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=2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 16999C83000 for ; Wed, 29 Apr 2020 17:29:10 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 D7CBA2082E for ; Wed, 29 Apr 2020 17:29:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Apt0ngun" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D7CBA2082E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jTqVz-0001Ak-3I; Wed, 29 Apr 2020 17:28:55 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jTqVx-0001Af-Qj for xen-devel@lists.xen.org; Wed, 29 Apr 2020 17:28:53 +0000 X-Inumbo-ID: e5662e94-8a3e-11ea-ae69-bc764e2007e4 Received: from mail-oi1-x22b.google.com (unknown [2607:f8b0:4864:20::22b]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id e5662e94-8a3e-11ea-ae69-bc764e2007e4; Wed, 29 Apr 2020 17:28:53 +0000 (UTC) Received: by mail-oi1-x22b.google.com with SMTP id q204so2500861oia.13 for ; Wed, 29 Apr 2020 10:28:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4U+CbPsYJzZOuV7fYM3/9Vnh9J75q+MjwFmxdff0SVU=; b=Apt0ngunMXGwlSy6/ECTZZ7YElz/d2VZxWkKVarABAmzeibDDAFAu6/b26NUGygYDG hsWOfbjv8m6w8TN9L+27KbU7JsgTSg6Um0ytXqJMjwciwhzonlfQu/3tP9XecTDLenX4 enedlEtI60vLbXF1Q0qjNnx5EmuBjS6yRWdZC+t5lSmw7pI6DgESJ+BrVha7I70ZpgPE 8lQIEkcQSwBJYLmniYTYRfq+FOqTO5vpg/unlW9N0XhIESMg6p90a+1ZnL030tB73qYf /TpPpz8YzidLVy9yvyx1o5sNEj3YhxcQQanH1vMRcCCkasoKb6n1Uh93OMcb6F+6eBe3 clGA== 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=4U+CbPsYJzZOuV7fYM3/9Vnh9J75q+MjwFmxdff0SVU=; b=etTcP3yaFt3szIsUgRJkwC5N4qWgeoztGfXR8c81vH58s1JIbilhHVqgoATnLVPec4 4HsmSZSLhRRXwjfP5Qmuvkezg7CV0Vqv29VOhPUNpihkEo/QrdF6MNZoO9VJ+7YoSqlw vUAVfPQIAnIVWU/i1dXt/acu3FGnT4Pcpmc768noj+sUFrd/6FTNpfAOVPwtTAWlG8ui vUmbSS1c1Ux2XReabXx0wM4Oqrc0PwTO3j2DoP0XjBOrv+JlsOUUi+9YagR5Nn82lrSr mVCv7NcI5lWWPHyzzUZeaa1c5Jx5nxkL174KDHhwbNvZxPRTNHl0v57kD7V8tx6wyvjS /7iw== X-Gm-Message-State: AGi0PubVDepQhN1t497EXq7TlDOI04gl7mheP8jQIlb01TuI1jMnXQz2 gSUHc4AffCbA17cn2VVWgb9wiTxAMUyxRvm5saE= X-Google-Smtp-Source: APiQypI/wTBxHfkvThL9OCVtbTfg8EslNNNt0NdZAFXDdjTIgwP5R45MglsVHbC2c3242PZmPgi2VW23EEog59Tjj80= X-Received: by 2002:aca:4bc2:: with SMTP id y185mr2380206oia.164.1588181332450; Wed, 29 Apr 2020 10:28:52 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Ayush Dosaj Date: Wed, 29 Apr 2020 22:58:40 +0530 Message-ID: Subject: Re: Xen Compilation Error on Ubuntu 20.04 To: Andrew Cooper Content-Type: multipart/alternative; boundary="00000000000028e2e905a47148af" X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xen.org Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" --00000000000028e2e905a47148af Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Awesome, thanks! On Wed, Apr 29, 2020 at 10:55 PM Andrew Cooper wrote: > On 29/04/2020 18:17, Ayush Dosaj wrote: > > Hi Xen development team, > > > > I am Ayush. I compiled Xen Hypervisor from source on Ubuntu 20.04 > > machine running on an intel-i9 CPU. > > I am getting compilation error due to the following two flags. > > Error: error: =E2=80=98-mindirect-branch=E2=80=99 and =E2=80=98-fcf-pro= tection=E2=80=99 are not > compatible. > > > > Complete Error logs can be found at > https://paste.ubuntu.com/p/xvvyPnhW5c/ > > > > And when I compiled Xen commenting the two flags in Rules.mk file, it > > compiles and installs properly but on boot-up i see a blank black scree= n > > and i am stuck there. > > That is a GCC bug (these options are actually fine in combination). It > got fixed earlier today in master, and backported for GCC 9.4 > > You can work around it by appending -fcf-protection=3Dnone to CFLAGS > > I wouldn't try editing the logic around -mindirect-branch, as that is > related to retpoline safety for Spectre v2, and probably relies on the > build matching the code. > > ~Andrew > --=20 Ayush Dosaj VIT Vellore --00000000000028e2e905a47148af Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Awesome, thanks!

On Wed, Apr = 29, 2020 at 10:55 PM Andrew Cooper <andrew.cooper3@citrix.com> wrote:
On 29/04/2020 18:17, Ayush Dosaj wrote: > Hi Xen development team,
>
> I am Ayush. I compiled Xen Hypervisor from source on Ubuntu 20.04
> machine running on an intel-i9 CPU.
> I am getting compilation error due to the following two flags.
> Error: error: =E2=80=98-mindirect-branch=E2=80=99 and =E2=80=98-fcf-pr= otection=E2=80=99 are not compatible.
>
> Complete Error logs can be found at https://paste.ubuntu.= com/p/xvvyPnhW5c/
>
> And when I compiled Xen commenting the two flags in Rules.mk file, it<= br> > compiles and installs properly but on boot-up i see a blank black scre= en
> and i am stuck there.

That is a GCC bug (these options are actually fine in combination).=C2=A0 I= t
got fixed earlier today in master, and backported for GCC 9.4

You can work around it by appending -fcf-protection=3Dnone to CFLAGS

I wouldn't try editing the logic around -mindirect-branch, as that is related to retpoline safety for Spectre v2, and probably relies on the
build matching the code.

~Andrew


--
Ayush Dosa= j
VIT Vellore

--00000000000028e2e905a47148af--