On Fri, Sep 29, 2017 at 04:51:10PM +0000, Bob Ball wrote: > Hi Sahid, > > > > a second device emulator along-side QEMU. There is no mdev > > > integration. I'm concerned about how much mdev-specific functionality > > > would have to be faked up in the XenServer-specific driver for vGPU to > > > be used in this way. > > > > What you are refering with your DEMU it's what QEMU/KVM have with its > > vfio-pci. XenServer is > > reading through MDEV since the vendors provide drivers on *Linux* using the > > MDEV framework. > > MDEV is a kernel layer, used to expose hardwares, it's not hypervisor > > specific. > > It is possible that the vendor's userspace libraries use mdev, > however DEMU has no concept of mdev at all. If the vendor's > userspace libraries do use mdev then this is entirely abstracted > from XenServer's integration. While I don't have access to the > vendors source for the userspace libraries or the kernel module my > understanding was that the kernel module in XenServer's integration > is for the userspace libraries to talk to the kernel module and for > IOCTLS. My reading of mdev implies that /sys/class/mdev_bus should > exist for it to be used? It does not exist in XenServer, which to > me implies that the vendor's driver for XenServer do not use mdev?
I shared our discussion to Alex Williamson, it's response: > Hi Sahid, > > XenServer does not use mdev for vGPU support. The mdev/vfio > infrastructure was developed in response to DEMU used on XenServer, > which we felt was not an upstream acceptable solution. There has > been cursory interest in porting vfio to Xen, so it's possible that > they might use the same mechanism some day, but for now they are > different solutions, the vifo/mdev solution being the only one > accepted upstream so far. Thanks, > > Alex It's my mistake. It seems clear now that XenSever can't take the benefice of that mdev support I have added in /pci module. The support of vGPUs for Xen will have to wait for the generic device management I guess. > > Bob > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: [email protected]?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
