From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops
Date: Thu, 17 Sep 2015 13:40:30 +0200
Message-ID: <55FAA6AE.9050503@redhat.com>
References: <cover.1442445946.git.luto@kernel.org>
 <20150917085807.GH3816@twins.programming.kicks-ass.net>
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Cc: x86@kernel.org, KVM list <kvm@vger.kernel.org>,
	Arjan van de Ven <arjan@linux.intel.com>,
	xen-devel <Xen-devel@lists.xen.org>, linux-kernel@vger.kernel.org
To: Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>
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On 17/09/2015 10:58, Peter Zijlstra wrote:
> But the far greater problem I have with the whole virt thing is that
> you cannot use rdmsr_safe() to probe if an MSR exists at all because, as
> you told me, these virt thingies return 0 for all 'unknown' MSRs instead
> of faulting.

At least for KVM, that behavior is opt-in (the ignore_msrs parameter)
and no distro that I know enables it by default.

Paolo