From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752846AbeBFR5Z (ORCPT ); Tue, 6 Feb 2018 12:57:25 -0500 Received: from foss.arm.com ([217.140.101.70]:40984 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752710AbeBFR4z (ORCPT ); Tue, 6 Feb 2018 12:56:55 -0500 From: Marc Zyngier To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: Catalin Marinas , Will Deacon , Peter Maydell , Christoffer Dall , Lorenzo Pieralisi , Mark Rutland , Robin Murphy , Ard Biesheuvel , Andrew Jones , Hanjun Guo , Jayachandran C , Jon Masters , Russell King - ARM Linux Subject: [PATCH v4 03/17] arm64: KVM: Increment PC after handling an SMC trap Date: Tue, 6 Feb 2018 17:56:07 +0000 Message-Id: <20180206175621.929-4-marc.zyngier@arm.com> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20180206175621.929-1-marc.zyngier@arm.com> References: <20180206175621.929-1-marc.zyngier@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When handling an SMC trap, the "preferred return address" is set to that of the SMC, and not the next PC (which is a departure from the behaviour of an SMC that isn't trapped). Increment PC in the handler, as the guest is otherwise forever stuck... Cc: stable@vger.kernel.org Fixes: acfb3b883f6d ("arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls") Reviewed-by: Christoffer Dall Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier --- arch/arm64/kvm/handle_exit.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 520b0dad3c62..5493bbefbd0d 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -62,7 +62,16 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) { + /* + * "If an SMC instruction executed at Non-secure EL1 is + * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a + * Trap exception, not a Secure Monitor Call exception [...]" + * + * We need to advance the PC after the trap, as it would + * otherwise return to the same address... + */ vcpu_set_reg(vcpu, 0, ~0UL); + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); return 1; } -- 2.14.2