Re: [edk2-devel] [PATCH 03/13] MdePkg/Register/Amd: define GHCB macros for hypervisor feature detection

["Laszlo Ersek" <lersek@redhat.com>]

On 05/07/21 22:38, Brijesh Singh wrote:
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
> 
> Version 2 of GHCB introduces advertisement of features that are supported
> by the hypervisor. See the GHCB spec section 2.2 for an additional details.
> 
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Min Xu <min.m.xu@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Cc: Zhiguang Liu <zhiguang.liu@intel.com>
> Reviewd-by: Laszlo Ersek <lersek@redhat.com>

(1) It's best to use the clipboard for picking up feedback tags -- I
didn't mistype my R-b. (I've checked, plus I use keyboard shortcuts to
insert them; I don't type them out individually).

Anyway I can fix this up upon merge.

> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  MdePkg/Include/Register/Amd/Fam17Msr.h | 7 +++++++
>  MdePkg/Include/Register/Amd/Ghcb.h     | 8 ++++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/MdePkg/Include/Register/Amd/Fam17Msr.h b/MdePkg/Include/Register/Amd/Fam17Msr.h
> index 7368ce7af02a..cdb8f588ccf8 100644
> --- a/MdePkg/Include/Register/Amd/Fam17Msr.h
> +++ b/MdePkg/Include/Register/Amd/Fam17Msr.h
> @@ -48,6 +48,11 @@ typedef union {
>      UINT32  Reserved2:32;
>    } GhcbTerminate;
>  
> +  struct {
> +    UINT64  Function:12;
> +    UINT64  Features:52;
> +  } GhcbHypervisorFeatures;
> +
>    VOID    *Ghcb;
>  
>    UINT64  GhcbPhysicalAddress;
> @@ -57,6 +62,8 @@ typedef union {
>  #define GHCB_INFO_SEV_INFO_GET                      2
>  #define GHCB_INFO_CPUID_REQUEST                     4
>  #define GHCB_INFO_CPUID_RESPONSE                    5
> +#define GHCB_HYPERVISOR_FEATURES_REQUEST            128
> +#define GHCB_HYPERVISOR_FEATURES_RESPONSE           129
>  #define GHCB_INFO_TERMINATE_REQUEST                 256
>  
>  #define GHCB_TERMINATE_GHCB                0
> diff --git a/MdePkg/Include/Register/Amd/Ghcb.h b/MdePkg/Include/Register/Amd/Ghcb.h
> index 712dc8e769c0..326b11479779 100644
> --- a/MdePkg/Include/Register/Amd/Ghcb.h
> +++ b/MdePkg/Include/Register/Amd/Ghcb.h
> @@ -54,6 +54,7 @@
>  #define SVM_EXIT_NMI_COMPLETE                   0x80000003ULL
>  #define SVM_EXIT_AP_RESET_HOLD                  0x80000004ULL
>  #define SVM_EXIT_AP_JUMP_TABLE                  0x80000005ULL
> +#define SVM_EXIT_HYPERVISOR_FEATURES            0x8000FFFDULL
>  #define SVM_EXIT_UNSUPPORTED                    0x8000FFFFULL
>  
>  //
> @@ -154,4 +155,11 @@ typedef union {
>  #define GHCB_EVENT_INJECTION_TYPE_EXCEPTION  3
>  #define GHCB_EVENT_INJECTION_TYPE_SOFT_INT   4
>  
> +//
> +// Hypervisor features dections
> +//

(2) The comment style is OK now, but the comment itself has some kind of
typo. I can't really guess what "dections" was supposed to be. I guess I
can replace the comment with "Hypervisor feature sets".

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks
Laszlo

> +#define GHCB_HV_FEATURES_SNP                              BIT0
> +#define GHCB_HV_FEATURES_SNP_AP_CREATE                    (GHCB_HV_FEATURES_SNP | BIT1)
> +#define GHCB_HV_FEATURES_SNP_RESTRICTED_INJECTION         (GHCB_HV_FEATURES_SNP_AP_CREATE | BIT2)
> +#define GHCB_HV_FEATURES_SNP_RESTRICTED_INJECTION_TIMER   (GHCB_HV_FEATURES_SNP_RESTRICTED_INJECTION | BIT3)
>  #endif
>