From patchwork Wed May 26 05:17:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 1483874 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FqfNM1f3Kz9sW6; Wed, 26 May 2021 15:17:55 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1lllvT-00025W-PD; Wed, 26 May 2021 05:17:51 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lllvS-00024y-4N for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:50 +0000 Received: from mail-ed1-f70.google.com ([209.85.208.70]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lllvR-0004NJ-Qh for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:49 +0000 Received: by mail-ed1-f70.google.com with SMTP id q18-20020a0564025192b02903888712212fso18607692edd.19 for ; Tue, 25 May 2021 22:17:49 -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:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=b+ahStrFNd73ekZGSav8vwQDEy+ByVA9UhkZl6i9www=; b=URoWiJLrADmJeN2JdCjCWBrvoD4ZcI3O78ruwoKuNqOyGaG9U4W63qGrM+kEKdxE2X b156WnGNJ6znsc8XPlySQdIM5SJSjFUIJbc/ynJEJd7qB3slnlnMymnpydR+vEjy428k 3ieQs8p4h2dVcqpH0F2i6kHAT2keJaPoRTxokomHYyM9RP9h9/hyR4qeo4umclTaHR7f IeASwBsQQgIec2x4gGRp6ZV3Nb10OKa0rwAOH6D1ZH7emy7K8cH5eNF1hdsCum2YIp1d 6qrrsOi+8e4zDTMjlVMoYB5XnwS9JH5edj1Fp231sieJ7Vs/TJED3pJoQCVoSRsCsmhc yNew== X-Gm-Message-State: AOAM5311zGG+8bOc5e3dxY+CkzZ+Gk2BBPTgBRtw3ogDyXZbug3w14bL /ZwP0WeYoOO/d9neYbAvjiF6MFSC4PKxWpOv/heopnc/GRnsrRfnBvMUXuTjdPvX5fw5ccPhMx0 VD26ccG4BOkUKdV055BiqDNGfkvP+m7N//jxce12F/A== X-Received: by 2002:a05:6402:60a:: with SMTP id n10mr9011733edv.241.1622006269483; Tue, 25 May 2021 22:17:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxndr82BSsTtbyeRRUjgeWdjTt8BQRhsE0TqUz7CbezY5oo1unN5tUVo4LBGLl8x7px1uMqng== X-Received: by 2002:a05:6402:60a:: with SMTP id n10mr9011716edv.241.1622006269320; Tue, 25 May 2021 22:17:49 -0700 (PDT) Received: from xps-13-7390.homenet.telecomitalia.it (host-87-19-3-42.retail.telecomitalia.it. [87.19.3.42]) by smtp.gmail.com with ESMTPSA id bh3sm9783270ejb.19.2021.05.25.22.17.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 22:17:49 -0700 (PDT) From: Andrea Righi To: kernel-team@lists.ubuntu.com Subject: [SRU][G][PATCH v2 1/5] x86/kvm: Fix pr_info() for async PF setup/teardown Date: Wed, 26 May 2021 07:17:40 +0200 Message-Id: <20210526051744.218062-2-andrea.righi@canonical.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210526051744.218062-1-andrea.righi@canonical.com> References: <20210526051744.218062-1-andrea.righi@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Vitaly Kuznetsov BugLink: https://bugs.launchpad.net/bugs/1920944 'pr_fmt' already has 'kvm-guest: ' so 'KVM' prefix is redundant. "Unregister pv shared memory" is very ambiguous, it's hard to say which particular PV feature it relates to. Signed-off-by: Vitaly Kuznetsov Message-Id: <20210414123544.1060604-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini (cherry picked from commit 0a269a008f837e76ce285679ab3005059fadc2a6) Signed-off-by: Andrea Righi --- arch/x86/kernel/kvm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index df63786e7bfa..0fee42222a8f 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -324,7 +324,7 @@ static void kvm_guest_cpu_init(void) wrmsrl(MSR_KVM_ASYNC_PF_EN, pa); __this_cpu_write(apf_reason.enabled, 1); - pr_info("KVM setup async PF for cpu %d\n", smp_processor_id()); + pr_info("setup async PF for cpu %d\n", smp_processor_id()); } if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) { @@ -350,7 +350,7 @@ static void kvm_pv_disable_apf(void) wrmsrl(MSR_KVM_ASYNC_PF_EN, 0); __this_cpu_write(apf_reason.enabled, 0); - pr_info("Unregister pv shared memory for cpu %d\n", smp_processor_id()); + pr_info("disable async PF for cpu %d\n", smp_processor_id()); } static void kvm_pv_guest_cpu_reboot(void *unused) From patchwork Wed May 26 05:17:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 