Re: [edk2-devel] [PATCH V2 4/4] MdeModulePkg/CapsuleRuntimeDxe: Implement RuntimeServicesSupported

["Michael D Kinney" <michael.d.kinney@intel.com>]

Zhichao,

The GetVariable and ExitBootServices events should be
removed from this patch.  I recommend RT drivers that
produce RT services consume the new PCD to determine
if the services return EFI_UNSUPPORTED or not after
ExitBootServices().  This keeps RT Driver as simple as
possible and removes the need for the UEFI Variable to
be in a known state earlier in the boot and removes the
need for RT Drivers to setup extra notification events.

The new UEFI Variable is intended to be used by OS Loaders
and OS Kernels that call ExitBootServices() and need to 
know if specific RT services are available or not after 
ExitBootServices().

Thanks,

Mike

> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io]
> On Behalf Of Gao, Zhichao
> Sent: Friday, July 19, 2019 1:09 AM
> To: devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> <hao.a.wu@intel.com>; Ni, Ray <ray.ni@intel.com>; Zeng,
> Star <star.zeng@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Sean Brogan
> <sean.brogan@microsoft.com>; Michael Turner
> <Michael.Turner@microsoft.com>; Bret Barkelew
> <Bret.Barkelew@microsoft.com>; Laszlo Ersek
> <lersek@redhat.com>
> Subject: [edk2-devel] [PATCH V2 4/4]
> MdeModulePkg/CapsuleRuntimeDxe: Implement
> RuntimeServicesSupported
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1907
> 
> Control the capsule services supported at runtime base
> on the variable L"RuntimeServicesSupported".
> It would update a global variable
> mRuntimeServicesSupported at ExitBootServices event.
> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Liming gao <liming.gao@intel.com>
> Cc: Sean Brogan <sean.brogan@microsoft.com>
> Cc: Michael Turner <Michael.Turner@microsoft.com>
> Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
> ---
>  .../CapsuleRuntimeDxe/CapsuleRuntimeDxe.inf   |  2 +
>  .../CapsuleRuntimeDxe/CapsuleService.c        | 68
> +++++++++++++++++++
>  2 files changed, 70 insertions(+)
> 
> diff --git
> a/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleRuntim
> eDxe.inf
> b/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleRuntim
> eDxe.inf
> index 9da450722b..15d498863a 100644
> ---
> a/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleRuntim
> eDxe.inf
> +++
> b/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleRuntim
> eDxe.inf
> @@ -72,6 +72,8 @@
>    ## SOMETIMES_PRODUCES   ##
> Variable:L"CapsuleLongModeBuffer" # The long mode buffer
> used by IA32 Capsule PEIM to call X64 CapsuleCoalesce
> code to handle >4GB capsule blocks
>    gEfiCapsuleVendorGuid
>    gEfiFmpCapsuleGuid                            ##
> SOMETIMES_CONSUMES   ## GUID # FMP capsule GUID
> +  gEfiGlobalVariableGuid                        ##
> CONSUMES             ## Variable
> L"RuntimeServicesSupported"
> +  gEfiEventExitBootServicesGuid                 ##
> CONSUMES
> 
>  [Protocols]
>    gEfiCapsuleArchProtocolGuid                   ##
> PRODUCES
> diff --git
> a/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleServic
> e.c
> b/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleServic
> e.c
> index 77b8f00062..e4e700764b 100644
> ---
> a/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleServic
> e.c
> +++
> b/MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleServic
> e.c
> @@ -24,6 +24,13 @@ UINTN       mTimes      = 0;
>  UINT32      mMaxSizePopulateCapsule     = 0;
