Merge pull request #10477 from MicrosoftDocs/main

Publish main to live, 12/17/24, 3:30 PM PT

windows/deployment/windows-autopatch/manage/windows-autopatch-hotpatch-updates.md

@@ -1,7 +1,7 @@
 ---
 title: Hotpatch updates
 description: Use Hotpatch updates to receive security updates without restarting your device
-ms.date: 12/17/2024
+ms.date: 11/19/2024
 ms.service: windows-client
 ms.subservice: autopatch
 ms.topic: how-to
@@ -30,17 +30,33 @@ Hotpatch updates are [Monthly B release security updates](/windows/deployment/up
 - No changes are required to your existing update ring configurations. Your existing ring configurations are honored alongside Hotpatch policies.
 - The [Hotpatch quality update report](../monitor/windows-autopatch-hotpatch-quality-update-report.md) provides a per policy level view of the current update statuses for all devices that receive Hotpatch updates.
 
+## Operating system configuration prerequisites 
+
+To prepare a device to receive Hotpatch updates, configure the following operating system settings on the device. You must configure these settings for the device to be offered the Hotpatch update and to apply all Hotpatch updates.
+
+### Virtualization based security (VBS)
+
+VBS must be turned on for a device to be offered Hotpatch updates. For information on how to set and detect if VBS is enabled, see [Virtualization-based Security (VBS)](/windows/security/hardware-security/enable-virtualization-based-protection-of-code-integrity?tabs=security).
+
+### Arm 64 devices must disable compiled hybrid PE usage (CHPE) (Arm 64 CPU Only)
+
+This requirement only applies to Arm 64 CPU devices when using Hotpatch updates. Hotpatch updates aren't compatible with servicing CHPE OS binaries located in the `%SystemRoot%\SyChpe32` folder. To ensure all the Hotpatch updates are applied, you must set the CHPE disable flag and restart the device to disable CHPE usage. You only need to set this flag one time. The registry setting remains applied through updates. To disable CHPE, set the following registry key:
+Path: `**HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management**`
+Key value: `**HotPatchRestrictions=1**`
+
+> [!IMPORTANT:]
+> This setting is required because it forces the operating system to use the emulation x86-only binaries insetad of CHPE binaries on Arm 64 devices. CHPE binaries include native Arm 64 code to improve performance, excluding the CHPE binaries might affect performance or compatibility. Be sure to test application compatibility and performance before rolling out Hotpatch updates widely on Arm 64 CPU based devices.
+
+If you choose to no longer use Hotpatch updates, clear the CHPE disasble flag (`HotPatchRestrictions=0`) then restart the device to turn on CHPE usage.  
+
 ## Eligible devices
 
 To benefit from Hotpatch updates, devices must meet the following prerequisites:
 
 - Operating System: Devices must be running Windows 11 24H2 or later.
-- VBS (Virtualization-based security): VBS must be enabled to ensure secure installation of Hotpatch updates. For more information on how to set and detect if VBS is enabled, see [Virtualization-based Security](/windows/security/hardware-security/enable-virtualization-based-protection-of-code-integrity?tabs=security).
+- VBS (Virtualization-based security): VBS must be enabled to ensure secure installation of Hotpatch updates.
 - Latest Baseline Release: Devices must be on the latest baseline release version to qualify for Hotpatch updates. Microsoft releases Baseline updates quarterly as standard cumulative updates. For more information on the latest schedule for these releases, see [Release notes for Hotpatch](https://support.microsoft.com/topic/release-notes-for-hotpatch-in-azure-automanage-for-windows-server-2022-4e234525-5bd5-4171-9886-b475dabe0ce8?preview=true).
 
-> [!NOTE]
-> Hotpatch is available on Windows Server. For more information, see [Hotpatch for Windows Server Azure Edition](/windows-server/get-started/enable-hotpatch-azure-edition).
-
 ## Ineligible devices
 
 Devices that don't meet one or more prerequisites automatically receive the Latest Cumulative Update (LCU) instead. Latest Cumulative Update (LCU) contains monthly updates that supersede the previous month's updates containing both security and nonsecurity releases.  
@@ -48,7 +64,7 @@ Devices that don't meet one or more prerequisites automatically receive the Late
 LCUs requires you to restart the device, but the LCU ensures that the device remains fully secure and compliant.
 
 > [!NOTE]
-> If devices aren't eligible for Hotpatch updates, these devices are offered the LCU. The LCU keeps your configured Update ring settings, it doesn't change the settings.<p>For **ARM64 devices**, Compiled Hybrid PE Usage (CHPE) is turned on by default. You must turn off CHPE to receive regular LCU to keep your ARM64 device compliant and secure.</p>
+> If devices aren't eligible for Hotpatch updates, these devices are offered the LCU. The LCU keeps your configured Update ring settings, it doesn't change the settings.
 
 ## Release cycles
 
@@ -70,7 +86,7 @@ For more information about the release calendar for Hotpatch updates, see [Relea
 1. Go to the **Quality updates** tab.
 1. Select **Create**, and select **Windows quality update policy (preview)**.
 1. Under the **Basics** section, enter a name for your new policy and select Next.
-1. Under the **Settings** section, set **"When available, apply without restarting the device ("hotpatch")** to **Allow**. Then, select **Next**.
+1. Under the **Settings** section, set **"When available, apply without restarting the device ("Hotpatch")** to **Allow**. Then, select **Next**.
 1. Select the appropriate Scope tags or leave as Default and select **Next**.
 1. Assign the devices to the policy and select **Next**.
 1. Review the policy and select **Create**.