GcpPlugin.dll

What this program actually does

GcpPlugin.dll is the GameSeat Content Patching (GCP) plugin. It manages seat patching state, interacts with ContentController (CC) for app install/prewarm/session lifecycle messages, and performs Windows image certificate / watermark (WM) file operations on game VHDs during patching workflows.

It subscribes to AIN messages from ContentController and exposes patching queries via GciPlugin's GetPatchingState API. MB endpoint: GcpPlugin. Build: version 1.0 2026-04-07-b253f97.

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Architecture / control flow

NvContainerGcis.exe
  └─ GcpPlugin.dll
        ├─ GcisPluginTaskQueue / GSConfigClient
        ├─ ContentController client
        │     ├─ Subscribe / Unsubscribe (AIN messages)
        │     ├─ LaunchSession / ShutdownSession
        │     ├─ InstallApp / Prewarm / PlatformPrewarm
        │     └─ NotificationType dispatch
        ├─ Patching state manager
        │     └─ GetPatchingState (GCIS API + internal)
        ├─ Image/certificate operations
        │     ├─ ImageAddCertificate / ImageGetCertificateData
        │     └─ WM file writes (GSEC_GCP_Error_FailedToWmFile)
        └─ GsecTasTelemetry

Key protobuf namespaces: ContentControllerAPI, ContentControllerAPI.Generic.Request/Response/Notification.

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External interfaces

ContentController API

Message	Purpose
ContentControllerAPI.Generic.Request.Subscribe	AIN message subscription (shared with all GCIS plugins)
ContentControllerAPI.Generic.Request.Unsubscribe	Tear down CC subscription
ContentControllerAPI.Generic.Request.LaunchSession	Session start from CC
ContentControllerAPI.Generic.Request.ShutdownSession	Session end
ContentControllerAPI.Generic.Request.InstallApp	App install/patch trigger
ContentControllerAPI.Generic.Request.Prewarm	App prewarm
ContentControllerAPI.AppType / AppState	App lifecycle enums

GCIS Service API

Message	Purpose
GCISServiceAPI_GCISRequest_GetPatchingState	Query current patching state (also served by GciPlugin)

Message Bus

• Endpoint: GcpPlugin
• CC peer communication for AIN subscribe (all GCIS plugins post AIN subscription to CC)

File system / crypto

• CreateFileW, SetFileAttributesW, SetFileInformationByHandle — VHD/image patching
• Authenticode: ImageAddCertificateFailed, WritterCertificateMismatch

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Runtime timeline

Time (UTC)	Event	Source
19:04:52.072	Secure-load GcpPlugin 1.0.0.0	NvContainerGcis.log
19:04:52.536	Init OK; AIN subscription fails error 1	GcpPluginCurrent.log
19:04:52.883	PluginStart: TAS session initiated	GcpPluginCurrent.log
19:04:53.025	GcisConfigData not found → start failure	GcpPluginCurrent.log
19:04:53.045	Mandatory plugin Starting failure	NvContainerGcis.log

First run (18:43): GcpPlugin AIN subscription succeeded (Successfully subscribed CC for AIN messages in GciPluginOld.log context — CC was available).

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Failure modes

Error string	Meaning
GSEC_GCP_Error_FailedToWmFile	Watermark file write on game image failed
GSEC_GCP_Error_ImageAddCertificateFailed	Authenticode cert injection failed
GSEC_GCP_Error_WritterCertificateMismatch	Cert thumbprint mismatch
GSEC_GCP_Error_FailedToLocatePluginConfig	GcisConfigData section missing/malformed
GSEC_Common_Error_FailedToSubscribeContentControllerAinMessages	CC AIN subscribe failed
GSEC_Common_Error_MissingSubscribeResultInContentControllerMessage	CC response malformed
GSEC_Common_Warning_ParseContentControllerAPIGenericMessageFailed	CC protobuf parse error
Missing GcisConfigData	PluginStart abort (observed)

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Not verified

• Exact WM file format and target paths on game VHDs.
• Patching state enum values and transitions.
• Whether GcpPlugin or GciPlugin is authoritative for GetPatchingState.
• ContentController peer address on message bus for this seat build.

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Evidence

• strings / RTTI on services/GCIS/plugins/GcpPlugin.dll
• logs/GCIS/GcpPluginCurrent.log, GcpPluginOld.log
• logs/GCIS/NvContainerGcis.log
• logs/GSP/GSConfiguratorPluginCurrent.log