On Wed, Jun 05, 2024 at 10:18:45AM -0500, Tom Lendacky wrote:
During early boot phases, check for the presence of an SVSM when running
as an SEV-SNP guest.
An SVSM is present if not running at VMPL0 and the 64-bit value at offset
0x148 into the secrets page is non-zero. If an SVSM is present, save the
SVSM Calling Area address (CAA), located at offset 0x150 into the secrets
page, and set the VMPL level of the guest, which should be non-zero, to
indicate the presence of an SVSM.
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
.../arch/x86/amd-memory-encryption.rst | 23 ++++++
arch/x86/boot/compressed/sev.c | 21 +++---
arch/x86/include/asm/sev-common.h | 4 ++
arch/x86/include/asm/sev.h | 34 ++++++++-
arch/x86/kernel/sev-shared.c | 71 +++++++++++++++++++
arch/x86/kernel/sev.c | 7 ++
6 files changed, 151 insertions(+), 9 deletions(-)
I did some touch-ups ontop: