linux-kernel - Re: [PATCH v5 0/9] Improve non-"safe" MSR access failure handling

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Date:	Mon, 4 Apr 2016 18:23:38 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Andy Lutomirski <luto@...nel.org>
Cc:	X86 ML <x86@...nel.org>, Paolo Bonzini <pbonzini@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	KVM list <kvm@...r.kernel.org>,
	Arjan van de Ven <arjan@...ux.intel.com>,
	xen-devel <Xen-devel@...ts.xen.org>,
	linux-kernel@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH v5 0/9] Improve non-"safe" MSR access failure handling

On Sat, Apr 02, 2016 at 07:01:31AM -0700, Andy Lutomirski wrote:
> There are two parts here:
> 
> ***** FIRST PART: EARLY EXCEPTIONS *****
> 
> The first few patches move some early panic code into C, add pt_regs
> to early exception handling, and make fancy exception handlers work early.
> 
> ***** SECOND PART: MSRs *****
> 
> Setting CONFIG_PARAVIRT=y has an unintended side effect: it silently
> turns all rdmsr and wrmsr operations into the safe variants without
> any checks that the operations actually succeed.


...

FWIW:

Reviewed-by: Borislav Petkov <bp@...e.de>

Definitely a step in the right direction, regardless of how we're going
to be doing early_printk(), which is a tangential topic. This pile could
be taken for a spin in tip.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.