Re: [PATCH] iommu/dma: Handle MSI mappings separately
From: Andre Przywara <andre.przywara@arm.com>
Date: 2019-07-29 16:18:15
Also in:
linux-iommu
On Mon, 29 Jul 2019 16:32:38 +0100 Robin Murphy [off-list ref] wrote: Hi,
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: b61d271e59d7 ("iommu/dma: Move domain lookup into __iommu_dma_{map,unmap}")
Reported-by: Shameer Kolothum <redacted>
Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>Thanks, that indeed fixes the pass through problem for me, the NVMe and SATA controller can now happily receive MSIs again. Tested-by: Andre Przywara <andre.przywara@arm.com> Cheers, Andre.
quoted hunk ↗ jump to hunk
--- drivers/iommu/dma-iommu.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index a7f9c3edbcb2..6441197a75ea 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c@@ -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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