[PATCH v1 14/26] crypto: ccp: Provide API to issue SEV and SNP commands

Michael Roth
2023-12-30T16:23:34Z

From: Brijesh Singh <brijesh.singh@amd.com>

Export sev_do_cmd() as a generic API for the hypervisor to issue
commands to manage an SEV and SNP guest. The commands for SEV and SNP
are defined in the SEV and SEV-SNP firmware specifications.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
[mdr: kernel-doc fixups]
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
drivers/crypto/ccp/sev-dev.c | 3 ++-
include/linux/psp-sev.h | 19 +++++++++++++++++++
2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 85634d4f8cfe..767f0ec3d5bb 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -431,7 +431,7 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
return ret;
}

-static int sev_do_cmd(int cmd, void *data, int *psp_ret)
+int sev_do_cmd(int cmd, void *data, int *psp_ret)
{
int rc;

@@ -441,6 +441,7 @@ static int sev_do_cmd(int cmd, void *data, int *psp_ret)

return rc;
}
+EXPORT_SYMBOL_GPL(sev_do_cmd);

static int __sev_init_locked(int *error)
{
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index a39a9e5b5bc4..0581f194cdd0 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -914,6 +914,22 @@ int sev_guest_df_flush(int *error);
*/
int sev_guest_decommission(struct sev_data_decommission *data, int *error);

+/**
+ * sev_do_cmd - issue an SEV or an SEV-SNP command
+ *
+ * @cmd: SEV or SEV-SNP firmware command to issue
+ * @data: arguments for firmware command
+ * @psp_ret: SEV command return code
+ *
+ * Returns:
+ * 0 if the SEV successfully processed the command
+ * -%ENODEV if the PSP device is not available
+ * -%ENOTSUPP if PSP device does not support SEV
+ * -%ETIMEDOUT if the SEV command timed out
+ * -%EIO if PSP device returned a non-zero return code
+ */
+int sev_do_cmd(int cmd, void *data, int *psp_ret);
+
void *psp_copy_user_blob(u64 uaddr, u32 len);

#else /* !CONFIG_CRYPTO_DEV_SP_PSP */
@@ -929,6 +945,9 @@ sev_guest_deactivate(struct sev_data_deactivate *data, int *error) { return -ENO
static inline int
sev_guest_decommission(struct sev_data_decommission *data, int *error) { return -ENODEV; }

+static inline int
+sev_do_cmd(int cmd, void *data, int *psp_ret) { return -ENODEV; }
+
static inline int
sev_guest_activate(struct sev_data_activate *data, int *error) { return -ENODEV; }

--
2.25.1