From: Ashish Kalra <ashish.kalra@xxxxxxx> Ciphertext hiding prevents host accesses from reading the ciphertext of SNP guest private memory. Instead of reading ciphertext, the host will see constant default values (0xff). Ciphertext hiding separates the ASID space into SNP guest ASIDs and host ASIDs. All SNP active guests must have an ASID less than or equal to MAX_SNP_ASID provided to the SNP_INIT_EX command. All SEV-legacy guests must be greater than MAX_SNP_ASID. This patch-set adds a new module parameter to the CCP driver defined as psp_max_snp_asid which is a user configurable MAX_SNP_ASID to define the system-wide maximum SNP ASID value. If this value is not set, then the ASID space is equally divided between SEV-SNP and SEV-ES guests. Ashish Kalra (3): crypto: ccp: Extend SNP_PLATFORM_STATUS command crypto: ccp: Add support for SNP_FEATURE_INFO command x86/sev: Add SEV-SNP CipherTextHiding support arch/x86/kvm/svm/sev.c | 24 ++++++++-- drivers/crypto/ccp/sev-dev.c | 90 ++++++++++++++++++++++++++++++++++++ drivers/crypto/ccp/sev-dev.h | 3 ++ include/linux/psp-sev.h | 41 +++++++++++++++- include/uapi/linux/psp-sev.h | 10 +++- 5 files changed, 162 insertions(+), 6 deletions(-) -- 2.34.1
