this one. Can I route it to
Linus through the iommu tree?

Best regards,
baolu
Dave Jiang April 3, 2023, 4:57 p.m. UTC | #2 
On 4/2/23 10:49 PM, Baolu Lu wrote:
> On 3/24/23 8:02 PM, Lu Baolu wrote:
>> The iommu subsystem requires IOMMU_DEV_FEAT_IOPF must be enabled before
>> and disabled after IOMMU_DEV_FEAT_SVA, if device's I/O page faults rely
>> on the IOMMU. Add explicit IOMMU_DEV_FEAT_IOPF enabling/disabling in this
>> driver.
>>
>> At present, missing IOPF enabling/disabling doesn't cause any real issue,
>> because the IOMMU driver places the IOPF enabling/disabling in the path
>> of SVA feature handling. But this may change.
>>
>> Reviewed-by: Dave Jiang<dave.jiang@intel.com>
>> Reviewed-by: Fenghua Yu<fenghua.yu@intel.com>
>> Reviewed-by: Kevin Tian<kevin.tian@intel.com>
>> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>
> 
> Hi Dave and Fenghua,
> 
> The following iommu patches depends on this one. Can I route it to
> Linus through the iommu tree?

Hi Baolu, you'll need an ack from Vinod, who is the dmaengine subsystem 
maintainer. I have no objections.


> 
> Best regards,
> baolu
Baolu Lu April 4, 2023, 5:19 a.m. UTC | #3 
On 4/4/23 12:57 AM, Dave Jiang wrote:
> On 4/2/23 10:49 PM, Baolu Lu wrote:
>> On 3/24/23 8:02 PM, Lu Baolu wrote:
>>> The iommu subsystem requires IOMMU_DEV_FEAT_IOPF must be enabled before
>>> and disabled after IOMMU_DEV_FEAT_SVA, if device's I/O page faults rely
>>> on the IOMMU. Add explicit IOMMU_DEV_FEAT_IOPF enabling/disabling in 
>>> this
>>> driver.
>>>
>>> At present, missing IOPF enabling/disabling doesn't cause any real 
>>> issue,
>>> because the IOMMU driver places the IOPF enabling/disabling in the path
>>> of SVA feature handling. But this may change.
>>>
>>> Reviewed-by: Dave Jiang<dave.jiang@intel.com>
>>> Reviewed-by: Fenghua Yu<fenghua.yu@intel.com>
>>> Reviewed-by: Kevin Tian<kevin.tian@intel.com>
>>> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>
>>
>> Hi Dave and Fenghua,
>>
>> The following iommu patches depends on this one. Can I route it to
>> Linus through the iommu tree?
> 
> Hi Baolu, you'll need an ack from Vinod, who is the dmaengine subsystem 
> maintainer. I have no objections.

Hi Vinod,

Does this work work for you?

Best regards,
baolu
diff mbox series

Patch

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 640d3048368e..09ef62aa0635 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -516,6 +516,27 @@  static void idxd_disable_system_pasid(struct idxd_device *idxd)
 	idxd->sva = NULL;
 }
 
+static int idxd_enable_sva(struct pci_dev *pdev)
+{
+	int ret;
+
+	ret = iommu_dev_enable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
+	if (ret)
+		return ret;
+
+	ret = iommu_dev_enable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+	if (ret)
+		iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
+
+	return ret;
+}
+
+static void idxd_disable_sva(struct pci_dev *pdev)
+{
+	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
+}
+
 static int idxd_probe(struct idxd_device *idxd)
 {
 	struct pci_dev *pdev = idxd->pdev;
@@ -530,7 +551,7 @@  static int idxd_probe(struct idxd_device *idxd)
 	dev_dbg(dev, "IDXD reset complete\n");
 
 	if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
-		if (iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA)) {
+		if (idxd_enable_sva(pdev)) {
 			dev_warn(dev, "Unable to turn on user SVA feature.\n");
 		} else {
 			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
@@ -578,21 +599,19 @@  static int idxd_probe(struct idxd_device *idxd)
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
 	if (device_user_pasid_enabled(idxd))
-		iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+		idxd_disable_sva(pdev);
 	return rc;
 }
 
 static void idxd_cleanup(struct idxd_device *idxd)
 {
-	struct device *dev = &idxd->pdev->dev;
-
 	perfmon_pmu_remove(idxd);
 	idxd_cleanup_interrupts(idxd);
 	idxd_cleanup_internals(idxd);
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
 	if (device_user_pasid_enabled(idxd))
-		iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+		idxd_disable_sva(idxd->pdev);
 }
 
 static int idxd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
@@ -710,7 +729,7 @@  static void idxd_remove(struct pci_dev *pdev)
 	pci_free_irq_vectors(pdev);
 	pci_iounmap(pdev, idxd->reg_base);
 	if (device_user_pasid_enabled(idxd))
-		iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+		idxd_disable_sva(pdev);
 	pci_disable_device(pdev);
 	destroy_workqueue(idxd->wq);
 	perfmon_pmu_remove(idxd);