Re: [PATCH] crypto: ccp - State in dmesg that TSME is enabled

From: Tom Lendacky
Date: Tue Feb 06 2024 - 13:57:08 EST


On 2/5/24 09:46, Borislav Petkov wrote:
From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>

In the case when only TSME is enabled, it is useful to state that fact
too, so that users are aware that memory encryption is still enabled
even when the corresponding software variant of memory encryption is not
enabled.

Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>

Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>

---
drivers/crypto/ccp/psp-dev.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 124a2e0c8999..56bf832c2947 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -156,11 +156,14 @@ static unsigned int psp_get_capability(struct psp_device *psp)
}
psp->capability = val;
- /* Detect if TSME and SME are both enabled */
+ /* Detect TSME and/or SME status */
if (PSP_CAPABILITY(psp, PSP_SECURITY_REPORTING) &&
- psp->capability & (PSP_SECURITY_TSME_STATUS << PSP_CAPABILITY_PSP_SECURITY_OFFSET) &&
- cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
- dev_notice(psp->dev, "psp: Both TSME and SME are active, SME is unnecessary when TSME is active.\n");
+ psp->capability & (PSP_SECURITY_TSME_STATUS << PSP_CAPABILITY_PSP_SECURITY_OFFSET)) {
+ if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+ dev_notice(psp->dev, "psp: Both TSME and SME are active, SME is unnecessary when TSME is active.\n");
+ else
+ dev_notice(psp->dev, "psp: TSME enabled\n");
+ }
return 0;
}