On Sat, 22 Nov 2008 08:18:02 -0800
"Yu, Fenghua" <fenghua.yu@xxxxxxxxx> wrote:
>
> >+int intel_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
> >+{
> >+ return !dma_addr;
> >+}
>
> The implementation of inte_dma_mapping_error is incomplete.
>
> Dma_addr is valid only when it belongs to hwdev's domain. This is all about VT-d isolation fundamental.
>
> +int intel_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
> +{
> + struct pci_dev *pdev = to_pci_dev(hwdev);
> + struct dmar_domain *domain;
> + struct iova *iova;
> +
> + domain = find_domain(pdev);
> +
> + iova = find_iova(&domain->iovad, IOVA_PFN(dma_addr));
> + if (!iova)
> + return -EINVAL;
> + return 0;
> +}
Hmm, intel_dma_mapping_error is used to test only the value that
intel_map_single() returns. If intel_map_single() returns a non-zero
dma address, it belongs to hwdev's domain. So intel_dma_mapping_error
can simply return 1 (failure) if the dma_addr is zero.
Do I misunderstand something?
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