From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 10 Apr 2019 10:46:49 +0200 From: Cornelia Huck Subject: Re: [RFC PATCH 10/12] virtio/s390: consolidate DMA allocations Message-ID: <20190410104649.12cdbcba.cohuck@redhat.com> In-Reply-To: <20190404231622.52531-11-pasic@linux.ibm.com> References: <20190404231622.52531-1-pasic@linux.ibm.com> <20190404231622.52531-11-pasic@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Halil Pasic Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, Martin Schwidefsky , Sebastian Ott , virtualization@lists.linux-foundation.org, Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman List-ID: On Fri, 5 Apr 2019 01:16:20 +0200 Halil Pasic wrote: > We can reduce the number of DMA allocations by pulling the bits > of memory that belongs to virtio_ccw_device and needs to be DMA > memory into a single area. That makes a lot of sense (maybe start with introducing the dma area from the beginning?), but... > > Signed-off-by: Halil Pasic > --- > drivers/s390/virtio/virtio_ccw.c | 48 ++++++++++++++-------------------------- > 1 file changed, 16 insertions(+), 32 deletions(-) > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > index aa45a6a027ae..7268149f2ee8 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -49,12 +49,12 @@ struct vq_config_block { > struct vcdev_dma_area { > unsigned long indicators; > unsigned long indicators2; > + struct vq_config_block config_block; > + __u8 status; /* TODO check __aligned(8); */ ...I think that needs attention. > }; > > struct virtio_ccw_device { > struct virtio_device vdev; > - __u8 *status; > - dma_addr_t status_dma_addr; > __u8 config[VIRTIO_CCW_CONFIG_SIZE]; > struct ccw_device *cdev; > __u32 curr_io;