On Fri, Aug 03, 2018 at 08:21:26PM -0500, Benjamin Herrenschmidt wrote: > On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: > > > > > Please go through these patches and review whether this approach broadly > > > > > makes sense. I will appreciate suggestions, inputs, comments regarding > > > > > the patches or the approach in general. Thank you. > > > > > > > > Jason did some work on profiling this. Unfortunately he reports > > > > about 4% extra overhead from this switch on x86 with no vIOMMU. > > > > > > The test is rather simple, just run pktgen (pktgen_sample01_simple.sh) in > > > guest and measure PPS on tap on host. > > > > > > Thanks > > > > Could you supply host configuration involved please? > > I wonder how much of that could be caused by Spectre mitigations > blowing up indirect function calls... > > Cheers, > Ben. I won't be surprised. If yes I suggested a way to mitigate the overhead. -- MSR _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
