[libvirt-users] If it's possible for a third-party PCIe card to be shared by multiple containers

[WANG Cheng D]

Dear Daniel,

The thirty-party PCIe card is based on the Xilinx’ FPGA which is off the shelf, the main features are as follows:
1) x8 Gen3, 8Gb/s per lane/direction
2) MSI and legacy interrupt support
3) Scatter-gather packet DMA engine provide by Northwest Logic
We hope multiple Linux Containers to access the PCIe card in time division mode, for example, during slot 1, lxc1 read/write the PCIe card; during slot 2, lxc2 read/write the PCIe card.
Taking reading operation (data flows from PCIe card to host memory) as example, in native mode, the PCIe driver should tell PCIe card the host memory address where to store the incoming data from PCIe card. With this address, the PCIe card will transmit the data to host memory itself.
In container case, the problem is how application running in the container knows the expected host memory address.
I wonder if we can have a process running in the which solely operates the PCIe card, all the containers will send/receive data to this process via socket.

With my warmest regards,
Cheng Wang


-----Original Message-----
From: Daniel P. Berrange [mailto:berrange at redhat.com] 
Sent: 2014年1月15日 18:46
To: WANG Cheng D
Cc: libvirt-users at redhat.com
Subject: Re: [libvirt-users] If it's possible for a third-party PCIe card to be shared by multiple containers

On Wed, Jan 15, 2014 at 12:58:54AM +0000, WANG Cheng D wrote:
> Dear all,
> 
> I have a thirty-party PCIe card in my host which can work properly in native mode.
> 
> I wonder if this card can be shared by multiple containers.
> 
> As far as the network interface is concerned, too many efforts have 
> been made for it. Two dedicated cgroup resource schedulers/subsystem 
> (net_cls, net_prio) have been provided at the kernel level, and 
> libvirt has also done a lot of work on virtual networking to enable 
> network interface sharing between containers.
> 
> As it's difficult for me to implement all these things that have been 
> done for network interface, I should find other way to enable sharing 
> of this card.
> 
> Do you have any idea?

You don't mention what kind of PCI card it is and how you want the guest to use it. It may or may not be possible to share it depending on the answer to those questions.

Daniel
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