[PATCH v5 06/17] iommufd: Use the iommufd_group to avoid duplicate MSI setup

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, Nicolin Chen <nicolinc@nvidia.com>,
	Yi Liu <yi.l.liu@intel.com>
Subject: [PATCH v5 06/17] iommufd: Use the iommufd_group to avoid duplicate MSI setup
Date: Tue, 11 Apr 2023 13:43:07 -0300	[thread overview]
Message-ID: <6-v5-6716da355392+c5-iommufd_alloc_jgg@nvidia.com> (raw)
In-Reply-To: <0-v5-6716da355392+c5-iommufd_alloc_jgg@nvidia.com>

This only needs to be done once per group, not once per device. The once
per device was a way to make the device list work. Since we are abandoning
this we can optimize things a bit.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/iommufd/device.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index d2bcea7d9da815..b02f98dc02c284 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -315,10 +315,6 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 	if (rc)
 		return rc;
 
-	rc = iommufd_device_setup_msi(idev, hwpt, sw_msi_start);
-	if (rc)
-		goto err_unresv;
-
 	/*
 	 * Only attach to the group once for the first device that is in the
 	 * group. All the other devices will follow this attachment. The user
@@ -327,6 +323,10 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 	 * attachment.
 	 */
 	if (list_empty(&idev->igroup->device_list)) {
+		rc = iommufd_device_setup_msi(idev, hwpt, sw_msi_start);
+		if (rc)
+			goto err_unresv;
+
 		rc = iommu_attach_group(hwpt->domain, idev->igroup->group);
 		if (rc)
 			goto err_unresv;
-- 
2.40.0

