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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 C64E4C433DB for ; Fri, 12 Feb 2021 16:09:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4049064DEC for ; Fri, 12 Feb 2021 16:09:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4049064DEC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51312 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lAb0V-00012D-CR for qemu-devel@archiver.kernel.org; Fri, 12 Feb 2021 11:09:23 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56564) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lAawq-0005kZ-BS for qemu-devel@nongnu.org; Fri, 12 Feb 2021 11:05:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38041) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lAawo-0006Bq-L4 for qemu-devel@nongnu.org; Fri, 12 Feb 2021 11:05:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613145933; 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=U/EJ982m9Kcn0lN1l+VAmQGfXPp5H1MHwizJAbKNsUU=; b=GEJbaZVjCW8L0ee0rsZv1AHnRND0dVYfK+gJiGJqQn7vf6rcSjCRsBCZN3diV7gb47wZxd lBxPWAdVtUK1De9TcljGED9YHDio7GSJfzaAVTao6nBgjSMNHxMmQPbAu5F+zbSOdn0A24 0L8C5ad9Ny6nzjrHzhyivO/uNMBXY7w= 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-509-aJeS4iJcPwyjizV8IgSW7w-1; Fri, 12 Feb 2021 11:05:32 -0500 X-MC-Unique: aJeS4iJcPwyjizV8IgSW7w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 22DF8801994 for ; Fri, 12 Feb 2021 16:05:31 +0000 (UTC) Received: from localhost (unknown [10.40.208.60]) by smtp.corp.redhat.com (Postfix) with ESMTP id 52B526F134; Fri, 12 Feb 2021 16:05:29 +0000 (UTC) Date: Fri, 12 Feb 2021 17:05:27 +0100 From: Igor Mammedov To: Vitaly Kuznetsov Subject: Re: [PATCH v4 16/21] i386: track explicit 'hv-*' features enablement/disablement Message-ID: <20210212170527.0e93e6b2@redhat.com> In-Reply-To: <87h7mhl33o.fsf@vitty.brq.redhat.com> References: <20210210164033.607612-1-vkuznets@redhat.com> <20210210164033.607612-17-vkuznets@redhat.com> <20210211183555.2136b5c8@redhat.com> <87tuqhllmn.fsf@vitty.brq.redhat.com> <20210212151259.3db7406f@redhat.com> <87k0rdl3er.fsf@vitty.brq.redhat.com> <87h7mhl33o.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=imammedo@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.569, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , drjones@redhat.com, Marcelo Tosatti , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 12 Feb 2021 16:26:03 +0100 Vitaly Kuznetsov wrote: > Vitaly Kuznetsov writes: > > > Igor Mammedov writes: > > > >> > >> Please try reusing scratch CPU approach, see > >> kvm_arm_get_host_cpu_features() > >> for an example. You will very likely end up with simpler series, > >> compared to reinventing wheel. > > > > Even if I do that (and I serioulsy doubt it's going to be easier than > > just adding two 'u64's, kvm_arm_get_host_cpu_features() alone is 200 > > lines long) this is not going to give us what we need to distinguish > > between > > > > 'hv-passthrough,hv-evmcs' > > > > and > > > > 'hv-passthrough' > > > > when 'hv-evmcs' *is* supported by the host. When guest CPU lacks VMX we > > don't want to enable it unless it was requested explicitly (former but > > not the later). > > ... and if for whatever reason we decide that this is also bad/not > needed, I can just drop patches 16-18 from the series (leaving > 'hv-passthrough,hv-feature=off' problem to better times). that's also an option, we would need to make sure that hv-passthrough is mutually exclusive with ''all'' other hv- properties to avoid above combination being ever (mis)used.