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

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>

	-hpa