| Message ID | 20250319173202.78988-4-shameerali.kolothum.thodi@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iommu/arm-smmu-v3: Use pinned KVM VMID for stage 2 | expand |
On Wed, Mar 19, 2025 at 05:32:00PM +0000, Shameer Kolothum wrote: > diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c > index 69b88e8c7c26..e157d786f295 100644 > --- a/drivers/iommu/iommufd/viommu.c > +++ b/drivers/iommu/iommufd/viommu.c > @@ -47,7 +47,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) > goto out_put_hwpt; > } > > - viommu = ops->viommu_alloc(idev->dev, hwpt_paging->common.domain, > + viommu = ops->viommu_alloc(idev->dev, idev->kvm, > + hwpt_paging->common.domain, > ucmd->ictx, cmd->type); > if (IS_ERR(viommu)) { > rc = PTR_ERR(viommu); This has a lifetime issue on the kvm pointer. Because nothing is taking a refcount on the kvm we are relying on the caller to hold the kvm refcount for the lifetime of the iommufd_device_bind()/unbind() which is creating the idev. However, the lifetime of the viommu object is not linked to the lifetime of the idev. So the idev could be destroyed, and the kvm refcount put before the viommu is destroyed. Probably the right answer is to take a refcount on the kvm for the viommu object somewhere along this path. Jason
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c index 6f8be1164167..ee2fac5c899b 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c @@ -370,6 +370,7 @@ static const struct iommufd_viommu_ops arm_vsmmu_ops = { }; struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev, + struct kvm *kvm, struct iommu_domain *parent, struct iommufd_ctx *ictx, unsigned int viommu_type) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index 1f6696bc4f6c..9f49de52a700 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -1060,6 +1060,7 @@ struct arm_vsmmu { #if IS_ENABLED(CONFIG_ARM_SMMU_V3_IOMMUFD) void *arm_smmu_hw_info(struct device *dev, u32 *length, u32 *type); struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev, + struct kvm *kvm, struct iommu_domain *parent, struct iommufd_ctx *ictx, unsigned int viommu_type); diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c index 69b88e8c7c26..e157d786f295 100644 --- a/drivers/iommu/iommufd/viommu.c +++ b/drivers/iommu/iommufd/viommu.c @@ -47,7 +47,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) goto out_put_hwpt; } - viommu = ops->viommu_alloc(idev->dev, hwpt_paging->common.domain, + viommu = ops->viommu_alloc(idev->dev, idev->kvm, + hwpt_paging->common.domain, ucmd->ictx, cmd->type); if (IS_ERR(viommu)) { rc = PTR_ERR(viommu); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index cb01fe49f5df..2f61e0178cfa 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -44,6 +44,7 @@ struct iommu_dma_cookie; struct iommu_fault_param; struct iommufd_ctx; struct iommufd_viommu; +struct kvm; #define IOMMU_FAULT_PERM_READ (1 << 0) /* read */ #define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */ @@ -646,7 +647,8 @@ struct iommu_ops { int (*def_domain_type)(struct device *dev); struct iommufd_viommu *(*viommu_alloc)( - struct device *dev, struct iommu_domain *parent_domain, + struct device *dev, struct kvm *kvm, + struct iommu_domain *parent_domain, struct iommufd_ctx *ictx, unsigned int viommu_type); const struct iommu_domain_ops *default_domain_ops;
No functional changes. This will be used in a later patch to add support to use KVM VMID in ARM SMMUv3 s2 stage configuration. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 1 + drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 + drivers/iommu/iommufd/viommu.c | 3 ++- include/linux/iommu.h | 4 +++- 4 files changed, 7 insertions(+), 2 deletions(-)