From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: [PATCH 5/5] arm64: KVM: Fix guest dead loop when register accessor returns false Date: Thu, 28 Jan 2016 10:30:38 +0000 Message-ID: <1453977038-13516-6-git-send-email-marc.zyngier@arm.com> References: <1453977038-13516-1-git-send-email-marc.zyngier@arm.com> Cc: Shannon Zhao , Christoffer Dall , Dave Martin , linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, Gleb Natapov To: Paolo Bonzini Return-path: Received: from foss.arm.com ([217.140.101.70]:58880 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964971AbcA1Ka6 (ORCPT ); Thu, 28 Jan 2016 05:30:58 -0500 In-Reply-To: <1453977038-13516-1-git-send-email-marc.zyngier@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: From: Shannon Zhao Currently emulate_cp will return 0 (Handled) no matter what the accessor returns. If register accessor returns false, it will not skip current PC while emulate_cp return handled. Then guest will stuck in a dead loop. Reviewed-by: Marc Zyngier Signed-off-by: Shannon Zhao Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4048934..2e90371 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1007,10 +1007,9 @@ static int emulate_cp(struct kvm_vcpu *vcpu, if (likely(r->access(vcpu, params, r))) { /* Skip instruction, since it was emulated */ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); + /* Handled */ + return 0; } - - /* Handled */ - return 0; } /* Not handled */ -- 2.1.4