[dpdk-dev] Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance

[Vlad Zolotarov]

On 09/30/15 15:03, Michael S. Tsirkin wrote:
> On Wed, Sep 30, 2015 at 02:53:19PM +0300, Vlad Zolotarov wrote:
>>
>> On 09/30/15 14:41, Michael S. Tsirkin wrote:
>>> On Wed, Sep 30, 2015 at 02:26:01PM +0300, Vlad Zolotarov wrote:
>>>> The whole idea is to bypass kernel. Especially for networking...
>>> ... on dumb hardware that doesn't support doing that securely.
>> On a very capable HW that supports whatever security requirements needed
>> (e.g. 82599 Intel's SR-IOV VF devices).
> Network card type is irrelevant as long as you do not have an IOMMU,
> otherwise you would just use e.g. VFIO.

Sorry, but I don't follow your logic here - Amazon EC2 environment is a 
example where there *is* iommu but it's not virtualized and thus VFIO is 
useless and there is an option to use directly assigned SR-IOV 
networking device there where using the kernel drivers impose a 
performance impact compared to user space UIO-based user space kernel 
bypass mode of usage. How is it irrelevant? Could u, pls, clarify your 
point?

>
>>> Colour me unimpressed.
>>>