lkml.org 
[lkml]   [2009]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRE: [PATCH ACS v4 1/1] Enabling PCI ACS P2P upstream forwarding
Thanks Chris, I was not aware of these two functions.  I have made the following change:

if (iommu_found() || xen_initial_domain())
pci_enable_acs(dev);

xen_intial_domain() should take care of dom0 case. We just make the rough assumption that P2P upstream forwarding is needed if we are running on top of xen HV - similar to what we are doing for native kernel case.

If this is ok, I'm going to re-spin the patch. Separate out xen_initial_domain() modification since it is predicated on Jeremy's xen.h patch.

-----Original Message-----
From: Chris Wright [mailto:chrisw@sous-sol.org]
Sent: Tuesday, October 06, 2009 4:42 PM
To: Kay, Allen M
Cc: linux-kernel@vger.kernel.org; linux-pci@vger.kernel.org; jbarnes@virtuousgeek.org; matthew@wil.cx; chris@sous-sol.org; jeremy@goop.org
Subject: Re: [PATCH ACS v4 1/1] Enabling PCI ACS P2P upstream forwarding

* Allen Kay (allen.m.kay@intel.com) 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


\
 
 \ /
  Last update: 2009-10-07 02:27    [W:0.090 / U:0.532 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site