On Mon, 30 Apr 2018 13:44:23 -0400 Jintack Lim <jintack@xxxxxxxxxxxxxxx> wrote: > Add iommu mailing list since this question might be more related to iommu. > > On Mon, Apr 30, 2018 at 10:11 AM, Jintack Lim <jintack@xxxxxxxxxxxxxxx> wrote: > > Hi, > > > > I wonder how to check if Vt-d is capable of posted-interrupt? I'm > > using Intel E5-2630 v3. > > > > I was once told that APICv and posted-interrupt capability always come > > together. But it seems like my cpu support APICv > > (/sys/module/kvm_intel/parameters/enable_apicv is Y), but > > posted-interrupt capability is only shipped with the next generation > > of the cpu (E5-2600 v4, which is Broadwell). > > > > What would be an easy way to check this? PI support is bit 59 in the capability register which is exposed through sysfs at /sys/class/iommu/dmar*/intel-iommu/cap so you could do something like: # for i in $(find /sys/class/iommu/dmar* -type l); do echo -n "$i: "; echo $(( ( 0x$(cat $i/intel-iommu/cap) >> 59 ) & 1 )); done I think the relationship between APICv and PI goes the other direction, if you have PI, you probably have APICv. Having APICv implies nothing about having PI. Thanks, Alex
