Greg KH wrote: > On Sun, Nov 09, 2008 at 02:44:06PM +0200, Avi Kivity wrote: > >> Greg KH wrote: >> >>> It's that "second" part that I'm worried about. How is that going to >>> happen? Do you have any patches that show this kind of "assignment"? >>> >>> >>> >> For kvm, this is in 2.6.28-rc. >> > > Where? I just looked and couldn't find anything, but odds are I was > looking in the wrong place :( > > arch/x86/kvm/vtd.c: iommu integration (allows assigning the device's memory resources) virt/kvm/irq*: interrupt redirection (allows assigning the device's interrupt resources) the rest (pci config space, pio redirection) are in userspace. >> Note there are two ways to assign a device to a guest: >> >> - run the VF driver in the guest: this has the advantage of best >> performance, but requires pinning all guest memory, makes live migration a >> tricky proposition, and ties the guest to the underlying hardware. >> > > Is this what you would prefer for kvm? > > It's not my personal preference, but it is a supported configuration. For some use cases it is the only one that makes sense. Again, VF-in-guest and VF-in-host both have their places. And since Linux can be both guest and host, it's best if the VF driver knows nothing about SR-IOV; it's just a pci driver. The PF driver should emulate anything that SR-IOV does not provide (like missing pci config space). -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