1483875 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FqfNN2bpDz9sW7; Wed, 26 May 2021 15:17:56 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1lllvV-00026M-18; Wed, 26 May 2021 05:17:53 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lllvS-000254-Ls for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:50 +0000 Received: from mail-ej1-f72.google.com ([209.85.218.72]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lllvS-0004NW-DY for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:50 +0000 Received: by mail-ej1-f72.google.com with SMTP id p5-20020a17090653c5b02903db1cfa514dso46347ejo.13 for ; Tue, 25 May 2021 22:17:50 -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:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5shXqSq94BD7EbdsG7sg/d43dq5eHsrbGEBDcUivfTA=; b=YbtatMzA82fGja+eMcoTFNrbXN46mlMgNJs+BsoITFabAxWtxNT6ITn+Pkc56Hmoxd qBno+HsJZbLfgKqUD1IY3QgKCzEigJwyzBsVb8OWGh7XETBZTd096IcQDhN8DPuujkDs M9o3NYUQaLeA7XAlU4bBumo2mohgMgdVCnlWxh3FQWTL4DGOFATa/Kgn0l0498LgDoV2 dLg96RbmA8m2QADthems9G2WQ2VaDt7uYjxk1QlIRJWN3ttJap6Dxb0RR3qzkJvghUb8 mYNcpw8Myh1acHisOoYsOsSIgJ9DEBIy5Qg1uvazKy1HaxhU/lQJ/hiSSdusdQH7fWkQ tm4w== X-Gm-Message-State: AOAM531Llidy3jJevN3CN3ZFYRhkR8c7RU/CWnsvAYtwkxvRFUzFtRHR o0UTcP3g3BEaoc8CDpiQN8+dQ9bO+xRn+IkgYWt1i1+oSECiT569gxq/V1c0QATtP99Iuqgxs3z iSi17Rz4SmcU+lR4DlmtqmDI+F3I0UZHMhuz8clEUPw== X-Received: by 2002:a50:bf0f:: with SMTP id f15mr33805479edk.205.1622006270133; Tue, 25 May 2021 22:17:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxLVs1Vn3OjDKUSMnRThL2JNA68djtNWTnmjorz0JYkle2dQMt7kRxEBlGxi7bfNC7eD3kaiQ== X-Received: by 2002:a50:bf0f:: with SMTP id f15mr33805460edk.205.1622006269913; Tue, 25 May 2021 22:17:49 -0700 (PDT) Received: from xps-13-7390.homenet.telecomitalia.it (host-87-19-3-42.retail.telecomitalia.it. [87.19.3.42]) by smtp.gmail.com with ESMTPSA id bh3sm9783270ejb.19.2021.05.25.22.17.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 22:17:49 -0700 (PDT) From: Andrea Righi To: kernel-team@lists.ubuntu.com Subject: [SRU][G][PATCH v2 2/5] x86/kvm: Teardown PV features on boot CPU as well Date: Wed, 26 May 2021 07:17:41 +0200 Message-Id: <20210526051744.218062-3-andrea.righi@canonical.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210526051744.218062-1-andrea.righi@canonical.com> References: <20210526051744.218062-1-andrea.righi@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Vitaly Kuznetsov BugLink: https://bugs.launchpad.net/bugs/1920944 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. Signed-off-by: Vitaly Kuznetsov Message-Id: <20210414123544.1060604-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini (backported from commit 8b79feffeca28c5459458fe78676b081e87c93a4) Signed-off-by: Andrea Righi --- arch/x86/kernel/kvm.c | 57 +++++++++++++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 0fee42222a8f..4dc69777417a 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -430,6 +431,25 @@ static void __init sev_map_percpu_data(void) } } +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; +} + static bool pv_tlb_flush_supported(void) { return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) && @@ -571,31 +591,34 @@ static void __init kvm_smp_prepare_boot_cpu(void) 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) @@ -664,6 +687,8 @@ 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 From patchwork Wed May 26 05:17:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 1483876 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FqfNP5ZhWz9s1l; Wed, 26 May 2021 15:17:57 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1lllvV-00026p-DE; Wed, 26 May 2021 05:17:53 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lllvT-00025A-96 for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:51 +0000 Received: from