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 5/6] vdpa: add get_vq_num_unchangeable callback in vdpa_config_ops
Date: Thu, 9 Sep 2021 17:28:26 +0800 [thread overview]
Message-ID: <CACGkMEsnp7-axbZWuB_w7ZkSWKa0Y+Ej-Kq0QSfO2-DNN=ShVA@mail.gmail.com> (raw)
In-Reply-To: <20210909080157.GA17383@L-PF27918B-1352.localdomain>
On Thu, Sep 9, 2021 at 4:02 PM Wu Zongyong <wuzongyong@linux.alibaba.com> wrote:
>
> On Thu, Sep 09, 2021 at 10:55:03AM +0800, Jason Wang wrote:
> > On Wed, Sep 8, 2021 at 8:23 PM Wu Zongyong <wuzongyong@linux.alibaba.com> wrote:
> > >
> > > This new callback is used to indicate whether the vring size can be
> > > change or not. It is useful when we have a legacy virtio pci device as
> > > the vdpa device for there is no way to negotiate the vring num by the
> > > specification.
> >
> > So I'm not sure it's worth bothering. E.g what if we just fail
> > VHOST_SET_VRING_NUM it the value doesn't match what hardware has?
> >
> > Thanks
> >
> I think we should not call VHOST_SET_VRING_NUM in that case.
>
> If the hardware reports that the virtqueue size cannot be changed, we
> should call VHOST_GET_VRING_NUM to get the static virtqueue size
> firstly, then allocate the same size memory for the virtqueues and write
> the address to hardware finally.
>
> For QEMU, we will ignore the properties rx/tx_queue_size and just get it
> from the hardware if this new callback return true.
This will break live migration. My understanding is that we can
advertise those capability/limitation via the netlink management
protocol then management layer can choose to use the correct queue
size.
Thanks
>
> What do you think?
> > >
> > > Signed-off-by: Wu Zongyong <wuzongyong@linux.alibaba.com>
> > > ---
> > > drivers/vhost/vdpa.c | 19 +++++++++++++++++++
> > > drivers/virtio/virtio_vdpa.c | 5 ++++-
> > > include/linux/vdpa.h | 4 ++++
> > > include/uapi/linux/vhost.h | 2 ++
> > > 4 files changed, 29 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> > > index 9479f7f79217..2204d27d1e5d 100644
> > > --- a/drivers/vhost/vdpa.c
> > > +++ b/drivers/vhost/vdpa.c
> > > @@ -350,6 +350,22 @@ static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
> > > return 0;
> > > }
> > >
> > > +static long vhost_vdpa_get_vring_num_unchangeable(struct vhost_vdpa *v,
> > > + u32 __user *argp)
> > > +{
> > > + struct vdpa_device *vdpa = v->vdpa;
> > > + const struct vdpa_config_ops *ops = vdpa->config;
> > > + bool unchangeable = false;
> > > +
> > > + if (ops->get_vq_num_unchangeable)
> > > + unchangeable = ops->get_vq_num_unchangeable(vdpa);
> > > +
> > > + if (copy_to_user(argp, &unchangeable, sizeof(unchangeable)))
> > > + return -EFAULT;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
> > > void __user *argp)
> > > {
> > > @@ -487,6 +503,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
> > > case VHOST_VDPA_GET_IOVA_RANGE:
> > > r = vhost_vdpa_get_iova_range(v, argp);
> > > break;
> > > + case VHOST_VDPA_GET_VRING_NUM_UNCHANGEABLE:
> > > + r = vhost_vdpa_get_vring_num_unchangeable(v, argp);
> > > + break;
> > > default:
> > > r = vhost_dev_ioctl(&v->vdev, cmd, argp);
> > > if (r == -ENOIOCTLCMD)
> > > diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
> > > index 72eaef2caeb1..afb47465307a 100644
> > > --- a/drivers/virtio/virtio_vdpa.c
> > > +++ b/drivers/virtio/virtio_vdpa.c
> > > @@ -146,6 +146,7 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
> > > struct vdpa_vq_state state = {0};
> > > unsigned long flags;
> > > u32 align, num;
> > > + bool may_reduce_num = true;
> > > int err;
> > >
> > > if (!name)
> > > @@ -171,8 +172,10 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
> > >
> > > /* Create the vring */
> > > align = ops->get_vq_align(vdpa);
> > > + if (ops->get_vq_num_unchangeable)
> > > + may_reduce_num = !ops->get_vq_num_unchangeable(vdpa);
> > > vq = vring_create_virtqueue(index, num, align, vdev,
> > > - true, true, ctx,
> > > + true, may_reduce_num, ctx,
> > > virtio_vdpa_notify, callback, name);
> > > if (!vq) {
> > > err = -ENOMEM;
> > > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> > > index 35648c11e312..f809b7ada00d 100644
> > > --- a/include/linux/vdpa.h
> > > +++ b/include/linux/vdpa.h
> > > @@ -195,6 +195,9 @@ struct vdpa_iova_range {
> > > * @vdev: vdpa device
> > > * Returns the iova range supported by
> > > * the device.
> > > + * @get_vq_num_unchangeable Check if size of virtqueue is unchangeable (optional)
> > > + * @vdev: vdpa device
> > > + * Returns boolean: unchangeable (true) or not (false)
> > > * @set_map: Set device memory mapping (optional)
> > > * Needed for device that using device
> > > * specific DMA translation (on-chip IOMMU)
> > > @@ -262,6 +265,7 @@ struct vdpa_config_ops {
> > > const void *buf, unsigned int len);
> > > u32 (*get_generation)(struct vdpa_device *vdev);
> > > struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
> > > + bool (*get_vq_num_unchangeable)(struct vdpa_device *vdev);
> > >
> > > /* DMA ops */
> > > int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
> > > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > > index c998860d7bbc..184f1f7f8498 100644
> > > --- a/include/uapi/linux/vhost.h
> > > +++ b/include/uapi/linux/vhost.h
> > > @@ -150,4 +150,6 @@
> > > /* Get the valid iova range */
> > > #define VHOST_VDPA_GET_IOVA_RANGE _IOR(VHOST_VIRTIO, 0x78, \
> > > struct vhost_vdpa_iova_range)
> > > +/* Check if the vring size can be change */
> > > +#define VHOST_VDPA_GET_VRING_NUM_UNCHANGEABLE _IOR(VHOST_VIRTIO, 0X79, bool)
> > > #endif
> > > --
> > > 2.31.1
> > >
>
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next prev parent reply other threads:[~2021-09-09 9:28 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 [this message]
[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
[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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