On Tue, Jan 19, 2021 at 09:16:08AM +0100, Cornelia Huck wrote: > On Mon, 18 Jan 2021 19:47:30 +0000 > "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx> wrote: > > > * David Gibson (david@xxxxxxxxxxxxxxxxxxxxx) wrote: > > > The platform specific details of mechanisms for implementing > > > confidential guest support may require setup at various points during > > > initialization. Thus, it's not really feasible to have a single cgs > > > initialization hook, but instead each mechanism needs its own > > > initialization calls in arch or machine specific code. > > > > > > However, to make it harder to have a bug where a mechanism isn't > > > properly initialized under some circumstances, we want to have a > > > common place, relatively late in boot, where we verify that cgs has > > > been initialized if it was requested. > > > > > > This patch introduces a ready flag to the ConfidentialGuestSupport > > > base type to accomplish this, which we verify just before the machine > > > specific initialization function. > > > > You may find you need to define 'ready' and the answer might be a bit > > variable; for example, on SEV there's a setup bit and then you may end > > up doing an attestation and receiving some data before you actaully let > > the guest execute code. Is it ready before it's received the > > attestation response or only when it can run code? > > Is a Power or 390 machine 'ready' before it's executed the magic > > instruction to enter the confidential mode? > > I would consider those machines where the guest makes the transition > itself "ready" as soon as everything is set up so that the guest can > actually initiate the transition. Otherwise, those machines would never > be "ready" if the guest does not transition. > > Maybe we can define "ready" as "the guest can start to execute in > secure mode", where "guest" includes the bootloader and everything that > runs in a guest context, and "start to execute" implies that some setup > may be done only after the guest has kicked it off? That was pretty much my intention. I've put a big comment on the field definition and tweaked things around a bit in the hopes of making that clearer for the next spin. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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