{"id":9260,"date":"2021-11-08T08:41:25","date_gmt":"2021-11-08T16:41:25","guid":{"rendered":"https:\/\/www.microsoft.com\/insidetrack\/blog\/?p=9260"},"modified":"2026-04-06T08:31:44","modified_gmt":"2026-04-06T15:31:44","slug":"using-shielded-virtual-machines-to-help-protect-highvalue-assets","status":"publish","type":"post","link":"https:\/\/www.microsoft.com\/insidetrack\/blog\/using-shielded-virtual-machines-to-help-protect-highvalue-assets\/","title":{"rendered":"Using shielded virtual machines to help protect high-value assets"},"content":{"rendered":"
Microsoft Digital Employee Experience (MDEE) protects our high-value corporate assets\u2014beyond just the network. We use shielded virtual machines (shielded VMs) and Host Guardian Services (HGS) in Windows Server 2019 to isolate our data. This ensures that control and administration of infrastructure and environment remain completely isolated from control and administration of data and applications.<\/p>\n At MDEE, we classify approximately one percent of the services and data that we host as High\u00a0Value\u00a0Assets\u00a0(HVAs). An HVA is a single isolated environment that provides a secure space for company workloads. Access to HVA data by unauthorized users could negatively affect Microsoft business in a significant way.<\/p>\n In our organization, we host several HVAs for different business groups that need a highly secure environment to prevent unauthorized access or data leaks. Most data in an HVA is classified as highly confidential. HVAs also host data that\u2019s regulated by government policy or other legal restrictions, or that\u2019s physically isolated from other datacenter assets and from our corporate network. A typical HVA can be broken down into several components:<\/p>\n A standard HVA host includes the three-tier administrative model and uses the HVA fabric for storage, network, and related services. The components of an HVA are distributed and managed in highly secured datacenters. Each access tier gives a layer of protection against credential theft.<\/p>\n The HVA system is multi-tenant. Each HVA stamp is an isolated environment that\u2019s built for a specific customer or isolated workload. We use isolation techniques to help create clear boundaries between HVA stamps. HVA stamps can be of mixed size (with a different number of virtual machines, different sizes of virtual machines, and so on) and can host a variety of environments. One HVA stamp might host a single Tier 2 service, and others might host full end-to-end environments that have hundreds of servers.<\/p>\n The following figure shows a high-level view of an HVA environment with several HVA stamps.<\/p>\n To create the private cloud environment that hosts our HVA resources, we use Windows Server\u00a02019, System\u00a0Center Virtual\u00a0Machine\u00a0Manager, and Windows Azure Pack (WAP). Windows Server 2019 introduces the shielded VM feature in Hyper-V. It protects virtual machines from threats outside and inside the fabric. It does this by encrypting disk and virtual machine states so that only virtual machine admins or tenant admins can access them.<\/p>\n By using System Center Virtual Machine Manager and Hyper-V host clusters in our private cloud environment, we can quickly and efficiently provision HVAs. We don\u2019t have to worry about provisioning specific hardware to host HVA resources. The Windows Azure Pack offers a familiar, browser-based interface that our internal customers can use to provision resources. When needed, we provision shielded VMs and provide the computing resources to host an HVA workload.<\/p>\n Shielded VMs are part of the guarded fabric system in Windows Server 2019 Hyper-V. The guarded fabric consists of several layered components:<\/p>\n As illustrated in the figure below, HGS handles the attestation process for the guarded Hyper-V hosts on which the shielded\u00a0VMs reside, including key requests and health information. This process ensures the health of the host, the protection of the shielded VM, and the appropriate access for users.<\/p>\n The attestation process includes the following steps:<\/p>\n The implementation of HVAs using shielded VMs starts at the datacenter. All HVA servers should be in physically isolated and secure environments. Physical access to the datacenter requires two-person access, and it\u2019s limited to the HVA fabric team and the administrative team.<\/p>\n Best practices for implementing physical security components for the HVA include:<\/p>\n We use only specifically configured hardware in our HVA fabric. Our host hardware runs Windows Server 2019 and Hyper-V. The following table lists the components and management responsibilities.<\/p>\n Hardware components and management responsibilities<\/em><\/p>\n
We periodically update our stories, but we can\u2019t verify that they represent the full picture of our current situation at Microsoft. We leave them on the site so you can see what our thinking and experience was at the time.<\/em><\/p>\nCritical data and high risk environments<\/h2>\n
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HVA topology<\/h3>\n

Using shielded VMs for HVA<\/h2>\n
Guarded fabric health attestation and key release<\/h3>\n
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Guarded host attestation<\/h4>\n

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Implementing HVA fabric using shielded VMs<\/h3>\n
Physical access implementation<\/h4>\n
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Hardware implementation<\/h4>\n