From: Jason Wang <jasowang@redhat.com> To: "Tian, Kevin" <kevin.tian@intel.com>, Jason Gunthorpe <jgg@mellanox.com> Cc: "mst@redhat.com" <mst@redhat.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "virtualization@lists.linux-foundation.org" <virtualization@lists.linux-foundation.org>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "Bie, Tiwei" <tiwei.bie@intel.com>, "maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>, "Liang, Cunming" <cunming.liang@intel.com>, "Wang, Zhihong" <zhihong.wang@intel.com>, "rob.miller@broadcom.com" <rob.miller@broadcom.com>, "Wang, Xiao W" <xiao.w.wang@intel.com>, "haotian.wang@sifive.com" <haotian.wang@sifive.com>, "Zhu, Lingshan" <lingshan.zhu@intel.com>, "eperezma@redhat.com" <eperezma@redhat.com>, "lulu@redhat.com" <lulu@redhat.com>, Parav Pandit <parav@mellanox.com>, "stefanha@redhat.com" <stefanha@redhat.com>, "rdunlap@infradead.org" <rdunlap@infradead.org>, "hch@infradead.org" <hch@infradead.org>, "aadam@redhat.com" <aadam@redhat.com>, "jakub.kicinski@netronome.com" <jakub.kicinski@netronome.com>, Jiri Pirko <jiri@mellanox.com>, Shahaf Shuler <shahafs@mellanox.com>, "hanand@xilinx.com" <hanand@xilinx.com>, "mhabets@solarflare.com" <mhabets@solarflare.com> Subject: Re: [PATCH 3/5] vDPA: introduce vDPA bus Date: Tue, 21 Jan 2020 17:41:21 +0800 Message-ID: <f27d59b7-1c91-5870-55f5-e21311fcef99@redhat.com> (raw) In-Reply-To: <AADFC41AFE54684AB9EE6CBC0274A5D19D73EBA4@SHSMSX104.ccr.corp.intel.com> On 2020/1/21 下午4:40, Tian, Kevin wrote: >> From: Jason Wang <jasowang@redhat.com> >> Sent: Friday, January 17, 2020 11:03 AM >> >> >> On 2020/1/16 下午11:22, Jason Gunthorpe wrote: >>> On Thu, Jan 16, 2020 at 08:42:29PM +0800, Jason Wang wrote: >>>> vDPA device is a device that uses a datapath which complies with the >>>> virtio specifications with vendor specific control path. vDPA devices >>>> can be both physically located on the hardware or emulated by >>>> software. vDPA hardware devices are usually implemented through PCIE >>>> with the following types: >>>> >>>> - PF (Physical Function) - A single Physical Function >>>> - VF (Virtual Function) - Device that supports single root I/O >>>> virtualization (SR-IOV). Its Virtual Function (VF) represents a >>>> virtualized instance of the device that can be assigned to different >>>> partitions >>>> - VDEV (Virtual Device) - With technologies such as Intel Scalable >>>> IOV, a virtual device composed by host OS utilizing one or more >>>> ADIs. > the concept of VDEV includes both software bits and ADIs. If you > only take about hardware types, using ADI is more accurate. Ok. > >>>> - SF (Sub function) - Vendor specific interface to slice the Physical >>>> Function to multiple sub functions that can be assigned to different >>>> partitions as virtual devices. >>> I really hope we don't end up with two different ways to spell this >>> same thing. >> >> I think you meant ADI vs SF. It looks to me that ADI is limited to the >> scope of scalable IOV but SF not. > ADI is just a term for minimally assignable resource in Scalable IOV. > 'assignable' implies several things, e.g. the resource can be independently > mapped to/accessed by user space or guest, DMAs between two > ADIs are isolated, operating one ADI doesn't