[PATCH v3 6/6] iommu/virtio: Enable x86 support

[Jean-Philippe Brucker]

With the VIOT support in place, x86 platforms can now use the
virtio-iommu.

Because the other x86 IOMMU drivers aren't yet ready to use the
acpi_dma_setup() path, x86 doesn't implement arch_setup_dma_ops() at the
moment. Similarly to Vt-d and AMD IOMMU, call iommu_setup_dma_ops() from
probe_finalize().

Acked-by: Joerg Roedel <jroedel at suse.de>
Acked-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
---
 drivers/iommu/Kconfig        | 3 ++-
 drivers/iommu/dma-iommu.c    | 1 +
 drivers/iommu/virtio-iommu.c | 8 ++++++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index aff8a4830dd1..07b7c25cbed8 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -400,8 +400,9 @@ config HYPERV_IOMMU
 config VIRTIO_IOMMU
 	tristate "Virtio IOMMU driver"
 	depends on VIRTIO
-	depends on ARM64
+	depends on (ARM64 || X86)
 	select IOMMU_API
+	select IOMMU_DMA
 	select INTERVAL_TREE
 	select ACPI_VIOT if ACPI
 	help
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 175f8eaeb5b3..46ed43c400cf 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1332,6 +1332,7 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)
 	 pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
 		 dev_name(dev));
 }
+EXPORT_SYMBOL_GPL(iommu_setup_dma_ops);
 
 static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 		phys_addr_t msi_addr, struct iommu_domain *domain)
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 218fe8560e8d..77aee1207ced 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -1026,6 +1026,13 @@ static struct iommu_device *viommu_probe_device(struct device *dev)
 	return ERR_PTR(ret);
 }
 
+static void viommu_probe_finalize(struct device *dev)
+{
+#ifndef CONFIG_ARCH_HAS_SETUP_DMA_OPS
+	iommu_setup_dma_ops(dev, 0, U64_MAX);
+#endif
+}
+
 static void viommu_release_device(struct device *dev)
 {
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
@@ -1062,6 +1069,7 @@ static struct iommu_ops viommu_ops = {
 	.iova_to_phys		= viommu_iova_to_phys,
 	.iotlb_sync		= viommu_iotlb_sync,
 	.probe_device		= viommu_probe_device,
+	.probe_finalize		= viommu_probe_finalize,
 	.release_device		= viommu_release_device,
 	.device_group		= viommu_device_group,
 	.get_resv_regions	= viommu_get_resv_regions,
-- 
2.31.1