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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 73387C4363A for ; Fri, 23 Oct 2020 17:03:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17EDA20795 for ; Fri, 23 Oct 2020 17:03:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tjp99hRn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752265AbgJWRDo (ORCPT ); Fri, 23 Oct 2020 13:03:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S464587AbgJWRDm (ORCPT ); Fri, 23 Oct 2020 13:03:42 -0400 Received: from mail-oo1-xc43.google.com (mail-oo1-xc43.google.com [IPv6:2607:f8b0:4864:20::c43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CB7DC0613CE for ; Fri, 23 Oct 2020 10:03:40 -0700 (PDT) Received: by mail-oo1-xc43.google.com with SMTP id l18so553203ooa.9 for ; Fri, 23 Oct 2020 10:03:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=kDz4gn4LXn8aroBJkBNj8TPyfOZEVwrvC4JEhPovxCc=; b=tjp99hRnrJBWxkp6Vt0ZTXhFtCr8W0JWcM22W0i9CA7yy4mHa6ojSztPNyjJ3u7rtD 7sCLlloe1t0myru2qd38kAns9VptXqnUuhDcXVC5gohNzj3MXvXdYgxqizZ3I3VtllXf p5Xk4rlkLzsQHoKm9imbgsaeTbeHmYfx3sZz7CylGiqMZtt89WZzVA4LxCybWYkjDbXs UFgov1fNAKJ1g1C3CbOHJNiAiNpSzX2y2ovtd1Ekthm8VPID/De9cCy9ciEvaMT/P5Pt S++RquTwOhZMxYYRa1KSo/UDyv3g/bbC9cF0E5TRG0Jsn0GdNfx4nlaWOeGd8hoH+c5D f5AQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=kDz4gn4LXn8aroBJkBNj8TPyfOZEVwrvC4JEhPovxCc=; b=Vo+4lc5ZsNhaC4BRVASR6vAuapy7SeE88gvLU7AP1jGYu4w9pG8D7xkbHJQCslKlyc VZolXUWGGrPQ0o1ScTeOPmk0RxZW6Ms0WozpWNIDv0R7wbhyzbodZ/YL1ya4pwCh8Qxj vBd/KMPMCjmEA/NCJH0jY9iQpdD5pmVz1EbwIbxWS3vzKyvavsDfMtzEcA6Y7sNJv5LZ Fn2oYZGutFpkkT8/mXBvoh3mtHzTThEQco7c2c2NMhnYZAilqsrIm38rAISJiOr+Wdcc T/rNgNqmUSaID7scWhw8FwQyRrwYKL4rUcmLu4DHn3D2cJvbMVJpXkuSI55axvT9OHSS hX8A== X-Gm-Message-State: AOAM530fgq3PHLpB0Nop48wFjP+XeUY4wAXWmodgS3ZxVI8vLeU6Mksb yZKjmz7YR5BuXCGuUX8OHhi3pjDxFAJ4FMawhs/Lf0cZ6Wg= X-Google-Smtp-Source: ABdhPJyUiPATpJxZtE/yL8srFLqEuuE6XYH/4Xen/h6AQ79x3D9IEVDVce9xV4+7I+k6nfpkG46wmc1vDcpKbn81EoA= X-Received: by 2002:a4a:dcc8:: with SMTP id h8mr2435632oou.81.1603472619282; Fri, 23 Oct 2020 10:03:39 -0700 (PDT) MIME-Version: 1.0 References: <1603330475-7063-1-git-send-email-wanpengli@tencent.com> <281bca2d-d534-1032-eed3-7ee7705cb12c@redhat.com> <823d5027-a1e5-4b91-2d35-693f3c2b9642@redhat.com> In-Reply-To: <823d5027-a1e5-4b91-2d35-693f3c2b9642@redhat.com> From: Jim Mattson Date: Fri, 23 Oct 2020 10:03:27 -0700 Message-ID: Subject: Re: [PATCH] KVM: X86: Expose KVM_HINTS_REALTIME in KVM_GET_SUPPORTED_CPUID To: Paolo Bonzini Cc: Wanpeng Li , LKML , kvm list , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Joerg Roedel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 23, 2020 at 2:07 AM Paolo Bonzini wrote: > > On 22/10/20 19:13, Jim Mattson wrote: > > We don't actually use KVM_GET_SUPPORTED_CPUID at all today. If it's > > commonly being misinterpreted as you say, perhaps we should add a > > KVM_GET_TRUE_SUPPORTED_CPUID ioctl. Or, perhaps we can just fix this > > in the documentation? > > Yes, I think we should fix the documentation and document the best > practices around MSRs and CPUID bits. Mostly documenting what QEMU > does, perhaps without all the quirks it has to support old kernels that > messed things up even more. > > Paolo I'd really like to be able to call an ioctl that will help me determine whether the host can support the guest CPUID information that I already have (e.g. on the target of a live migration). At first glance, KVM_GET_SUPPORTED_CPUID appeared to be that ioctl. Sadly, it appears that no such ioctl exists.