File s390-tools-sles15sp2-02-zipl-stage3-correctly-handle-diag308-response-code.patch of Package s390-tools.17667

Subject: [PATCH] [BZ 186940] zipl/stage3: correctly handle diag308 response code
From: Stefan Haberland <sth@linux.ibm.com>

Description:   zipl: Fix KVM IPL without bootindex
Symptom:       Failed IPL on KVM when no bootindex is specified.
Problem:       Without bootindex specified there is no IPL parmblock
               on KVM which can be read by the stage3 loader.
Solution:      In case diag308 gives a response code 0x102 the stage3
               loader can safely assume that no secure IPL is required
               since no IPL report block exists.
Reproduction:  IPL on KVM without 'bootindex=' attached.
Upstream-ID:   b7f1977d3f9332f82e7f388fb18076b89b83944e
Problem-ID:    186940

Upstream-Description:

              zipl/stage3: correctly handle diag308 response code

              In case diag308 gives a response code 0x102 the stage3 loader can
              safely assume that no secure IPL is required since no IPL report
              block exists.

              Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
              Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
              Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
              Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
              Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>


Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
---
 include/boot/s390.h |    1 +
 zipl/boot/stage3.c  |   25 +++++++++++--------------
 2 files changed, 12 insertions(+), 14 deletions(-)

--- a/include/boot/s390.h
+++ b/include/boot/s390.h
@@ -279,6 +279,7 @@ enum diag308_subcode {
 
 enum diag308_rc {
 	DIAG308_RC_OK	      = 0x0001,
+	DIAG308_RC_NO_CONF    = 0x0102,
 };
 
 static __always_inline unsigned long diag308(unsigned long subcode, void *addr)
--- a/zipl/boot/stage3.c
+++ b/zipl/boot/stage3.c
@@ -55,18 +55,6 @@ static inline void __noreturn start_kern
 	while (1);
 }
 
-unsigned int store_ipl_parmblock(struct ipl_pl_hdr *pl_hdr)
-{
-	int rc;
-
-	rc = diag308(DIAG308_STORE, pl_hdr);
-	if (rc == DIAG308_RC_OK &&
-		pl_hdr->version <= IPL_MAX_SUPPORTED_VERSION)
-		return 0;
-
-	return 1;
-}
-
 unsigned int
 is_verified_address(unsigned long image_addr)
 {
@@ -124,9 +112,18 @@ secure_boot_enabled()
 	unsigned int rc;
 
 	pl_hdr = (void *)get_zeroed_page();
-	if (!pl_hdr || store_ipl_parmblock(pl_hdr))
+	switch (diag308(DIAG308_STORE, pl_hdr)) {
+	case DIAG308_RC_OK:
+		rc = pl_hdr->version <= IPL_MAX_SUPPORTED_VERSION &&
+			!!(pl_hdr->flags & IPL_FLAG_SECURE);
+		break;
+	case DIAG308_RC_NO_CONF:
+		rc = 0;
+		break;
+	default:
 		panic(ESECUREBOOT, "%s", msg_sipl_noparm);
-	rc = !!(pl_hdr->flags & IPL_FLAG_SECURE);
+		break;
+	}
 	free_page((unsigned long) pl_hdr);
 
 	return rc;