On 04/30/21 13:51, Brijesh Singh wrote: > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275 > > Define the SEV-SNP MSR bits. > > Cc: James Bottomley <[email protected]> > Cc: Min Xu <[email protected]> > Cc: Jiewen Yao <[email protected]> > Cc: Tom Lendacky <[email protected]> > Cc: Jordan Justen <[email protected]> > Cc: Ard Biesheuvel <[email protected]> > Cc: Laszlo Ersek <[email protected]> > Cc: Erdem Aktas <[email protected]> > Signed-off-by: Brijesh Singh <[email protected]> > --- > MdePkg/Include/Register/Amd/Fam17Msr.h | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/MdePkg/Include/Register/Amd/Fam17Msr.h > b/MdePkg/Include/Register/Amd/Fam17Msr.h > index e4db09c518..4d33bef220 100644 > --- a/MdePkg/Include/Register/Amd/Fam17Msr.h > +++ b/MdePkg/Include/Register/Amd/Fam17Msr.h > @@ -87,7 +87,12 @@ typedef union { > /// > UINT32 SevEsBit:1; > > - UINT32 Reserved:30; > + /// > + /// [Bit 2] Secure Nested Paging (SevSnp) is enabled > + /// > + UINT32 SevSnpBit:1; > + > + UINT32 Reserved:29; > } Bits; > /// > /// All bit fields as a 32-bit value >
(1) When changing a Reserved field's meaning, the field should be renamed. Usually we do this by numbering, and the numbers only ever increase. This is because code might exist that uses a Reserved field. Such code should be prevented from compiling, because that's much better than silently breaking its behavior. So the new name of the field should be Reserved2. (If we modify Reserved2 later, it should be renamed to Reserved3, and so on -- we should never return to a field name used before.) Thanks Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#74694): https://edk2.groups.io/g/devel/message/74694 Mute This Topic: https://groups.io/mt/82479047/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
