On 05/26/17 16:43, Brijesh Singh wrote: > 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 <[email protected]> > Cc: Laszlo Ersek <[email protected]> > Cc: Leo Duran <[email protected]> > Contributed-under: TianoCore Contribution Agreement 1.0 > Suggested-by: Jordan Justen <[email protected]> > Suggested-by: Laszlo Ersek <[email protected]> > Signed-off-by: Brijesh Singh <[email protected]> > --- > OvmfPkg/OvmfPkg.dec | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec > index 5627be0bab0a..4241af10c3d0 100644 > --- a/OvmfPkg/OvmfPkg.dec > +++ b/OvmfPkg/OvmfPkg.dec > @@ -69,6 +69,7 @@ [Protocols] > 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 >
Reviewed-by: Laszlo Ersek <[email protected]> _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