mail-ed1-f70.google.com ([209.85.208.70]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lllvT-0004Ng-1E for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:51 +0000 Received: by mail-ed1-f70.google.com with SMTP id c21-20020a0564021015b029038c3f08ce5aso18769738edu.18 for ; Tue, 25 May 2021 22:17:51 -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:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RDtaF0XulObDXaTH81Eo+oZvgVxGgr9fJViIuqZBWqc=; b=nFwKo0uhDJxzMqnNExhCXQTZSkh4f3GW2EivUcIXd++e9/4+7QJubfgWOmMIoBkaVM N0vOlXq/ZA5NswCwxhmRL93VVhZlF6RugxuGBTBABmHH1pg0hv7WXl1KLR3lixljufRT j49GCbjVPstfqM2XnSr+5MFzPZj0eb5qyfOI0JG/FC27DlHR5qGHB4bhpsfp2pZMHeGo Djb5n+007Vi8ToJNMwWURQMwWZRRESvFWpBn1pvZzgn4nu1CW/uKRFd8Mwp+zrIlHnkD Fb42QocTHPwX7ZJVIQr4M5JED3qrY+vgJ2pTYqXm2YCQax09SkWK95h8MwPZYDkkJ1TH duPw== X-Gm-Message-State: AOAM531fWYgCpUM4hxS2rADDFY0y2WSELdCGbSAQaRT09/FISEzyhjD+ sc2VyI/3LmGtntCkf5RM4VQgAEkVpdjUr/LkMln4WPP2FmFhY6uiAfPzL+Yyi90Z5nWBRpy2JKy M4v1uLgWtlJBz7Rlrrj2BGKzmdFlYmBCTZ2QxC4kLBQ== X-Received: by 2002:a05:6402:1052:: with SMTP id e18mr36646568edu.366.1622006270786; Tue, 25 May 2021 22:17:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzqVdG9QV1RJxHjYZXPVxdYE7+qpmfXETqd7ieVUDukhB2yBo9cLkRKF8dprLNZvjZxdMPe+A== X-Received: by 2002:a05:6402:1052:: with SMTP id e18mr36646547edu.366.1622006270527; Tue, 25 May 2021 22:17:50 -0700 (PDT) Received: from xps-13-7390.homenet.telecomitalia.it (host-87-19-3-42.retail.telecomitalia.it. [87.19.3.42]) by smtp.gmail.com with ESMTPSA id bh3sm9783270ejb.19.2021.05.25.22.17.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 22:17:50 -0700 (PDT) From: Andrea Righi To: kernel-team@lists.ubuntu.com Subject: [SRU][G][PATCH v2 3/5] x86/kvm: Disable kvmclock on all CPUs on shutdown Date: Wed, 26 May 2021 07:17:42 +0200 Message-Id: <20210526051744.218062-4-andrea.righi@canonical.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210526051744.218062-1-andrea.righi@canonical.com> References: <20210526051744.218062-1-andrea.righi@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Vitaly Kuznetsov BugLink: https://bugs.launchpad.net/bugs/1920944 Currenly, we disable kvmclock from machine_shutdown() hook and this only happens for boot CPU. We need to disable it for all CPUs to guard against memory corruption e.g. on restore from hibernate. Note, writing '0' to kvmclock MSR doesn't clear memory location, it just prevents hypervisor from updating the location so for the short while after write and while CPU is still alive, the clock remains usable and correct so we don't need to switch to some other clocksource. Signed-off-by: Vitaly Kuznetsov Message-Id: <20210414123544.1060604-4-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini (cherry picked from commit c02027b5742b5aa804ef08a4a9db433295533046) Signed-off-by: Andrea Righi --- arch/x86/include/asm/kvm_para.h | 4 ++-- arch/x86/kernel/kvm.c | 1 + arch/x86/kernel/kvmclock.c | 5 +---- 3 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 49d3a9edb06f..43cc4a396bee 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -6,8 +6,6 @@ #include #include -extern void kvmclock_init(void); - #ifdef CONFIG_KVM_GUEST bool kvm_check_and_clear_guest_paused(void); #else @@ -85,6 +83,8 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1, } #ifdef CONFIG_KVM_GUEST +void kvmclock_init(void); +void kvmclock_disable(void); bool kvm_para_available(void); unsigned int kvm_arch_para_features(void); unsigned int kvm_arch_para_hints(void); diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 4dc69777417a..74d6c0e344ba 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -438,6 +438,7 @@ static void kvm_guest_cpu_offline(void) wrmsrl(MSR_KVM_PV_EOI_EN, 0); kvm_pv_disable_apf(); apf_task_wake_all(); + kvmclock_disable(); } static int kvm_cpu_online(unsigned int