Re: [RFC XEN PATCH v4 1/5] xen/vpci: Clear all vpci status of device

[Stewart Hildebrand <stewart.hildebrand@xxxxxxx>]

On 1/5/24 02:09, Jiqian Chen wrote:
> diff --git a/xen/drivers/pci/physdev.c b/xen/drivers/pci/physdev.c
> index 42db3e6d133c..552ccbf747cb 100644
> --- a/xen/drivers/pci/physdev.c
> +++ b/xen/drivers/pci/physdev.c
> @@ -67,6 +68,39 @@ ret_t pci_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) 
> arg)
>          break;
>      }
>  
> +    case PHYSDEVOP_pci_device_state_reset: {
> +        struct physdev_pci_device dev;
> +        struct pci_dev *pdev;
> +        pci_sbdf_t sbdf;
> +
> +        if ( !is_pci_passthrough_enabled() )
> +            return -EOPNOTSUPP;
> +
> +        ret = -EFAULT;
> +        if ( copy_from_guest(&dev, arg, 1) != 0 )
> +            break;
> +        sbdf = PCI_SBDF(dev.seg, dev.bus, dev.devfn);
> +
> +        ret = xsm_resource_setup_pci(XSM_PRIV, sbdf.sbdf);
> +        if ( ret )
> +            break;
> +
> +        pcidevs_lock();
> +        pdev = pci_get_pdev(NULL, sbdf);
> +        if ( !pdev )
> +        {
> +            pcidevs_unlock();
> +            ret = -ENODEV;
> +            break;
> +        }
> +

        write_lock(&pdev->domain->pci_lock);

> +        ret = vpci_reset_device_state(pdev);

        write_unlock(&pdev->domain->pci_lock);

> +        pcidevs_unlock();
> +        if ( ret )
> +            printk(XENLOG_ERR "%pp: failed to reset PCI device state\n", 
> &sbdf);
> +        break;
> +    }
> +
>      default:
>          ret = -ENOSYS;
>          break;
> diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
> index 72ef277c4f8e..3c64cb10ccbb 100644
> --- a/xen/drivers/vpci/vpci.c
> +++ b/xen/drivers/vpci/vpci.c
> @@ -107,6 +107,15 @@ int vpci_add_handlers(struct pci_dev *pdev)
>  
>      return rc;
>  }
> +
> +int vpci_reset_device_state(struct pci_dev *pdev)
> +{
> +    ASSERT(pcidevs_locked());

    ASSERT(rw_is_write_locked(&pdev->domain->pci_lock));

> +
> +    vpci_remove_device(pdev);
> +    return vpci_add_handlers(pdev);
> +}
> +
>  #endif /* __XEN__ */
>  
>  static int vpci_register_cmp(const struct vpci_register *r1,