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From: Jason Gunthorpe <jgg@nvidia.com>
To: iommu@lists.linux.dev, linux-kselftest@vger.kernel.org
Cc: Lu Baolu <baolu.lu@linux.intel.com>,
	Kevin Tian <kevin.tian@intel.com>,
	kvm@vger.kernel.org, Lixiao Yang <lixiao.yang@intel.com>,
	Matthew Rosato <mjrosato@linux.ibm.com>,
	Nicolin Chen <nicolinc@nvidia.com>, Yi Liu <yi.l.liu@intel.com>
Subject: [PATCH v6 09/19] iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc()
Date: Thu, 20 Apr 2023 15:51:24 -0300	[thread overview]
Message-ID: <9-v6-fdb604df649a+369-iommufd_alloc_jgg@nvidia.com> (raw)
In-Reply-To: <0-v6-fdb604df649a+369-iommufd_alloc_jgg@nvidia.com>

Logically the HWPT should have the coherency set properly for the device
that it is being created for when it is created.

This was happening implicitly if the immediate_attach was set because
iommufd_hw_pagetable_attach() does it as the first thing.

Do it unconditionally so !immediate_attach works properly.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/iommufd/device.c          | 19 ++++-------------
 drivers/iommu/iommufd/hw_pagetable.c    | 27 +++++++++++++++++++++++++
 drivers/iommu/iommufd/iommufd_private.h |  1 +
 3 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index ca9776432c56e8..782b4fd76f31eb 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -295,22 +295,11 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 		goto err_unlock;
 	}
 
-	/*
-	 * Try to upgrade the domain we have, it is an iommu driver bug to
-	 * report IOMMU_CAP_ENFORCE_CACHE_COHERENCY but fail
-	 * enforce_cache_coherency when there are no devices attached to the
-	 * domain.
-	 */
-	if (idev->enforce_cache_coherency && !hwpt->enforce_cache_coherency) {
-		if (hwpt->domain->ops->enforce_cache_coherency)
-			hwpt->enforce_cache_coherency =
-				hwpt->domain->ops->enforce_cache_coherency(
-					hwpt->domain);
-		if (!hwpt->enforce_cache_coherency) {
-			WARN_ON(list_empty(&idev->igroup->device_list));
-			rc = -EINVAL;
+	/* Try to upgrade the domain we have */
+	if (idev->enforce_cache_coherency) {
+		rc = iommufd_hw_pagetable_enforce_cc(hwpt);
+		if (rc)
 			goto err_unlock;
-		}
 	}
 
 	rc = iopt_table_enforce_dev_resv_regions(&hwpt->ioas->iopt, idev->dev,
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index bdb76cdb1dc347..e0699d7f4c64af 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -25,6 +25,20 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)
 	refcount_dec(&hwpt->ioas->obj.users);
 }
 
+int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt)
+{
+	if (hwpt->enforce_cache_coherency)
+		return 0;
+
+	if (hwpt->domain->ops->enforce_cache_coherency)
+		hwpt->enforce_cache_coherency =
+			hwpt->domain->ops->enforce_cache_coherency(
+				hwpt->domain);
+	if (!hwpt->enforce_cache_coherency)
+		return -EINVAL;
+	return 0;
+}
+
 /**
  * iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device
  * @ictx: iommufd context
@@ -60,6 +74,19 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 		goto out_abort;
 	}
 
+	/*
+	 * Set the coherency mode before we do iopt_table_add_domain() as some
+	 * iommus have a per-PTE bit that controls it and need to decide before
+	 * doing any maps. It is an iommu driver bug to report
+	 * IOMMU_CAP_ENFORCE_CACHE_COHERENCY but fail enforce_cache_coherency on
+	 * a new domain.
+	 */
+	if (idev->enforce_cache_coherency) {
+		rc = iommufd_hw_pagetable_enforce_cc(hwpt);
+		if (WARN_ON(rc))
+			goto out_abort;
+	}
+
 	/*
 	 * immediate_attach exists only to accommodate iommu drivers that cannot
 	 * directly allocate a domain. These drivers do not finish creating the
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 8bf053f4d4a9ce..471a3fdff1e0b6 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -254,6 +254,7 @@ struct iommufd_hw_pagetable {
 struct iommufd_hw_pagetable *
 iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 			   struct iommufd_device *idev, bool immediate_attach);
+int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt);
 int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 				struct iommufd_device *idev);
 struct iommufd_hw_pagetable *
-- 
2.40.0


  parent reply	other threads:[~2023-04-20 18:52 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-20 18:51 [PATCH v6 00/19] Add iommufd physical device operations for replace and alloc hwpt Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 01/19] iommufd: Move isolated msi enforcement to iommufd_device_bind() Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 02/19] iommufd: Add iommufd_group Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 03/19] iommufd: Replace the hwpt->devices list with iommufd_group Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 04/19] iommu: Export iommu_get_resv_regions() Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 05/19] iommufd: Keep track of each device's reserved regions instead of groups Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 06/19] iommufd: Use the iommufd_group to avoid duplicate MSI setup Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 07/19] iommufd: Make sw_msi_start a group global Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 08/19] iommufd: Move putting a hwpt to a helper function Jason Gunthorpe
2023-04-20 18:51 ` Jason Gunthorpe [this message]
2023-04-20 18:51 ` [PATCH v6 10/19] iommufd: Allow a hwpt to be aborted after allocation Jason Gunthorpe
2023-04-21  7:29   ` Tian, Kevin
2023-04-20 18:51 ` [PATCH v6 11/19] iommufd: Fix locking around hwpt allocation Jason Gunthorpe
2023-04-21  7:30   ` Tian, Kevin
2023-04-20 18:51 ` [PATCH v6 12/19] iommufd: Reorganize iommufd_device_attach into iommufd_device_change_pt Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 13/19] iommu: Introduce a new iommu_group_replace_domain() API Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 14/19] iommufd: Add iommufd_device_replace() Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 15/19] iommufd: Make destroy_rwsem use a lock class per object type Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 16/19] iommufd/selftest: Test iommufd_device_replace() Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 17/19] iommufd: Add IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 18/19] iommufd/selftest: Return the real idev id from selftest mock_domain Jason Gunthorpe
2023-04-20 18:51 ` [PATCH v6 19/19] iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-04-21  1:35 ` [PATCH v6 00/19] Add iommufd physical device operations for replace and alloc hwpt Nicolin Chen

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