From patchwork Mon May 10 16:58:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 12248941 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E161CC43460 for ; Mon, 10 May 2021 17:27:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC3CF61554 for ; Mon, 10 May 2021 17:27:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232864AbhEJR2x (ORCPT ); Mon, 10 May 2021 13:28:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:53106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232902AbhEJR2i (ORCPT ); Mon, 10 May 2021 13:28:38 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 947C061480; Mon, 10 May 2021 17:27:33 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lg9Fx-000Uqg-Ff; Mon, 10 May 2021 17:59:45 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Jintack Lim , Haibo Xu , James Morse , Suzuki K Poulose , Alexandru Elisei , kernel-team@android.com Subject: [PATCH v4 11/66] KVM: arm64: nv: Handle trapped ERET from virtual EL2 Date: Mon, 10 May 2021 17:58:25 +0100 Message-Id: <20210510165920.1913477-12-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210510165920.1913477-1-maz@kernel.org> References: <20210510165920.1913477-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, andre.przywara@arm.com, christoffer.dall@arm.com, jintack@cs.columbia.edu, haibo.xu@linaro.org, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Christoffer Dall When a guest hypervisor running virtual EL2 in EL1 executes an ERET instruction, we will have set HCR_EL2.NV which traps ERET to EL2, so that we can emulate the exception return in software. Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/esr.h | 5 +++++ arch/arm64/include/asm/kvm_arm.h | 2 +- arch/arm64/kvm/handle_exit.c | 10 ++++++++++ 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index 29f97eb3dad4..9e6bc2757a05 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -253,6 +253,11 @@ (((e) & ESR_ELx_SYS64_ISS_OP2_MASK) >> \ ESR_ELx_SYS64_ISS_OP2_SHIFT)) +/* ISS field definitions for ERET/ERETAA/ERETAB trapping */ + +#define ESR_ELx_ERET_ISS_ERET_ERETAx 0x2 +#define ESR_ELx_ERET_ISS_ERETA_ERATAB 0x1 + /* * ISS field definitions for floating-point exception traps * (FP_EXC_32/FP_EXC_64). diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index e27da4165d43..4fd52af7f538 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -329,7 +329,7 @@ ECN(SP_ALIGN), ECN(FP_EXC32), ECN(FP_EXC64), ECN(SERROR), \ ECN(BREAKPT_LOW), ECN(BREAKPT_CUR), ECN(SOFTSTP_LOW), \ ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \ - ECN(BKPT32), ECN(VECTOR32), ECN(BRK64) + ECN(BKPT32), ECN(VECTOR32), ECN(BRK64), ECN(ERET) #define CPACR_EL1_FPEN (3 << 20) #define CPACR_EL1_TTA (1 << 28) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 6add422d63b8..fca0d44afe96 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -183,6 +183,15 @@ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) return 1; } +static int kvm_handle_eret(struct kvm_vcpu *vcpu) +{ + if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_ERET_ISS_ERET_ERETAx) + return kvm_handle_ptrauth(vcpu); + + kvm_emulate_nested_eret(vcpu); + return 1; +} + static exit_handle_fn arm_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec, [ESR_ELx_EC_WFx] = kvm_handle_wfx, @@ -197,6 +206,7 @@ static exit_handle_fn arm_exit_handlers[] = { [ESR_ELx_EC_SMC64] = handle_smc, [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg, [ESR_ELx_EC_SVE] = handle_sve, + [ESR_ELx_EC_ERET] = kvm_handle_eret, [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug,