From: Jason Wang <jasowang@redhat.com>
To: Wu Zongyong <wuzongyong@linux.alibaba.com>
Cc: wei.yang1@linux.alibaba.com, mst <mst@redhat.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
virtualization <virtualization@lists.linux-foundation.org>
Subject: Re: [PATCH 0/6] vDPA driver for legacy virtio-pci device
Date: Thu, 9 Sep 2021 17:29:57 +0800 [thread overview]
Message-ID: <CACGkMEt9GByyZf7ArPiKFA-mr1qA89x5nKU_VniM+w4TfuQN=Q@mail.gmail.com> (raw)
In-Reply-To: <20210909081211.GB17383@L-PF27918B-1352.localdomain>
On Thu, Sep 9, 2021 at 4:12 PM Wu Zongyong <wuzongyong@linux.alibaba.com> wrote:
>
> On Thu, Sep 09, 2021 at 11:05:06AM +0800, Jason Wang wrote:
> > On Wed, Sep 8, 2021 at 8:22 PM Wu Zongyong <wuzongyong@linux.alibaba.com> wrote:
> > >
> > > This series implements the vDPA driver for legacy virtio-pci device.
> > > Currently we already have the vDPA driver for modern virtio-pci device
> > > only, but there are some legacy virtio-pci devices conforming to the
> > > virtio-pci specifications of 0.9.x or older versions. For example,
> > > ENI(Elastic Network Interface) of Alibaba ECS baremetal instance is a
> > > hardware virtio network device which follows the Virtio PCI Card 0.9.5
> > > Draft specification. Such legacy virtio-pci devices have some
> > > inconsistent behaviour with modern virtio-pci devices, so some common
> > > codes are split out and modern device specific codes are moved to a
> > > separated file.
> >
> > What worries me a little bit are:
> >
> > 1) vDPA requires IOMMU_PLATFORM to be supported by the device to work,
> > if I understand ENI correctly, it's a legacy device so it can't
> > support ACCESS_PLATFORM. Or is it a legacy device that supports
> > ACCESS_PLATFORM implicitly.
> > 2) vDPA tries to present a 1.0 device, in this case the behavior could
> > be ruled by the spec. If we tries to present an 1.0 device on top of
> > legacy device we may suffer a lot of issues:
> >
> > - endian issue: 1.0 use le but legacy may use native endian
> > - queue_enable semantic which is missed in the legacy
>
> Writting the queue_address is regarded as enable queue in the legacy.
> Right?
It's implementation specific details that virtio spec can't mandate.
E.g if your ENI behaves like this, you can delay the queue_address
write to hardware until set_vq_ready() in the ENI vDPA driver.
Thanks
>
> > - virtqueue size, as you mentioned below
> >
> > I guess what the device(ENI) supports are:
> >
> > 1) semantic of ACCESS_PLATFORM without a feature
> > 2) little endian
> > 3) but a legacy device
> >
> > So I think it might be better:
> >
> > 1) introduce the library for legacy as you did in this patch
> > 2) having a dedicated ENI vDPA driver
> >
> > 3) live migration support, though it was not supported by the spec
> > yet, but we are working on the support, and we know legacy device can
> > support this.
> >
> > Thanks
> >
>
> I agree.
> It's better to implement a dedicated vDPA driver for ENI only. ENI is
> not a standard legacy virtio-pci device.
>
> > >
> > > For legacy devices, it is not supported to negotiate the virtqueue size
> > > by the specification. So a new callback get_vq_num_unchangeable is
> > > introduced to indicate user not to try change the virtqueue size of the
> > > legacy vdpa device. For example, QEMU should not allocate memory for
> > > virtqueue according to the properties tx_queue_size and rx_queue_size if
> > > we use legacy virtio-pci device as the vhost-vdpa backend. Instead, QEMU
> > > should use the new callback get_vq_num_unchangeable first to check if
> > > the vdpa device support to change virtqueue size. If not, QEMU should
> > > call the callback get_vq_num_max to get the static virtqueue size then
> > > allocate the same size memory for the virtqueue.
> > >
> > > This series have been tested with the ENI in Alibaba ECS baremetal
> > > instance.
> > >
> > > These patches may under consideration, welcome for comments.
> > >
> > >
> > > Wu Zongyong (6):
> > > virtio-pci: introduce legacy device module
> > > vdpa: fix typo
> > > vp_vdpa: add vq irq offloading support
> > > vp_vdpa: split out reusable and device specific codes to separate file
> > > vdpa: add get_vq_num_unchangeable callback in vdpa_config_ops
> > > vp_vdpa: introduce legacy virtio pci driver
> > >
> > > drivers/vdpa/Kconfig | 7 +
> > > drivers/vdpa/virtio_pci/Makefile | 3 +
> > > drivers/vdpa/virtio_pci/vp_vdpa.c | 8 +
> > > drivers/vdpa/virtio_pci/vp_vdpa_common.c | 220 ++++++++++++++
> > > drivers/vdpa/virtio_pci/vp_vdpa_common.h | 67 +++++
> > > drivers/vdpa/virtio_pci/vp_vdpa_legacy.c | 346 +++++++++++++++++++++++
> > > drivers/vdpa/virtio_pci/vp_vdpa_modern.c | 327 +++++++++++++++++++++
> > > drivers/vhost/vdpa.c | 19 ++
> > > drivers/virtio/Kconfig | 10 +
> > > drivers/virtio/Makefile | 1 +
> > > drivers/virtio/virtio_pci_common.c | 10 +-
> > > drivers/virtio/virtio_pci_common.h | 9 +-
> > > drivers/virtio/virtio_pci_legacy.c | 101 ++-----
> > > drivers/virtio/virtio_pci_legacy_dev.c | 220 ++++++++++++++
> > > drivers/virtio/virtio_vdpa.c | 5 +-
> > > include/linux/vdpa.h | 6 +-
> > > include/linux/virtio_pci_legacy.h | 44 +++
> > > include/uapi/linux/vhost.h | 2 +
> > > 18 files changed, 1320 insertions(+), 85 deletions(-)
> > > create mode 100644 drivers/vdpa/virtio_pci/vp_vdpa_common.c
> > > create mode 100644 drivers/vdpa/virtio_pci/vp_vdpa_common.h
> > > create mode 100644 drivers/vdpa/virtio_pci/vp_vdpa_legacy.c
> > > create mode 100644 drivers/vdpa/virtio_pci/vp_vdpa_modern.c
> > > create mode 100644 drivers/virtio/virtio_pci_legacy_dev.c
> > > create mode 100644 include/linux/virtio_pci_legacy.h
> > >
> > > --
> > > 2.31.1
> > >
>
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next prev parent reply other threads:[~2021-09-09 9:32 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1631101392.git.wuzongyong@linux.alibaba.com>
[not found] ` <88701e88ab061f5d1b94bd046afcb9d3588414c3.1631101392.git.wuzongyong@linux.alibaba.com>
2021-09-09 2:53 ` [PATCH 3/6] vp_vdpa: add vq irq offloading support Jason Wang
[not found] ` <ebd83066e3897aae63e4b02f8729a73dd09931c6.1631101392.git.wuzongyong@linux.alibaba.com>
2021-09-09 2:55 ` [PATCH 5/6] vdpa: add get_vq_num_unchangeable callback in vdpa_config_ops Jason Wang
2021-09-09 9:18 ` Michael S. Tsirkin
2021-09-09 9:32 ` Jason Wang
[not found] ` <20210909080157.GA17383@L-PF27918B-1352.localdomain>
2021-09-09 9:28 ` Jason Wang
[not found] ` <20210909095726.GA17469@L-PF27918B-1352.localdomain>
2021-09-10 1:45 ` Jason Wang
[not found] ` <20210910073231.GA17715@L-PF27918B-1352.localdomain>
[not found] ` <CACLfguWeXwWJ9yd18vHbYicOk5=eMZJ0X=m86EKjmgHu35NdVA@mail.gmail.com>
[not found] ` <20210910092013.GA17783@L-PF27918B-1352.localdomain>
[not found] ` <CACLfguXFDra77Nqiv+ArUEOzTf9rzi0gLK4_r0ofCfJHSO056Q@mail.gmail.com>
2021-09-13 1:43 ` Jason Wang
[not found] ` <20210913025920.GB17820@L-PF27918B-1352.localdomain>
2021-09-13 3:13 ` Jason Wang
2021-09-09 3:05 ` [PATCH 0/6] vDPA driver for legacy virtio-pci device Jason Wang
2021-09-09 3:20 ` Jason Wang
2021-09-09 9:21 ` Michael S. Tsirkin
2021-09-09 9:31 ` Jason Wang
[not found] ` <20210909081211.GB17383@L-PF27918B-1352.localdomain>
2021-09-09 9:29 ` Jason Wang [this message]
[not found] ` <20210909125338.GA17535@L-PF27918B-1352.localdomain>
2021-09-10 1:44 ` Jason Wang
[not found] ` <8b084e5beb1111ad98bb64177ebd0e9845c178fa.1631101392.git.wuzongyong@linux.alibaba.com>
2021-09-09 13:57 ` [PATCH 6/6] vp_vdpa: introduce legacy virtio pci driver Michael S. Tsirkin
[not found] ` <20210910022818.GB17535@L-PF27918B-1352.localdomain>
2021-09-10 9:57 ` Michael S. Tsirkin
2021-10-22 9:37 ` Michael S. Tsirkin
[not found] ` <cover.1631621507.git.wuzongyong@linux.alibaba.com>
[not found] ` <834528d24c839080215b2e077f100e9ed5073edc.1631621507.git.wuzongyong@linux.alibaba.com>
2021-09-14 12:58 ` [PATCH v2 4/5] vdpa: add new vdpa attribute VDPA_ATTR_DEV_F_VERSION_1 Michael S. Tsirkin
2021-09-15 3:18 ` Jason Wang
2021-09-15 7:38 ` Michael S. Tsirkin
2021-09-15 8:06 ` Jason Wang
2021-09-15 11:08 ` Michael S. Tsirkin
2021-09-16 1:05 ` Jason Wang
[not found] ` <20210917023451.GA19669@L-PF27918B-1352.localdomain>
2021-09-17 7:51 ` Jason Wang
[not found] ` <20210915121234.GA19232@L-PF27918B-1352.localdomain>
2021-09-16 1:11 ` Jason Wang
[not found] ` <20210915032453.GA18793@L-PF27918B-1352.localdomain>
2021-09-15 7:30 ` Michael S. Tsirkin
2021-09-15 8:05 ` Jason Wang
2021-09-15 11:10 ` Michael S. Tsirkin
[not found] ` <f833e77685cd1dfadc5c3b6688d29a0d1383dbb9.1631621507.git.wuzongyong@linux.alibaba.com>
2021-09-14 22:37 ` [PATCH v2 1/5] virtio-pci: introduce legacy device module Randy Dunlap
[not found] ` <42c5a09aacae346449bcc7b7b54d63f9d265e622.1631621507.git.wuzongyong@linux.alibaba.com>
2021-09-15 3:15 ` [PATCH v2 2/5] vdpa: fix typo Jason Wang
[not found] ` <11a491e2200e17319989ff9043b8d58867610197.1631621507.git.wuzongyong@linux.alibaba.com>
2021-09-15 3:16 ` [PATCH v2 3/5] vp_vdpa: add vq irq offloading support Jason Wang
[not found] ` <20210915033102.GB18793@L-PF27918B-1352.localdomain>
2021-09-15 4:13 ` Jason Wang
[not found] ` <ab98427764198053b4277a127eaea3f32cd40ed5.1631621507.git.wuzongyong@linux.alibaba.com>
