From patchwork Thu Nov 21 18:53:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mingwei Zhang X-Patchwork-Id: 13882292 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFFC61E0DD4 for ; Thu, 21 Nov 2024 18:53:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732215226; cv=none; b=CVD4xtMdjioDgHe92DxRkhb0vJmo6wDKKt834e3uGIQFZeABBOWclj3PG8Ei02tqTcKtK/JuG/saNqFUpx2X6tO3bOA7J6q7yU1Q5vFD4qFfWTfLGt0Q1Sl0wMfyRc+aBaGou4O/k/i36ZYlS733ISDdqnDTr+pUXhOf8Ej2804= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732215226; c=relaxed/simple; bh=E9JI3Pd2om4q8RKGN7/yj9E3VkNXyoDn/zNLNHrykuQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=TuUc1YAha589eBipo+wSOvxYGfFX1MUNgkUNe1rn9k32Z5tIl6p5BjfHeuwEFIGKfXKyOmrW3aUdJcPICk7wAzttgT/MIUZ2IvyZqZrfxYjS9ETwaMGshsfT73CEnuIfbFHcOhMrl0PJRVHYJ+l+IAmHlR5v7QhCrgDuNrbQ4PM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mizhang.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=oCmsRzS5; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--mizhang.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="oCmsRzS5" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-724d6a812b6so621927b3a.3 for ; Thu, 21 Nov 2024 10:53:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1732215224; x=1732820024; darn=vger.kernel.org; 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=SnSGQmraT80AADBF0uMReh/30q4TRUP6V5ySJUvAAIk=; b=oCmsRzS5dt2UE7gkJk1GB7BUosxs5Hyb/g1ZGI4fCoWSqXPokVndRZVLWWERDKa9ru +l2DR0IllkhPdrvH/xS08qHJZjIE68yE0jpT/j1zt2araBGF3O4mpteRVMkUWJBE68yU /aWkmvhUykH0AdcOjCnGJYLSyYU2vWAAtazmqVqr6NI4r8gCZev7LkmHupXuSZsWSH0P EopJtRgVuha2OgmFLGYwOfEfU0QWygQ7S02evEL+iMkRvLqFnwLrRORCRa1ZaYkZNlp1 pMzCWbcLq5d3LWGwu1sZDt0SfsQJQS9TqQFnUiMzZyw/taj3AOkqGxkhyN1bXADHqmF/ N8iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732215224; x=1732820024; 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=SnSGQmraT80AADBF0uMReh/30q4TRUP6V5ySJUvAAIk=; b=Hr8BBdEDTE1590DkvyU6e9+AYh0+mJpte/xlI/dGwcZgTdgms1Of0I0M0t0dy57vaz 2/h9pPUcX8I8tNDoQS1+6waY4d6EEVaK+0PwsetC1FRdNGLOnZTpXlPYSZ9NKjeFzI0Z LjAqRtLJPuSILPEU48kmsb/q/wq3dH/YgFms2BSOb5EYlZeuMDbYYHO5QOUrGwGMGfWE XeWjvylZNkpBXinY3CA9kyzIpvejQGkSFPvzPv43K8Mqdo/twCYiDXlkhI72zewwrKX6 d3jRcPP/pAnBqZFenbGok17dw7xS/RJoKprBy/9OsUnHrixFIM3R5EZOW9mSivTwO+Ok buiQ== X-Forwarded-Encrypted: i=1; AJvYcCU+fAE2vaDSBsZMTK0yJ/RjLcsE79waLTNqyanWcyppjy8SWS+BpmaueKprsl1tfaWCafkkn6vlPA==@vger.kernel.org X-Gm-Message-State: AOJu0Yz1fr3TZ9iEJ5Z4QkBBdv2QRcUliUL2vI6ks+M5gtqVTo+Agkus ki9sJNV7S5Kj2AjFMwAzGd/MJaA1N7z0PUPBcpcU5Iz4yjMQxRXnQwS1yY4bSulDZXwUZ3Y+tZp AOblOZw== X-Google-Smtp-Source: AGHT+IGyVXzczMNxhGjYz9B0YSQ0wD+pGCEGi8sb3RmGy5Whzw9pkoB0H3zOHOP/5JzV1UzbqMu+KUIB6p/E X-Received: from mizhang-super.c.googlers.com ([34.105.13.176]) (user=mizhang job=sendgmr) by 2002:a17:902:d4cf:b0:212:6061:251c with SMTP id d9443c01a7336-2129f2717c3mr535ad.7.1732215224004; Thu, 21 Nov 2024 10:53:44 -0800 (PST) Reply-To: Mingwei Zhang Date: Thu, 21 Nov 2024 18:53:07 +0000 In-Reply-To: <20241121185315.3416855-1-mizhang@google.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241121185315.3416855-1-mizhang@google.com> X-Mailer: git-send-email 2.47.0.371.ga323438b13-goog Message-ID: <20241121185315.3416855-16-mizhang@google.com> Subject: [RFC PATCH 15/22] KVM: x86: Restore host IA32_[AM]PERF on userspace return From: Mingwei Zhang To: Sean Christopherson , Paolo Bonzini , Huang Rui , "Gautham R. Shenoy" , Mario Limonciello , "Rafael J. Wysocki" , Viresh Kumar , Srinivas Pandruvada , Len Brown Cc: "H. Peter Anvin" , Perry Yuan , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Jim Mattson , Mingwei Zhang From: Jim Mattson Add support for restoring host IA32_APERF and IA32_MPERF values when returning to userspace. While not strictly necessary since reads of /dev/cpu/*/msr now reconstruct host values, restoring the host values maintains cleaner system state. Leverage KVM's existing user return notifier infrastructure but add a separate flag since these MSRs require dynamic value restoration rather than static value restoration. Restoration is only performed when guest values have been loaded into the hardware MSRs. Signed-off-by: Jim Mattson --- arch/x86/kvm/x86.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6df8f21b83eb1..ad5351673362c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -207,6 +207,7 @@ module_param(mitigate_smt_rsb, bool, 0444); struct kvm_user_return_msrs { struct user_return_notifier urn; bool registered; + bool restore_aperfmperf; struct kvm_user_return_msr_values { u64 host; u64 curr; @@ -571,6 +572,11 @@ static void kvm_on_user_return(struct user_return_notifier *urn) * interrupted and executed through kvm_arch_disable_virtualization_cpu() */ local_irq_save(flags); + if (msrs->restore_aperfmperf) { + restore_host_aperf(); + restore_host_mperf(); + msrs->restore_aperfmperf = false; + } if (msrs->registered) { msrs->registered = false; user_return_notifier_unregister(urn); @@ -5003,6 +5009,7 @@ static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu) static void kvm_load_guest_aperfmperf(struct kvm_vcpu *vcpu, bool update_mperf) { + struct kvm_user_return_msrs *msrs; unsigned long flags; local_irq_save(flags); @@ -5011,6 +5018,9 @@ static void kvm_load_guest_aperfmperf(struct kvm_vcpu *vcpu, bool update_mperf) set_guest_aperf(vcpu->arch.aperfmperf.guest_aperf); set_guest_mperf(vcpu->arch.aperfmperf.guest_mperf); vcpu->arch.aperfmperf.loaded_while_running = true; + msrs = this_cpu_ptr(user_return_msrs); + kvm_user_return_notifier_register(msrs); + msrs->restore_aperfmperf = true; local_irq_restore(flags); }