From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753419AbeAZOcX (ORCPT ); Fri, 26 Jan 2018 09:32:23 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48126 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752033AbeAZO3F (ORCPT ); Fri, 26 Jan 2018 09:29:05 -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 , Jon Masters Subject: [PATCH 02/14] arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls Date: Fri, 26 Jan 2018 14:28:35 +0000 Message-Id: <20180126142847.31240-3-marc.zyngier@arm.com> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20180126142847.31240-1-marc.zyngier@arm.com> References: <20180126142847.31240-1-marc.zyngier@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KVM doesn't follow the SMCCC when it comes to unimplemented calls, and inject an UNDEF instead of returning an error. Since firmware calls are now used for security mitigation, they are becoming more common, and the undef is counter productive. Instead, let's follow the SMCCC which states that -1 must be returned to the caller when getting an unknown function number. Cc: Signed-off-by: Marc Zyngier --- arch/arm/kvm/handle_exit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index cf8bf6bf87c4..d15ac772d186 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -38,7 +38,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) ret = kvm_psci_call(vcpu); if (ret < 0) { - kvm_inject_undefined(vcpu); + vcpu_set_reg(vcpu, 0, ~0UL); return 1; } @@ -47,7 +47,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) { - kvm_inject_undefined(vcpu); + vcpu_set_reg(vcpu, 0, ~0UL); return 1; } -- 2.14.2