From patchwork Tue Jun 8 18:28:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 457538 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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 44D3DC48BE5 for ; Tue, 8 Jun 2021 19:20:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CD77613DF for ; Tue, 8 Jun 2021 19:20:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234090AbhFHTV4 (ORCPT ); Tue, 8 Jun 2021 15:21:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:40918 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235662AbhFHTSD (ORCPT ); Tue, 8 Jun 2021 15:18:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2496961182; Tue, 8 Jun 2021 18:51:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623178303; bh=RnamPyzzLgDAjpmq5+G3y1v3oSxEB4jU6/3szJu2PRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nk0Xuv7v+eFN/if5AwMFyRCfnzh1P8Y8NfRO0YO5846skG8uYM1PFMz45OvVDVogr 5Zfvwr/eWUtZN8LuYVasfuQvYmh4sIrUu5KpKelLIFBrJjj6LrJDgsT0aPLxd4EUQf F75sYMCkjzHlwNQ892ayYCDnmR51viubUFYuquUU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Vitaly Kuznetsov , Paolo Bonzini , Andrea Righi , Krzysztof Kozlowski Subject: [PATCH 5.12 151/161] x86/kvm: Teardown PV features on boot CPU as well Date: Tue, 8 Jun 2021 20:28:01 +0200 Message-Id: <20210608175950.551225770@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210608175945.476074951@linuxfoundation.org> References: <20210608175945.476074951@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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, adjust for v5.10 context] Signed-off-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kvm.c | 57 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 16 deletions(-) --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -460,6 +461,25 @@ static bool pv_tlb_flush_supported(void) static DEFINE_PER_CPU(cpumask_var_t, __pv_cpu_mask); +static void kvm_guest_cpu_offline(void) +{ + kvm_disable_steal_time(); + if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) + wrmsrl(MSR_KVM_PV_EOI_EN, 0); + kvm_pv_disable_apf(); + apf_task_wake_all(); +} + +static int kvm_cpu_online(unsigned int cpu) +{ + unsigned long flags; + + local_irq_save(flags); + kvm_guest_cpu_init(); + local_irq_restore(flags); + return 0; +} + #ifdef CONFIG_SMP static bool pv_ipi_supported(void) @@ -587,31 +607,34 @@ static void __init kvm_smp_prepare_boot_ kvm_spinlock_init(); } -static void kvm_guest_cpu_offline(void) +static int kvm_cpu_down_prepare(unsigned int cpu) { - kvm_disable_steal_time(); - if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) - wrmsrl(MSR_KVM_PV_EOI_EN, 0); - kvm_pv_disable_apf(); - apf_task_wake_all(); -} + unsigned long flags; -static int kvm_cpu_online(unsigned int cpu) -{ - local_irq_disable(); - kvm_guest_cpu_init(); - local_irq_enable(); + local_irq_save(flags); + kvm_guest_cpu_offline(); + local_irq_restore(flags); return 0; } -static int kvm_cpu_down_prepare(unsigned int cpu) +#endif + +static int kvm_suspend(void) { - local_irq_disable(); kvm_guest_cpu_offline(); - local_irq_enable(); + return 0; } -#endif + +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 kvm_flush_tlb_others(const struct cpumask *cpumask, const struct flush_tlb_info *info) @@ -681,6 +704,8 @@ 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