From: Leon Romanovsky <leon@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Alex Williamson <alex.williamson@redhat.com>,
Bjorn Helgaas <bhelgaas@google.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org,
netdev@vger.kernel.org, Saeed Mahameed <saeedm@nvidia.com>,
Yishai Hadas <yishaih@nvidia.com>
Subject: Re: [PATCH mlx5-next 1/7] PCI/IOV: Provide internal VF index
Date: Thu, 23 Sep 2021 09:35:32 +0300 [thread overview]
Message-ID: <YUwgNPL++APsFJ49@unreal> (raw)
In-Reply-To: <20210922215930.GA231505@bhelgaas>
On Wed, Sep 22, 2021 at 04:59:30PM -0500, Bjorn Helgaas wrote:
> On Wed, Sep 22, 2021 at 01:38:50PM +0300, Leon Romanovsky wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> >
> > The PCI core uses the VF index internally, often called the vf_id,
> > during the setup of the VF, eg pci_iov_add_virtfn().
> >
> > This index is needed for device drivers that implement live migration
> > for their internal operations that configure/control their VFs.
> >
> > Specifically, mlx5_vfio_pci driver that is introduced in coming patches
> > from this series needs it and not the bus/device/function which is
> > exposed today.
> >
> > Add pci_iov_vf_id() which computes the vf_id by reversing the math that
> > was used to create the bus/device/function.
> >
> > Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
> > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
>
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
>
> mlx5_core_sriov_set_msix_vec_count() looks like it does basically the
> same thing as pci_iov_vf_id() by iterating through VFs until it finds
> one with a matching devfn (although it *doesn't* check for a matching
> bus number, which seems like a bug).
>
> Maybe that should use pci_iov_vf_id()?
Yes, I gave same comment internally and we decided to simply reduce the
amount of changes in mlx5_core to have less distractions and submit as a
followup. Most likely will add this hunk in v1.
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
index e8185b69ac6c..b66be0b4244a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
@@ -209,15 +209,8 @@ int mlx5_core_sriov_set_msix_vec_count(struct pci_dev *vf, int msix_vec_count)
/* Reversed translation of PCI VF function number to the internal
* function_id, which exists in the name of virtfn symlink.
*/
- for (id = 0; id < pci_num_vf(pf); id++) {
- if (!sriov->vfs_ctx[id].enabled)
- continue;
-
- if (vf->devfn == pci_iov_virtfn_devfn(pf, id))
- break;
- }
-
- if (id == pci_num_vf(pf) || !sriov->vfs_ctx[id].enabled)
+ id = pci_iov_vf_id(vf);
+ if (id < 0 || !sriov->vfs_ctx[id].enabled)
return -EINVAL;
return mlx5_set_msix_vec_count(dev, id + 1, msix_vec_count);
Thanks
>
> > ---
> > drivers/pci/iov.c | 14 ++++++++++++++
> > include/linux/pci.h | 7 ++++++-
> > 2 files changed, 20 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> > index dafdc652fcd0..e7751fa3fe0b 100644
> > --- a/drivers/pci/iov.c
> > +++ b/drivers/pci/iov.c
> > @@ -33,6 +33,20 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
> > }
> > EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);
> >
> > +int pci_iov_vf_id(struct pci_dev *dev)
> > +{
> > + struct pci_dev *pf;
> > +
> > + if (!dev->is_virtfn)
> > + return -EINVAL;
> > +
> > + pf = pci_physfn(dev);
> > + return (((dev->bus->number << 8) + dev->devfn) -
> > + ((pf->bus->number << 8) + pf->devfn + pf->sriov->offset)) /
> > + pf->sriov->stride;
> > +}
> > +EXPORT_SYMBOL_GPL(pci_iov_vf_id);
> > +
> > /*
> > * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
> > * change when NumVFs changes.
> > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > index cd8aa6fce204..4d6c73506e18 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -2153,7 +2153,7 @@ void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
> > #ifdef CONFIG_PCI_IOV
> > int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
> > int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);
> > -
> > +int pci_iov_vf_id(struct pci_dev *dev);
> > int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
> > void pci_disable_sriov(struct pci_dev *dev);
> >
> > @@ -2181,6 +2181,11 @@ static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
> > {
> > return -ENOSYS;
> > }
> > +static inline int pci_iov_vf_id(struct pci_dev *dev)
> > +{
> > + return -ENOSYS;
> > +}
> > +
>
> Drop the blank line to match the surrounding stubs.
