Re: [PATCH 2/2] x86: sgx_vepc: implement SGX_IOC_VEPC_REMOVE ioctl
From: Dave Hansen
Date: Mon Sep 13 2021 - 18:53:07 EST
On 9/13/21 2:11 PM, Sean Christopherson wrote:
> My argument against handling this fully in the kernel is that to handle a vNUMA
> setup with multiple vEPC sections, the ioctl() would need to a take a set of file
> descriptors to handle the case where an SECS is pinned by a child page in a
> diferent vEPC.
Bah, I'm always forgetting about the multiple vepc fd's case.
I completely agree that there's no sane way to do this with a per-vepc
ioctl() when the EREMOVE failures can originate from other vepc instances.
The only other possible thing would be keep an mm_list for vepc
instances and have this ioctl() (or another interface) blast them all.
But that's going to be a heck of a lot more complicated than this is.
OK... you two are wearing me down on this one.
Let's just get this all documented in the changelogs, especially the
retry behavior.