On Tue, Oct 6, 2009 at 11:23 AM, Fenghua Yu <fenghua.yu@xxxxxxxxx> wrote:
> To support PCIe hot plug in IOMMU, we register a notifier to respond to device
> change action.
>
> When the notifier gets BUS_NOTIFY_UNBOUND_DRIVER, it removes the device from its
> DMAR domain.
>
> A hot added device will be added into an IOMMU domain when it first does IOMMU
> op. So there is no need to add more code for hot add.
>
> Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
>
> ---
>
> intel-iommu.c | 29 +++++++++++++++++++++++++++++
> 1 files changed, 29 insertions(+)
>
> diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
> index 855dd7c..d8b8cfc 100644
> --- a/drivers/pci/intel-iommu.c
> +++ b/drivers/pci/intel-iommu.c
> @@ -3193,6 +3193,33 @@ static int __init init_iommu_sysfs(void)
> }
> #endif /* CONFIG_PM */
>
> +/*
> + * Here we only respond to action of unbound device from driver.
> + *
> + * Added device is not attached to its DMAR domain here yet. That will happen
> + * when mapping the device to iova.
> + */
> +static int device_notifier(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + struct device *dev = data;
> + struct pci_dev *pdev = to_pci_dev(dev);
> + struct dmar_domain *domain;
> +
> + domain = find_domain(pdev);
> + if (!domain)
> + return 0;
> +
> + if (action == BUS_NOTIFY_UNBOUND_DRIVER && !iommu_pass_through)
> + domain_remove_one_dev_info(domain, pdev);
> +
> + return 0;
> +}
> +
> +static struct notifier_block device_nb = {
> + .notifier_call = device_notifier,
> +};
> +
> int __init intel_iommu_init(void)
> {
> int ret = 0;
> @@ -3245,6 +3272,8 @@ int __init intel_iommu_init(void)
>
> register_iommu(&intel_iommu_ops);
>
> + bus_register_notifier(&pci_bus_type, &device_nb);
> +
> return 0;
> }
>
it seems this one should be get into 2.6.32....and .stable
otherwise second hot plug in the same pcie slot will not work with dma.
YH
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