iommu/s390: Fix duplicate domain attachments
Since commit fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev
calls") we can end up with duplicates in the list of devices attached to
a domain. This is inefficient and confusing since only one domain can
actually be in control of the IOMMU translations for a device. Fix this
by detaching the device from the previous domain, if any, on attach.
Add a WARN_ON() in case we still have attached devices on freeing the
domain. While here remove the re-attach on failure dance as it was
determined to be unlikely to help and may confuse debug and recovery.
Fixes: fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev calls")
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-2-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Niklas Schnelle
Joerg Roedel
parent
30a0b95b13
commit
bf8d2dd2ed
@ -79,10 +79,36 @@ static void s390_domain_free(struct iommu_domain *domain)
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{
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struct s390_domain *s390_domain = to_s390_domain(domain);
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WARN_ON(!list_empty(&s390_domain->devices));
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dma_cleanup_tables(s390_domain->dma_table);
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kfree(s390_domain);
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}
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static void __s390_iommu_detach_device(struct zpci_dev *zdev)
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{
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struct s390_domain *s390_domain = zdev->s390_domain;
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struct s390_domain_device *domain_device, *tmp;
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unsigned long flags;
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if (!s390_domain)
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return;
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spin_lock_irqsave(&s390_domain->list_lock, flags);
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list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
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list) {
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if (domain_device->zdev == zdev) {
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list_del(&domain_device->list);
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kfree(domain_device);
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break;
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}
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}
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spin_unlock_irqrestore(&s390_domain->list_lock, flags);
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zpci_unregister_ioat(zdev, 0);
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zdev->s390_domain = NULL;
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zdev->dma_table = NULL;
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}
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static int s390_iommu_attach_device(struct iommu_domain *domain,
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struct device *dev)
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{
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@ -90,7 +116,7 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
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struct zpci_dev *zdev = to_zpci_dev(dev);
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struct s390_domain_device *domain_device;
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unsigned long flags;
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int cc, rc;
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int cc, rc = 0;
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if (!zdev)
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return -ENODEV;
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@ -99,24 +125,18 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
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if (!domain_device)
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return -ENOMEM;
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if (zdev->dma_table && !zdev->s390_domain) {
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cc = zpci_dma_exit_device(zdev);
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if (cc) {
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rc = -EIO;
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goto out_free;
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}
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}
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if (zdev->s390_domain)
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zpci_unregister_ioat(zdev, 0);
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__s390_iommu_detach_device(zdev);
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else if (zdev->dma_table)
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zpci_dma_exit_device(zdev);
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zdev->dma_table = s390_domain->dma_table;
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cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
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virt_to_phys(zdev->dma_table));
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virt_to_phys(s390_domain->dma_table));
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if (cc) {
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rc = -EIO;
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goto out_restore;
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goto out_free;
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}
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zdev->dma_table = s390_domain->dma_table;
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spin_lock_irqsave(&s390_domain->list_lock, flags);
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/* First device defines the DMA range limits */
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@ -127,9 +147,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
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/* Allow only devices with identical DMA range limits */
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} else if (domain->geometry.aperture_start != zdev->start_dma ||
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domain->geometry.aperture_end != zdev->end_dma) {
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rc = -EINVAL;
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spin_unlock_irqrestore(&s390_domain->list_lock, flags);
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goto out_restore;
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rc = -EINVAL;
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goto out_unregister;
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}
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domain_device->zdev = zdev;
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zdev->s390_domain = s390_domain;
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@ -138,14 +158,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
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return 0;
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out_restore:
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if (!zdev->s390_domain) {
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zpci_dma_init_device(zdev);
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} else {
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zdev->dma_table = zdev->s390_domain->dma_table;
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zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
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virt_to_phys(zdev->dma_table));
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}
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out_unregister:
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zpci_unregister_ioat(zdev, 0);
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zdev->dma_table = NULL;
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out_free:
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kfree(domain_device);
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@ -155,32 +170,12 @@ out_free:
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static void s390_iommu_detach_device(struct iommu_domain *domain,
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struct device *dev)
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{
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struct s390_domain *s390_domain = to_s390_domain(domain);
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struct zpci_dev *zdev = to_zpci_dev(dev);
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struct s390_domain_device *domain_device, *tmp;
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unsigned long flags;
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int found = 0;
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if (!zdev)
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return;
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WARN_ON(zdev->s390_domain != to_s390_domain(domain));
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spin_lock_irqsave(&s390_domain->list_lock, flags);
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list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
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list) {
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if (domain_device->zdev == zdev) {
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list_del(&domain_device->list);
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kfree(domain_device);
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found = 1;
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break;
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}
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}
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spin_unlock_irqrestore(&s390_domain->list_lock, flags);
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if (found && (zdev->s390_domain == s390_domain)) {
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zdev->s390_domain = NULL;
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zpci_unregister_ioat(zdev, 0);
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zpci_dma_init_device(zdev);
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}
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__s390_iommu_detach_device(zdev);
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zpci_dma_init_device(zdev);
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}
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static struct iommu_device *s390_iommu_probe_device(struct device *dev)
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@ -198,24 +193,13 @@ static struct iommu_device *s390_iommu_probe_device(struct device *dev)
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static void s390_iommu_release_device(struct device *dev)
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{
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struct zpci_dev *zdev = to_zpci_dev(dev);
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struct iommu_domain *domain;
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/*
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* This is a workaround for a scenario where the IOMMU API common code
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* "forgets" to call the detach_dev callback: After binding a device
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* to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers
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* the attach_dev), removing the device via
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* "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev,
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* only release_device will be called via the BUS_NOTIFY_REMOVED_DEVICE
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* notifier.
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*
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* So let's call detach_dev from here if it hasn't been called before.
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* release_device is expected to detach any domain currently attached
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* to the device, but keep it attached to other devices in the group.
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*/
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if (zdev && zdev->s390_domain) {
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domain = iommu_get_domain_for_dev(dev);
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if (domain)
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s390_iommu_detach_device(domain, dev);
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}
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if (zdev)
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__s390_iommu_detach_device(zdev);
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}
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static int s390_iommu_update_trans(struct s390_domain *s390_domain,
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