From: Ilya Maximets <i.maximets@samsung.com>
To: dev@dpdk.org, Thanneeru Srinivasulu <dev.srinivasulu@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>,
Konstantin Ananyev <konstantin.ananyev@intel.com>,
Anatoly Burakov <anatoly.burakov@intel.com>
Subject: Re: [dpdk-dev] Query : Does Binding with vfio-pci is supported inside qemu-kvm guest/vm instance.?
Date: Tue, 12 Mar 2019 14:09:56 +0300 [thread overview]
Message-ID: <d5fe89c3-0871-ab22-e309-55ab763d760a@samsung.com> (raw)
In-Reply-To: <38327cd0-7fa2-9172-5343-0cded8e51594@intel.com>
> On 12-Mar-19 10:20 AM, Bruce Richardson wrote:
>> On Tue, Mar 12, 2019 at 05:54:39PM +0800, Jason Wang wrote:
>>>
>>> On 2019/3/12 下午5:42, Thanneeru Srinivasulu wrote:
>>>> Thanks Bruce..
>>>>
>>>> On Tue, Mar 12, 2019 at 3:08 PM Bruce Richardson
>>>> <bruce.richardson at intel.com> wrote:
>>>>> On Tue, Mar 12, 2019 at 10:57:55AM +0530, Thanneeru Srinivasulu wrote:
>>>>>> Hi Everyone.
>>>>>>
>>>>>> I did attached pice to Guest VM using vfio-pci with qemu command, and then
>>>>>> tried binding the pcie bdf with vfio-pci, observing binding failure with
>>>>>> vfio-pci.
>>>>>>
>>>>>> Where as when tryied with igb_uio, everything works fine.
>>>>>>
>>>>>> Does Binding with vfio-pci is supported inside VM/guest?
>>>>>>
>>>>> vfio support requires the presence of an IOMMU, and you generally don't
>>>>> have an IOMMU available in a VM.
>>>>>
>>>>> /Bruce
>>>
>>>
>>> Actually, Qemu support vIOMMU + VFIO in guest[1], all you need is to add a
>>> intel IOMMU and enabling caching mode.
>>>
>>> Thanks
>>>
>>>
>>> [1]
>>>
>>> https://www.lfasiallc.com/wp-content/uploads/2017/11/Device-Assignment-with-Nested-Guests-and-DPDK_Peter-Xu.pdf
>>>
>> Thanks for the info.
>>
>> /Bruce
>>
>
> One more thing: even without vIOMMU, VFIO has no-IOMMU mode which can be
> enabled (for a recent-enough kernel). This will make VFIO work even in
> cases where the guest doesn't have IOMMU emulation. See? There's no
> reason to use igb_uio, ever! :D
Agree.
You could use following commands to enable no-IOMMU mode:
modprobe vfio-pci
echo 1 > /sys/module/vfio/parameters/enable_unsafe_noiommu_mode
This should allow using vfio-pci driver without IOMMU emulation.
However, there will be no any security accordingly.
Best regards, Ilya Maximets.
>
> --
> Thanks,
> Anatoly
>
next prev parent reply other threads:[~2019-03-12 11:09 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-12 5:27 Thanneeru Srinivasulu
2019-03-12 9:38 ` Bruce Richardson
2019-03-12 9:42 ` Thanneeru Srinivasulu
2019-03-12 9:54 ` Jason Wang
2019-03-12 10:20 ` Bruce Richardson
2019-03-12 10:57 ` Burakov, Anatoly
[not found] ` <CGME20190312110957eucas1p1af74c8d26bf80fd815847ed8086a1e78@eucas1p1.samsung.com>
2019-03-12 11:09 ` Ilya Maximets [this message]
2019-04-02 10:38 ` John Sucaet
2019-04-02 10:38 ` John Sucaet
2019-04-02 13:38 ` Burakov, Anatoly
2019-04-02 13:38 ` Burakov, Anatoly
2019-04-03 7:49 ` John Sucaet
2019-04-03 7:49 ` John Sucaet
2019-04-03 7:54 ` Maxime Coquelin
2019-04-03 7:54 ` Maxime Coquelin
2019-04-04 8:23 ` John Sucaet
2019-04-04 8:23 ` John Sucaet
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