Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752361AbaKYQxY (ORCPT ); Tue, 25 Nov 2014 11:53:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49884 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751916AbaKYQmr (ORCPT ); Tue, 25 Nov 2014 11:42:47 -0500 Date: Tue, 25 Nov 2014 18:42:32 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: David Miller , cornelia.huck@de.ibm.com, rusty@au1.ibm.com, nab@linux-iscsi.org, pbonzini@redhat.com, Christian Borntraeger , linux390@de.ibm.com, Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org Subject: [PATCH v4 16/42] KVM: s390 allow virtio_ccw status writes to fail Message-ID: <1416933600-21398-17-git-send-email-mst@redhat.com> References: <1416933600-21398-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1416933600-21398-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Gracefully handle failure to write device status. We really should handle other errors as well, but this one is needed for virtio 1.0 compliance. Signed-off-by: Michael S. Tsirkin --- drivers/s390/kvm/virtio_ccw.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 9330065..50306b2 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -863,7 +863,9 @@ static u8 virtio_ccw_get_status(struct virtio_device *vdev) static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status) { struct virtio_ccw_device *vcdev = to_vc_device(vdev); + u8 old_status = *vcdev->status; struct ccw1 *ccw; + int ret; ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL); if (!ccw) @@ -875,7 +877,10 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status) ccw->flags = 0; ccw->count = sizeof(status); ccw->cda = (__u32)(unsigned long)vcdev->status; - ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS); + ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS); + /* Write failed? We assume status is unchanged. */ + if (ret) + *vcdev->status = old_status; kfree(ccw); } -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/