cpu) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 5ee705b44560..327a0de01066 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -221,11 +221,9 @@ static void kvm_crash_shutdown(struct pt_regs *regs) } #endif -static void kvm_shutdown(void) +void kvmclock_disable(void) { native_write_msr(msr_kvm_system_time, 0, 0); - kvm_disable_steal_time(); - native_machine_shutdown(); } static void __init kvmclock_init_mem(void) @@ -352,7 +350,6 @@ void __init kvmclock_init(void) #endif x86_platform.save_sched_clock_state = kvm_save_sched_clock_state; x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state; - machine_ops.shutdown = kvm_shutdown; #ifdef CONFIG_KEXEC_CORE machine_ops.crash_shutdown = kvm_crash_shutdown; #endif From patchwork Wed May 26 05:17:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 1483878 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FqfNY6lvjz9s1l; Wed, 26 May 2021 15:18:05 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1lllvd-0002Bw-NH; 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[87.19.3.42]) by smtp.gmail.com with ESMTPSA id bh3sm9783270ejb.19.2021.05.25.22.17.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 22:17:50 -0700 (PDT) From: Andrea Righi To: kernel-team@lists.ubuntu.com Subject: [SRU][G][PATCH v2 4/5] x86/kvm: Disable all PV features on crash Date: Wed, 26 May 2021 07:17:43 +0200 Message-Id: <20210526051744.218062-5-andrea.righi@canonical.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210526051744.218062-1-andrea.righi@canonical.com> References: <20210526051744.218062-1-andrea.righi@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Vitaly Kuznetsov BugLink: https://bugs.launchpad.net/bugs/1920944 Crash shutdown handler only disables kvmclock and steal time, other PV features remain active so we risk corrupting memory or getting some side-effects in kdump kernel. Move crash handler to kvm.c and unify with CPU offline. Signed-off-by: Vitaly Kuznetsov Message-Id: <20210414123544.1060604-5-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini (backported from commit 3d6b84132d2a57b5a74100f6923a8feb679ac2ce) Signed-off-by: Andrea Righi --- arch/x86/include/asm/kvm_para.h | 6 ----- arch/x86/kernel/kvm.c | 44 ++++++++++++++++++++++++--------- arch/x86/kernel/kvmclock.c | 21 ---------------- 3 files changed, 32 insertions(+), 39 deletions(-) diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 43cc4a396bee..b2bfcbffcd74 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -91,7 +91,6 @@ unsigned int kvm_arch_para_hints(void); void kvm_async_pf_task_wait_schedule(u32 token); void kvm_async_pf_task_wake(u32 token); u32 kvm_read_and_reset_apf_flags(void); -void kvm_disable_steal_time(void); bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token); DECLARE_STATIC_KEY_FALSE(kvm_async_pf_enabled); @@ -136,11 +135,6 @@ static inline u32 kvm_read_and_reset_apf_flags(void) return 0; } -static inline void kvm_disable_steal_time(void) -{ - return; -} - static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token) { return false; diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 74d6c0e344ba..83aaefceef7b 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -33,6 +33,7 @@ #include #include #include +#include #include DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled); @@ -354,6 +355,14 @@ static void kvm_pv_disable_apf(void) pr_info("disable async PF for cpu %d\n", smp_processor_id()); } +static void kvm_disable_steal_time(void) +{ + if (!has_steal_clock) + return; + + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); +} + static void kvm_pv_guest_cpu_reboot(void *unused) { /* @@ -396,14 +405,6 @@ static u64 kvm_steal_clock(int cpu) return steal; } -void kvm_disable_steal_time(void) -{ - if (!has_steal_clock) - return; - - wrmsr(MSR_KVM_STEAL_TIME, 0, 0); -} - static