From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Huth <thuth@redhat.com>
Subject: Re: [kvm-unit-tests PATCH v3 11/17] powerpc/ppc64: add hcall support
 and putchar
Date: Mon, 15 Feb 2016 09:58:56 +0100
Message-ID: <56C19350.3010507@redhat.com>
References: <1455380910-30604-1-git-send-email-drjones@redhat.com>
 <1455380910-30604-12-git-send-email-drjones@redhat.com>
 <20160214232954.GJ2732@voom.fritz.box>
 <20160215085406.5u5344qpaoixnjod@hawk.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, dgibson@redhat.com,
	agraf@suse.de, lvivier@redhat.com, pbonzini@redhat.com
To: Andrew Jones <drjones@redhat.com>,
	David Gibson <david@gibson.dropbear.id.au>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:43105 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752650AbcBOI7D (ORCPT <rfc822;kvm@vger.kernel.org>);
	Mon, 15 Feb 2016 03:59:03 -0500
In-Reply-To: <20160215085406.5u5344qpaoixnjod@hawk.localdomain>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 15.02.2016 09:54, Andrew Jones wrote:
> On Mon, Feb 15, 2016 at 10:29:54AM +1100, David Gibson wrote:
>> On Sat, Feb 13, 2016 at 05:28:24PM +0100, Andrew Jones wrote:
>>> +bool hcall_have_broken_sc1(void)
>>> +{
>>> +	register unsigned long r3 asm("r3") = H_SET_DABR;
>>> +	register unsigned long r4 asm("r4") = 0;
>>> +
>>> +	asm volatile("sc 1"
>>> +	: "=r" (r3)
>>> +	: "r" (r3), "r" (r4)
>>> +	: "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12");
>>> +
>>> +	return !(r3 == H_SUCCESS || r3 == (unsigned long)H_HARDWARE);
>>
>> It might be safer to explicitly check for H_PRIVILEGE, which is what
>> you'll get in the case of a broken sc 1 under nested virtualization.
>> That way you won't get false positives if H_SET_DABR ever gets any new
>> error codes it can return.
> 
> Will do. Thanks. Should we consider a SLOF patch too? (As I stole this
> condition from there, see check_broken_sc1 in lib/libhvcall/brokensc1.c)

Yes, I think it should be fixed there, too.

 Thomas