On Wed, Mar 24, 2021 at 05:53:26AM -0700, Christopher Clark wrote: > On Wed, Mar 24, 2021 at 1:01 AM Roger Pau Monné <roger....@citrix.com> wrote: > > > > On Tue, Mar 23, 2021 at 10:39:53AM -0700, Christopher Clark wrote: > > > On Thu, Mar 18, 2021 at 9:43 AM Roger Pau Monné <roger....@citrix.com> > > > wrote: > > If you offload domain creation of guests with > > pci-passthrough devices to a control domain and/or hardware domain, > > I'm not sure I see the difference from normal domain creation, ie: > > it's no longer something specific to hyperlaunch, as I could achieve > > the same by using the existing xendomains init script. > > So that's not what we've proposed, and hopefully not what we'll need to do. > > Do you know if there is a need to perform work to support the > assignment of PCI devices at the point of domain creation (ie. in > domain_create), rather than handling it in a later step of domain > configuration, prior to the domain being started?
So while I think you could indeed create a domain from the hypervisor in a paused state and attach the pci devices later from a control/hardware domain, I don't see much benefit in doing it. If you need to end up waiting for a control/hardware domain to attach the devices and unpause you might as well do the whole domain creation from such control/hardware domain. Is this split done because the control/hardware domain would have a very strict set of permissions only allowing attachment of pci devices but not domain creation? I think the permissions required by a control/hardware domain to attach a pci device to another guests would end up being fairly similar to the ones required to just create a domain from scratch, because a pci attachment requires modifications to the p2m. Thanks, Roger.
