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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 8BD09C2D0C0 for ; Fri, 20 Dec 2019 09:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60F6324683 for ; Fri, 20 Dec 2019 09:51:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IVln0UOQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727177AbfLTJvF (ORCPT ); Fri, 20 Dec 2019 04:51:05 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:40479 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727176AbfLTJvD (ORCPT ); Fri, 20 Dec 2019 04:51:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576835461; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=99eauVFberJXv2fQAwZtixMy3egbUdn3Of2y1/7QSBo=; b=IVln0UOQ+zyEwEHp55eUIZiZy/FvqttwaBseZUpaEi7qW2GKRk21WB3vBefLls1NXRIba7 mTZBO7WsPcULlQ8CaX2KBHZHTnf2YOwlQPFXXXyOPKD/UeoA8CHkVQQ21Cdub+kB1Vagr4 EjLD6zOjQX+oe7DSP6lxjcGM4VP2kJo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-232-KSOnSj7mOiGqSWdMbp1wmw-1; Fri, 20 Dec 2019 04:51:00 -0500 X-MC-Unique: KSOnSj7mOiGqSWdMbp1wmw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 04477189CD00; Fri, 20 Dec 2019 09:50:58 +0000 (UTC) Received: from gondolin (dhcp-192-245.str.redhat.com [10.33.192.245]) by smtp.corp.redhat.com (Postfix) with ESMTP id B0B7C26FC4; Fri, 20 Dec 2019 09:50:51 +0000 (UTC) Date: Fri, 20 Dec 2019 10:50:49 +0100 From: Cornelia Huck To: Sean Christopherson Cc: Marc Zyngier , James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini , James Morse , Julien Thierry , Suzuki K Poulose , David Hildenbrand , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kurz Subject: Re: [PATCH v2 32/45] KVM: Move initialization of preempt notifier to kvm_vcpu_init() Message-ID: <20191220105049.3fbdbbcc.cohuck@redhat.com> In-Reply-To: <20191218215530.2280-33-sean.j.christopherson@intel.com> References: <20191218215530.2280-1-sean.j.christopherson@intel.com> <20191218215530.2280-33-sean.j.christopherson@intel.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Wed, 18 Dec 2019 13:55:17 -0800 Sean Christopherson wrote: > Initialize the preempt notifier immediately in kvm_vcpu_init() to pave > the way for removing kvm_arch_vcpu_setup(), i.e. to allow arch specific > code to call vcpu_load() during kvm_arch_vcpu_create(). > > Back when preemption support was added, the location of the call to init > the preempt notifier was perfectly sane. The overall vCPU creation flow > featured a single arch specific hook and the preempt notifer was used > immediately after its initialization (by vcpu_load()). E.g.: > > vcpu = kvm_arch_ops->vcpu_create(kvm, n); > if (IS_ERR(vcpu)) > return PTR_ERR(vcpu); > > preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops); > > vcpu_load(vcpu); > r = kvm_mmu_setup(vcpu); > vcpu_put(vcpu); > if (r < 0) > goto free_vcpu; > > Today, the call to preempt_notifier_init() is sandwiched between two > arch specific calls, kvm_arch_vcpu_create() and kvm_arch_vcpu_setup(), > which needlessly forces x86 (and possibly others?) to split its vCPU > creation flow. Init the preempt notifier prior to any arch specific > call so that each arch can independently decide how best to organize > its creation flow. > > Acked-by: Christoffer Dall > Signed-off-by: Sean Christopherson > --- > virt/kvm/kvm_main.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) Reviewed-by: Cornelia Huck