Re: [PATCH] x86, paravirt: BUG_ON on {rd,wr}msr exceptions

From: H. Peter Anvin
Date: Mon Jul 28 2014 - 15:18:53 EST

On 07/28/2014 12:04 PM, Eduardo Habkost wrote:
> When CONFIG_PARAVIRT is enabled, the kernel is ignoring exceptions on
> the {rd,wr}msr instructions. This makes serious issues (either on the
> guest kernel, or on the host) be silently ignored, and is different from
> the native MSR code (which does not ignore the exceptions).
> As paravirt.h already includes linux/bug.h, I don't see what was the
> original issue preventing BUG_ON from being used.
> Change rdmsr(), wrmsr(), and rdmsrl() to BUG_ON() on errors.

How much does this bloat the kernel?

#include <stdparavirtrant.h>


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