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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2309E7490C for ; Mon, 2 Oct 2023 19:01:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238511AbjJBTBT (ORCPT ); Mon, 2 Oct 2023 15:01:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229502AbjJBTBR (ORCPT ); Mon, 2 Oct 2023 15:01:17 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D392BC6 for ; Mon, 2 Oct 2023 12:01:13 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-59b5a586da6so336137b3.1 for ; Mon, 02 Oct 2023 12:01:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696273273; x=1696878073; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ckwzzbSxH95zbV9Ph3aAP9Fp5FbPi93+Tiiv+0bzk7M=; b=dWkherERAXJwUbcB4LVAVI1asYxXGO6aXixpYhOyv9kIuSGUTcEjwh4BLaWTgxTXzG 7K75V63eR7A9o2tbKD9nu3ZUi6DCeuqdVU46vGgMHiVcsE7jyOrIIRC2Dd45vyIhwQD8 52XgV67+fPs2zds8XPK82H1yn3qWhe2Spt9tYu3s8ojXckAEtHGQ8zuIDyJ9UmRPpnUm nO1+y0hjz5Cn/WLMQiq9x+AFz0CHu1mcIKMPgkAo1L4Toou4V5CTnOJLtm7xJJgG1keC xT/3VtMtPu+S9SeTzmV3HEeYnN+D3NvCIS6yYJtY6Isn/07bXyW3PiKNOzTBvWTNemd7 hNsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696273273; x=1696878073; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ckwzzbSxH95zbV9Ph3aAP9Fp5FbPi93+Tiiv+0bzk7M=; b=sm/iO8PlukUrrFgLeB0Jm88w1sQNXUp46skReOSbFxB9HpEAqo0ZNPhzbsDKdKQjKc 9GENdgRK6egEivzVNya35sXv8+QSQBrHjyqUTQ1YqcBTNaudzcddhZDDQDKKwbHLv4uO VmSAbEW1PygT922AgmYK2K+7uDgX8E5Q5MJmzuBDRgG9Z5R4qsYN2zZEFHe+Hdk4MqtY d6G46b84W7Iq141OKH/zyuAjyU1ip0I4P9hCqQaI8eV76I/RuJts4ujQksyPsNSVUAA8 mTAClswTrm+x1HK+RyoAOYpsL3CQv1zTOtzrDh3ScX23mXiKrM0Qe9ZpnQ0pwL2qvsoS FZZw== X-Gm-Message-State: AOJu0Yzz+NId64MGuSgVahDQfFCtQN++ZfiZGC2Egke4wAskrvykuggj QHqIE+SZ4Q4S8ycEBOi6QLxveA5Jg1s= X-Google-Smtp-Source: AGHT+IFYEOOv4UwLqviXbR+k+OW+wIzCw/xJ4qlPUj28o767UlOg6AdRosVhdf5F+RckQFM18g4YOtNNMdw= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a81:ac07:0:b0:59b:eb4b:2cad with SMTP id k7-20020a81ac07000000b0059beb4b2cadmr9775ywh.5.1696273272964; Mon, 02 Oct 2023 12:01:12 -0700 (PDT) Date: Mon, 2 Oct 2023 12:01:11 -0700 In-Reply-To: <0da9874b6e9fcbaaa5edeb345d7e2a7c859fc818.1696271334.git.thomas.lendacky@amd.com> Mime-Version: 1.0 References: <0da9874b6e9fcbaaa5edeb345d7e2a7c859fc818.1696271334.git.thomas.lendacky@amd.com> Message-ID: Subject: Re: [PATCH] KVM: SVM: Fix build error when using -Werror=unused-but-set-variable From: Sean Christopherson To: Tom Lendacky Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, Paolo Bonzini , Borislav Petkov , Dave Hansen , Ingo Molnar , Thomas Gleixner Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Oct 02, 2023, Tom Lendacky wrote: > Commit 916e3e5f26ab ("KVM: SVM: Do not use user return MSR support for > virtualized TSC_AUX") introduced a local variable used for the rdmsr() > function for the high 32-bits of the MSR value. This variable is not used > after being set and triggers a warning or error, when treating warnings > as errors, when the unused-but-set-variable flag is set. Mark this > variable as __maybe_unused to fix this. > > Fixes: 916e3e5f26ab ("KVM: SVM: Do not use user return MSR support for virtualized TSC_AUX") > Signed-off-by: Tom Lendacky > --- > arch/x86/kvm/svm/svm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 9507df93f410..4c917c74a4d3 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -691,7 +691,7 @@ static int svm_hardware_enable(void) > */ > if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) { > struct sev_es_save_area *hostsa; > - u32 msr_hi; > + u32 __maybe_unused msr_hi; Argh, the abomination that is rdmsrl() strikes again :-/ We really should be able to do: hostsa->tsc_aux = (u32)rdmsrl(MSR_TSC_AUX); I don't see a better quick fix than __maybe_unused though. Reviewed-by: Sean Christopherson