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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 514CAC433F5 for ; Tue, 16 Nov 2021 09:46:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23AEC61B3E for ; Tue, 16 Nov 2021 09:46:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233496AbhKPJtm (ORCPT ); Tue, 16 Nov 2021 04:49:42 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:59483 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232326AbhKPJtl (ORCPT ); Tue, 16 Nov 2021 04:49:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637056004; 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=fc0gngviw+IZIFxYalZL+iadKVgfg2lYYkw0vHrMjNs=; b=QbR1ciX3tLM6g4dkKlMBaTjICIk+VuCNgHLSFY4UaMfwAC3KipC009sa+puyjvfhd9eRnb kRRZR6kVTYPs5UUbpOFkoRtlOc3KhBHrNTfagj9V1Xy1ciDlckdbYstpndMgwCobGXnybE KvRb/7IM1ul/XUMtcFyz5lSTirrD6yg= 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-177-vYO4E3Y2OJOwOt0j00Id4g-1; Tue, 16 Nov 2021 04:46:39 -0500 X-MC-Unique: vYO4E3Y2OJOwOt0j00Id4g-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1BD291923769; Tue, 16 Nov 2021 09:46:37 +0000 (UTC) Received: from [10.39.192.245] (unknown [10.39.192.245]) by smtp.corp.redhat.com (Postfix) with ESMTP id 69C385DF5D; Tue, 16 Nov 2021 09:46:30 +0000 (UTC) Message-ID: <1f7c6347-368b-0959-d506-a938f2585591@redhat.com> Date: Tue, 16 Nov 2021 10:46:29 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH] KVM: Fix steal time asm constraints in 32-bit mode Content-Language: en-US To: David Woodhouse , kernel test robot , kvm Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, Boris Ostrovsky , Joao Martins , "jmattson@google.com" , "wanpengli@tencent.com" , "seanjc@google.com" , "vkuznets@redhat.com" , "mtosatti@redhat.com" , "joro@8bytes.org" , karahmed@amazon.com References: <202111141550.hY7mszt8-lkp@intel.com> <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org> From: Paolo Bonzini In-Reply-To: <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/14/21 09:59, David Woodhouse wrote: > From: David Woodhouse > > In 64-bit mode, x86 instruction encoding allows us to use the low 8 bits > of any GPR as an 8-bit operand. In 32-bit mode, however, we can only use > the [abcd] registers. For which, GCC has the "q" constraint instead of > the less restrictive "r". > > Fixes: 7e2175ebd695 ("KVM: x86: Fix recording of guest steal time / preempted status") > Reported-by: kernel test robot > Signed-off-by: David Woodhouse > --- > arch/x86/kvm/x86.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 8f156905ae38..0a689bb62e9e 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3307,7 +3307,7 @@ static void record_steal_time(struct kvm_vcpu *vcpu) > "xor %1, %1\n" > "2:\n" > _ASM_EXTABLE_UA(1b, 2b) > - : "+r" (st_preempted), > + : "+q" (st_preempted), > "+&r" (err) > : "m" (st->preempted)); > if (err) > Queued with the addition of the "m" -> "+m" change, thanks. Paolo