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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 1F3DEC47082 for ; Sat, 5 Jun 2021 10:00:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED01761380 for ; Sat, 5 Jun 2021 10:00:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229996AbhFEKBt (ORCPT ); Sat, 5 Jun 2021 06:01:49 -0400 Received: from mail-pg1-f179.google.com ([209.85.215.179]:41795 "EHLO mail-pg1-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229892AbhFEKBs (ORCPT ); Sat, 5 Jun 2021 06:01:48 -0400 Received: by mail-pg1-f179.google.com with SMTP id r1so9810453pgk.8 for ; Sat, 05 Jun 2021 02:59:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=rU2usZ6VpDrKQ/HrTkQUgy/LgHtMhtKYtSjZTXup1js=; b=FNbHgZgVHC73euLBNurTr2gkMzOg9gUTR9Xn/anWwvF5F/LJ1cWHmTL/AMCZ96DOpb cW9ljrC5vSTCKlvBmB+T7wuci/0UqH8tmGwp8Ymb4t6uJfrLXsOzdsE/aCipTiLwQwQJ CFzWyXdBitc+67wvyN3ObwB8U5WHQjJtS7U5I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=rU2usZ6VpDrKQ/HrTkQUgy/LgHtMhtKYtSjZTXup1js=; b=PS7dmKmex/JYHCeXchUe2gDfnT+OprGWMAaqFcr3FvcUyAuY1xqsHydgHaz7QnHpH9 D75Gc3Bp+BVquiyi/p0/b7AXaKEKHfI3AT/pSYpXcODR0wx6NAPixDi3kx0Wp1IZtpOB p2thFu+DFRI2OjkH95D5uVk8A4PnAO0ymrhdXiSbmZidnlX4mzxCwpdFD4HazqAr50rD dTIXrd2UhAi6Ak6L6j8YOyNi4ZmrqfdqakH2gpMY6HdWgYC4p2BpfBEQXy1/xLE/tZXj QbTLWZj1OLFNrT6rOQY6xqF5hfdpHuYZdlgwD9ioc85A0zOEiwLKnt4cUqhTuZ4T5Guh tWKA== X-Gm-Message-State: AOAM532Cq9HC/yXW3jqBflDmYVpLU/DuPStTGBCvI+86XQ5VXy+aQ45o X+eIKZhmbsbWIrTibd7uXgtB4Q== X-Google-Smtp-Source: ABdhPJwGDuNhrymzH8+2TldAhTJbECpNX2SQAoAgQnmb139POYKcBzQCqbfUJo5CsVrYUjn2f6SSog== X-Received: by 2002:a63:6644:: with SMTP id a65mr9070398pgc.431.1622887129571; Sat, 05 Jun 2021 02:58:49 -0700 (PDT) Received: from google.com ([2409:10:2e40:5100:5981:261e:350c:bb45]) by smtp.gmail.com with ESMTPSA id b23sm3659986pfi.34.2021.06.05.02.58.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Jun 2021 02:58:48 -0700 (PDT) Date: Sat, 5 Jun 2021 18:58:43 +0900 From: Sergey Senozhatsky To: Marc Zyngier Cc: Sergey Senozhatsky , 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 Message-ID: References: <20210605023042.543341-1-senozhatsky@chromium.org> <20210605023042.543341-2-senozhatsky@chromium.org> <87k0n8u1nk.wl-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87k0n8u1nk.wl-maz@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (21/06/05 10:00), Marc Zyngier wrote: [..] > > + select HAVE_KVM_PM_NOTIFIER > > if you write this as: > > select HAVE_KVM_PM_NOTIFIER if PM [..] > > +#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. Thanks. > > +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. No opinion. What shall we do when we fail to suspend the VM? VM's watchdogs will trigger and maybe panic the system after resume.