From patchwork Sat Apr 8 16:04:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13205777 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7325C7619A for ; Sat, 8 Apr 2023 16:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230139AbjDHQFA (ORCPT ); Sat, 8 Apr 2023 12:05:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229899AbjDHQEy (ORCPT ); Sat, 8 Apr 2023 12:04:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A12FFF15 for ; Sat, 8 Apr 2023 09:04:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 554DF60C97 for ; Sat, 8 Apr 2023 16:04:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D938C433AC; Sat, 8 Apr 2023 16:04:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680969891; bh=34/Zlt4htBGJgLYgA2mf1PBt32s5lUf3YI5evv+PwzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jV+8Kwh1lmVgBvYGcG+iC3fyA5kwntvZUgWIUpSeVIpcdceElV3iV+G9LYPudTIRy +pn5TobDu3KgReOMqXKiQDtiXrwrrd8dmySbRIn0nISnHCfGol9ZKg4wWN6dLPFgej VJydRLx166oCho6nN2S4d252TcUO9v+v6BE6Ax2t9fnt8yYgDYJCgxcLaynT7x5cwu qo6nM5tRALtzxPYYKI4AzH0V7C5QpD1lmRlxcmPkIEo2H4I0G8OLuUpGHlGY1wzLRs JaO7AKKGjvRr7I7MEBIrt1T5yftAoQL47I2Vd+6ssVptEYHn4BOrGeqRWCuHCMQ7KI LQ9JyBNFr1a0Q== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1plB3Z-006wc5-LH; Sat, 08 Apr 2023 17:04:49 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Will Deacon Subject: [PATCH v2 5/5] KVM: arm64: vhe: Drop extra isb() on guest exit Date: Sat, 8 Apr 2023 17:04:27 +0100 Message-Id: <20230408160427.10672-6-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230408160427.10672-1-maz@kernel.org> References: <20230408160427.10672-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, will@kernel.org 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 __kvm_vcpu_run_vhe() end on VHE with an isb(). However, this function is only reachable via kvm_call_hyp_ret(), which already contains an isb() in order to mimick the behaviour of nVHE and provide a context synchronisation event. We thus have two isb()s back to back, which is one too many. Drop the first one and solely rely on the one in the helper. Signed-off-by: Marc Zyngier Reviewed-by: Oliver Upton --- arch/arm64/kvm/hyp/vhe/switch.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index cd3f3117bf16..3d868e84c7a0 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -227,11 +227,10 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) /* * When we exit from the guest we change a number of CPU configuration - * parameters, such as traps. Make sure these changes take effect - * before running the host or additional guests. + * parameters, such as traps. We rely on the isb() in kvm_call_hyp*() + * to make sure these changes take effect before running the host or + * additional guests. */ - isb(); - return ret; }