[PATCH v2] crypto: ccp: Sanitize sev_platform_init() error messages

[Jarkko Sakkinen <jarkko@profian.com>]

The following functions end up calling sev_platform_init() or
__sev_platform_init_locked():

* sev_guest_init()
* sev_ioctl_do_pek_csr
* sev_ioctl_do_pdh_export()
* sev_ioctl_do_pek_import()
* sev_ioctl_do_pek_pdh_gen()
* sev_pci_init()

However, only sev_pci_init() prints out the failed command error code, and
even there the error message does not specify, SEV which command failed.

Address this by printing out the SEV command errors inside
__sev_platform_init_locked(), and differentiate between DF_FLUSH, INIT and
INIT_EX commands.  As a side-effect, @error can be removed from the
parameter list.

This extra information is particularly useful if firmware loading and/or
initialization is going to be made more robust, e.g. by allowing firmware
loading to be postponed.

Signed-off-by: Jarkko Sakkinen <jarkko@profian.com>
---
v2:
* Address David Rientjes's feedback:
  https://lore.kernel.org/all/6a16bbe4-4281-fb28-78c4-4ec44c8aa679@google.com/
* Remove @error.
* Remove "SEV_" prefix: it is obvious from context so no need to make klog
  line longer.
---
 arch/x86/kvm/svm/sev.c       |  2 +-
 drivers/crypto/ccp/sev-dev.c | 33 +++++++++++++++++----------------
 include/linux/psp-sev.h      |  4 +---
 3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index efaaef2b7ae1..42e6bd637896 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -254,7 +254,7 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 		goto e_no_asid;
 	sev->asid = asid;
 
-	ret = sev_platform_init(&argp->error);
+	ret = sev_platform_init();
 	if (ret)
 		goto e_free;
 
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 06fc7156c04f..3b66cb1495d4 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -440,7 +440,7 @@ static int __sev_init_ex_locked(int *error)
 	return __sev_do_cmd_locked(SEV_CMD_INIT_EX, &data, error);
 }
 
-static int __sev_platform_init_locked(int *error)
+static int __sev_platform_init_locked(void)
 {
 	struct psp_device *psp = psp_master;
 	struct sev_device *sev;
@@ -476,19 +476,21 @@ static int __sev_platform_init_locked(int *error)
 		dev_err(sev->dev, "SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state.");
 		rc = init_function(&psp_ret);
 	}
-	if (error)
-		*error = psp_ret;
-
-	if (rc)
+	if (rc) {
+		dev_err(sev->dev, "SEV: %s failed error %#x",
+			sev_init_ex_buffer ? "CMD_INIT_EX" : "CMD_INIT", psp_ret);
 		return rc;
+	}
 
 	sev->state = SEV_STATE_INIT;
 
 	/* Prepare for first SEV guest launch after INIT */
 	wbinvd_on_all_cpus();
-	rc = __sev_do_cmd_locked(SEV_CMD_DF_FLUSH, NULL, error);
-	if (rc)
+	rc = __sev_do_cmd_locked(SEV_CMD_DF_FLUSH, NULL, &psp_ret);
+	if (rc) {
+		dev_err(sev->dev, "SEV: CMD_DF_FLUSH failed error %#x", psp_ret);
 		return rc;
+	}
 
 	dev_dbg(sev->dev, "SEV firmware initialized\n");
 
@@ -498,12 +500,12 @@ static int __sev_platform_init_locked(int *error)
 	return 0;
 }
 
-int sev_platform_init(int *error)
+int sev_platform_init(void)
 {
 	int rc;
 
 	mutex_lock(&sev_cmd_mutex);
-	rc = __sev_platform_init_locked(error);
+	rc = __sev_platform_init_locked();
 	mutex_unlock(&sev_cmd_mutex);
 
 	return rc;
@@ -610,7 +612,7 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
 		return -EPERM;
 
 	if (sev->state == SEV_STATE_UNINIT) {
-		rc = __sev_platform_init_locked(&argp->error);
+		rc = __sev_platform_init_locked();
 		if (rc)
 			return rc;
 	}
@@ -653,7 +655,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 
 cmd:
 	if (sev->state == SEV_STATE_UNINIT) {
-		ret = __sev_platform_init_locked(&argp->error);
+		ret = __sev_platform_init_locked();
 		if (ret)
 			goto e_free_blob;
 	}
@@ -849,7 +851,7 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
 
 	/* If platform is not in INIT state then transition it to INIT */
 	if (sev->state != SEV_STATE_INIT) {
-		ret = __sev_platform_init_locked(&argp->error);
+		ret = __sev_platform_init_locked();
 		if (ret)
 			goto e_free_oca;
 	}
@@ -973,7 +975,7 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 		if (!writable)
 			return -EPERM;
 
-		ret = __sev_platform_init_locked(&argp->error);
+		ret = __sev_platform_init_locked();
 		if (ret)
 			return ret;
 	}
@@ -1335,10 +1337,9 @@ void sev_pci_init(void)
 		return;
 
 	/* Initialize the platform */
-	rc = sev_platform_init(&error);
+	rc = sev_platform_init();
 	if (rc)
-		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
-			error, rc);
+		dev_err(sev->dev, "SEV: failed to INIT rc %d\n", rc);
 
 	return;
 
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 1595088c428b..2f8681b753d0 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -536,8 +536,6 @@ struct sev_data_attestation_report {
 /**
  * sev_platform_init - perform SEV INIT command
  *
- * @error: SEV command return code
- *
  * Returns:
  * 0 if the SEV successfully processed the command
  * -%ENODEV    if the SEV device is not available
@@ -545,7 +543,7 @@ struct sev_data_attestation_report {
  * -%ETIMEDOUT if the SEV command timed out
  * -%EIO       if the SEV returned a non-zero return code
  */
-int sev_platform_init(int *error);
+int sev_platform_init(void);
 
 /**
  * sev_platform_status - perform SEV PLATFORM_STATUS command
-- 
2.38.1