From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1163744AbdAIGgb (ORCPT ); Mon, 9 Jan 2017 01:36:31 -0500 Received: from outprodmail01.cc.columbia.edu ([128.59.72.39]:38231 "EHLO outprodmail01.cc.columbia.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S939648AbdAIG0C (ORCPT ); Mon, 9 Jan 2017 01:26:02 -0500 From: Jintack Lim To: christoffer.dall@linaro.org, marc.zyngier@arm.com, pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, vladimir.murzin@arm.com, suzuki.poulose@arm.com, mark.rutland@arm.com, james.morse@arm.com, lorenzo.pieralisi@arm.com, kevin.brodsky@arm.com, wcohen@redhat.com, shankerd@codeaurora.org, geoff@infradead.org, andre.przywara@arm.com, eric.auger@redhat.com, anna-maria@linutronix.de, shihwei@cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: jintack@cs.columbia.edu Subject: [RFC 22/55] KVM: arm64: Handle PSCI call from the guest Date: Mon, 9 Jan 2017 01:24:18 -0500 Message-Id: <1483943091-1364-23-git-send-email-jintack@cs.columbia.edu> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1483943091-1364-1-git-send-email-jintack@cs.columbia.edu> References: <1483943091-1364-1-git-send-email-jintack@cs.columbia.edu> X-No-Spam-Score: Local Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org VMs used to execute hvc #0 for the psci call. However, when we come to provide virtual EL2 to the VM, the host OS inside the VM also calls kvm_call_hyp which is also hvc #0. So, it's hard to differentiate between them from the host hypervisor's point of view. So, let the VM execute smc for the psci call. On ARMv8.3, even if EL3 is not implemented, a smc instruction executed at non-secure EL1 is trapped to EL2 if HCR_EL2.TSC==1, rather than being treated as UNDEFINED. So, the host hypervisor can handle this psci call without any confusion. Signed-off-by: Jintack Lim --- arch/arm64/kvm/handle_exit.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 208be16..ce6d2ef 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -64,8 +64,27 @@ 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); - return 1; + int ret; + + /* If imm is non-zero, it's not defined */ + if (kvm_vcpu_hvc_get_imm(vcpu)) { + kvm_inject_undefined(vcpu); + return 1; + } + + /* + * If imm is zero, it's a psci call. + * Note that on ARMv8.3, even if EL3 is not implemented, SMC executed + * at Non-secure EL1 is trapped to EL2 if HCR_EL2.TSC==1, rather than + * being treated as UNDEFINED. + */ + ret = kvm_psci_call(vcpu); + if (ret < 0) { + kvm_inject_undefined(vcpu); + return 1; + } + + return ret; } /** -- 1.9.1