Re: [PATCH v2 1/2] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops

From: Paolo Bonzini
Date: Mon Sep 21 2015 - 08:27:39 EST




On 21/09/2015 10:46, Ingo Molnar wrote:
> Or we could extend exception table entry encoding to include a 'warning bit', to
> not bloat the kernel. If the exception handler code encounters such an exception
> it would generate a one-time warning for that entry, but otherwise not crash the
> kernel and continue execution with an all-zeroes result for the MSR read.

The 'warning bit' already exists, it is the opcode that caused the fault. :)

The concern about bloat is a good one. However, why is it necessary to
keep native_*_msr* inline? If they are moved out-of-line, using the
exception table becomes the obvious solution and doesn't cause bloat
anymore.

Paolo
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