From patchwork Thu Feb 28 09:22:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 2196161 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id DD095DF2A2 for ; Thu, 28 Feb 2013 09:22:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751442Ab3B1JWm (ORCPT ); Thu, 28 Feb 2013 04:22:42 -0500 Received: from e06smtp18.uk.ibm.com ([195.75.94.114]:35238 "EHLO e06smtp18.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751163Ab3B1JWk (ORCPT ); Thu, 28 Feb 2013 04:22:40 -0500 Received: from /spool/local by e06smtp18.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 28 Feb 2013 09:20:18 -0000 Received: from d06dlp03.portsmouth.uk.ibm.com (9.149.20.15) by e06smtp18.uk.ibm.com (192.168.101.148) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 28 Feb 2013 09:20:15 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 7FCEB1B08066; Thu, 28 Feb 2013 09:22:34 +0000 (GMT) Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by b06cxnps4074.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1S9MPd135061782; Thu, 28 Feb 2013 09:22:25 GMT Received: from d06av04.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1S9MXNO011055; Thu, 28 Feb 2013 02:22:34 -0700 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r1S9MWI1010951; Thu, 28 Feb 2013 02:22:33 -0700 From: Cornelia Huck To: Marcelo Tosatti , Gleb Natapov Cc: Christian Borntraeger , Carsten Otte , Alexander Graf , Heiko Carstens , Martin Schwidefsky , "Michael S. Tsirkin" , KVM , linux-s390 , qemu-devel Subject: [PATCH v4 1/6] virtio_ccw: pass a cookie value to kvm hypercall Date: Thu, 28 Feb 2013 10:22:27 +0100 Message-Id: <1362043352-56889-2-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1362043352-56889-1-git-send-email-cornelia.huck@de.ibm.com> References: <1362043352-56889-1-git-send-email-cornelia.huck@de.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13022809-6892-0000-0000-0000047447D0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "Michael S. Tsirkin" Lookups by channel/vq pair on host during virtio notifications might be expensive. Interpret hypercall return value as a cookie which host can use to do device lookups for the next notification more efficiently. [CH: Fix line > 80 chars] Tested-by: Christian Borntraeger Reviewed-by: Christian Borntraeger Signed-off-by: Michael S. Tsirkin Signed-off-by: Cornelia Huck --- drivers/s390/kvm/virtio_ccw.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 3217dfe..259a2fb 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -77,6 +77,7 @@ struct virtio_ccw_vq_info { void *queue; struct vq_info_block *info_block; struct list_head node; + long cookie; }; #define KVM_VIRTIO_CCW_RING_ALIGN 4096 @@ -145,15 +146,18 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev, } static inline long do_kvm_notify(struct subchannel_id schid, - unsigned long queue_index) + unsigned long queue_index, + long cookie) { register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY; register struct subchannel_id __schid asm("2") = schid; register unsigned long __index asm("3") = queue_index; register long __rc asm("2"); + register long __cookie asm("4") = cookie; asm volatile ("diag 2,4,0x500\n" - : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index) + : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index), + "d"(__cookie) : "memory", "cc"); return __rc; } @@ -166,7 +170,8 @@ static void virtio_ccw_kvm_notify(struct virtqueue *vq) vcdev = to_vc_device(info->vq->vdev); ccw_device_get_schid(vcdev->cdev, &schid); - do_kvm_notify(schid, virtqueue_get_queue_index(vq)); + info->cookie = do_kvm_notify(schid, virtqueue_get_queue_index(vq), + info->cookie); } static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,