> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx> > Sent: Thursday, August 3, 2023 11:25 AM > > On 2023/8/2 15:46, Tian, Kevin wrote: > >> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > >> Sent: Monday, July 24, 2023 7:14 PM > >> > >> + > >> + spin_lock_irqsave(&dmar_domain->lock, flags); > >> + list_for_each_entry(info, &dmar_domain->devices, link) > >> + intel_nested_invalidate(info->dev, dmar_domain, > >> + req->addr, req->npages); > >> + spin_unlock_irqrestore(&dmar_domain->lock, flags); > > > > Disabling interrupt while invalidating iotlb is certainly unacceptable. > > > > Actually there is no need to walk devices. Under dmar_domain there > > is already a list of attached iommu's. > > Walking device is only necessary when invalidating device TLB. For iotlb > invalidation, it only needs to know the iommu's. > even for device tlb we may think whether there is any better way to avoid disabling interrupt. It's a slow path, especially in a guest.
