Commit a97590e5 added unlinking domains from iommus to reciprocate the iommu from domains unlinking that was already done. We actually want to only do this for device domains and never for the static identity map domain or VM domains. The SI domain is special and never freed, while VM domain->id lives in their own special address space, separate from iommu->domain_ids. In the current code, a VM can get domain->id zero, then mark that domain unused when unbound from pci-stub. This leads to DMAR write faults when the device is re-bound to the host driver. Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> --- This should also be queued for stable drivers/pci/intel-iommu.c | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 284fe72..096c9ad 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -3447,10 +3447,13 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain, domain_update_iommu_cap(domain); spin_unlock_irqrestore(&domain->iommu_lock, tmp_flags); - spin_lock_irqsave(&iommu->lock, tmp_flags); - clear_bit(domain->id, iommu->domain_ids); - iommu->domains[domain->id] = NULL; - spin_unlock_irqrestore(&iommu->lock, tmp_flags); + if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) && + !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY)) { + spin_lock_irqsave(&iommu->lock, tmp_flags); + clear_bit(domain->id, iommu->domain_ids); + iommu->domains[domain->id] = NULL; + spin_unlock_irqrestore(&iommu->lock, tmp_flags); + } } spin_unlock_irqrestore(&device_domain_lock, flags); -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html