iommu/dma: Handle MSI mappings separately (8af23fad) · Commits · 戴 / test

MSI pages must always be mapped into a device's *current* domain, which *might* be the default DMA domain, but might instead be a VFIO domain with its own MSI cookie. This subtlety got accidentally lost in the streamlining of __iommu_dma_map(), but rather than reintroduce more complexity and/or special-casing, it turns out neater to just split this path out entirely. Since iommu_dma_get_msi_page() already duplicates much of what __iommu_dma_map() does, it can easily just make the allocation and mapping calls directly as well. That way we can further streamline the helper back to exclusively operating on DMA domains. Fixes: ("iommu/dma: Move domain lookup into __iommu_dma_{map,unmap}") Reported-by:

Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reported-by:

Andre Przywara <andre.przywara@arm.com> Signed-off-by:

Robin Murphy <robin.murphy@arm.com> Tested-by:

Marc Zyngier <maz@kernel.org> Tested-by:

Andre Przywara <andre.przywara@arm.com> Tested-by:

Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by:

Joerg Roedel <jroedel@suse.de>

drivers/iommu/dma-iommu.c

+10 −7

Original line number	Diff line number	Diff line
		@@ -459,13 +459,11 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
		{
		struct iommu_domain *domain = iommu_get_dma_domain(dev);
		struct iommu_dma_cookie *cookie = domain->iova_cookie;
		size_t iova_off = 0;
		struct iova_domain *iovad = &cookie->iovad;
		size_t iova_off = iova_offset(iovad, phys);
		dma_addr_t iova;

		if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
		iova_off = iova_offset(&cookie->iovad, phys);
		size = iova_align(&cookie->iovad, size + iova_off);
		}
		size = iova_align(iovad, size + iova_off);

		iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
		if (!iova)
		@@ -1147,16 +1145,21 @@ static struct iommu_dma_msi_page iommu_dma_get_msi_page(struct device dev,
		if (!msi_page)
		return NULL;

		iova = __iommu_dma_map(dev, msi_addr, size, prot);
		if (iova == DMA_MAPPING_ERROR)
		iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
		if (!iova)
		goto out_free_page;

		if (iommu_map(domain, iova, msi_addr, size, prot))
		goto out_free_iova;

		INIT_LIST_HEAD(&msi_page->list);
		msi_page->phys = msi_addr;
		msi_page->iova = iova;
		list_add(&msi_page->list, &cookie->msi_page_list);
		return msi_page;

		out_free_iova:
		iommu_dma_free_iova(cookie, iova, size);
		out_free_page:
		kfree(msi_page);
		return NULL;

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