Re: PCI passthrough with VT-d - native performance

2008-07-16 Thread Ben-Ami Yassour
On Wed, 2008-07-16 at 17:36 +0300, Avi Kivity wrote: Ben-Ami Yassour wrote: In last few tests that we made with PCI-passthrough and VT-d using iperf, we were able to get the same throughput as on native OS with a 1G NIC Excellent! (with higher CPU utilization). How much

Re: PCI passthrough with VT-d - native performance

2008-07-16 Thread Avi Kivity
Ben-Ami Yassour wrote: (with higher CPU utilization). How much higher? Here are some numbers for running iperf -l 1M: e1000 NIC (behind a PCI bridge) Bandwidth (Mbit/sec)CPU utilization Native OS 771 18% Native

Re: PCI passthrough with VT-d - native performance

2008-07-16 Thread Anthony Liguori
Ben-Ami Yassour wrote: On Wed, 2008-07-16 at 17:36 +0300, Avi Kivity wrote: Ben-Ami Yassour wrote: In last few tests that we made with PCI-passthrough and VT-d using iperf, we were able to get the same throughput as on native OS with a 1G NIC Excellent! (with higher CPU

Re: PCI passthrough with VT-d - native performance

2008-07-16 Thread Avi Kivity
Ben-Ami Yassour wrote: That CPU utilization is extremely high and somewhat illogical if native w/vt-d has almost no CPU impact. Have you run oprofile yet or have any insight into where CPU is being burnt? What does kvm_stat look like? I wonder if there are a large number of PIO exits.

RE: PCI passthrough with VT-d - native performance

2008-07-16 Thread Han, Weidong
Anthony Liguori wrote: Ben-Ami Yassour wrote: On Wed, 2008-07-16 at 17:36 +0300, Avi Kivity wrote: Ben-Ami Yassour wrote: In last few tests that we made with PCI-passthrough and VT-d using iperf, we were able to get the same throughput as on native OS with a 1G NIC Excellent!