In recent years, numerous instances of data breaches have emerged due to the inadvertent or intentional disclosure of cryptographic keys. To address this issue, this paper proposes SVSM-KMS, which utilizes AMD’s latest Encrypted Virtualization technology (AMD SEV-SNP) to deliver an efficient and seamless integrated secure key management service. We realized multilayered defense by integrating our mechanism within a privileged layer of a confidential virtual machine (CVM), thereby minimizing the trusted computing base (TCB) to prevent key leakage from compromised CVMs. Notably, we incorporated a zero-copy mechanism between the most privileged service module and the least privileged user applications, eliminating redundant data copies. To facilitate seamless integration, we propose a proxy server for existing cloud services. A prototype of SVSM-KMS has been developed based on the latest AMD SEV-SNP hardware platform. Evaluation results indicate that the performance of the Encrypted Virtualization-empowered SVSM-KMS is on par with Hadoop KMS, highlighting the practicality.