> I was thinking that ACS could be enabled if an IOMMU is enabled. Not a > perfect fit, but seems reasonably close. Chris, I'm working on a new version of the patch that incorporates iommu check. I'm also adding a check for dom0 kernel as HW iommu is not visible to dom0. Allen -----Original Message----- From: Chris Wright [mailto:chrisw@xxxxxxxxxxxx] Sent: Wednesday, September 30, 2009 6:17 PM To: Kay, Allen M Cc: Chris Wright; linux-kernel@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; jbarnes@xxxxxxxxxxxxxxxx; matthew@xxxxxx Subject: Re: [PATCH ACS v3 1/1] * Kay, Allen M (allen.m.kay@xxxxxxxxx) wrote: > On the other hand, can we say VT-d PT mode is mainly for KVM > virtualization use case? If so, is it reasonable to say performance of > host P2P in this mode is not of highest priority? Guess it depends on the workload. Would be helpful to identify a use case that is p2p heavy (and then the impact of enabling ACS). > If not, another option is to have a kernel boot parameter to > configure an kernel boot instance to be either host kernel optimized or > virtualization optimized. I don't know whether this is a reasonable or > not ... I was thinking that ACS could be enabled if an IOMMU is enabled. Not a perfect fit, but seems reasonably close. thanks, -chris -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
