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From:   Andrew Donnellan <ajd@linux.ibm.com>
To:     linuxppc-dev@lists.ozlabs.org, linux-integrity@vger.kernel.org
Cc:     gregkh@linuxfoundation.org, gcwilson@linux.ibm.com,
        linux-kernel@vger.kernel.org, nayna@linux.ibm.com,
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        gjoyce@linux.ibm.com, sudhakar@linux.ibm.com, bgray@linux.ibm.com,
        erichte@linux.ibm.com, joel@jms.id.au
Subject: [PATCH v4 20/24] powerpc/pseries: Add helpers to get PLPKS password
Date:   Fri, 20 Jan 2023 18:43:02 +1100
Message-Id: <20230120074306.1326298-21-ajd@linux.ibm.com>
In-Reply-To: <20230120074306.1326298-1-ajd@linux.ibm.com>
References: <20230120074306.1326298-1-ajd@linux.ibm.com>
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From: Russell Currey <ruscur@russell.cc>

Add helper functions to get the PLPKS password. This will be used in a
later patch to support passing the password between kernels over kexec.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>

---

v3: New patch
---
 arch/powerpc/include/asm/plpks.h       | 11 +++++++++++
 arch/powerpc/platforms/pseries/plpks.c | 10 ++++++++++
 2 files changed, 21 insertions(+)

diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
index 0c49969b0864..08355c89f5fd 100644
--- a/arch/powerpc/include/asm/plpks.h
+++ b/arch/powerpc/include/asm/plpks.h
@@ -171,6 +171,17 @@ u32 plpks_get_maxlargeobjectsize(void);
  */
 u64 plpks_get_signedupdatealgorithms(void);
 
+/**
+ * Returns the PLPKS password generated by the hypervisor.
+ * Should only be used to prepare a different OS to use the PLPKS, i.e. kexec.
+ */
+u8 *plpks_get_password(void);
+
+/**
+ * Returns the length of the PLPKS password in bytes.
+ */
+u16 plpks_get_passwordlen(void);
+
 #endif // CONFIG_PSERIES_PLPKS
 
 #endif // _ASM_POWERPC_PLPKS_H
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index 5d9c6a3b2014..b3c7410a4f13 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -359,6 +359,16 @@ u64 plpks_get_signedupdatealgorithms(void)
 	return signedupdatealgorithms;
 }
 
+u8 *plpks_get_password(void)
+{
+	return ospassword;
+}
+
+u16 plpks_get_passwordlen(void)
+{
+	return ospasswordlength;
+}
+
 bool plpks_is_available(void)
 {
 	int rc;
-- 
2.39.0