From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59538) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciANB-0003xY-BZ for qemu-devel@nongnu.org; Sun, 26 Feb 2017 20:45:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciAN8-0004g4-8p for qemu-devel@nongnu.org; Sun, 26 Feb 2017 20:45:09 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38380 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ciAN8-0004ft-2W for qemu-devel@nongnu.org; Sun, 26 Feb 2017 20:45:06 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1R1iKZV125818 for ; Sun, 26 Feb 2017 20:45:04 -0500 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0b-001b2d01.pphosted.com with ESMTP id 28u7baqx0q-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 26 Feb 2017 20:45:04 -0500 Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 26 Feb 2017 18:45:03 -0700 Date: Mon, 27 Feb 2017 09:44:57 +0800 From: Dong Jia Shi References: <20170217082939.33208-1-bjsdjshi@linux.vnet.ibm.com> <20170217082939.33208-12-bjsdjshi@linux.vnet.ibm.com> <20170224162724.6dd2eb0e@t450s.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170224162724.6dd2eb0e@t450s.home> Message-Id: <20170227014457.GW562@bjsdjshi@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH RFC v3 11/15] vfio: ccw: realize VFIO_DEVICE_G(S)ET_IRQ_INFO ioctls List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: Dong Jia Shi , kvm@vger.kernel.org, linux-s390@vger.kernel.org, qemu-devel@nongnu.org, renxiaof@linux.vnet.ibm.com, cornelia.huck@de.ibm.com, borntraeger@de.ibm.com, agraf@suse.com, pmorel@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, wkywang@linux.vnet.ibm.com * Alex Williamson [2017-02-24 16:27:24 -0700]: > On Fri, 17 Feb 2017 09:29:35 +0100 > Dong Jia Shi wrote: > > > Realize VFIO_DEVICE_GET_IRQ_INFO ioctl to retrieve > > VFIO_CCW_IO_IRQ information. > > > > Realize VFIO_DEVICE_SET_IRQS ioctl to set an eventfd fd for > > VFIO_CCW_IO_IRQ. Once a write operation to the ccw_io_region > > was performed, trigger a signal on this fd. > > > > Signed-off-by: Dong Jia Shi > > Reviewed-by: Pierre Morel > > --- > > drivers/s390/cio/vfio_ccw_ops.c | 123 +++++++++++++++++++++++++++++++++++- > > drivers/s390/cio/vfio_ccw_private.h | 4 ++ > > include/uapi/linux/vfio.h | 10 ++- > > 3 files changed, 134 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c > > index 125818c..ebc38fb 100644 > > --- a/drivers/s390/cio/vfio_ccw_ops.c > > +++ b/drivers/s390/cio/vfio_ccw_ops.c > > @@ -202,6 +202,9 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev, > > if (region->ret_code != 0) > > return region->ret_code; > > > > + if (private->io_trigger) > > + eventfd_signal(private->io_trigger, 1); > > + > > return count; > > } > > > > @@ -209,7 +212,7 @@ static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info) > > { > > info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET; > > info->num_regions = VFIO_CCW_NUM_REGIONS; > > - info->num_irqs = 0; > > + info->num_irqs = VFIO_CCW_NUM_IRQS; > > > > return 0; > > } > > @@ -230,6 +233,83 @@ static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info, > > } > > } > > > > +int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info) > > +{ > > + if (info->index != VFIO_CCW_IO_IRQ_INDEX) > > + return -EINVAL; > > + > > + info->count = 1; > > + info->flags = VFIO_IRQ_INFO_EVENTFD | VFIO_IRQ_INFO_NORESIZE; > > I tend to think that NORESIZE isn't relevant when count is one. We > don't expose this flag on vfio-pci for INTx where there's only a single > interrupt. I don't really see how it applies, it's really trying to > indicate if there are multiple sub-indexes within an index, if some are > enabled, we cannot enable others without first disabling them all. > Thus we can't resize the number of enabled sub-indexes. There really > are no sub-indexes when count is one. Thanks, Hi Alex, I read the description of NORESIZE again, and I think you are right. Since we do not have a subset of indexes here, I will remove this flag. Thanks! > > Alex > > > + > > + return 0; > > +} > > + [...] -- Dong Jia