From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v2 1/2] x86/msr: Carry on after a non-"safe" MSR access
 fails without !panic_on_oops
Date: Mon, 21 Sep 2015 14:27:31 +0200
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Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	xen-devel <Xen-devel@lists.xen.org>,
	Arjan van de Ven <arjan@linux.intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	KVM list <kvm@vger.kernel.org>,
	the arch/x86 maintainers <x86@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>,
	Andy Lutomirski <luto@amacapital.net>
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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