summaryrefslogtreecommitdiff
path: root/drivers/crypto
diff options
context:
space:
mode:
authorTom Lendacky <thomas.lendacky@amd.com>2025-10-27 14:33:50 -0500
committerSean Christopherson <seanjc@google.com>2025-11-14 10:30:10 -0800
commitc9434e64e8b4d17511f514f7495008f573595e3e (patch)
treeff7207b9f62317bcff47f130d0b680ceb353c5dc /drivers/crypto
parentce62118a2e4838bcef1050fff55001a0bf87f0cb (diff)
crypto: ccp - Add an API to return the supported SEV-SNP policy bits
Supported policy bits are dependent on the level of SEV firmware that is currently running. Create an API to return the supported policy bits for the current level of firmware. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://patch.msgid.link/e3f711366ddc22e3dd215c987fd2e28dc1c07f54.1761593632.git.thomas.lendacky@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/ccp/sev-dev.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 0d13d47c164b..db7c7c50cebc 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -2777,6 +2777,43 @@ void sev_platform_shutdown(void)
}
EXPORT_SYMBOL_GPL(sev_platform_shutdown);
+u64 sev_get_snp_policy_bits(void)
+{
+ struct psp_device *psp = psp_master;
+ struct sev_device *sev;
+ u64 policy_bits;
+
+ if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
+ return 0;
+
+ if (!psp || !psp->sev_data)
+ return 0;
+
+ sev = psp->sev_data;
+
+ policy_bits = SNP_POLICY_MASK_BASE;
+
+ if (sev->snp_plat_status.feature_info) {
+ if (sev->snp_feat_info_0.ecx & SNP_RAPL_DISABLE_SUPPORTED)
+ policy_bits |= SNP_POLICY_MASK_RAPL_DIS;
+
+ if (sev->snp_feat_info_0.ecx & SNP_CIPHER_TEXT_HIDING_SUPPORTED)
+ policy_bits |= SNP_POLICY_MASK_CIPHERTEXT_HIDING_DRAM;
+
+ if (sev->snp_feat_info_0.ecx & SNP_AES_256_XTS_POLICY_SUPPORTED)
+ policy_bits |= SNP_POLICY_MASK_MEM_AES_256_XTS;
+
+ if (sev->snp_feat_info_0.ecx & SNP_CXL_ALLOW_POLICY_SUPPORTED)
+ policy_bits |= SNP_POLICY_MASK_CXL_ALLOW;
+
+ if (sev_version_greater_or_equal(1, 58))
+ policy_bits |= SNP_POLICY_MASK_PAGE_SWAP_DISABLE;
+ }
+
+ return policy_bits;
+}
+EXPORT_SYMBOL_GPL(sev_get_snp_policy_bits);
+
void sev_dev_destroy(struct psp_device *psp)
{
struct sev_device *sev = psp->sev_data;