Re: [PATCH ACS v4 1/1] Enabling PCI ACS P2P upstream forwarding

From: Chris Wright
Date: Tue Oct 06 2009 - 19:44:09 EST


* Allen Kay (allen.m.kay@xxxxxxxxx) wrote:
> +#ifdef CONFIG_DMAR
> +extern int iommu_detected;
> +#endif

This should not be needed.

> +
> +#ifdef CONFIG_XEN
> +extern int xen_domain_type;
> +#endif

Nor this (there's already a check for is dom0 called xen_initial_domain(),
but unclear it's relevant yet for this patch).

> +
> + /* Enable ACS P2P upstream forwarding if HW iommu is detected */
> + if (iommu_detected)

I think you'd want iommu_found() instead. To avoid, e.g., GART
triggering this one.

> + pci_enable_acs(dev);
> +
> +#ifdef CONFIG_XEN
> + /* HW iommu is not visible in xen dom0 */
> + if (xen_domain_type)
> + pci_enable_acs(dev);

could do this (xen_initial_domain()) above, but it's only relevant for
dom0 (so not needed yet?), and really seems to like it should be done by hv.

thanks,
-chris
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