>> >> We are trying to paravirtualize the IPMI device (/dev/ipmi0). > > From http://en.wikipedia.org/wiki/Intelligent_Platform_Management_Interface: > "An implementation of IPMI version 1.5 can communicate via a direct > serial connection or via a side-band local area network (LAN) > connection to a remote client." > > Why do you need a new virtio device? Can't you use virtio-serial? > This is what other management channels are using for host<->guest > agents.
It might be possible. However, we are doing it this way because : (a) I am not sure of the interactions with the real ipmi device on the host when the device is shared with multiple guests (we are not using pci passthrough to attach the device to a single guest). The device itself is stateless - that is, it can not handle multiple requests at one time. When multiple users use the device, the driver has to serialize the requests and send it to the device. The existing ipmi driver within Linux (drivers/char/ipmi) does that now. But this driver on one guest would not know the existence of another guest. May be it might have to be reworked to work with virtio-serial. Dunno. So, we wanted to keep this driver as is in the host and build a lightweight interface layer in the guest that can talk to the real driver on the host. Multiple guests would then be like multiple processes accessing the device. (b) We wanted to gain some experience paravirtualizing devices this way through virtio since we have other proprietary hardware that needs to be paravirtualized. Makes sense? Ani ============================================================ The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any reproduction, dissemination or distribution of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Tellabs ============================================================
