[PATCH v6 0/3] x86/snp: Add kexec support

[Ashish Kalra <Ashish.Kalra@amd.com>]

From: Ashish Kalra <ashish.kalra@amd.com>

The patchset adds bits and pieces to get kexec (and crashkernel) work on
SNP guest.

The series is based off of and tested against Kirill Shutemov's tree:
  https://github.com/intel/tdx.git guest-kexec

----

v6:
- Updated and restructured the commit message for patch 1/3 to
  explain the issue in detail.
- Updated inline comments in patch 1/3 to explain the issue in 
  detail.
- Moved back to checking efi_setup for detecting if running
  under kexec kernel.

v5:
- Removed sev_es_enabled() function and using sev_status directly to
  check for SEV-ES/SEV-SNP guest.
- used --base option to generate patches to specify Kirill's TDX guest
  kexec patches as prerequisite patches to fix kernel test robot
  build errors.

v4:
- Rebased to current tip/master.
- Reviewed-bys from Sathya.
- Remove snp_kexec_unprep_rom_memory() as it is not needed any more as 
  SEV-SNP code is not validating the ROM range in probe_roms() anymore.
- Fix kernel test robot build error/warnings.

v3:
- Rebased;
- moved Keep page tables that maps E820_TYPE_ACPI patch to Kirill's tdx
  guest kexec patch series.
- checking the md attribute instead of checking the efi_setup for
  detecting if running under kexec kernel.
- added new sev_es_enabled() function.
- skip video memory access in decompressor for SEV-ES/SNP systems to 
  prevent guest termination as boot stage2 #VC handler does not handle
  MMIO.

v2:
- address zeroing of unaccepted memory table mappings at all page table levels
  adding phys_pte_init(), phys_pud_init() and phys_p4d_init().
- include skip efi_arch_mem_reserve() in case of kexec as part of this 
  patch set.
- rename last_address_shd_kexec to a more appropriate 
  kexec_last_address_to_make_private.
- remove duplicate code shared with TDX and use common interfaces
  defined for SNP and TDX for kexec/kdump.
- remove set_pte_enc() dependency on pg_level_to_pfn() and make the 
  function simpler.
- rename unshare_pte() to make_pte_private().
- clarify and make the comment for using kexec_last_address_to_make_private  
  more understandable.
- general cleanup. 


Ashish Kalra (3):
  efi/x86: Fix EFI memory map corruption with kexec
  x86/boot/compressed: Skip Video Memory access in Decompressor for
    SEV-ES/SNP.
  x86/snp: Convert shared memory back to private on kexec

 arch/x86/boot/compressed/misc.c |   6 +-
 arch/x86/include/asm/sev.h      |   4 +
 arch/x86/kernel/sev.c           | 161 ++++++++++++++++++++++++++++++++
 arch/x86/mm/mem_encrypt_amd.c   |   3 +
 arch/x86/platform/efi/quirks.c  |  20 ++++
 5 files changed, 192 insertions(+), 2 deletions(-)


base-commit: 7fcd76de8a7bc12e930ef383a157ce99d711715d
prerequisite-patch-id: a911f230c2524bd791c47f62f17f0a93cbf726b6
prerequisite-patch-id: bfe2fa046349978ac1825275eb205acecfbc22f3
prerequisite-patch-id: 5e60d292457c7cd98fd3e45c23127e9463b56a69
prerequisite-patch-id: 1f97d0a2edb7509dd58276f628d1a4bda62c154c
prerequisite-patch-id: cbc2507b5c2810c3015aaf836d774d32f969c19a
prerequisite-patch-id: cbdfea1e50ecb3b4cee3a25a27df4d35bd95d532
prerequisite-patch-id: 99382c42348b9a076ba930eca0dfc9d000ec951d
prerequisite-patch-id: 469a0a3c78b0eca82527cd85e2205fb8fb89d645
prerequisite-patch-id: 2974ef211db5253d9782018e352d2a6ff0b0ef54
prerequisite-patch-id: 2cfffd80947941892421dae99b7fa0f9f9715884
prerequisite-patch-id: 466c2cb9f0a107bbd1dbd8526f4eff2bdb55f1ce
prerequisite-patch-id: d4966ae63e86d24b0bf578da4dae871cd9002b12
prerequisite-patch-id: fccde6f1fa385b5af0195f81fcb95acd71822428
prerequisite-patch-id: 16048ee15e392b0b9217b8923939b0059311abd2
prerequisite-patch-id: 5c9ae9aa294f72f63ae2c3551507dfbd92525803
prerequisite-patch-id: 758bdb686290c018cbd5b7d005354019f9d15248
prerequisite-patch-id: c85fd0bb6d183a40da73720eaa607481b1d51daf
prerequisite-patch-id: 60760e0c98ab7ccd2ca22ae3e9f20ff5a94c6e91
-- 
2.34.1