2021-09-14 22:35 ` [PATCH v2 5/5] eni_vdpa: add vDPA driver for Alibaba ENI Randy Dunlap
2021-09-15 3:14 ` Jason Wang
2021-09-15 13:36 ` kernel test robot
[not found] ` <cover.1632313398.git.wuzongyong@linux.alibaba.com>
[not found] ` <296014fa3b765f2088a3183bf04e09863651a584.1632313398.git.wuzongyong@linux.alibaba.com>
2021-09-26 2:24 ` [PATCH v3 7/7] " Jason Wang
[not found] ` <20210926032434.GA32570@L-PF27918B-1352.localdomain>
2021-09-26 4:18 ` Jason Wang
2021-09-27 10:36 ` Michael S. Tsirkin
2021-09-28 2:17 ` Jason Wang
2021-09-26 2:26 ` Jason Wang
[not found] ` <20210926032701.GA32606@L-PF27918B-1352.localdomain>
2021-09-26 4:19 ` Jason Wang
2021-09-29 12:54 ` kernel test robot
[not found] ` <cover.1632882380.git.wuzongyong@linux.alibaba.com>
[not found] ` <a068c730a0707d35afbbf72a5e0eb29f427f6045.1632882380.git.wuzongyong@linux.alibaba.com>
2021-10-11 3:00 ` [PATCH v4 1/7] virtio-pci: introduce legacy device module Jason Wang
2021-10-11 3:02 ` Jason Wang
[not found] ` <49dc74038cdfaa7af7dab1565ba5da5d6cc4ec7d.1632882380.git.wuzongyong@linux.alibaba.com>
2021-10-11 3:03 ` [PATCH v4 2/7] vdpa: fix typo Jason Wang
[not found] ` <451ce3c272ebd5d532db1ed19c2ab53c4609f7ad.1632882380.git.wuzongyong@linux.alibaba.com>
2021-10-11 3:04 ` [PATCH v4 4/7] vdpa: add new callback get_vq_num_min in vdpa_config_ops Jason Wang
[not found] ` <e971b011b9224a4da4fcab6e904fcee0b7393ac6.1632882380.git.wuzongyong@linux.alibaba.com>
2021-10-11 3:06 ` [PATCH v4 5/7] virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max,min} Jason Wang
[not found] ` <ab430c611c3d8074fddc6c4e0f747852678d6b3f.1632882380.git.wuzongyong@linux.alibaba.com>
2021-10-11 3:10 ` [PATCH v4 6/7] vdpa: add new attribute VDPA_ATTR_DEV_MIN_VQ_SIZE Jason Wang
[not found] ` <68d4ffac2ed9c21f352c272efbdf21e567d7d48e.1632882380.git.wuzongyong@linux.alibaba.com>
2021-10-11 3:18 ` [PATCH v4 7/7] eni_vdpa: add vDPA driver for Alibaba ENI Jason Wang
[not found] ` <cover.1634281805.git.wuzongyong@linux.alibaba.com>
[not found] ` <57a04a9e516ec4055cb887e9c7b24658ca5b0228.1634281805.git.wuzongyong@linux.alibaba.com>
2021-10-15 8:18 ` [PATCH v5 8/8] " Jason Wang
2021-10-15 19:13 ` Randy Dunlap
[not found] ` <17a38d70dd6f598f98eca68731746b6945a36d36.1634281805.git.wuzongyong@linux.alibaba.com>
2021-10-15 8:22 ` [PATCH v5 1/8] virtio-pci: introduce legacy device module Jason Wang
[not found] ` <25435d5cde12f298133196e866662b0ef2225205.1634281805.git.wuzongyong@linux.alibaba.com>
2021-10-15 8:22 ` [PATCH v5 4/8] vdpa: add new callback get_vq_num_min in vdpa_config_ops Jason Wang
[not found] ` <5b75093fc4a866a4502485ec208ca0e55440bdf7.1634281805.git.wuzongyong@linux.alibaba.com>
