From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 0/9] S390x KVM support
Date: Thu, 22 Oct 2009 11:08:29 +0200
Message-ID: <4AE0210D.9020409@redhat.com>
References: <1255963059-10298-1-git-send-email-agraf@suse.de> <4ADDE7E3.9090601@de.ibm.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: Alexander Graf <agraf@suse.de>, qemu-devel <qemu-devel@nongnu.org>,
	uli@suse.de, Carsten Otte <cotte@de.ibm.com>, hare@suse.de,
	KVM list <kvm@vger.kernel.org>
To: Carsten Otte <carsteno@de.ibm.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:37643 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751612AbZJVJIc (ORCPT <rfc822;kvm@vger.kernel.org>);
	Thu, 22 Oct 2009 05:08:32 -0400
In-Reply-To: <4ADDE7E3.9090601@de.ibm.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 10/20/2009 06:40 PM, Carsten Otte wrote:
>
> This patch moves s390 processor status word into the base kvm_run
> struct and keeps it up-to date on all userspace exits.
>
> +#include <linux/autoconf.h>
> #include <linux/types.h>
> #include <linux/compiler.h>
> #include <linux/ioctl.h>

Not needed.

> @@ -116,6 +117,11 @@
>     __u64 cr8;
>     __u64 apic_base;
>
> +#ifdef CONFIG_S390
> +    /* the processor status word for s390 */
> +    __u64 psw_mask; /* psw upper half */
> +    __u64 psw_addr; /* psw lower half */
> +#endif

Doesn't this break backward compatibility by changing the structure?

Best to put it after the union (and as a copy, so userspace that expects 
the previous location still works).  If you're reading it from the 
kernel, also need a way to tell the kernel which copy to read from.

Also advertise with a KVM_CAP.

Additionally, CONFIG_ in public headers are frowned upon as 
non-portable.  A workaround is to #define __KVM_S390 in <asm/kvm.h> and 
depend on that.

> --- kvm.orig/arch/s390/kvm/kvm-s390.c    2009-10-20 15:01:02.000000000 
> +0200
> +++ kvm/arch/s390/kvm/kvm-s390.c    2009-10-20 18:13:45.000000000 +0200
> @@ -421,7 +421,8 @@
>     if (atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_RUNNING)
>         rc = -EBUSY;
>     else
> -        vcpu->arch.sie_block->gpsw = psw;
> +        vcpu->run->psw_mask = psw.mask;
> +        vcpu->run->psw_addr = psw.addr;

It's traditional to add braces around multi-line else blocks.

I'd also appreciate an explanation of what this is all about.

-- 
error compiling committee.c: too many arguments to function