From: Zhang Zekun <zhangzekun11@huawei.com> mainline inclusion from mainline-v5.1-rc3 commit 8bc32a285660e13fdcf92ddaf5b8653abe112040 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I72C6P CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Print the warning about the fall-back to IOMMU_DOMAIN_DMA in iommu_group_get_for_dev() only when such a domain was actually allocated. Otherwise the user will get misleading warnings in the kernel log when the iommu driver used doesn't support IOMMU_DOMAIN_DMA and IOMMU_DOMAIN_IDENTITY. Fixes: fccb4e3b8ab09 ('iommu: Allow default domain type to be set on the kernel command line') Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/iommu/iommu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 16aa8f79eed4..1c39d1b8a80a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1307,10 +1307,12 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev) #endif dom = __iommu_domain_alloc(dev->bus, type); if (!dom && type != IOMMU_DOMAIN_DMA) { - dev_warn(dev, - "failed to allocate default IOMMU domain of type %u; falling back to IOMMU_DOMAIN_DMA", - iommu_def_domain_type); dom = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_DMA); + if (dom) { + dev_warn(dev, + "failed to allocate default IOMMU domain of type %u; falling back to IOMMU_DOMAIN_DMA", + iommu_def_domain_type); + } } group->default_domain = dom; -- 2.25.1