[kvm-unit-tests GIT PULL 14/26] s390x: topology: Refine stsi header test

[Nico Boehr <nrb@linux.ibm.com>]

From: Nina Schoetterl-Glausch <nsg@linux.ibm.com>

Add checks for length field.
Also minor refactor.

Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Link: https://lore.kernel.org/r/20231030160349.458764-7-nsg@linux.ibm.com
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 s390x/topology.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/s390x/topology.c b/s390x/topology.c
index 03bc3d3..6a5f100 100644
--- a/s390x/topology.c
+++ b/s390x/topology.c
@@ -187,18 +187,23 @@ static void stsi_check_maxcpus(struct sysinfo_15_1_x *info)
 }
 
 /*
- * stsi_check_mag
+ * stsi_check_header
  * @info: Pointer to the stsi information
+ * @sel2: stsi selector 2 value
  *
  * MAG field should match the architecture defined containers
  * when MNEST as returned by SCLP matches MNEST of the SYSIB.
  */
-static void stsi_check_mag(struct sysinfo_15_1_x *info)
+static void stsi_check_header(struct sysinfo_15_1_x *info, int sel2)
 {
 	int i;
 
-	report_prefix_push("MAG");
+	report_prefix_push("Header");
 
+	/* Header is 16 bytes, each TLE 8 or 16, therefore alignment must be 8 at least */
+	report(IS_ALIGNED(info->length, 8), "Length %d multiple of 8", info->length);
+	report(info->length < PAGE_SIZE, "Length %d in bounds", info->length);
+	report(sel2 == info->mnest, "Valid mnest");
 	stsi_check_maxcpus(info);
 
 	/*
@@ -328,7 +333,6 @@ static int stsi_get_sysib(struct sysinfo_15_1_x *info, int sel2)
 
 	if (max_nested_lvl >= sel2) {
 		report(!ret, "Valid instruction");
-		report(sel2 == info->mnest, "Valid mnest");
 	} else {
 		report(ret, "Invalid instruction");
 	}
@@ -367,7 +371,7 @@ static void check_sysinfo_15_1_x(struct sysinfo_15_1_x *info, int sel2)
 		goto vertical;
 	}
 
-	stsi_check_mag(info);
+	stsi_check_header(info, sel2);
 	stsi_check_tle_coherency(info);
 
 vertical:
@@ -380,7 +384,7 @@ vertical:
 		goto end;
 	}
 
-	stsi_check_mag(info);
+	stsi_check_header(info, sel2);
 	stsi_check_tle_coherency(info);
 	report_prefix_pop();
 
-- 
2.41.0