On Fri, Mar 28, 2014 at 11:14:49PM -0400, Steve Gordon wrote: > ----- Original Message ----- > > This is the approach mentioned by linux-kvm.org > > > > http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM > > > > 3. reboot and verify that your system has IOMMU support > > > > AMD Machine > > dmesg | grep AMD-Vi > > ... > > AMD-Vi: Enabling IOMMU at 0000:00:00.2 cap 0x40 > > AMD-Vi: Lazy IO/TLB flushing enabled > > AMD-Vi: Initialized for Passthrough Mode > > ... > > Intel Machine > > dmesg | grep -e DMAR -e IOMMU > > ... > > DMAR:DRHD base: 0x000000feb03000 flags: 0x0 > > IOMMU feb03000: ver 1:0 cap c9008020e30260 ecap 1000 > > ... > > Right, but the question is whether grepping dmesg is an acceptable/stable > API to be relying on from the Nova level. Basically what I'm saying is > the reason there isn't a robust way to check this from OpenStack is that > there doesn't appear to be a robust way to check this from the kernel? Historically there was no good way to determine this from the kernel. Dmesg logs were the "best" there is. With new style VFIO, however, we can now reliably determine the level of support and even more importantly what PCI devices must be handled together as a group. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|