Hi Jacob, On Wed, 3 Mar 2021 13:17:26 -0800, Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> wrote: > Hi Tejun, > > On Wed, 3 Mar 2021 10:44:28 -0500, Tejun Heo <tj@xxxxxxxxxx> wrote: > > > On Sat, Feb 27, 2021 at 02:01:23PM -0800, Jacob Pan wrote: > > > IOASIDs are used to associate DMA requests with virtual address > > > spaces. They are a system-wide limited resource made available to the > > > userspace applications. Let it be VMs or user-space device drivers. > > > > > > This RFC patch introduces a cgroup controller to address the following > > > problems: > > > 1. Some user applications exhaust all the available IOASIDs thus > > > depriving others of the same host. > > > 2. System admins need to provision VMs based on their needs for > > > IOASIDs, e.g. the number of VMs with assigned devices that perform > > > DMA requests with PASID. > > > > Please take a look at the proposed misc controller: > > > > http://lkml.kernel.org/r/20210302081705.1990283-2-vipinsh@xxxxxxxxxx > > > > Would that fit your bill? > The interface definitely can be reused. But IOASID has a different > behavior in terms of migration and ownership checking. I guess SEV key > IDs are not tied to a process whereas IOASIDs are. Perhaps this can be > solved by adding > + .can_attach = ioasids_can_attach, > + .cancel_attach = ioasids_cancel_attach, > Let me give it a try and come back. > While I am trying to fit the IOASIDs cgroup in to the misc cgroup proposal. I'd like to have a direction check on whether this idea of using cgroup for IOASID/PASID resource management is viable. Alex/Jason/Jean and everyone, your feedback is much appreciated. > Thanks for the pointer. > > Jacob > > > > > Thanks. > > > > > Thanks, > > Jacob Thanks, Jacob