inline void __set_percpu_decrypted(void *ptr, unsigned long size) { early_set_memory_decrypted((unsigned long) ptr, size); @@ -431,13 +432,14 @@ static void __init sev_map_percpu_data(void) } } -static void kvm_guest_cpu_offline(void) +static void kvm_guest_cpu_offline(bool shutdown) { 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(); + if (!shutdown) + apf_task_wake_all(); kvmclock_disable(); } @@ -597,7 +599,7 @@ static int kvm_cpu_down_prepare(unsigned int cpu) unsigned long flags; local_irq_save(flags); - kvm_guest_cpu_offline(); + kvm_guest_cpu_offline(false); local_irq_restore(flags); return 0; } @@ -606,7 +608,7 @@ static int kvm_cpu_down_prepare(unsigned int cpu) static int kvm_suspend(void) { - kvm_guest_cpu_offline(); + kvm_guest_cpu_offline(false); return 0; } @@ -647,6 +649,20 @@ static void kvm_flush_tlb_others(const struct cpumask *cpumask, native_flush_tlb_others(flushmask, info); } +/* + * After a PV feature is registered, the host will keep writing to the + * registered memory location. If the guest happens to shutdown, this memory + * won't be valid. In cases like kexec, in which you install a new kernel, this + * means a random memory location will be kept being written. + */ +#ifdef CONFIG_KEXEC_CORE +static void kvm_crash_shutdown(struct pt_regs *regs) +{ + kvm_guest_cpu_offline(true); + native_machine_crash_shutdown(regs); +} +#endif + static void __init kvm_guest_init(void) { int i; @@ -688,6 +704,10 @@ static void __init kvm_guest_init(void) kvm_guest_cpu_init(); #endif +#ifdef CONFIG_KEXEC_CORE + machine_ops.crash_shutdown = kvm_crash_shutdown; +#endif + register_syscore_ops(&kvm_syscore_ops); /* diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 327a0de01066..c4ac26333bc4 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -20,7 +20,6 @@ #include #include #include -#include #include static int kvmclock __initdata = 1; @@ -204,23 +203,6 @@ static void kvm_setup_secondary_clock(void) } #endif -/* - * After the clock is registered, the host will keep writing to the - * registered memory location. If the guest happens to shutdown, this memory - * won't be valid. In cases like kexec, in which you install a new kernel, this - * means a random memory location will be kept being written. So before any - * kind of shutdown from our side, we unregister the clock by writing anything - * that does not have the 'enable' bit set in the msr - */ -#ifdef CONFIG_KEXEC_CORE -static void kvm_crash_shutdown(struct pt_regs *regs) -{ - native_write_msr(msr_kvm_system_time, 0, 0); - kvm_disable_steal_time(); - native_machine_crash_shutdown(regs); -} -#endif - void kvmclock_disable(void) { native_write_msr(msr_kvm_system_time, 0, 0); @@ -350,9 +332,6 @@ void __init kvmclock_init(void) #endif x86_platform.save_sched_clock_state = kvm_save_sched_clock_state; x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state; -#ifdef CONFIG_KEXEC_CORE - machine_ops.crash_shutdown = kvm_crash_shutdown; -#endif kvm_get_preset_lpj(); /* From patchwork Wed May 26 05:17:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 1483877 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FqfNV02WWz9s1l; Wed, 26 May 2021 15:18:01 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1lllvY-00028a-9z; Wed, 26 May 2021 05:17:56 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lllvU-00026B-N9 for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:52 +0000 Received: from mail-ed1-f71.google.com ([209.85.208.71]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lllvU-0004O0-BN for kernel-team@lists.ubuntu.com; Wed, 26 May 2021 05:17:52 +0000 Received: by mail-ed1-f71.google.com with SMTP id m6-20020aa7c4860000b029038d4e973878so14407543edq.10 for ; Tue, 25 May 2021 22:17:52 -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:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=OAENZd26QlTHH8Sbnta84AUDZo/1QezQ7eOfZ7q/qGo=; b=ZQnpJXgxoGJRp6hZ7CFYNYApyxxpai8TzgP7lGN7Jb0jGYBaGmJD3td2+400tRTKiZ qUhMbtEl2A6BrsYxUTqE235bkr0WotHclQFj1cxMPJ1HTKBBhFA5fv7Vv5+l6OhYr8/B z9Lc8mzOr2IbIBaxu5DEsl7d0c4Ki/NBkUlSZZsLWXLZ8x3CV9rgkeoZ+W9Rt6IBrV/U CIy7UIjuFcztAIh4gHbAgzmRqEEpJ68XaND8zal3zC/erTUhegxGfTRZiblQNy9V0EOn gdpEKYLMHA7TeyEsiulLB2xzR1WthKD4YJA5tCfc4FvSdlkuaugl/Zi9Fse7WxKogJhc 29SQ== X-Gm-Message-State: AOAM531A/s41pnEStQhQeKTBQuJV9pEW9gN5iGVonY8FavVT1bZ52FqC gglbplu2X5vZ6c6PmeUJTwcf7AHQeo+CDmpM94g1urQv2G6EayuRw6GRuhRhYogcFzvcNPE9lgU +sUhAcZXyb1+1wq2QpHETFm8wo4zjD+zepze0moLE6Q== X-Received: by 2002:a05:6402:4394:: with SMTP id o20mr17606756edc.357.1622006272027; Tue, 25 May 2021 22:17:52 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyL6WNySVOxVEzOfRo7Mv5Y6503oiks2UOD9salhLfWxaQKbHYYXVAaSwXgxXLiQsvy/nOotg== X-Received: by 2002:a05:6402:4394:: with SMTP id o20mr17606741edc.357.1622006271782; Tue, 25 May 2021 22:17:51 -0700 (PDT) Received: from xps-13-7390.homenet.telecomitalia.it (host-87-19-3-42.retail.telecomitalia.it. [87.19.3.42]) by smtp.gmail.com with ESMTPSA id bh3sm9783270ejb.19.2021.05.25.22.17.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 22:17:51 -0700 (PDT) From: Andrea Righi To: kernel-team@lists.ubuntu.com Subject: [SRU][G][PATCH v2 5/5] x86/kvm: Unify kvm_pv_guest_cpu_reboot() with kvm_guest_cpu_offline() Date: Wed, 26 May 2021 07:17:44 +0200 Message-Id: <20210526051744.218062-6-andrea.righi@canonical.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210526051744.218062-1-andrea.righi@canonical.com> References: <20210526051744.218062-1-andrea.righi@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Vitaly Kuznetsov BugLink: https://bugs.launchpad.net/bugs/1920944 Simplify the code by making PV features shutdown happen in one place. Signed-off-by: Vitaly Kuznetsov Message-Id: <20210414123544.1060604-6-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini (backported from commit 384fc672f528d3b84eacd9a86ecf35df3363b8ba) Signed-off-by: Andrea Righi --- arch/x86/kernel/kvm.c | 42 +++++++++++++++++------------------------- 1 file changed, 17 insertions(+), 25 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 83aaefceef7b..7c8d29936fa2 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -363,31 +363,6 @@ static void kvm_disable_steal_time(void) wrmsr(MSR_KVM_STEAL_TIME, 0, 0); } -static void kvm_pv_guest_cpu_reboot(void *unused) -{ - /* - * We disable PV EOI before we load a new kernel by kexec, - * since MSR_KVM_PV_EOI_EN stores a pointer into old kernel's memory. - * New kernel can re-enable when it boots. - */ - if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) - wrmsrl(MSR_KVM_PV_EOI_EN, 0); - kvm_pv_disable_apf(); - kvm_disable_steal_time(); -} - -static int kvm_pv_reboot_notify(struct notifier_block *nb, - unsigned long code, void *unused) -{ - if (code == SYS_RESTART) - on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1); - return NOTIFY_DONE; -} - -static struct notifier_block kvm_pv_reboot_nb = { - .notifier_call = kvm_pv_reboot_notify, -}; - static u64 kvm_steal_clock(int cpu) { u64 steal; @@ -649,6 +624,23 @@ static void kvm_flush_tlb_others(const struct cpumask *cpumask, native_flush_tlb_others(flushmask, info); } +static void kvm_pv_guest_cpu_reboot(void *unused) +{ + kvm_guest_cpu_offline(true); +} + +static int kvm_pv_reboot_notify(struct notifier_block *nb, + unsigned long code, void *unused) +{ + if (code == SYS_RESTART) + on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1); + return NOTIFY_DONE; +} + +static struct notifier_block kvm_pv_reboot_nb = { + .notifier_call = kvm_pv_reboot_notify, +}; + /* * After a PV feature is registered, the host will keep writing to the * registered memory location. If the guest happens to shutdown, this memory