On 05/21/2018 12:46 PM, speck for Greg KH wrote:
> On Sun, May 20, 2018 at 04:59:04PM -0400, speck for Jon Masters wrote:
>> * ARM. They have a new SMCC (Secure Monitor Call) interface (similar to
>> the one they did for branch predictor invalidation for Spectre-v2) that
>> will be wired up with kernel patches. Each of the vendors will implement
>> the new SMCC in ATF (Arm Trusted Firmware) on their parts, using the
>> best back-end mitigation (similar to microcode). Arm know to ping Thomas
>> with those patches, yet this has not happened yet (to my knowledge), nor
>> to Greg. Will has point on this in any case. He and the team are working
>> hard on this. Still, I am saddened by these patches not being available
>> prior to disclosure since this is not how we do things in the server
>> space. But in anticipation that this would happen, I worked directly
>> with Cavium (the only server-class CPU vendor with production RHEL
>> support for which we need an answer tomorrow on our end) to create a
>> firmware knob that can be used in the short term until this is fixed. I
>> also have pinged all of the Arm server vendors to let them know I expect
>> all of the SMCC wiring to be in place within the next few weeks.
> 
> Just heard from ARM, they are going to wait a week or so and then send
> patches for inclusion in 4.18 and then send some backports for the older
> kernels then.  The kernel patches are useless without firmware updates
> and I don't know what the state of them are.

They're on the keybase channel and have been receiving all of the
updated patches. I also specifically sent them a copy previously.

> They also complained that they can not finalize their patches as they do
> not know what we agreed on for the prctl() interface.  Which sucks as
> that was hashed out here weeks ago.

Nah. As Konrad says, several folk from Arm are on keybase. They also
could have pinged us at any time if this was blocking progress. I know
resources are tight and committed, but since none of us were pinged, I'm
calling BS on that. I've also not been given even an early draft, nor
know anyone who has, even though I asked their kernel lead working on
this for a copy. I've made my peace with where we are today, sadly.

> Another proof of how when we are not "allowed" to talk to the right
> people, Linux users suffer.  That is not ok.

One of the problems does seem to be that we didn't have a dedicated list
for v4 earlier. I think it's important to tackle that next time around.

Jon.

-- 
Computer Architect | Sent from my Fedora powered laptop