>  UINT32      mMaxSizeNonPopulateCapsule  = 0;
> 
> +//
> +// Runtime Services Supported Flag
> +// Initialize it to 0x3FFF to indicate it is all
> supported before
> +runtime //
> +static UINT16     mRuntimeServicesSupported = 0x3FFF;
> +
> +
>  /**
>    Passes capsules to the firmware with both virtual and
> physical mapping. Depending on the intended
>    consumption, the firmware may process the capsule
> immediately. If the payload should persist @@ -71,6
> +78,10 @@ UpdateCapsule (
>    CHAR16                    CapsuleVarName[30];
>    CHAR16                    *TempVarName;
> 
> +  if (!(mRuntimeServicesSupported |
> EFI_RT_SUPPORTED_UPDATE_CAPSULE)) {
> +    return EFI_UNSUPPORTED;
> +  }
> +
>    //
>    // Check if platform support Capsule In RAM or not.
>    // Platform could choose to drop
> CapsulePei/CapsuleX64 and do not support Capsule In RAM.
> @@ -259,6 +270,10 @@ QueryCapsuleCapabilities (
>    EFI_CAPSULE_HEADER        *CapsuleHeader;
>    BOOLEAN                   NeedReset;
> 
> +  if (!(mRuntimeServicesSupported |
> EFI_RT_SUPPORTED_QUERY_CAPSULE_CAPABILITIES)) {
> +    return EFI_UNSUPPORTED;
> +  }
> +
>    //
>    // Capsule Count can't be less than one.
>    //
> @@ -343,6 +358,48 @@ QueryCapsuleCapabilities (
>    return EFI_SUCCESS;
>  }
> 
> +/**
> +  ExitBootServices Event to update the
> mRuntimeServicesSupported to
> +  affect the runtime services.
> +
> +  @param[in]  Event     Event whose notification
> function is being invoked
> +  @param[in]  Context   Pointer to the notification
> function's context
> +**/
> +static
> +VOID
> +EFIAPI
> +UpdateRuntimeServicesSupported (
> +  IN      EFI_EVENT                 Event,
> +  IN      VOID                      *Context
> +  )
> +{
> +  EFI_STATUS    Status;
> +  UINT16        RuntimeServicesSupported;
> +  UINT32        Attributes;
> +  UINTN         DataSize;
> +
> +  Attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> + EFI_VARIABLE_RUNTIME_ACCESS;  DataSize = sizeof
> (UINT16);  Status =
> + gRT->GetVariable (
> +                  L"RuntimeServicesSupported",
> +                  &gEfiGlobalVariableGuid,
> +                  &Attributes,
> +                  &DataSize,
> +                  &RuntimeServicesSupported
> +                  );
> +
> +  if (!EFI_ERROR (Status)) {
> +    mRuntimeServicesSupported =
> RuntimeServicesSupported;
> +  } else if (Status == EFI_NOT_FOUND) {
> +    mRuntimeServicesSupported = 0x3FFF;
> +  } else {
> +    //
> +    // Should never arrive here.
> +    //
> +    ASSERT_EFI_ERROR (Status);
> +  }
> +}
> +
> 
>  /**
> 
> @@ -362,6 +419,7 @@ CapsuleServiceInitialize (
>    )
>  {
>    EFI_STATUS  Status;
> +  EFI_EVENT   Event;
> 
>    mMaxSizePopulateCapsule =
> PcdGet32(PcdMaxSizePopulateCapsule);
>    mMaxSizeNonPopulateCapsule =
> PcdGet32(PcdMaxSizeNonPopulateCapsule);
> @@ -381,6 +439,16 @@ CapsuleServiceInitialize (
>    gRT->UpdateCapsule                    =
> UpdateCapsule;
>    gRT->QueryCapsuleCapabilities         =
> QueryCapsuleCapabilities;
> 
> +  Status = gBS->CreateEventEx(
> +                  EVT_NOTIFY_SIGNAL,
> +                  TPL_NOTIFY,
> +                  UpdateRuntimeServicesSupported,
> +                  NULL,
> +                  &gEfiEventExitBootServicesGuid,
> +                  &Event
> +                  );
> +  ASSERT_EFI_ERROR (Status);
> +
>    //
>    // Install the Capsule Architectural Protocol on a
> new handle
>    // to signify the capsule runtime services are ready.
> --
> 2.21.0.windows.1
> 
> 
>