Re: [PATCH 1/2] intel-iommu: PCIe hot plug for Intel iommu - IOMMU API

David Woodhouse
2009-10-05T07:00:23Z

On Fri, 2009-10-02 at 14:18 -0700, Fenghua Yu wrote:
> We expand existing IOMMU API iommu_detach_device for PCIe hot remove. We don't
> need IOMMU API for hot add.

I think this could do with more explanation. A hot remove will cause
detach_device() to be called with a NULL domain parameter? Surely we
shouldn't be printing an error with KERN_ERR just because such a device
hasn't been used for DMA before it was removed?

> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
>
> drivers/pci/intel-iommu.c | 13 ++++++++++++-
> 1 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
> index 855dd7c..5c12283 100644
> --- a/drivers/pci/intel-iommu.c
> +++ b/drivers/pci/intel-iommu.c
> @@ -3559,9 +3559,20 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
> static void intel_iommu_detach_device(struct iommu_domain *domain,
> struct device *dev)
> {
> - struct dmar_domain *dmar_domain = domain->priv;
> + struct dmar_domain *dmar_domain;
> struct pci_dev *pdev = to_pci_dev(dev);
>
> + /* If domain=NULL, we'll find a valid domain for the device.*/
> + if (!domain) {
> + dmar_domain = find_domain(pdev);
> + if (!dmar_domain) {
> + printk(KERN_ERR "Can not find IOMMU domain for %s\n",
> + pci_name(pdev));
> + return;
> + }
> + } else
> + dmar_domain = domain->priv;
> +
> domain_remove_one_dev_info(dmar_domain, pdev);
> }
>
--
dwmw2