> I'm not sure what they mean here. Firecracker doesn't restrict the set of system calls guests can use. In my mind, that's one of the biggest advantages of Firecracker's approach - there's no hard tradeoff to be made between isolation strength and guest software compatibility.
gVisor is also not artificially restricting this set (it is limited by what's implemented, but that's not a hard trade-off); the sentence means that both Firecracker and gVisor restrict the host surface available to the effective "supervisor", either the VMM or the Sentry.
gVisor is also not artificially restricting this set (it is limited by what's implemented, but that's not a hard trade-off); the sentence means that both Firecracker and gVisor restrict the host surface available to the effective "supervisor", either the VMM or the Sentry.