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Date: Mon, 26 May 2014 19:06:43 +0200
From: Luigi Rizzo <rizzo@iet.unipi.it>
To: Prashant Upadhyaya <praupadhyaya@gmail.com>
Subject: Re: Regarding Netmap in VM
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On Thu, May 22, 2014 at 09:28:45AM +0530, Prashant Upadhyaya wrote:
> Hi,
> 
> Suppose I am on x86 with Intel 82599 NIC.
> Now I spawn a VM (running FreeBSD as guest OS with Netmap support)
> For better I/O performance, I have two main choices --
> 
> 1. Pass the 82599 NIC as a PCI passthrough device into the VM
> 2. Use SRIOV VF of 82599 into the VM
> 
> Question is, will Netmap be able to utilize both the above environments
> when I run the userspace application in the guest OS in the VM, or will
> there be any issues.

if i remember well we do not have sriov vf support yet in freebsd
so you should follow the pci-passthrough approach.

It should probably work, i am not 100% sure who is in charge of
programming the IOMMU for the guest os when accessing a device
through pci passthrough. If this part is missing, the symptoms
you should see is that packets will have all bytes set to 0x00

cheers
luigi