On Fri, 8 Dec 2017 13:47:58 -0800
Jeff Kirsher <jeffrey.t.kirs...@intel.com> wrote:
> From: Liang-Min Wang <liang-min.w...@intel.com>
>
> When a SR-IOV capable device is bound with vfio-pci, the
> device loses capability of creating SR-IOV instances through /sy/bus/
> pci/devices/.../sriov_numvfs. This patch re-activates this capability
> for a PCIe device that is SR-IOV capable and is bound with vfio-pci.ko.
> This patch also disables drivers_autoprobe attribute of SR-IOV devices
> created from vfio-pci bound device by default, so user-space PF device
> can coordinate the bring-up of SR-IOV devices
>
> Signed-off-by: Liang-Min Wang <liang-min.w...@intel.com>
> ---
> drivers/pci/pci-driver.c | 12 ++++++++++++
> drivers/vfio/pci/vfio_pci.c | 22 ++++++++++++++++++++++
> include/linux/pci.h | 1 +
> 3 files changed, 35 insertions(+)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 7f47bb7..19522fe 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -1467,6 +1467,18 @@ void pci_dev_put(struct pci_dev *dev)
> }
> EXPORT_SYMBOL(pci_dev_put);
>
> +/**
> + * pci_dev_sriov_autoprobe_set - set device sriov driver autoprobe
> + * @dev: device with which sriov autoprobe will be set
> + *
> + */
> +void pci_dev_sriov_autoprobe_set(struct pci_dev *dev, bool autoprobe)
> +{
> + if (dev && dev->sriov)
> + dev->sriov->drivers_autoprobe = autoprobe;
> +}
> +EXPORT_SYMBOL(pci_dev_sriov_autoprobe_set);
_GPL?
It'd also be best to separate the pci and vfio changes into different
patches. Bjorn would need to at least ack this PCI interface.
> +
> static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
> {
> struct pci_dev *pdev;
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index f041b1a..004836c 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -1213,6 +1213,8 @@ static int vfio_pci_probe(struct pci_dev *pdev, const
> struct pci_device_id *id)
> return -ENOMEM;
> }
>
> + /* disable sriov automatic driver attachment */
> + pci_dev_sriov_autoprobe_set(pdev, false);
This looks stateful, VF autoprobe is not restored on release. Also,
how would we know the initial state to restore it to?
> vdev->pdev = pdev;
> vdev->irq_type = VFIO_PCI_NUM_IRQS;
> mutex_init(&vdev->igate);
> @@ -1256,6 +1258,7 @@ static void vfio_pci_remove(struct pci_dev *pdev)
> if (!vdev)
> return;
>
> + pci_disable_sriov(pdev);
> vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
> kfree(vdev->region);
> kfree(vdev);
> @@ -1303,12 +1306,31 @@ static pci_ers_result_t
> vfio_pci_aer_err_detected(struct pci_dev *pdev,
> .error_detected = vfio_pci_aer_err_detected,
> };
>
> +static int vfio_sriov_configure(struct pci_dev *pdev, int num_vfs)
> +{
> + int status;
> +
> + if (!num_vfs) {
> + pci_disable_sriov(pdev);
> + return 0;
> + }
> +
> + status = pci_enable_sriov(pdev, num_vfs);
> + if (!status) {
> + pr_crit("Created %d SR-IOV from a user-space driver based upon
> vfio-pci\n", num_vfs);
> + add_taint(TAINT_USER, LOCKDEP_STILL_OK);
> + }
This probably deserves more explanation, in comment and commit log.
Probably a dev_crit() is also justified, knowing the PF would be
useful. Thanks,
Alex
> +
> + return status;
> +}
> +
> static struct pci_driver vfio_pci_driver = {
> .name = "vfio-pci",
> .id_table = NULL, /* only dynamic ids */
> .probe = vfio_pci_probe,
> .remove = vfio_pci_remove,
> .err_handler = &vfio_err_handlers,
> + .sriov_configure = vfio_sriov_configure,
> };
>
> struct vfio_devices {
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 0403894..e04b69d 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -921,6 +921,7 @@ struct resource *pci_find_parent_resource(const struct
> pci_dev *dev,
> struct pci_dev *pci_dev_get(struct pci_dev *dev);
> void pci_dev_put(struct pci_dev *dev);
> void pci_remove_bus(struct pci_bus *b);
> +void pci_dev_sriov_autoprobe_set(struct pci_dev *dev, bool autoprobe);
> void pci_stop_and_remove_bus_device(struct pci_dev *dev);
> void pci_stop_and_remove_bus_device_locked(struct pci_dev *dev);
> void pci_stop_root_bus(struct pci_bus *bus);
