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Instead, xenstore will become > available later, and a notification of xenstore readiness will be > signalled to the guest using the xenstore event channel. In addition to what Julien has said, I'd like to point out that Linux'es xenbus driver already has means to deal with xenstored not being around right away (perhaps because of living in a stubdom which starts in parallel). I therefore wonder whether what you want can't be achieved entirely inside that driver, without any new feature flag. Jan