From mboxrd@z Thu Jan  1 00:00:00 1970
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Subject: Re: [PATCH 06/12] KVM: s390: exploit GISA and AIV for emulated
 interrupts
Date: Wed, 17 Jan 2018 09:14:03 +0100
Message-ID: <20180117081403.GB5708@osiris>
References: <20180116200217.211897-1-borntraeger@de.ibm.com>
 <20180116200217.211897-7-borntraeger@de.ibm.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Cornelia Huck <cohuck@redhat.com>, KVM <kvm@vger.kernel.org>,
        linux-s390 <linux-s390@vger.kernel.org>,
        Janosch Frank <frankja@linux.vnet.ibm.com>,
        David Hildenbrand <david@redhat.com>,
        Michael Mueller <mimu@linux.vnet.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:53454 "EHLO
        mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK)
        by vger.kernel.org with ESMTP id S1750810AbeAQIOM (ORCPT
        <rfc822;kvm@vger.kernel.org>); Wed, 17 Jan 2018 03:14:12 -0500
Received: from pps.filterd (m0098409.ppops.net [127.0.0.1])
        by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0H8E7lY043850
        for <kvm@vger.kernel.org>; Wed, 17 Jan 2018 03:14:11 -0500
Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110])
        by mx0a-001b2d01.pphosted.com with ESMTP id 2fhyr876y1-1
        (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)
        for <kvm@vger.kernel.org>; Wed, 17 Jan 2018 03:14:11 -0500
Received: from localhost
        by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted
        for <kvm@vger.kernel.org> from <heiko.carstens@de.ibm.com>;
        Wed, 17 Jan 2018 08:14:08 -0000
Content-Disposition: inline
In-Reply-To: <20180116200217.211897-7-borntraeger@de.ibm.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On Tue, Jan 16, 2018 at 09:02:11PM +0100, Christian Borntraeger wrote:
> +static int __do_deliver_io(struct kvm_vcpu *vcpu, struct kvm_s390_io_info *io)
> +{
> +	int rc;
> +
> +	rc  = put_guest_lc(vcpu, io->subchannel_id,
> +			   (u16 *)__LC_SUBCHANNEL_ID);
> +	rc |= put_guest_lc(vcpu, io->subchannel_nr,
> +			   (u16 *)__LC_SUBCHANNEL_NR);
> +	rc |= put_guest_lc(vcpu, io->io_int_parm,
> +			   (u32 *)__LC_IO_INT_PARM);
> +	rc |= put_guest_lc(vcpu, io->io_int_word,
> +			   (u32 *)__LC_IO_INT_WORD);

They all fit into one line now ;)

> +	rc |= write_guest_lc(vcpu, __LC_IO_OLD_PSW,
> +			     &vcpu->arch.sie_block->gpsw,
> +			     sizeof(psw_t));
> +	rc |= read_guest_lc(vcpu, __LC_IO_NEW_PSW,
> +			    &vcpu->arch.sie_block->gpsw,
> +			    sizeof(psw_t));
> +	return rc;
> +}

return rc = -EFAULT : 0;

from below should be moved to this function, so it has a well defined
return value instead of random garbage. Well, it's -EFAULT or 0 currently
anyway, but nobody knows...

>  static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
>  				     unsigned long irq_type)
>  {
...
> +out:
>  	return rc ? -EFAULT : 0;
>  }