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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 036BCC282C3 for ; Thu, 24 Jan 2019 17:39:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC079218AF for ; Thu, 24 Jan 2019 17:39:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729101AbfAXRj0 (ORCPT ); Thu, 24 Jan 2019 12:39:26 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:43637 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728134AbfAXRjZ (ORCPT ); Thu, 24 Jan 2019 12:39:25 -0500 Received: by mail-wr1-f65.google.com with SMTP id r10so7403492wrs.10 for ; Thu, 24 Jan 2019 09:39:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=KJYC6aQdTAezeJ8Z5hmL7iHtHcoWplSiWC+qJCJ6By0=; b=eH9BewTkXWKh4F9oR6kwIaszD5rt3nSNZPNvqkmj2kvWcamtmI4MGyaBUICkhsj5J2 9oRAH/Aw9toPnwt/GVggsC0hbUvLw/motMx7Ayk6eCJFK8tcDvQPwpreVL9wW0xyxFfk O+83JDou7Xk3VBnjRapvsZAJ4NFqQi8Xoyz5HTwIpGHutkNRqPsP5uRqPULZC9axrOay 2NfIi6KAE4N37Y2PMQIc7WRcTy/5l1dGE+oAPuP4T9B+uwLoOXAv524L6V8zD8YTqHy9 DjqXbQzFY1Dl/plreRpARD2fiEhgsJmUVs8zTJKGDm0rZSQn59+xXATXiiTozITvbpPT b/sQ== X-Gm-Message-State: AJcUukdkZfA8RTcZqoUCL3+qAhHRzQF1DomDkQZq+nJcfxKhPWoGYgn0 lU1uDMvgB2U/Jls0TMBl4SRYkfVK7ReNAA== X-Google-Smtp-Source: ALg8bN6kMcp0hO2Z6xN8LGcHpfSQjVePcZpfZfZHA8Zm9IfqNLwioP2Fx1uMv5Aah470mnvzm36sPw== X-Received: by 2002:adf:8122:: with SMTP id 31mr8263422wrm.48.1548351563795; Thu, 24 Jan 2019 09:39:23 -0800 (PST) Received: from vitty.brq.redhat.com (nat-pool-brq-t.redhat.com. [213.175.37.10]) by smtp.gmail.com with ESMTPSA id 143sm129809788wml.14.2019.01.24.09.39.22 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 24 Jan 2019 09:39:22 -0800 (PST) From: Vitaly Kuznetsov To: Liran Alon Cc: kvm@vger.kernel.org, Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Roman Kagan , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/kvm/hyper-v: tweak HYPERV_CPUID_ENLIGHTMENT_INFO In-Reply-To: <805B7B08-734E-4A96-AF98-D33065C59105@oracle.com> References: <20190124171516.23626-1-vkuznets@redhat.com> <805B7B08-734E-4A96-AF98-D33065C59105@oracle.com> Date: Thu, 24 Jan 2019 18:39:21 +0100 Message-ID: <8736pigdkm.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Liran Alon writes: >> On 24 Jan 2019, at 19:15, Vitaly Kuznetsov wrote: >> >> We shouldn't probably be suggesting using Enlightened VMCS when it's not >> enabled (not supported from guest's point of view). System reset through >> synthetic MSR is not recommended neither by genuine Hyper-V nor my QEMU. >> >> Windows seems to be fine either way but let's be consistent. >> >> Fixes: 2bc39970e932 ("x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID") >> Signed-off-by: Vitaly Kuznetsov >> --- >> arch/x86/kvm/hyperv.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c >> index ac44a681f065..4730fcaa70cf 100644 >> --- a/arch/x86/kvm/hyperv.c >> +++ b/arch/x86/kvm/hyperv.c >> @@ -1847,11 +1847,11 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, >> case HYPERV_CPUID_ENLIGHTMENT_INFO: >> ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED; >> ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED; >> - ent->eax |= HV_X64_SYSTEM_RESET_RECOMMENDED; >> ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED; >> ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED; >> ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED; >> - ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; >> + if (evmcs_ver) >> + ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; >> >> /* >> * Default number of spinlock retry attempts, matches >> -- >> 2.20.1 >> > > Seems to me that there are 2 unrelated separated patches here. Why not > split them? They seem to be too small :-) No problem, I'll split them up in v2. > For content itself: Reviewed-by: Liran Alon > Thanks! -- Vitaly