affecting another ADI, > etc. I'm not clear about other vendor specific interfaces, but supposing > they need match the similar requirements. Then do we really want to > differentiate ADI vs. SF? What about merging them with ADI as just > one example of finer-grained slicing? I think so. That what Jason G want as well. Thanks > >> >>>> @@ -0,0 +1,2 @@ >>>> +# SPDX-License-Identifier: GPL-2.0 >>>> +obj-$(CONFIG_VDPA) += vdpa.o >>>> diff --git a/drivers/virtio/vdpa/vdpa.c b/drivers/virtio/vdpa/vdpa.c >>>> new file mode 100644 >>>> index 000000000000..2b0e4a9f105d >>>> +++ b/drivers/virtio/vdpa/vdpa.c >>>> @@ -0,0 +1,141 @@ >>>> +// SPDX-License-Identifier: GPL-2.0-only >>>> +/* >>>> + * vDPA bus. >>>> + * >>>> + * Copyright (c) 2019, Red Hat. All rights reserved. >>>> + * Author: Jason Wang <jasowang@redhat.com> >>> 2020 tests days >> >> Will fix. >> >> >>>> + * >>>> + */ >>>> + >>>> +#include <linux/module.h> >>>> +#include <linux/idr.h> >>>> +#include <linux/vdpa.h> >>>> + >>>> +#define MOD_VERSION "0.1" >>> I think module versions are discouraged these days >> >> Will remove. >> >> >>>> +#define MOD_DESC "vDPA bus" >>>> +#define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>" >>>> +#define MOD_LICENSE "GPL v2" >>>> + >>>> +static DEFINE_IDA(vdpa_index_ida); >>>> + >>>> +struct device *vdpa_get_parent(struct vdpa_device *vdpa) >>>> +{ >>>> + return vdpa->dev.parent; >>>> +} >>>> +EXPORT_SYMBOL(vdpa_get_parent); >>>> + >>>> +void vdpa_set_parent(struct vdpa_device *vdpa, struct device *parent) >>>> +{ >>>> + vdpa->dev.parent = parent; >>>> +} >>>> +EXPORT_SYMBOL(vdpa_set_parent); >>>> + >>>> +struct vdpa_device *dev_to_vdpa(struct device *_dev) >>>> +{ >>>> + return container_of(_dev, struct vdpa_device, dev); >>>> +} >>>> +EXPORT_SYMBOL_GPL(dev_to_vdpa); >>>> + >>>> +struct device *vdpa_to_dev(struct vdpa_device *vdpa) >>>> +{ >>>> + return &vdpa->dev; >>>> +} >>>> +EXPORT_SYMBOL_GPL(vdpa_to_dev); >>> Why these trivial assessors? Seems unnecessary, or should at least be >>> static inlines in a header >> >> Will fix. >> >> >>>> +int register_vdpa_device(struct vdpa_device *vdpa) >>>> +{ >>> Usually we want to see symbols consistently prefixed with vdpa_*, is >>> there a reason why register/unregister are swapped? >> >> I follow the name from virtio. I will switch to vdpa_*. >> >> >>>> + int err; >>>> + >>>> + if (!vdpa_get_parent(vdpa)) >>>> + return -EINVAL; >>>> + >>>> + if (!vdpa->config) >>>> + return -EINVAL; >>>> + >>>> + err = ida_simple_get(&vdpa_index_ida, 0, 0, GFP_KERNEL); >>>> + if (err < 0) >>>> + return -EFAULT; >>>> + >>>> + vdpa->dev.bus = &vdpa_bus; >>>> + device_initialize(&vdpa->dev); >>> IMHO device_initialize should not be called inside something called >>> register, toooften we find out that the caller drivers need the device >>> to be initialized earlier, ie to use the kref, or something. >>> >>> I find the best flow is to have some init function that does the >>> device_initialize and sets the device_name that the driver can call >>> early. >> >> Ok, will do. >> >> >>> Shouldn't there be a device/driver matching process of some kind? >> >> The question is what do we want do match here. >> >> 1) "virtio" vs "vhost", I implemented matching method for this in mdev >> series, but it looks unnecessary for vDPA device driver to know about >> this. Anyway we can use sysfs driver bind/unbind to switch drivers >> 2) virtio device id and vendor id. I'm not sure we need this consider >> the two drivers so far (virtio/vhost) are all bus drivers. >> >> Thanks >> >> >>> Jason >>>
