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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 91D83C4743D for ; Sat, 5 Jun 2021 09:00:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 702A0613EA for ; Sat, 5 Jun 2021 09:00:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230049AbhFEJCH (ORCPT ); Sat, 5 Jun 2021 05:02:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:58672 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229864AbhFEJCH (ORCPT ); Sat, 5 Jun 2021 05:02:07 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8B58F6115B; Sat, 5 Jun 2021 09:00:19 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lpSAD-005ctJ-Fg; Sat, 05 Jun 2021 10:00:17 +0100 Date: Sat, 05 Jun 2021 10:00:15 +0100 Message-ID: <87k0n8u1nk.wl-maz@kernel.org> From: Marc Zyngier To: Sergey Senozhatsky Cc: Paolo Bonzini , Vitaly Kuznetsov , Peter Zijlstra , Suleiman Souhlal , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 2/2] kvm: x86: implement KVM PM-notifier In-Reply-To: <20210605023042.543341-2-senozhatsky@chromium.org> References: <20210605023042.543341-1-senozhatsky@chromium.org> <20210605023042.543341-2-senozhatsky@chromium.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: senozhatsky@chromium.org, pbonzini@redhat.com, vkuznets@redhat.com, peterz@infradead.org, suleiman@google.com, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 05 Jun 2021 03:30:42 +0100, Sergey Senozhatsky wrote: > > Implement PM hibernation/suspend prepare notifiers so that KVM > can reliably set PVCLOCK_GUEST_STOPPED on VCPUs and properly > suspend VMs. > > Signed-off-by: Sergey Senozhatsky > --- > arch/x86/kvm/Kconfig | 1 + > arch/x86/kvm/x86.c | 33 +++++++++++++++++++++++++++++++++ > 2 files changed, 34 insertions(+) > > diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig > index fb8efb387aff..f8e6689f490b 100644 > --- a/arch/x86/kvm/Kconfig > +++ b/arch/x86/kvm/Kconfig > @@ -43,6 +43,7 @@ config KVM > select KVM_GENERIC_DIRTYLOG_READ_PROTECT > select KVM_VFIO > select SRCU > + select HAVE_KVM_PM_NOTIFIER if you write this as: select HAVE_KVM_PM_NOTIFIER if PM ... > help > Support hosting fully virtualized guest machines using hardware > virtualization extensions. You will need a fairly recent > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index b594275d49b5..533d3d010a21 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -58,6 +58,7 @@ > #include > #include > #include > +#include > > #include > > @@ -5615,6 +5616,38 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) > return 0; > } > > +#if defined(CONFIG_PM) && defined(CONFIG_HAVE_KVM_PM_NOTIFIER) ... you can simplify this expression to be a simple #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER in both patches. > +static int kvm_arch_suspend_notifier(struct kvm *kvm) > +{ > + struct kvm_vcpu *vcpu; > + int i, ret; > + > + mutex_lock(&kvm->lock); > + kvm_for_each_vcpu(i, vcpu, kvm) { > + ret = kvm_set_guest_paused(vcpu); > + if (ret) { > + pr_err("Failed to pause guest VCPU%d: %d\n", > + vcpu->vcpu_id, ret); Is it really a good idea to fail suspend when a guest doesn't have PV time enabled? I also wonder how useful the pr_err() is, given that it contains no information that would help identifying which guest failed to pause. > + break; > + } > + } > + mutex_unlock(&kvm->lock); > + > + return ret ? NOTIFY_BAD : NOTIFY_DONE; > +} > + > +int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state) > +{ > + switch (state) { > + case PM_HIBERNATION_PREPARE: > + case PM_SUSPEND_PREPARE: > + return kvm_arch_suspend_notifier(kvm); > + } > + > + return NOTIFY_DONE; > +} > +#endif /* CONFIG_PM && CONFIG_HAVE_KVM_PM_NOTIFIER */ > + > long kvm_arch_vm_ioctl(struct file *filp, > unsigned int ioctl, unsigned long arg) > { > -- > 2.32.0.rc1.229.g3e70b5a671-goog > > Thanks, M. -- Without deviation from the norm, progress is not possible.