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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 804C9C433ED for ; Thu, 20 May 2021 12:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62E6061004 for ; Thu, 20 May 2021 12:58:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238379AbhETNAN (ORCPT ); Thu, 20 May 2021 09:00:13 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37048 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242996AbhETM57 (ORCPT ); Thu, 20 May 2021 08:57:59 -0400 Received: from mail-qt1-f197.google.com ([209.85.160.197]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1ljiE7-0005Q5-Ax for linux-kernel@vger.kernel.org; Thu, 20 May 2021 12:56:35 +0000 Received: by mail-qt1-f197.google.com with SMTP id f17-20020ac87f110000b02901e117339ea7so12168447qtk.16 for ; Thu, 20 May 2021 05:56:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=GTsCI7Ul4nDoQha4vSzhm2s0jP3aZ/M4QD8W/QCV/+0=; b=UHjd0qj4Z7kILnp/EwEMmRImHdbxQm8abZWtMPbFT4DMXpl0QyQHPOrKwQeYFIPEuo HY32soyW0ZFTsIfVkfyRWkrmIF0hmLQvHK+qZibxkWrOuBsw4xtyqkrg8qDclSD596P4 ESwqzqhMLl7nBD2bOJtyX6eDh0WmgQfWKtHE4P4pVXyrMfMeuPS+GcLvGwH/GA83tHcY wOmQxorHql0z/i97wEcJhexYwkZq6mMAuYmmUh3BlGEQmbbC3meOcpMYa30NxqH8KhI+ ijPkGQiPsXY4WI+Ej8lZa8N2KKOncAU1xBxnesNtKpgR+2KDbCfYU4/sEtR/FjMogvnP blaA== X-Gm-Message-State: AOAM532vLkWiQdoZf8C0Q34PWhtx/3EJNqm7+IJqulQgF1xLaojwUDQA bA6unQ4pygAHBgyWBfj4pEXGbId+JF4aZm/2YJoNZ2hRbpScAxtdRqmWxUbzHtgQc0O1ku0AFBZ xiJbuom2mUkN7t6MO57gl2nM1mwvIJupB2UpZgtdy2A== X-Received: by 2002:a37:4697:: with SMTP id t145mr4889842qka.188.1621515394431; Thu, 20 May 2021 05:56:34 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzVA/A4t3ep/bU/SXqDGZuuLc1tdq3g7fGuJjWd5nWI06K1ldK6khe556QlVnqNuNVK+VNUrA== X-Received: by 2002:a37:4697:: with SMTP id t145mr4889807qka.188.1621515394226; Thu, 20 May 2021 05:56:34 -0700 (PDT) Received: from localhost.localdomain ([45.237.48.3]) by smtp.gmail.com with ESMTPSA id g185sm1931471qkf.62.2021.05.20.05.56.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 May 2021 05:56:33 -0700 (PDT) From: Krzysztof Kozlowski To: stable@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Vitaly Kuznetsov , Paolo Bonzini , Andrea Righi , Krzysztof Kozlowski Subject: [PATCH stable v5.4+ 1/3] x86/kvm: Teardown PV features on boot CPU as well Date: Thu, 20 May 2021 08:56:23 -0400 Message-Id: <20210520125625.12566-1-krzysztof.kozlowski@canonical.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov commit 8b79feffeca28c5459458fe78676b081e87c93a4 upstream. Various PV features (Async PF, PV EOI, steal time) work through memory shared with hypervisor and when we restore from hibernation we must properly teardown all these features to make sure hypervisor doesn't write to stale locations after we jump to the previously hibernated kernel (which can try to place anything there). For secondary CPUs the job is already done by kvm_cpu_down_prepare(), register syscore ops to do the same for boot CPU. Krzysztof: This fixes memory corruption visible after second resume from hibernation: BUG: Bad page state in process dbus-daemon pfn:18b01 page:ffffea000062c040 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 compound_mapcount: -30591 flags: 0xfffffc0078141(locked|error|workingset|writeback|head|mappedtodisk|reclaim) raw: 000fffffc0078141 dead0000000002d0 dead000000000100 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag set bad because of flags: 0x78141(locked|error|workingset|writeback|head|mappedtodisk|reclaim) Signed-off-by: Vitaly Kuznetsov Message-Id: <20210414123544.1060604-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini Signed-off-by: Andrea Righi [krzysztof: Extend the commit message] Signed-off-by: Krzysztof Kozlowski --- Backport to v5.4 seems reasonable. Might have sense to earlier versions, but this was not tested/investigated. arch/x86/kernel/kvm.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index e820568ed4d5..6b906a651fb1 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -558,17 +559,21 @@ static void kvm_guest_cpu_offline(void) static int kvm_cpu_online(unsigned int cpu) { - local_irq_disable(); + unsigned long flags; + + local_irq_save(flags); kvm_guest_cpu_init(); - local_irq_enable(); + local_irq_restore(flags); return 0; } static int kvm_cpu_down_prepare(unsigned int cpu) { - local_irq_disable(); + unsigned long flags; + + local_irq_save(flags); kvm_guest_cpu_offline(); - local_irq_enable(); + local_irq_restore(flags); return 0; } #endif @@ -606,6 +611,23 @@ static void kvm_flush_tlb_others(const struct cpumask *cpumask, native_flush_tlb_others(flushmask, info); } +static int kvm_suspend(void) +{ + kvm_guest_cpu_offline(); + + return 0; +} + +static void kvm_resume(void) +{ + kvm_cpu_online(raw_smp_processor_id()); +} + +static struct syscore_ops kvm_syscore_ops = { + .suspend = kvm_suspend, + .resume = kvm_resume, +}; + static void __init kvm_guest_init(void) { int i; @@ -649,6 +671,8 @@ static void __init kvm_guest_init(void) kvm_guest_cpu_init(); #endif + register_syscore_ops(&kvm_syscore_ops); + /* * Hard lockup detection is enabled by default. Disable it, as guests * can get false positives too easily, for example if the host is -- 2.27.0