[PATCH v4 0/4] x86/snp: Add kexec support

[Ashish Kalra]

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

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

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 (4):
  efi/x86: skip efi_arch_mem_reserve() in case of kexec.
  x86/sev: add sev_es_enabled() function.
  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/boot/compressed/misc.h |   1 +
 arch/x86/boot/compressed/sev.c  |   5 +
 arch/x86/boot/compressed/sev.h  |   2 +
 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 +++-
 8 files changed, 198 insertions(+), 4 deletions(-)

-- 
2.34.1