Sure, thanks
>
> > static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
> > { return -ENODEV; }
>
next prev parent reply other threads:[~2021-09-23 6:35 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1632305919.git.leonro@nvidia.com>
2021-09-22 10:38 ` [PATCH mlx5-next 1/7] PCI/IOV: Provide internal VF index Leon Romanovsky
2021-09-22 21:59 ` Bjorn Helgaas
2021-09-23 6:35 ` Leon Romanovsky [this message]
2021-09-24 13:08 ` Bjorn Helgaas
2021-09-25 10:10 ` Leon Romanovsky
2021-09-25 17:41 ` Bjorn Helgaas
2021-09-26 6:36 ` Leon Romanovsky
2021-09-26 20:23 ` Bjorn Helgaas
2021-09-27 11:55 ` Leon Romanovsky
2021-09-27 14:47 ` Bjorn Helgaas
2021-09-22 10:38 ` [PATCH mlx5-next 2/7] vfio: Add an API to check migration state transition validity Leon Romanovsky
2021-09-23 10:33 ` Shameerali Kolothum Thodi
2021-09-23 11:17 ` Leon Romanovsky
2021-09-23 13:55 ` Max Gurtovoy
2021-09-24 7:44 ` Shameerali Kolothum Thodi
2021-09-24 9:37 ` Kirti Wankhede
2021-09-26 9:09 ` Max Gurtovoy
2021-09-26 16:17 ` Shameerali Kolothum Thodi
2021-09-27 18:24 ` Max Gurtovoy
2021-09-27 18:29 ` Shameerali Kolothum Thodi
2021-09-27 22:46 ` Alex Williamson
2021-09-27 23:12 ` Jason Gunthorpe
2021-09-28 19:19 ` Alex Williamson
2021-09-28 19:35 ` Jason Gunthorpe
2021-09-28 20:18 ` Alex Williamson
2021-09-29 16:16 ` Jason Gunthorpe
2021-09-29 18:06 ` Alex Williamson
2021-09-29 18:26 ` Jason Gunthorpe
2021-09-29 10:57 ` Max Gurtovoy
2021-09-29 10:44 ` Max Gurtovoy
2021-09-29 12:35 ` Alex Williamson
2021-09-29 13:26 ` Max Gurtovoy
2021-09-29 13:50 ` Alex Williamson
2021-09-29 14:36 ` Max Gurtovoy
2021-09-29 15:17 ` Alex Williamson
2021-09-29 15:28 ` Max Gurtovoy
2021-09-29 16:14 ` Jason Gunthorpe
2021-09-29 21:48 ` Max Gurtovoy
2021-09-29 22:44 ` Alex Williamson
2021-09-30 9:25 ` Max Gurtovoy
2021-09-30 12:41 ` Alex Williamson
2021-09-29 23:21 ` Jason Gunthorpe
2021-09-30 9:34 ` Max Gurtovoy
2021-09-30 14:47 ` Jason Gunthorpe
2021-09-30 15:32 ` Max Gurtovoy
2021-09-30 16:24 ` Jason Gunthorpe
2021-09-30 16:51 ` Max Gurtovoy
2021-09-30 17:01 ` Jason Gunthorpe
2021-09-22 10:38 ` [PATCH mlx5-next 3/7] vfio/pci_core: Make the region->release() function optional Leon Romanovsky
2021-09-23 13:57 ` Max Gurtovoy
2021-09-22 10:38 ` [PATCH mlx5-next 4/7] net/mlx5: Introduce migration bits and structures Leon Romanovsky
2021-09-24 5:48 ` Mark Zhang
2021-09-22 10:38 ` [PATCH mlx5-next 5/7] net/mlx5: Expose APIs to get/put the mlx5 core device Leon Romanovsky
2021-09-22 10:38 ` [PATCH mlx5-next 6/7] mlx5_vfio_pci: Expose migration commands over mlx5 device Leon Romanovsky
2021-09-28 20:22 ` Alex Williamson
2021-09-29 5:36 ` Leon Romanovsky
2021-09-22 10:38 ` [PATCH mlx5-next 7/7] mlx5_vfio_pci: Implement vfio_pci driver for mlx5 devices Leon Romanovsky
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