diff mbox series

vp_vdpa: Check queue number of vdpa device from add_config

Message ID 20230602073442.1765-1-angus.chen@jaguarmicro.com
State New
Headers
Series vp_vdpa: Check queue number of vdpa device from add_config |

Commit Message

Angus Chen June 2, 2023, 7:34 a.m. UTC 
  When add virtio_pci vdpa device,check the vqs number of device cap
and max_vq_pairs from add_config.

Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
---
 drivers/vdpa/virtio_pci/vp_vdpa.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Comments

Jason Wang June 5, 2023, 6:53 a.m. UTC | #1 
On Fri, Jun 2, 2023 at 3:35 PM Angus Chen <angus.chen@jaguarmicro.com> wrote:
>
> When add virtio_pci vdpa device,check the vqs number of device cap
> and max_vq_pairs from add_config.
>
> Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
> ---
>  drivers/vdpa/virtio_pci/vp_vdpa.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index 281287fae89f..4bf1ab637d32 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -478,7 +478,7 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>         struct device *dev = &pdev->dev;
>         struct vp_vdpa *vp_vdpa = NULL;
>         u64 device_features;
> -       int ret, i;
> +       int ret, i, queues;
>
>         vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
>                                     dev, &vp_vdpa_ops, 1, 1, name, false);
> @@ -491,7 +491,14 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>         vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
>
>         vp_vdpa->vdpa.dma_dev = &pdev->dev;
> -       vp_vdpa->queues = vp_modern_get_num_queues(mdev);
> +       queues = vp_modern_get_num_queues(mdev);
> +       if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
> +               if (add_config->net.max_vq_pairs > queues / 2)
> +                       return -EINVAL;
> +               queues = min_t(u32, queues, 2 * add_config->net.max_vq_pairs);

Looks like you want to mediate the max_vqp here, but what happens:

1) harware have 4 queue paris
2) vp_vdpa cap it into 2 queue pairs
3) guest may still try to enable 4 queue paris

For 3), the kernel needs to mediate the control virtqueue which seems not easy.

How about simply starting from failing if the provisioned #qp is not
equal to the one that hardware has?

Thanks

> +       }
> +
> +       vp_vdpa->queues = queues;
>         vp_vdpa->mdev = mdev;
>
>         device_features = vp_modern_get_features(mdev);
> --
> 2.25.1
>
Angus Chen June 6, 2023, 6:19 a.m. UTC | #2 
Hi,Jason.

