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authorRobin Murphy <robin.murphy@arm.com>2025-08-14 17:47:16 +0100
committerJoerg Roedel <joerg.roedel@amd.com>2025-08-22 08:43:23 +0200
commit72b6f7cd89cea8251979b65528d302f9c0ed37bf (patch)
tree54386f086e2a4d61ad495443b6ab1376f16282d5
parentiommu/arm-smmu-v3: Fix smmu_domain->nr_ats_masters decrement (diff)
downloadwireguard-linux-72b6f7cd89cea8251979b65528d302f9c0ed37bf.tar.xz
wireguard-linux-72b6f7cd89cea8251979b65528d302f9c0ed37bf.zip
iommu/virtio: Make instance lookup robust
Much like arm-smmu in commit 7d835134d4e1 ("iommu/arm-smmu: Make instance lookup robust"), virtio-iommu appears to have the same issue where iommu_device_register() makes the IOMMU instance visible to other API callers (including itself) straight away, but internally the instance isn't ready to recognise itself for viommu_probe_device() to work correctly until after viommu_probe() has returned. This matters a lot more now that bus_iommu_probe() has the DT/VIOT knowledge to probe client devices the way that was always intended. Tweak the lookup and initialisation in much the same way as for arm-smmu, to ensure that what we register is functional and ready to go. Cc: stable@vger.kernel.org Fixes: bcb81ac6ae3c ("iommu: Get DT/ACPI parsing into the proper probe path") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/308911aaa1f5be32a3a709996c7bd6cf71d30f33.1755190036.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
-rw-r--r--drivers/iommu/virtio-iommu.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 532db1de201b..b39d6f134ab2 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -998,8 +998,7 @@ static void viommu_get_resv_regions(struct device *dev, struct list_head *head)
iommu_dma_get_resv_regions(dev, head);
}
-static const struct iommu_ops viommu_ops;
-static struct virtio_driver virtio_iommu_drv;
+static const struct bus_type *virtio_bus_type;
static int viommu_match_node(struct device *dev, const void *data)
{
@@ -1008,8 +1007,9 @@ static int viommu_match_node(struct device *dev, const void *data)
static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode)
{
- struct device *dev = driver_find_device(&virtio_iommu_drv.driver, NULL,
- fwnode, viommu_match_node);
+ struct device *dev = bus_find_device(virtio_bus_type, NULL, fwnode,
+ viommu_match_node);
+
put_device(dev);
return dev ? dev_to_virtio(dev)->priv : NULL;
@@ -1160,6 +1160,9 @@ static int viommu_probe(struct virtio_device *vdev)
if (!viommu)
return -ENOMEM;
+ /* Borrow this for easy lookups later */
+ virtio_bus_type = dev->bus;
+
spin_lock_init(&viommu->request_lock);
ida_init(&viommu->domain_ids);
viommu->dev = dev;
@@ -1229,10 +1232,10 @@ static int viommu_probe(struct virtio_device *vdev)
if (ret)
goto err_free_vqs;
- iommu_device_register(&viommu->iommu, &viommu_ops, parent_dev);
-
vdev->priv = viommu;
+ iommu_device_register(&viommu->iommu, &viommu_ops, parent_dev);
+
dev_info(dev, "input address: %u bits\n",
order_base_2(viommu->geometry.aperture_end));
dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap);