Re: [PATCH v3 1/1] iommu/sva: Invalidate KVA range on kernel TLB flush

On 8/11/2025 8:57 PM, Jason Gunthorpe wrote:

On Fri, Aug 08, 2025 at 01:15:12PM +0800, Baolu Lu wrote:

...

+static void kernel_pte_work_func(struct work_struct *work) +{

• struct ptdesc *ptdesc, *next;
• iommu_sva_invalidate_kva_range(0, TLB_FLUSH_ALL);
• guard(spinlock)(&kernel_pte_work.lock);
• list_for_each_entry_safe(ptdesc, next, &kernel_pte_work.list, pt_list) {

• list_del_init(&ptdesc->pt_list);
  

• pagetable_dtor_free(ptdesc);
  

• }

Do a list_move from kernel_pte_work.list to an on-stack list head and then immediately release the lock. No reason to hold the spinock while doing frees, also no reason to do list_del_init, that memory probably gets zerod in pagetable_dtor_free()

Yep，using guard(spinlock)() for scope-bound lock management sacrifices fine-grained control over the protected area. If offers convenience at the cost of precision.

Out of my bias, calling it sluggard(spinlock)() might be proper.

Thanks， Ethan

Jason