> -----Original Message-----
> From: Jason Wang <jasowang@redhat.com>
> Sent: Monday, June 5, 2023 2:54 PM
> To: Angus Chen <angus.chen@jaguarmicro.com>
> Cc: mst@redhat.com; virtualization@lists.linux-foundation.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] vp_vdpa: Check queue number of vdpa device from
> add_config
> 
> On Fri, Jun 2, 2023 at 3:35 PM Angus Chen <angus.chen@jaguarmicro.com>
> wrote:
> >
> > When add virtio_pci vdpa device,check the vqs number of device cap
> > and max_vq_pairs from add_config.
> >
> > Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
> > ---
> >  drivers/vdpa/virtio_pci/vp_vdpa.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c
> b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > index 281287fae89f..4bf1ab637d32 100644
> > --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> > +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > @@ -478,7 +478,7 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev
> *v_mdev, const char *name,
> >         struct device *dev = &pdev->dev;
> >         struct vp_vdpa *vp_vdpa = NULL;
> >         u64 device_features;
> > -       int ret, i;
> > +       int ret, i, queues;
> >
> >         vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
> >                                     dev, &vp_vdpa_ops, 1, 1, name,
> false);
> > @@ -491,7 +491,14 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev
> *v_mdev, const char *name,
> >         vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
> >
> >         vp_vdpa->vdpa.dma_dev = &pdev->dev;
> > -       vp_vdpa->queues = vp_modern_get_num_queues(mdev);
> > +       queues = vp_modern_get_num_queues(mdev);
> > +       if (add_config->mask &
> BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
> > +               if (add_config->net.max_vq_pairs > queues / 2)
> > +                       return -EINVAL;
> > +               queues = min_t(u32, queues, 2 *
> add_config->net.max_vq_pairs);
> 
> Looks like you want to mediate the max_vqp here, but what happens:
> 
> 1) harware have 4 queue paris
> 2) vp_vdpa cap it into 2 queue pairs
> 3) guest may still try to enable 4 queue paris
> 
Yes，you are right，this situation can occur.
> For 3), the kernel needs to mediate the control virtqueue which seems not
> easy.
> 
> How about simply starting from failing if the provisioned #qp is not
> equal to the one that hardware has?
Ok,You mean we just check it in vp_vdpa or check it in all other vdpa net drivers?
> 
> Thanks
> 
> > +       }
> > +
> > +       vp_vdpa->queues = queues;
> >         vp_vdpa->mdev = mdev;
> >
> >         device_features = vp_modern_get_features(mdev);
> > --
> > 2.25.1
> >
Jason Wang June 7, 2023, 2:11 a.m. UTC | #3 
On Tue, Jun 6, 2023 at 2:19 PM Angus Chen <angus.chen@jaguarmicro.com> wrote:
>
> Hi,Jason.
>
> > -----Original Message-----
> > From: Jason Wang <jasowang@redhat.com>
> > Sent: Monday, June 5, 2023 2:54 PM
> > To: Angus Chen <angus.chen@jaguarmicro.com>
> > Cc: mst@redhat.com; virtualization@lists.linux-foundation.org;
> > linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH] vp_vdpa: Check queue number of vdpa device from
> > add_config
> >
> > On Fri, Jun 2, 2023 at 3:35 PM Angus Chen <angus.chen@jaguarmicro.com>
> > wrote:
> > >
> > > When add virtio_pci vdpa device,check the vqs number of device cap
> > > and max_vq_pairs from add_config.
> > >
> > > Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
> > > ---
> > >  drivers/vdpa/virtio_pci/vp_vdpa.c | 11 +++++++++--
> > >  1 file changed, 9 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c
> > b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > index 281287fae89f..4bf1ab637d32 100644
> > > --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > @@ -478,7 +478,7 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev
> > *v_mdev, const char *name,
> > >         struct device *dev = &pdev->dev;
> > >         struct vp_vdpa *vp_vdpa = NULL;
> > >         u64 device_features;
> > > -       int ret, i;
> > > +       int ret, i, queues;
> > >
> > >         vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
> > >                                     dev, &vp_vdpa_ops, 1, 1, name,
> > false);
> > > @@ -491,7 +491,14 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev
> > *v_mdev, const char *name,
> > >         vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
> > >
> > >         vp_vdpa->vdpa.dma_dev = &pdev->dev;
> > > -       vp_vdpa->queues = vp_modern_get_num_queues(mdev);
> > > +       queues = vp_modern_get_num_queues(mdev);
> > > +       if (add_config->mask &
> > BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
> > > +               if (add_config->net.max_vq_pairs > queues / 2)
> > > +                       return -EINVAL;
> > > +               queues = min_t(u32, queues, 2 *
> > add_config->net.max_vq_pairs);
> >
> > Looks like you want to mediate the max_vqp here, but what happens:
> >
> > 1) harware have 4 queue paris
> > 2) vp_vdpa cap it into 2 queue pairs
> > 3) guest may still try to enable 4 queue paris
> >
> Yes，you are right，this situation can occur.
> > For 3), the kernel needs to mediate the control virtqueue which seems not
> > easy.
> >
> > How about simply starting from failing if the provisioned #qp is not
> > equal to the one that hardware has?
> Ok,You mean we just check it in vp_vdpa or check it in all other vdpa net drivers?

vp_vdpa only, since in some other kind of parents, #qps could be provisioned.

Thanks

> >
> > Thanks
> >
> > > +       }
> > > +
> > > +       vp_vdpa->queues = queues;
> > >         vp_vdpa->mdev = mdev;
> > >
> > >         device_features = vp_modern_get_features(mdev);
> > > --
> > > 2.25.1
> > >
>
diff mbox series

Patch

diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index 281287fae89f..4bf1ab637d32 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -478,7 +478,7 @@  static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
 	struct device *dev = &pdev->dev;
 	struct vp_vdpa *vp_vdpa = NULL;
 	u64 device_features;
-	int ret, i;
+	int ret, i, queues;
 
 	vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
 				    dev, &vp_vdpa_ops, 1, 1, name, false);
@@ -491,7 +491,14 @@  static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
 	vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
 
 	vp_vdpa->vdpa.dma_dev = &pdev->dev;
-	vp_vdpa->queues = vp_modern_get_num_queues(mdev);
+	queues = vp_modern_get_num_queues(mdev);
+	if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
+		if (add_config->net.max_vq_pairs > queues / 2)
+			return -EINVAL;
+		queues = min_t(u32, queues, 2 * add_config->net.max_vq_pairs);
+	}
+
+	vp_vdpa->queues = queues;
 	vp_vdpa->mdev = mdev;
 
 	device_features = vp_modern_get_features(mdev);