2021-10-15 8:24 ` [PATCH v5 5/8] vdpa: min vq num of vdpa device cannot be greater than max vq num Jason Wang
[not found] ` <4fae24ebd63ac4ec513bfe0688051469ea0588c0.1634281805.git.wuzongyong@linux.alibaba.com>
2021-10-15 8:30 ` [PATCH v5 6/8] virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max,min} Jason Wang
[not found] ` <cover.1634870456.git.wuzongyong@linux.alibaba.com>
[not found] ` <7bb4834a0638fabaf3ba1a585b607830392a088f.1634870456.git.wuzongyong@linux.alibaba.com>
2021-10-25 1:30 ` [PATCH v6 1/8] virtio-pci: introduce legacy device module Jason Wang
[not found] ` <7e4d859949fa37fce2289a4b287843cdeffcaf8a.1634870456.git.wuzongyong@linux.alibaba.com>
2021-10-25 2:17 ` [PATCH v6 4/8] vdpa: add new callback get_vq_num_min in vdpa_config_ops Jason Wang
[not found] ` <41e5d4e7d9e6f46429ce45a80f81f40fdb8e11cb.1634870456.git.wuzongyong@linux.alibaba.com>
2021-10-25 2:18 ` [PATCH v6 5/8] vdpa: min vq num of vdpa device cannot be greater than max vq num Jason Wang
[not found] ` <c75b4499f7ead922daa19bf67b32eed6f185d260.1634870456.git.wuzongyong@linux.alibaba.com>
2021-10-25 2:22 ` [PATCH v6 6/8] virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max, min} Jason Wang
[not found] ` <20211025024403.GA3684@L-PF27918B-1352.localdomain>
2021-10-25 4:45 ` [PATCH v6 6/8] virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max,min} Jason Wang
[not found] ` <20211025062454.GA4832@L-PF27918B-1352.localdomain>
2021-10-26 4:46 ` [PATCH v6 6/8] virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max, min} Jason Wang
[not found] ` <f3d36f0d7c9588aefaf6eeaa235b0a22fee23d56.1634870456.git.wuzongyong@linux.alibaba.com>
2021-10-25 2:23 ` [PATCH v6 7/8] vdpa: add new attribute VDPA_ATTR_DEV_MIN_VQ_SIZE Jason Wang
[not found] ` <6496b76a64303a3e23ea19e3e279644608de36fb.1634870456.git.wuzongyong@linux.alibaba.com>
2021-10-25 2:27 ` [PATCH v6 8/8] eni_vdpa: add vDPA driver for Alibaba ENI Jason Wang
[not found] ` <20211025032146.GC3684@L-PF27918B-1352.localdomain>
2021-10-25 4:40 ` Jason Wang
[not found] ` <20211027024700.GA23409@L-PF27918B-1352.localdomain>
2021-10-27 3:55 ` Jason Wang
[not found] ` <cover.1635493219.git.wuzongyong@linux.alibaba.com>
2021-11-01 3:31 ` [PATCH v7 0/9] " Jason Wang
[not found] ` <20211101062250.GA29814@L-PF27918B-1352.localdomain>
2021-11-01 7:02 ` Jason Wang
[not found] ` <20211101081159.GA4341@L-PF27918B-1352.localdomain>
2021-11-01 11:12 ` Michael S. Tsirkin
[not found] ` <0945b37f19b96ecadb79a4e1b01f486119a0b83a.1635493219.git.wuzongyong@linux.alibaba.com>
2021-11-01 8:18 ` [PATCH v7 9/9] eni_vdpa: alibaba: fix Kconfig typo Michael S. Tsirkin
2021-11-01 8:19 ` [PATCH v7 0/9] vDPA driver for Alibaba ENI Michael S. Tsirkin
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