From: Ashish Kalra
SNP guests allocate shared buffers to perform I/O. It is done by
allocating pages normally from the buddy allocator and converting them
to shared with set_memory_decrypted().
The second kernel has no idea what memory is converted this way. It only
sees E820_TYPE_RAM.
Accessin
From: Ashish Kalra
Accessing guest video memory/RAM during kernel decompressor
causes guest termination as boot stage2 #VC handler for
SEV-ES/SNP systems does not support MMIO handling.
This issue is observed with SEV-ES/SNP guest kexec as
kexec -c adds screen_info to the boot parameters
passed
From: Ashish Kalra
For kexec use case, need to use and stick to the EFI memmap passed
from the first kernel via boot-params/setup data, hence,
skip efi_arch_mem_reserve() during kexec.
Additionally during SNP guest kexec testing discovered that EFI memmap
is corrupted during chained kexec. kexec
From: Ashish Kalra
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
v5:
- Removed sev_es_enabled() function and using sev_status directly
Just a heads up: will add this to the sysctl-next tree
https://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl.git/log/?h=sysctl-next
so it has time to soak there for next merge window. If you are a
maintainer and are thinking of including any of these patches in your
tree, let me know and I'
