From c5d736eb6770ef80ab585aaf81fdf36ba5fd7607 Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Thu, 6 Jul 2017 09:26:50 -0400 Subject: [PATCH] OvmfPkg: Introduce IoMmuAbsent Protocol GUID Platforms that optionally provide an IOMMU protocol should do so by including a DXE driver (usually called IoMmuDxe) that produces either the IOMMU protocol -- if the underlying capabilities are available --, or gIoMmuAbsentProtocolGuid, to signal that the IOMMU capability detection completed with negative result (i.e., no IOMMU will be available in the system). In turn, DXE drivers (and library instances) that are supposed to use the IOMMU protocol if it is available should add the following to their DEPEX: gEdkiiIoMmuProtocolGuid OR gIoMmuAbsentProtocolGuid This ensures these client modules will only be dispatched after IOMMU detection completes (with positive or negative result). Cc: Jordan Justen Cc: Laszlo Ersek Cc: Leo Duran Contributed-under: TianoCore Contribution Agreement 1.0 Suggested-by: Jordan Justen Suggested-by: Laszlo Ersek Signed-off-by: Brijesh Singh Reviewed-by: Laszlo Ersek Reviewed-by: Jordan Justen --- OvmfPkg/OvmfPkg.dec | 1 + 1 file changed, 1 insertion(+) diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec index e5f74a1248..27bcfc141e 100644 --- a/OvmfPkg/OvmfPkg.dec +++ b/OvmfPkg/OvmfPkg.dec @@ -69,6 +69,7 @@ gBlockMmioProtocolGuid = {0x6b558ce3, 0x69e5, 0x4c67, {0xa6, 0x34, 0xf7, 0xfe, 0x72, 0xad, 0xbe, 0x84}} gXenBusProtocolGuid = {0x3d3ca290, 0xb9a5, 0x11e3, {0xb7, 0x5d, 0xb8, 0xac, 0x6f, 0x7d, 0x65, 0xe6}} gXenIoProtocolGuid = {0x6efac84f, 0x0ab0, 0x4747, {0x81, 0xbe, 0x85, 0x55, 0x62, 0x59, 0x04, 0x49}} + gIoMmuAbsentProtocolGuid = {0xf8775d50, 0x8abd, 0x4adf, {0x92, 0xac, 0x85, 0x3e, 0x51, 0xf6, 0xc8, 0xdc}} [PcdsFixedAtBuild] gUefiOvmfPkgTokenSpaceGuid.PcdOvmfPeiMemFvBase|0x0|UINT32|0 -- 2.39.2