From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 ED959C4742C for ; Mon, 2 Nov 2020 16:41:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8065222BA for ; Mon, 2 Nov 2020 16:41:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604335278; bh=UNw6Ku4J/fjF4d6VHoCQAwTDkVrbDAGVMgz0t9OIWZo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lZw7OQoEzi10hcbX8wBTQFzTKbpgdSWigohGcCLUxyJCA297Lk/ZZSmmAvKVISbKf 9fLOIRn8GFgKyxaTrVZwhH5V7fQZaPMQp1Tv3leMw+q7QqukyofpOfcxIoPV0HV1gJ m/H3hGBwTW3hLQ7w1tmxht5QAah92hqVvuHFLzkk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727217AbgKBQlK (ORCPT ); Mon, 2 Nov 2020 11:41:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:46840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727194AbgKBQlI (ORCPT ); Mon, 2 Nov 2020 11:41:08 -0500 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 0F05122275; Mon, 2 Nov 2020 16:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604335268; bh=UNw6Ku4J/fjF4d6VHoCQAwTDkVrbDAGVMgz0t9OIWZo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hjswbo4t7uRt5kJCdyVFk0DeBKy7s4ZEhpNlKCPtk/UxsBS52tpZ/AS13MjDlCgC2 MbbckGXyBCqLdwf/x5FmLphXK71JtBzlTT8UfaM+mQCy2OVlNmoCuw5A+gZg1MMpS+ w3DTGijfjjSaJLexGBjas0jjlKN2lfyemvkEkoCY= 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) (envelope-from ) id 1kZctG-006jJf-A1; Mon, 02 Nov 2020 16:41:06 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: James Morse , Julien Thierry , Suzuki K Poulose , Andrew Scull , Will Deacon , Mark Rutland , Quentin Perret , David Brazdil , kernel-team@android.com Subject: [PATCH v2 04/11] KVM: arm64: Move PC rollback on SError to HYP Date: Mon, 2 Nov 2020 16:40:38 +0000 Message-Id: <20201102164045.264512-5-maz@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201102164045.264512-1-maz@kernel.org> References: <20201102164045.264512-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, ascull@google.com, will@kernel.org, mark.rutland@arm.com, qperret@google.com, dbrazdil@google.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 Instead of handling the "PC rollback on SError during HVC" at EL1 (which requires disclosing PC to a potentially untrusted kernel), let's move this fixup to ... fixup_guest_exit(), which is where we do all fixups. Isn't that neat? Signed-off-by: Marc Zyngier --- arch/arm64/kvm/handle_exit.c | 17 ----------------- arch/arm64/kvm/hyp/include/hyp/switch.h | 15 +++++++++++++++ 2 files changed, 15 insertions(+), 17 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index d4e00a864ee6..f79137ee4274 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -241,23 +241,6 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index) { struct kvm_run *run = vcpu->run; - if (ARM_SERROR_PENDING(exception_index)) { - u8 esr_ec = ESR_ELx_EC(kvm_vcpu_get_esr(vcpu)); - - /* - * HVC already have an adjusted PC, which we need to - * correct in order to return to after having injected - * the SError. - * - * SMC, on the other hand, is *trapped*, meaning its - * preferred return address is the SMC itself. - */ - if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64) - *vcpu_pc(vcpu) -= 4; - - return 1; - } - exception_index = ARM_EXCEPTION_CODE(exception_index); switch (exception_index) { diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 8b2328f62a07..84473574c2e7 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -411,6 +411,21 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ) vcpu->arch.fault.esr_el2 = read_sysreg_el2(SYS_ESR); + if (ARM_SERROR_PENDING(*exit_code)) { + u8 esr_ec = kvm_vcpu_trap_get_class(vcpu); + + /* + * HVC already have an adjusted PC, which we need to + * correct in order to return to after having injected + * the SError. + * + * SMC, on the other hand, is *trapped*, meaning its + * preferred return address is the SMC itself. + */ + if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64) + write_sysreg_el2(read_sysreg_el2(SYS_ELR) - 4, SYS_ELR); + } + /* * We're using the raw exception code in order to only process * the trap if no SError is pending. We will come back to the -- 2.28.0