Re: [Qemu-devel] [PATCH v2 03/13] iommu: IOMMU groups for VT-d and AMD-Vi

[Don Dutile <ddutile@redhat.com>]

On 05/22/2012 01:04 AM, Alex Williamson wrote:
> Add back group support for AMD&  Intel.  amd_iommu already tracks
> devices and has init and uninit routines to manage groups.
> intel-iommu does this on the fly, so we make use of the notifier
> support built into iommu groups to create and remove groups.
>
> Signed-off-by: Alex Williamson<alex.williamson@redhat.com>
> ---
>
>   drivers/iommu/amd_iommu.c   |   28 +++++++++++++++++++++++++-
>   drivers/iommu/intel-iommu.c |   46 +++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 73 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index 32c00cd..b7e5ddf 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -256,9 +256,11 @@ static bool check_device(struct device *dev)
>
>   static int iommu_init_device(struct device *dev)
>   {
> -	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct pci_dev *dma_pdev, *pdev = to_pci_dev(dev);
>   	struct iommu_dev_data *dev_data;
> +	struct iommu_group *group;
>   	u16 alias;
> +	int ret;
>
>   	if (dev->archdata.iommu)
>   		return 0;
> @@ -279,8 +281,30 @@ static int iommu_init_device(struct device *dev)
>   			return -ENOTSUPP;
>   		}
>   		dev_data->alias_data = alias_data;
> +
> +		dma_pdev = pci_get_bus_and_slot(alias>>  8, alias&  0xff);
> +	} else
> +		dma_pdev = pdev;
> +
> +	if (!pdev->is_virtfn&&  PCI_FUNC(pdev->devfn)&&  iommu_group_mf&&
> +	    pdev->hdr_type == PCI_HEADER_TYPE_NORMAL)
> +		dma_pdev = pci_get_slot(pdev->bus,
> +					PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
> +
> +	group = iommu_group_get(&dma_pdev->dev);
> +	if (!group) {
> +		group = iommu_group_alloc();
> +		if (IS_ERR(group))
> +			return PTR_ERR(group);
>   	}
>
> +	ret = iommu_group_add_device(group, dev);
> +
> +	iommu_group_put(group);
> +
do you want to do a put if there is a failure in the iommu_group_add_device()?
> +	if (ret)
> +		return ret;
> +
>   	if (pci_iommuv2_capable(pdev)) {
>   		struct amd_iommu *iommu;
>
> @@ -309,6 +333,8 @@ static void iommu_ignore_device(struct device *dev)
>
>   static void iommu_uninit_device(struct device *dev)
>   {
> +	iommu_group_remove_device(dev);
> +
>   	/*
>   	 * Nothing to do here - we keep dev_data around for unplugged devices
>   	 * and reuse it when the device is re-plugged - not doing so would
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index d4a0ff7..e63b33b 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -4087,6 +4087,50 @@ static int intel_iommu_domain_has_cap(struct iommu_domain *domain,
>   	return 0;
>   }
>
> +static int intel_iommu_add_device(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct pci_dev *bridge, *dma_pdev = pdev;
> +	struct iommu_group *group;
> +	int ret;
> +
> +	if (!device_to_iommu(pci_domain_nr(pdev->bus),
> +			     pdev->bus->number, pdev->devfn))
> +		return -ENODEV;
> +
> +	bridge = pci_find_upstream_pcie_bridge(pdev);
> +	if (bridge) {
> +		if (pci_is_pcie(bridge))
> +			dma_pdev = pci_get_domain_bus_and_slot(
> +						pci_domain_nr(pdev->bus),
> +						bridge->subordinate->number, 0);
> +		else
> +			dma_pdev = bridge;
> +	}
> +
> +	if (!pdev->is_virtfn&&  PCI_FUNC(pdev->devfn)&&  iommu_group_mf&&
> +	    pdev->hdr_type == PCI_HEADER_TYPE_NORMAL)
> +		dma_pdev = pci_get_slot(pdev->bus,
> +					PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
> +
> +	group = iommu_group_get(&dma_pdev->dev);
> +	if (!group) {
> +		group = iommu_group_alloc();
> +		if (IS_ERR(group))
> +			return PTR_ERR(group);
> +	}
> +
> +	ret = iommu_group_add_device(group, dev);
> +
ditto.
> +	iommu_group_put(group);
> +	return ret;
> +}
> +
> +static void intel_iommu_remove_device(struct device *dev)
> +{
> +	iommu_group_remove_device(dev);
> +}
> +
>   static struct iommu_ops intel_iommu_ops = {
>   	.domain_init	= intel_iommu_domain_init,
>   	.domain_destroy = intel_iommu_domain_destroy,
> @@ -4096,6 +4140,8 @@ static struct iommu_ops intel_iommu_ops = {
>   	.unmap		= intel_iommu_unmap,
>   	.iova_to_phys	= intel_iommu_iova_to_phys,
>   	.domain_has_cap = intel_iommu_domain_has_cap,
> +	.add_device	= intel_iommu_add_device,
> +	.remove_device	= intel_iommu_remove_device,
>   	.pgsize_bitmap	= INTEL_IOMMU_PGSIZES,
>   };
>
>