Commit fa7e9ecc authored by Matthew Rosato's avatar Matthew Rosato Committed by Joerg Roedel
Browse files

iommu/s390: Tolerate repeat attach_dev calls 



Since commit 0286300e ("iommu: iommu_group_claim_dma_owner() must
always assign a domain") s390-iommu will get called to allocate multiple
unmanaged iommu domains for a vfio-pci device -- however the current
s390-iommu logic tolerates only one.  Recognize that multiple domains can
be allocated and handle switching between DMA or different iommu domain
tables during attach_dev.

Signed-off-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220519182929.581898-1-mjrosato@linux.ibm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 0286300e

drivers/iommu/s390-iommu.c

+12 −3
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 
	if (!domain_device)

		return -ENOMEM;



	if (zdev->dma_table) {

	if (zdev->dma_table && !zdev->s390_domain) {

		cc = zpci_dma_exit_device(zdev);

		if (cc) {

			rc = -EIO;
@@ -107,6 +107,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 
		}

	}



	if (zdev->s390_domain)

		zpci_unregister_ioat(zdev, 0);



	zdev->dma_table = s390_domain->dma_table;

	cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,

				virt_to_phys(zdev->dma_table));
@@ -136,7 +139,13 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 
	return 0;



out_restore:

	if (!zdev->s390_domain) {

		zpci_dma_init_device(zdev);

	} else {

		zdev->dma_table = zdev->s390_domain->dma_table;

		zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,

				   virt_to_phys(zdev->dma_table));

	}

out_free:

	kfree(domain_device);
@@ -167,7 +176,7 @@ static void s390_iommu_detach_device(struct iommu_domain *domain, 
	}

	spin_unlock_irqrestore(&s390_domain->list_lock, flags);



	if (found) {

	if (found && (zdev->s390_domain == s390_domain)) {

		zdev->s390_domain = NULL;

		zpci_unregister_ioat(zdev, 0);

		zpci_dma_init_device(zdev);