From: Matthew Rosato <mjrosato@linux.ibm.com>
To: jgg@nvidia.com, joro@8bytes.org
Cc: will@kernel.org, alex.williamson@redhat.com, cohuck@redhat.com,
borntraeger@linux.ibm.com, schnelle@linux.ibm.com,
gerald.schaefer@linux.ibm.com, farman@linux.ibm.com,
iommu@lists.linux-foundation.org, linux-s390@vger.kernel.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] iommu/s390: tolerate repeat attach_dev calls
Date: Thu, 19 May 2022 14:29:29 -0400 [thread overview]
Message-ID: <20220519182929.581898-1-mjrosato@linux.ibm.com> (raw)
Since commit 0286300e6045 ("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: Matthew Rosato <mjrosato@linux.ibm.com>
---
drivers/iommu/s390-iommu.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 3833e86c6e7b..c898bcbbce11 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -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:
- zpci_dma_init_device(zdev);
+ 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);
--
2.27.0
next reply other threads:[~2022-05-19 18:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-19 18:29 Matthew Rosato [this message]
2022-05-19 18:30 ` [PATCH] iommu/s390: tolerate repeat attach_dev calls Matthew Rosato
2022-05-19 22:58 ` Jason Gunthorpe
2022-05-20 7:57 ` Joerg Roedel
2022-05-20 10:30 ` Niklas Schnelle
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