)]}'
{
  "commit": "c0461bd16666351f0de11578b1e02dcdae4db736",
  "tree": "22847008e23784cf036bae10cc09765ec2bb04a2",
  "parents": [
    "6c3211796326a9d35618b866826ca556c8f008a8"
  ],
  "author": {
    "name": "Dionna Glaze",
    "email": "dionnaglaze@google.com",
    "time": "Tue Jun 06 09:51:27 2023 -0500"
  },
  "committer": {
    "name": "Borislav Petkov (AMD)",
    "email": "bp@alien8.de",
    "time": "Tue Jun 06 18:32:59 2023 +0200"
  },
  "message": "x86/efi: Safely enable unaccepted memory in UEFI\n\nThe UEFI v2.9 specification includes a new memory type to be used in\nenvironments where the OS must accept memory that is provided from its\nhost. Before the introduction of this memory type, all memory was\naccepted eagerly in the firmware. In order for the firmware to safely\nstop accepting memory on the OS\u0027s behalf, the OS must affirmatively\nindicate support to the firmware. This is only a problem for AMD\nSEV-SNP, since Linux has had support for it since 5.19. The other\ntechnology that can make use of unaccepted memory, Intel TDX, does not\nyet have Linux support, so it can strictly require unaccepted memory\nsupport as a dependency of CONFIG_TDX and not require communication with\nthe firmware.\n\nEnabling unaccepted memory requires calling a 0-argument enablement\nprotocol before ExitBootServices. This call is only made if the kernel\nis compiled with UNACCEPTED_MEMORY\u003dy\n\nThis protocol will be removed after the end of life of the first LTS\nthat includes it, in order to give firmware implementations an\nexpiration date for it. When the protocol is removed, firmware will\nstrictly infer that a SEV-SNP VM is running an OS that supports the\nunaccepted memory type. At the earliest convenience, when unaccepted\nmemory support is added to Linux, SEV-SNP may take strict dependence in\nit. After the firmware removes support for the protocol, this should be\nreverted.\n\n  [tl: address some checkscript warnings]\n\nSigned-off-by: Dionna Glaze \u003cdionnaglaze@google.com\u003e\nSigned-off-by: Tom Lendacky \u003cthomas.lendacky@amd.com\u003e\nSigned-off-by: Borislav Petkov (AMD) \u003cbp@alien8.de\u003e\nReviewed-by: Ard Biesheuvel \u003cardb@kernel.org\u003e\nLink: https://lore.kernel.org/r/0d5f3d9a20b5cf361945b7ab1263c36586a78a42.1686063086.git.thomas.lendacky@amd.com\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "3cc7faac001de43f00499bc634ba973b7c8770d1",
      "old_mode": 33188,
      "old_path": "drivers/firmware/efi/libstub/x86-stub.c",
      "new_id": "220be75a5cdc1f4c7e5e6fb38832fedfd15a8369",
      "new_mode": 33188,
      "new_path": "drivers/firmware/efi/libstub/x86-stub.c"
    },
    {
      "type": "modify",
      "old_id": "67cb72d7a7640aa4d8029cfed3837ad1ea405ef0",
      "old_mode": 33188,
      "old_path": "include/linux/efi.h",
      "new_id": "18d83a613635bf942852a795a51f471b972bebd6",
      "new_mode": 33188,
      "new_path": "include/linux/efi.h"
    }
  ]
}