Re: [PATCH] IntelSiliconPkg/VTdDxe: Change EBS Event TPL to CALLBACK.

["Yao, Jiewen" <jiewen.yao@intel.com>]

That is fine.

Here, disabling IOMMU means to disable the protection and allow all DMA access.
I do not think it will bring any functional impact.

Thank you
Yao Jiewen


> -----Original Message-----
> From: Zeng, Star
> Sent: Thursday, October 26, 2017 12:58 PM
> To: Yao, Jiewen <jiewen.yao@intel.com>; edk2-devel@lists.01.org
> Cc: Laszlo Ersek (lersek@redhat.com) <lersek@redhat.com>; Zeng, Star
> <star.zeng@intel.com>
> Subject: RE: [PATCH] IntelSiliconPkg/VTdDxe: Change EBS Event TPL to CALLBACK.
> 
> Some device driver may also have exit boot service event at CALLBACK, for
> example AtaPassThruExitBootServices() that was added by Laszlo.
> 
> 
> Thanks,
> Star
> -----Original Message-----
> From: Yao, Jiewen
> Sent: Thursday, October 26, 2017 10:14 AM
> To: edk2-devel@lists.01.org
> Cc: Zeng, Star <star.zeng@intel.com>
> Subject: [PATCH] IntelSiliconPkg/VTdDxe: Change EBS Event TPL to CALLBACK.
> 
> Change ExitBootServices TPL to CALLBACK, so that a device can disable BME
> before IOMMU grants access right.
> 
> Cc: Star Zeng <star.zeng@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
> ---
>  IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> index f5de01f..4a4d82e 100644
> --- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> +++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> @@ -483,7 +483,7 @@ InitializeDmaProtection (
> 
>    Status = gBS->CreateEventEx (
>                    EVT_NOTIFY_SIGNAL,
> -                  TPL_NOTIFY,
> +                  TPL_CALLBACK,
>                    OnExitBootServices,
>                    NULL,
>                    &gEfiEventExitBootServicesGuid, @@ -492,7 +492,7 @@
> InitializeDmaProtection (
>    ASSERT_EFI_ERROR (Status);
> 
>    Status = EfiCreateEventLegacyBootEx (
> -             TPL_NOTIFY,
> +             TPL_CALLBACK,
>               OnLegacyBoot,
>               NULL,
>               &LegacyBootEvent
> --
> 2.7.4.windows.1