On 5/15/24 3:17 PM, Tian, Kevin wrote:
From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Sent: Tuesday, April 30, 2024 10:57 PM +/* Add an attach handle to the group's pasid array. */ +static struct iommu_attach_handle * +iommu_attach_handle_set(struct iommu_domain *domain, + struct iommu_group *group, ioasid_t pasid) +{ + struct iommu_attach_handle *handle; + void *curr; + + handle = kzalloc(sizeof(*handle), GFP_KERNEL); + if (!handle) + return ERR_PTR(-ENOMEM); + + handle->domain = domain; + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, handle, GFP_KERNEL);this could be just xa_insert() which returns -EBUSY if the entry isn't NULL.
Yes, exactly.
+ if (curr) { + kfree(handle); + return xa_err(curr) ? curr : ERR_PTR(-EBUSY);'curr' is not an error pointer. You need ERR_PTR(xa_err(curr)).
Fixed.
int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { + struct iommu_attach_handle *handle; int ret; mutex_lock(&group->mutex); + handle = iommu_attach_handle_set(domain, group, IOMMU_NO_PASID); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_unlock; + } ret = __iommu_attach_group(domain, group); + if (ret) + goto out_remove_handle; mutex_unlock(&group->mutex);It's slightly better to set the handler after __iommu_attach_group(). doing so is aligned to the sequence in iommu_group_replace_domain().
I did it in this way because erasing an attach handle is easier than rolling back the group to the previous domain from the perspective of coding. I didn't realize attaching the group and storing the attach handle had to be done in a specific order.
@@ -2211,13 +2307,33 @@ EXPORT_SYMBOL_GPL(iommu_attach_group); int iommu_group_replace_domain(struct iommu_group *group, struct iommu_domain *new_domain) { + struct iommu_domain *old_domain = group->domain; + struct iommu_attach_handle *handle; int ret; if (!new_domain) return -EINVAL; + if (new_domain == old_domain) + return 0; +__iommu_group_set_domain() already does the check.
Removed. Best regards, baolu
