On Wed, 2017-05-31 at 14:09 -0300, Maurício Almeida wrote: > My name is Maurício, we are making a study about Kvm Paravirtualized > and Full virtualized at our University, we are from University Federal > of Santa Maria. > Can you give us some papers about how the Kvm or Qemu executes the I/O > Network with one emulated Device? > > We executed some tests using Virtio Driver and e1000 emulated driver, > the network output of Virtio is normal and use four of the four > Machine Cpu's, but the output of e1000 Emulated driver was too low > about Virtio and It onlyused one of the four machine cpu's during the > network test execution. > The Traffic of Virtio was 956 MB/s while e1000 Emulated Driver was 192 > MB/s, both using Packet size of 1518 Bytes. > > Why when it used e1000 Emulated Driver the traffic was to low and use > only one Cpu all the time? > Do Qemu or Kvm Guest need some specific configuration to use all CPU's? > > Do you have any paper where we can find in details if Qemu is limited > to use one CPU when use Network Emulated Driver? A cursory look over the qemu e1000 driver would suggest that it does not support multithreading. virtio largely bypasses the qemu hw machinery. -- Mihai Donțu
