On Sat, Feb 08, 2025 at 01:02:39AM -0800, Nicolin Chen wrote:
+static struct iommufd_attach_handle * +iommu_group_get_iommufd_handle(struct iommu_group *group) +{
- struct iommu_attach_handle *handle;
- handle = iommu_attach_handle_get(group, IOMMU_NO_PASID, 0);
- if (IS_ERR(handle))
return NULL;- return to_iommufd_handle(handle);
+}
+/*
- Called by the irq code if the platform translates the MSI address through the
- IOMMU. msi_addr is the physical address of the MSI page. iommufd will
- allocate a fd global iova for the physical page that is the same on all
- domains and devices.
- */
+#ifdef CONFIG_IRQ_MSI_IOMMU +int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
phys_addr_t msi_addr)+{
- struct device *dev = msi_desc_to_dev(desc);
- struct iommufd_hwpt_paging *hwpt_paging;
- struct iommufd_attach_handle *handle;
- struct iommufd_sw_msi_map *msi_map;
- struct iommufd_ctx *ictx;
- unsigned long iova;
- int rc;
- handle = iommu_group_get_iommufd_handle(dev->iommu_group);
- if (!handle)
return 0;
I think you should open code this and leave the other function alone. The locking rules are different here.
iommufd_device_get_attach_handle() should be locked under the igroup->lock
While in this context we are locked under the iommu core group mutex.
A comment will help
/* * It is safe to call iommu_attach_handle_get() here because the iommu * core code invokes this under the group mutex which also prevents any * change of the attach handle for the duration of this function. */ iommu_group_mutex_assert(dev);
Jason