x86/sev: Do not initialize SNP if missing CPUs

The SEV firmware checks that the SNP enable bit is set on each CPU during SNP
initialization, and will fail if not. If there are some CPUs offline, they
will not run the setup functions, so SNP initialization will always fail.

Skip the IPIs in this case and return an error so that the CCP driver can
skip the SNP_INIT that will fail. Also print the CPU masks in order to leave
breadcrumbs so people can figure out what happened.

  [ bp: Massage commit message. ]

Suggested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://20260429155636.540040-1-tycho@kernel.org

0 files changed, 0 insertions, 0 deletions