diff options
| author | Dexuan Cui <decui@microsoft.com> | 2023-08-10 19:12:45 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-09-11 16:19:33 -0700 |
| commit | 019b383d1132e4051de0d2e43254454b86538cf4 (patch) | |
| tree | 59cb291696ed2672a506d4e4a2fc2243ea54feb6 /arch/x86/include/asm/shared | |
| parent | 0bb80ecc33a8fb5a682236443c1e740d5c917d1d (diff) | |
x86/tdx: Retry partially-completed page conversion hypercalls
TDX guest memory is private by default and the VMM may not access it.
However, in cases where the guest needs to share data with the VMM,
the guest and the VMM can coordinate to make memory shared between
them.
The guest side of this protocol includes the "MapGPA" hypercall. This
call takes a guest physical address range. The hypercall spec (aka.
the GHCI) says that the MapGPA call is allowed to return partial
progress in mapping this range and indicate that fact with a special
error code. A guest that sees such partial progress is expected to
retry the operation for the portion of the address range that was not
completed.
Hyper-V does this partial completion dance when set_memory_decrypted()
is called to "decrypt" swiotlb bounce buffers that can be up to 1GB
in size. It is evidently the only VMM that does this, which is why
nobody noticed this until now.
[ dhansen: rewrite changelog ]
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20230811021246.821-2-decui%40microsoft.com
Diffstat (limited to 'arch/x86/include/asm/shared')
| -rw-r--r-- | arch/x86/include/asm/shared/tdx.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index 7513b3bb69b7..22ee23a3f24a 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -24,6 +24,8 @@ #define TDVMCALL_MAP_GPA 0x10001 #define TDVMCALL_REPORT_FATAL_ERROR 0x10003 +#define TDVMCALL_STATUS_RETRY 1 + #ifndef __ASSEMBLY__ /* |