[kvm-unit-tests PATCH v5 5/8] lib: s390x: uv: Add pv host requirement check function

[Janosch Frank <frankja@xxxxxxxxxxxxx>]

When running PV guests some of the UV memory needs to be allocated
with > 31 bit addresses which means tests with PV guests will always
need a lot more memory than other tests.
Additionally facilities nr 158 and sclp.sief2 need to be available.

Let's add a function that checks for these requirements and prints a
helpful skip message.

Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
Reviewed-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
---
 lib/s390x/snippet.h |  7 +++++++
 lib/s390x/uv.c      | 20 ++++++++++++++++++++
 lib/s390x/uv.h      |  1 +
 s390x/pv-diags.c    |  8 +-------
 4 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/lib/s390x/snippet.h b/lib/s390x/snippet.h
index 57045994..11ec54c3 100644
--- a/lib/s390x/snippet.h
+++ b/lib/s390x/snippet.h
@@ -30,6 +30,13 @@
 #define SNIPPET_HDR_LEN(type, file) \
 	((uintptr_t)SNIPPET_HDR_END(type, file) - (uintptr_t)SNIPPET_HDR_START(type, file))
 
+/*
+ * Some of the UV memory needs to be allocated with >31 bit
+ * addresses which means we need a lot more memory than other
+ * tests.
+ */
+#define SNIPPET_PV_MIN_MEM_SIZE	(SZ_1M * 2200UL)
+
 #define SNIPPET_PV_TWEAK0	0x42UL
 #define SNIPPET_PV_TWEAK1	0UL
 #define SNIPPET_UNPACK_OFF	0
diff --git a/lib/s390x/uv.c b/lib/s390x/uv.c
index 383271a5..4ccb7bde 100644
--- a/lib/s390x/uv.c
+++ b/lib/s390x/uv.c
@@ -18,6 +18,7 @@
 #include <asm/uv.h>
 #include <uv.h>
 #include <sie.h>
+#include <snippet.h>
 
 static struct uv_cb_qui uvcb_qui = {
 	.header.cmd = UVC_CMD_QUI,
@@ -38,6 +39,25 @@ bool uv_os_is_host(void)
 	return test_facility(158) && uv_query_test_call(BIT_UVC_CMD_INIT_UV);
 }
 
+bool uv_host_requirement_checks(void)
+{
+	if (!test_facility(158)) {
+		report_skip("UV Call facility unavailable");
+		return false;
+	}
+	if (!sclp_facilities.has_sief2) {
+		report_skip("SIEF2 facility unavailable");
+		return false;
+	}
+	if (get_ram_size() < SNIPPET_PV_MIN_MEM_SIZE) {
+		report_skip("Not enough memory. This test needs about %ld MB of memory",
+			    SNIPPET_PV_MIN_MEM_SIZE / 1024 / 1024);
+		return false;
+	}
+
+	return true;
+}
+
 bool uv_query_test_call(unsigned int nr)
 {
 	/* Query needs to be called first */
diff --git a/lib/s390x/uv.h b/lib/s390x/uv.h
index 78b979b7..286933ca 100644
--- a/lib/s390x/uv.h
+++ b/lib/s390x/uv.h
@@ -7,6 +7,7 @@
 
 bool uv_os_is_guest(void);
 bool uv_os_is_host(void);
+bool uv_host_requirement_checks(void);
 bool uv_query_test_call(unsigned int nr);
 const struct uv_cb_qui *uv_get_query_data(void);
 void uv_init(void);
diff --git a/s390x/pv-diags.c b/s390x/pv-diags.c
index fa4e5532..3193ad99 100644
--- a/s390x/pv-diags.c
+++ b/s390x/pv-diags.c
@@ -149,14 +149,8 @@ static void test_diag_yield(void)
 int main(void)
 {
 	report_prefix_push("pv-diags");
-	if (!test_facility(158)) {
-		report_skip("UV Call facility unavailable");
+	if (!uv_host_requirement_checks())
 		goto done;
-	}
-	if (!sclp_facilities.has_sief2) {
-		report_skip("SIEF2 facility unavailable");
-		goto done;
-	}
 
 	uv_setup_asces();
 	snippet_setup_guest(&vm, true);
-- 
2.34.1