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Re: mcelog?

On Mon, Apr 08, 2019 at 11:39:31AM +0530, Mathew, Cherry G. wrote:
> On 8 April 2019 10:18:16 AM GMT+05:30, "Aaron J. Grier" <> wrote:
> >are we going to get an MSR interface for NetBSD any time soon?
> What would such an interface look like ?

- start with interface would be a set of ioctls on an i386/amd64-
  specific /dev/msr that generated kernel-mode rdmsr and wrmsr
  operations from the thread that made the ioctl.
- start hardening by only allowing a set of whitelisted MSRs to
  complete, so userland couldn't relocate the APIC for example.
- continue to harden with separate access for read vs write MSRs
- add data-massaging and bounds checking on per-MSR basis in case we
  have mix of permissions within fields.
- add arguments for running the MSR operation on a specific package /
  socket or hardware thread (rather than under the context of the the

if ioctls are out of style, possibly a sysctl interface of some sort.

it's probably a google SoC project waiting to happen (if it hasn't

end-goal would be ability to run a native x86info with feature parity to
linux, as well as capture machine check errors, gather die temperature
data, power states, poll hardware performance counters...

  Aaron J. Grier | "Not your ordinary poofy goof." |
  "The price of reliability is the pursuit of the utmost simplicity.  It
   is a price which the very rich find most hard to pay."  -- Tony Hoare

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