[rkpvm] Implement RKP VM rollback protection in pvmfw

Bug: 313608221
Test: atest rialto_test
Change-Id: Iba3836cae1b2df16d0da69f80310ff0552961c95
diff --git a/pvmfw/src/main.rs b/pvmfw/src/main.rs
index 8aa5274..1d55a84 100644
--- a/pvmfw/src/main.rs
+++ b/pvmfw/src/main.rs
@@ -115,6 +115,17 @@
 
     if verified_boot_data.has_capability(Capability::RemoteAttest) {
         info!("Service VM capable of remote attestation detected");
+        if service_vm_version::VERSION != verified_boot_data.rollback_index {
+            // For RKP VM, we only boot if the version in the AVB footer of its kernel matches
+            // the one embedded in pvmfw at build time.
+            // This prevents the pvmfw from booting a roll backed RKP VM.
+            error!(
+                "Service VM version mismatch: expected {}, found {}",
+                service_vm_version::VERSION,
+                verified_boot_data.rollback_index
+            );
+            return Err(RebootReason::InvalidPayload);
+        }
     }
 
     if verified_boot_data.has_capability(Capability::SecretkeeperProtection) {