Introduce GUEST_PERF_EVENTS and require architectures to select it to allow registering and using guest callbacks in perf. This will hopefully make it more difficult for new architectures to add useless "support" for guest callbacks, e.g. via copy+paste. Stubbing out the helpers has the happy bonus of avoiding a load of perf_guest_cbs when GUEST_PERF_EVENTS=n on arm64/x86. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20211111020738.2512932-9-seanjc@google.com (cherry picked from commit 2aef6f306b39bbe74e2287d6e2ee07c4867d87d0) Signed-off-by: Will Deacon <willdeacon@google.com> Bug: 233587962 Bug: 233588291 Change-Id: I098ae1986a3749ecef2d318c88094f551f3a128f