On Thu, Sep 10, 2020 at 10:21:07AM +0100, Steven Price wrote: > > We either need a KVM cap or a new CPU feature probing interface to avoid > > making userspace try features one at a time. It's too bad that VCPU_INIT > > doesn't clear all offending features from the feature set when returning > > EINVAL, because then userspace could create a scratch VCPU with everything > > it supports in order to see what KVM also supports in one go. > > If Peter's TELL_ME_WHAT_YOU_HAVE idea works out then perhaps we don't need > the cap? Or would it still be useful? > We wouldn't need it, but we don't _need_ it now either. It's not very convenient to probe vcpu features with scratch vcpus, especially if we must probe one at a time, but it works. The TELL_ME_WHAT_YOU_HAVE idea will only fix the one at a time issue, but still require a vcpu fd. If this feature becomes a VM feature then a cap or VM level API would help reduce the userspace probing work. Thanks, drew _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
