Commit fa4c4507 authored by Niklas Schnelle's avatar Niklas Schnelle Committed by Joerg Roedel
Browse files

iommu: Allow .iotlb_sync_map to fail and handle s390's -ENOMEM return 



On s390 when using a paging hypervisor, .iotlb_sync_map is used to sync
mappings by letting the hypervisor inspect the synced IOVA range and
updating a shadow table. This however means that .iotlb_sync_map can
fail as the hypervisor may run out of resources while doing the sync.
This can be due to the hypervisor being unable to pin guest pages, due
to a limit on mapped addresses such as vfio_iommu_type1.dma_entry_limit
or lack of other resources. Either way such a failure to sync a mapping
should result in a DMA_MAPPING_ERROR.

Now especially when running with batched IOTLB flushes for unmap it may
be that some IOVAs have already been invalidated but not yet synced via
.iotlb_sync_map. Thus if the hypervisor indicates running out of
resources, first do a global flush allowing the hypervisor to free
resources associated with these mappings as well a retry creating the
new mappings and only if that also fails report this error to callers.

Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun50i
Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-1-9e5fc4dacc36@linux.ibm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent ccb76c57

drivers/iommu/amd/iommu.c

+3 −2
Original line number Diff line number Diff line
@@ -2233,7 +2233,7 @@ static int amd_iommu_attach_device(struct iommu_domain *dom, 
	return ret;

}



static void amd_iommu_iotlb_sync_map(struct iommu_domain *dom,

static int amd_iommu_iotlb_sync_map(struct iommu_domain *dom,

				    unsigned long iova, size_t size)

{

	struct protection_domain *domain = to_pdomain(dom);
@@ -2241,6 +2241,7 @@ static void amd_iommu_iotlb_sync_map(struct iommu_domain *dom, 


	if (ops->map_pages)

		domain_flush_np_cache(domain, iova, size);

	return 0;

}



static int amd_iommu_map_pages(struct iommu_domain *dom, unsigned long iova,

drivers/iommu/apple-dart.c

+3 −2
Original line number Diff line number Diff line
@@ -506,10 +506,11 @@ static void apple_dart_iotlb_sync(struct iommu_domain *domain, 
	apple_dart_domain_flush_tlb(to_dart_domain(domain));

}



static void apple_dart_iotlb_sync_map(struct iommu_domain *domain,

static int apple_dart_iotlb_sync_map(struct iommu_domain *domain,

				     unsigned long iova, size_t size)

{

	apple_dart_domain_flush_tlb(to_dart_domain(domain));

	return 0;

}



static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain,

drivers/iommu/intel/iommu.c

+3 −2
Original line number Diff line number Diff line
@@ -4678,7 +4678,7 @@ static bool risky_device(struct pci_dev *pdev) 
	return false;

}



static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain,

static int intel_iommu_iotlb_sync_map(struct iommu_domain *domain,

				      unsigned long iova, size_t size)

{

	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
@@ -4689,6 +4689,7 @@ static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain, 


	xa_for_each(&dmar_domain->iommu_array, i, info)

		__mapping_notify_one(info->iommu, dmar_domain, pfn, pages);

	return 0;

}



static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)

drivers/iommu/iommu.c

+16 −4
Original line number Diff line number Diff line
@@ -2585,8 +2585,17 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova, 
		return -EINVAL;



	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);

	if (ret == 0 && ops->iotlb_sync_map)

		ops->iotlb_sync_map(domain, iova, size);

	if (ret == 0 && ops->iotlb_sync_map) {

		ret = ops->iotlb_sync_map(domain, iova, size);

		if (ret)

			goto out_err;

	}



	return ret;



out_err:

	/* undo mappings already done */

	iommu_unmap(domain, iova, size);



	return ret;

}
@@ -2714,8 +2723,11 @@ ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, 
			sg = sg_next(sg);

	}



	if (ops->iotlb_sync_map)

		ops->iotlb_sync_map(domain, iova, mapped);

	if (ops->iotlb_sync_map) {

		ret = ops->iotlb_sync_map(domain, iova, mapped);

		if (ret)

			goto out_err;

	}

	return mapped;



out_err:

drivers/iommu/msm_iommu.c

+3 −2
Original line number Diff line number Diff line
@@ -498,12 +498,13 @@ static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova, 
	return ret;

}



static void msm_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,

static int msm_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,

			      size_t size)

{

	struct msm_priv *priv = to_msm_priv(domain);



	__flush_iotlb_range(iova, size, SZ_4K, false, priv);

	return 0;

}



static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,