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Date:   Thu, 29 May 2014 12:36:09 +0200
From:   Paolo Bonzini <pbonzini@redhat.com>
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To:     James Hogan <james.hogan@imgtec.com>
CC:     Andreas Herrmann <andreas.herrmann@caviumnetworks.com>,
        Gleb Natapov <gleb@kernel.org>, kvm@vger.kernel.org,
        Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org,
        Sanjay Lal <sanjayl@kymasys.com>
Subject: Re: [PATCH v2 11/23] MIPS: KVM: Fix timer race modifying guest CP0_Cause
References: <1401355005-20370-1-git-send-email-james.hogan@imgtec.com> <1401355005-20370-12-git-send-email-james.hogan@imgtec.com>
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Il 29/05/2014 11:16, James Hogan ha scritto:
> Currently this is the only asynchronous modification of guest registers,
> therefore it is fixed by adjusting the implementations of the
> kvm_set_c0_guest_cause(), kvm_clear_c0_guest_cause(), and
> kvm_change_c0_guest_cause() macros which are used for modifying the
> guest CP0_Cause register to use ll/sc to ensure atomic modification.

Shouldn't you have a loop too around the ll/sc?

Paolo