From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Wolf Subject: Re: [Qemu-devel] [PATCH 14/19] block: insert event-tap to bdrv_aio_writev() and bdrv_aio_flush(). Date: Wed, 19 Jan 2011 10:47:58 +0100 Message-ID: <4D36B34E.8070301@redhat.com> References: <1295415904-11918-1-git-send-email-tamura.yoshiaki@lab.ntt.co.jp> <1295415904-11918-15-git-send-email-tamura.yoshiaki@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, aliguori@us.ibm.com, mtosatti@redhat.com, ananth@in.ibm.com, mst@redhat.com, dlaor@redhat.com, vatsa@linux.vnet.ibm.com, blauwirbel@gmail.com, ohmura.kei@lab.ntt.co.jp, avi@redhat.com, psuriset@linux.vnet.ibm.com, stefanha@linux.vnet.ibm.com To: Yoshiaki Tamura Return-path: Received: from mx1.redhat.com ([209.132.183.28]:13356 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753804Ab1ASJqh (ORCPT ); Wed, 19 Jan 2011 04:46:37 -0500 In-Reply-To: <1295415904-11918-15-git-send-email-tamura.yoshiaki@lab.ntt.co.jp> Sender: kvm-owner@vger.kernel.org List-ID: Am 19.01.2011 06:44, schrieb Yoshiaki Tamura: > event-tap function is called only when it is on, and requests sent > from device emulators. > > Signed-off-by: Yoshiaki Tamura > --- > block.c | 11 +++++++++++ > 1 files changed, 11 insertions(+), 0 deletions(-) > > diff --git a/block.c b/block.c > index ff2795b..85bd8b8 100644 > --- a/block.c > +++ b/block.c > @@ -28,6 +28,7 @@ > #include "block_int.h" > #include "module.h" > #include "qemu-objects.h" > +#include "event-tap.h" > > #ifdef CONFIG_BSD > #include > @@ -2111,6 +2112,11 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, > if (bdrv_check_request(bs, sector_num, nb_sectors)) > return NULL; > > + if (bs->device_name && event_tap_is_on()) { > + return event_tap_bdrv_aio_writev(bs, sector_num, qiov, nb_sectors, > + cb, opaque); > + } > + > if (bs->dirty_bitmap) { > blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb, > opaque); Just noticed the context here... Does this patch break block migration when event-tap is on? Another question that came to my mind is if we really hook everything we need. I think we'll need to have a hook in bdrv_flush as well. I don't know if you do hook qemu_aio_flush and friends - does a call cause event-tap to flush its queue? If not, a call to qemu_aio_flush might hang qemu because it's waiting for requests to complete which are actually stuck in the event-tap queue. Kevin