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" > <agr...@poofygoof.com> 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 caller). 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 already.) 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." | agr...@poofygoof.com "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