Re: [PATCH v2 6/8] virtio/s390: add indirection to indicators access

From: Cornelia Huck <cohuck@redhat.com>
To: Halil Pasic <pasic@linux.ibm.com>
Cc: Michael Mueller <mimu@linux.ibm.com>,
	KVM Mailing List <kvm@vger.kernel.org>,
	Linux-S390 Mailing List <linux-s390@vger.kernel.org>,
	Sebastian Ott <sebott@linux.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	virtualization@lists.linux-foundation.org,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Christoph Hellwig <hch@infradead.org>,
	Thomas Huth <thuth@redhat.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Viktor Mihajlovski <mihajlov@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Farhan Ali <alifm@linux.ibm.com>,
	Eric Farman <farman@linux.ibm.com>,
	Pierre Morel <pmorel@linux.ibm.com>
Subject: Re: [PATCH v2 6/8] virtio/s390: add indirection to indicators access
Date: Mon, 27 May 2019 14:10:29 +0200	[thread overview]
Message-ID: <20190527141029.102f838a.cohuck@redhat.com> (raw)
In-Reply-To: <20190527135706.34837062.pasic@linux.ibm.com>

On Mon, 27 May 2019 13:57:06 +0200
Halil Pasic <pasic@linux.ibm.com> wrote:

> On Mon, 27 May 2019 13:00:28 +0200
> Cornelia Huck <cohuck@redhat.com> wrote:
> 
> > On Thu, 23 May 2019 18:22:07 +0200
> > Michael Mueller <mimu@linux.ibm.com> wrote:
> >   
> > > From: Halil Pasic <pasic@linux.ibm.com>
> > > 
> > > This will come in handy soon when we pull out the indicators from
> > > virtio_ccw_device to a memory area that is shared with the hypervisor
> > > (in particular for protected virtualization guests).
> > > 
> > > Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
> > > Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
> > > ---
> > >  drivers/s390/virtio/virtio_ccw.c | 40 +++++++++++++++++++++++++---------------
> > >  1 file changed, 25 insertions(+), 15 deletions(-)
> > >   
> >   
> > > @@ -338,17 +348,17 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
> > >  		ccw->cda = (__u32)(unsigned long) thinint_area;
> > >  	} else {
> > >  		/* payload is the address of the indicators */
> > > -		indicatorp = kmalloc(sizeof(&vcdev->indicators),
> > > +		indicatorp = kmalloc(sizeof(indicators(vcdev)),
> > >  				     GFP_DMA | GFP_KERNEL);
> > >  		if (!indicatorp)
> > >  			return;
> > >  		*indicatorp = 0;
> > >  		ccw->cmd_code = CCW_CMD_SET_IND;
> > > -		ccw->count = sizeof(&vcdev->indicators);
> > > +		ccw->count = sizeof(indicators(vcdev));
> > >  		ccw->cda = (__u32)(unsigned long) indicatorp;
> > >  	}
> > >  	/* Deregister indicators from host. */
> > > -	vcdev->indicators = 0;
> > > +	*indicators(vcdev) = 0;  
> > 
> > I'm not too hot about this notation, but it's not wrong and a minor
> > thing :)  
> 
> I don't have any better ideas :/
> 
> >   
> > >  	ccw->flags = 0;
> > >  	ret = ccw_io_helper(vcdev, ccw,
> > >  			    vcdev->is_thinint ?  
> > 
> > Patch looks reasonable and not dependent on the other patches here.
> >   
> 
> looks reasonable == r-b?
> 
> Not dependent in a sense that this patch could be made a first patch in
> the series. A subsequent patch depends on it.

What is the plan with these patches? I can either pick patch 5+6 and
let them go through the virtio tree, or give my r-b and let them go
through the s390 tree. The former is probably the quicker route, but
the latter has less potential for dependency issues.