From nobody Fri Sep 19 02:20:02 2025 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 4710BC4321E for ; Wed, 30 Nov 2022 23:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230235AbiK3XQk (ORCPT ); Wed, 30 Nov 2022 18:16:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229899AbiK3XQD (ORCPT ); Wed, 30 Nov 2022 18:16:03 -0500 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D6ABA320F for ; Wed, 30 Nov 2022 15:11:26 -0800 (PST) Received: by mail-pg1-x549.google.com with SMTP id 38-20020a630b26000000b004773803dda1so64074pgl.17 for ; Wed, 30 Nov 2022 15:11:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=X0tmq9TjsMbdzf016NYPEZWLDrtJgEerkZwlPByjvHs=; b=ffiAil8tYfi3nQXQblraVPD6jbdbOOCVG7uQkkKJrYkDL25R/TkQAeFRDogqa/QMMv 6wZOWt9R/eeSPWTlpWV3IYmrtl04WJOPJAhS7DhGuKTgLTJnehBcyBsLWlgRsCVFi/Ix ksxZjkBOqqqo9hOr9qKhrYgS8WLlfTE4UM6Vkkhhf880kZVvVEdvLhl4X0FaFYBb/6vC 1lACz1AHExA2AbJQILx7vCyuTDoL44EAFEV/X6CifJwvfMkGg0ai47n8Yg94c4IO+cHQ jlRTeSXfVKpq0j3GPFNIBJZpOCvznvIZyM5DfqXmXJnRlhyCma48IFWCHmjS0A3NCAbs hdMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=X0tmq9TjsMbdzf016NYPEZWLDrtJgEerkZwlPByjvHs=; b=NaWc25oH8btg9akjfJEWPW5ic+2qoQiiSiIYiOtsePmjRswniuvfhHXmpTXzyFF6mN xn9K2Ut1JuaAp3YC27B3l4d5An+dH5NtsznvVr9OyrJT4Ftd868q25uZ+Qkb2mHc/3Po VmkrRgEn1Zj93zRUzNiUnsqdf7imtGTW+p1hPb7duw+GNDSc5hahzAtj9O2/8tff8a3p TWrWkdHggnl358CD7fB6IP8C4r8qS3qtM8ipmj+ymbEb2YiDgq8fYNtJWmHSlFm8UGTs Mj2u/I0zfiJsLRmxtn8OPrntasJJ4ntgJdO001cV7MGNXrGGTODknRGAqGPjWb//MhDG gaDQ== X-Gm-Message-State: ANoB5pmBLnNGWx49XMK//gqEwYBe9bmVdgTTut1RQRul5krTq+7IdT5z 6Wq7kwTobP6+aogGkZ3FWf/ygKcF9G8= X-Google-Smtp-Source: AA0mqf4tYdOmumtBwzOsj2b757evhXiqjnmJBxVweHABwP7YhX6XXp+28OecLtWsiEbLYyMEiAceUWRYidE= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:aa7:8487:0:b0:56c:3bb4:28a8 with SMTP id u7-20020aa78487000000b0056c3bb428a8mr44633084pfn.83.1669849852226; Wed, 30 Nov 2022 15:10:52 -0800 (PST) Reply-To: Sean Christopherson Date: Wed, 30 Nov 2022 23:09:27 +0000 In-Reply-To: <20221130230934.1014142-1-seanjc@google.com> Mime-Version: 1.0 References: <20221130230934.1014142-1-seanjc@google.com> X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221130230934.1014142-44-seanjc@google.com> Subject: [PATCH v2 43/50] KVM: Ensure CPU is stable during low level hardware enable/disable From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Matthew Rosato , Eric Farman , Sean Christopherson , Vitaly Kuznetsov , David Woodhouse , Paul Durrant Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Oliver Upton , Atish Patra , David Hildenbrand , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Yuan Yao , Cornelia Huck , Isaku Yamahata , "=?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?=" , Fabiano Rosas , Michael Ellerman , Kai Huang , Chao Gao , Thomas Gleixner Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Use the non-raw smp_processor_id() in the low hardware enable/disable helpers as KVM absolutely relies on the CPU being stable, e.g. KVM would end up with incorrect state if the task were migrated between accessing cpus_hardware_enabled and actually enabling/disabling hardware. Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d985b24c423b..a46d61e9c053 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5028,7 +5028,7 @@ static struct miscdevice kvm_dev =3D { =20 static void hardware_enable_nolock(void *junk) { - int cpu =3D raw_smp_processor_id(); + int cpu =3D smp_processor_id(); int r; =20 if (cpumask_test_cpu(cpu, cpus_hardware_enabled)) @@ -5070,7 +5070,7 @@ static int kvm_online_cpu(unsigned int cpu) =20 static void hardware_disable_nolock(void *junk) { - int cpu =3D raw_smp_processor_id(); + int cpu =3D smp_processor_id(); =20 if (!cpumask_test_cpu(cpu, cpus_hardware_enabled)) return; --=20 2.38.1.584.g0f3c55d4c2-goog