next prev parent reply index Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-16 12:42 [PATCH 0/5] vDPA support Jason Wang 2020-01-16 12:42 ` [PATCH 1/5] vhost: factor out IOTLB Jason Wang 2020-01-17 4:14 ` Randy Dunlap 2020-01-17 9:34 ` Jason Wang 2020-01-18 0:01 ` kbuild test robot 2020-01-18 0:40 ` kbuild test robot 2020-01-16 12:42 ` [PATCH 2/5] vringh: IOTLB support Jason Wang 2020-01-17 21:54 ` kbuild test robot 2020-01-17 22:33 ` kbuild test robot 2020-01-16 12:42 ` [PATCH 3/5] vDPA: introduce vDPA bus Jason Wang 2020-01-16 15:22 ` Jason Gunthorpe 2020-01-17 3:03 ` Jason Wang 2020-01-17 13:54 ` Jason Gunthorpe 2020-01-20 7:50 ` Jason Wang 2020-01-20 12:17 ` Michael S. Tsirkin 2020-01-20 17:50 ` Jason Gunthorpe 2020-01-20 21:56 ` Michael S. Tsirkin 2020-01-21 14:12 ` Jason Gunthorpe 2020-01-21 14:15 ` Michael S. Tsirkin 2020-01-21 14:16 ` Jason Gunthorpe 2020-01-21 8:40 ` Tian, Kevin 2020-01-21 9:41 ` Jason Wang [this message] 2020-01-17 4:16 ` Randy Dunlap 2020-01-17 9:34 ` Jason Wang 2020-01-17 12:13 ` Michael S. Tsirkin 2020-01-17 13:52 ` Jason Wang [not found] ` <CAJPjb1+fG9L3=iKbV4Vn13VwaeDZZdcfBPvarogF_Nzhk+FnKg@mail.gmail.com> 2020-01-19 9:07 ` Shahaf Shuler 2020-01-19 9:59 ` Michael S. Tsirkin 2020-01-20 8:44 ` Jason Wang 2020-01-20 12:09 ` Michael S. Tsirkin 2020-01-21 3:32 ` Jason Wang 2020-01-20 8:43 ` Jason Wang 2020-01-20 17:49 ` Jason Gunthorpe 2020-01-20 20:51 ` Shahaf Shuler 2020-01-20 21:25 ` Michael S. Tsirkin 2020-01-20 21:47 ` Shahaf Shuler 2020-01-20 21:59 ` Michael S. Tsirkin 2020-01-21 6:01 ` Shahaf Shuler 2020-01-21 7:57 ` Jason Wang 2020-01-21 14:07 ` Jason Gunthorpe 2020-01-21 14:16 ` Michael S. Tsirkin 2020-01-20 21:48 ` Michael S. Tsirkin 2020-01-21 4:00 ` Jason Wang 2020-01-21 5:47 ` Michael S. Tsirkin 2020-01-21 8:00 ` Jason Wang 2020-01-21 8:15 ` Michael S. Tsirkin 2020-01-21 8:35 ` Jason Wang 2020-01-21 11:09 ` Shahaf Shuler 2020-01-22 6:36 ` Jason Wang 2020-01-21 14:05 ` Jason Gunthorpe 2020-01-21 14:17 ` Michael S. Tsirkin 2020-01-22 6:18 ` Jason Wang 2020-01-20 8:19 ` Jason Wang 2020-01-16 12:42 ` [PATCH 4/5] virtio: introduce a vDPA based transport Jason Wang 2020-01-16 15:38 ` Jason Gunthorpe 2020-01-17 9:32 ` Jason Wang 2020-01-17 14:00 ` Jason Gunthorpe 2020-01-20 7:52 ` Jason Wang 2020-01-17 4:10 ` Randy Dunlap 2020-01-16 12:42 ` [PATCH 5/5] vdpasim: vDPA device simulator Jason Wang 2020-01-16 15:47 ` Jason Gunthorpe 2020-01-17 9:32 ` Jason Wang 2020-01-17 14:10 ` Jason Gunthorpe 2020-01-20 8:01 ` Jason Wang 2020-02-04 4:19 ` Jason Wang 2020-01-17 4:12 ` Randy Dunlap 2020-01-17 9:35 ` Jason Wang 2020-01-18 18:18 ` kbuild test robot 2020-01-28 3:32 ` Dan Carpenter 2020-02-04 4:07 ` Jason Wang 2020-02-04 8:21 ` Zhu Lingshan 2020-02-04 8:28 ` Jason Wang 2020-02-04 12:52 ` Jason Gunthorpe 2020-02-05 3:14 ` Jason Wang 2020-01-21 8:44 ` [PATCH 0/5] vDPA support Tian, Kevin 2020-01-21 9:39 ` Jason Wang
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