Messages in this thread | | | From | "Zhang, Cathy" <> | Subject | RE: [RFC PATCH v2 09/10] x86/cpu: Call ENCLS[EUPDATESVN] procedure in microcode update | Date | Tue, 22 Mar 2022 01:35:58 +0000 |
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Hi Jethro,
Thanks for helping review!
> -----Original Message----- > From: Jethro Beekman <jethro@fortanix.com> > Sent: Friday, March 18, 2022 5:06 PM > To: Hansen, Dave <dave.hansen@intel.com>; Zhang, Cathy > <cathy.zhang@intel.com>; linux-sgx@vger.kernel.org; linux-Hi > kernel@vger.kernel.org > Cc: Raj, Ashok <ashok.raj@intel.com> > Subject: Re: [RFC PATCH v2 09/10] x86/cpu: Call ENCLS[EUPDATESVN] > procedure in microcode update > > On 2022-03-16 16:47, Dave Hansen wrote: > > On 3/16/22 03:24, Jethro Beekman wrote: > >>> Doing this automatically and unconditionally during a microcode > >>> update seems undesirable. This requires the userland tooling that > >>> is coordinating the microcode update to be aware of any SGX > >>> enclaves that are running and possibly coordinate sequencing with > >>> the processes containing those enclaves. This coupling does not > >>> exist today. > >> Also, a microcode update may not affect SGX security at all and doing > >> the EUPDATESVN procedure may not be required for this particular > >> update. This case is called out specifically in the EUPDATESVN > >> documentation. > > > > I don't think Intel provides the metadata for the kernel to tell if an > > update requires an EUPDATESVN procedure or not. If this is inconvenient > > for you, I'd suggest reporting this to the folks at Intel who can fix > > it. It doesn't seem like something which they are motivated to fix. > > Whether or not metadata is currently made available is orthogonal to > creating a mechanism by which userspace can indidate that a particular > microcode update shouldn't trigger the EUPDATESVN procedure.
I'm not sure if you have noticed the discussions in v1: https://lore.kernel.org/all/1742be9e-c18e-28c9-75c8-144bf1f6a311@intel.com/T/#m18e6fecd8c9c517c68cb4d62e53f24909abd50a7
We remove the sysfs which allows userspace to decide if and when to trigger the EUPDATESVN procedure. Please comment if you have other suggestion.
> > -- > Jethro Beekman | Fortanix
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