[kvm-unit-tests PATCH 3/6] s390x: uv: Add UV lib

[Janosch Frank <frankja@xxxxxxxxxxxxx>]

Let's add a UV library to make checking the UV feature bit easier.
In the future this library file can take care of handling UV
initialization and UV guest creation.

Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
---
 lib/s390x/asm/uv.h |  4 ++--
 lib/s390x/io.c     |  2 ++
 lib/s390x/uv.c     | 48 ++++++++++++++++++++++++++++++++++++++++++++++
 lib/s390x/uv.h     | 10 ++++++++++
 s390x/Makefile     |  1 +
 5 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 lib/s390x/uv.c
 create mode 100644 lib/s390x/uv.h

diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
index 11f70a9f..b22cbaa8 100644
--- a/lib/s390x/asm/uv.h
+++ b/lib/s390x/asm/uv.h
@@ -9,8 +9,8 @@
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2.
  */
-#ifndef UV_H
-#define UV_H
+#ifndef ASM_S390X_UV_H
+#define ASM_S390X_UV_H
 
 #define UVC_RC_EXECUTED		0x0001
 #define UVC_RC_INV_CMD		0x0002
diff --git a/lib/s390x/io.c b/lib/s390x/io.c
index ef9f59e3..a4f1b113 100644
--- a/lib/s390x/io.c
+++ b/lib/s390x/io.c
@@ -14,6 +14,7 @@
 #include <asm/facility.h>
 #include <asm/sigp.h>
 #include "sclp.h"
+#include "uv.h"
 #include "smp.h"
 
 extern char ipl_args[];
@@ -38,6 +39,7 @@ void setup(void)
 	sclp_facilities_setup();
 	sclp_console_setup();
 	sclp_memory_setup();
+	uv_setup();
 	smp_setup();
 }
 
diff --git a/lib/s390x/uv.c b/lib/s390x/uv.c
new file mode 100644
index 00000000..a84a85fc
--- /dev/null
+++ b/lib/s390x/uv.c
@@ -0,0 +1,48 @@
+#include <libcflat.h>
+#include <bitops.h>
+#include <alloc.h>
+#include <alloc_page.h>
+#include <asm/page.h>
+#include <asm/arch_def.h>
+
+#include <asm/facility.h>
+#include <asm/uv.h>
+#include <uv.h>
+
+static struct uv_cb_qui uvcb_qui = {
+	.header.cmd = UVC_CMD_QUI,
+	.header.len = sizeof(uvcb_qui),
+};
+
+bool uv_os_is_guest(void)
+{
+	return uv_query_test_feature(BIT_UVC_CMD_SET_SHARED_ACCESS)
+		&& uv_query_test_feature(BIT_UVC_CMD_REMOVE_SHARED_ACCESS);
+}
+
+bool uv_os_is_host(void)
+{
+	return uv_query_test_feature(BIT_UVC_CMD_INIT_UV);
+}
+
+bool uv_query_test_feature(int nr)
+{
+	/* Query needs to be called first */
+	if (!uvcb_qui.header.rc)
+		return false;
+
+	return test_bit_inv(nr, uvcb_qui.inst_calls_list);
+}
+
+int uv_setup(void)
+{
+	int cc;
+
+	if (!test_facility(158))
+		return 0;
+
+	cc = uv_call(0, (u64)&uvcb_qui);
+	assert(cc == 0);
+
+	return cc == 0;
+}
diff --git a/lib/s390x/uv.h b/lib/s390x/uv.h
new file mode 100644
index 00000000..159bf8e5
--- /dev/null
+++ b/lib/s390x/uv.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef UV_H
+#define UV_H
+
+bool uv_os_is_guest(void);
+bool uv_os_is_host(void);
+bool uv_query_test_feature(int nr);
+int uv_setup(void);
+
+#endif /* UV_H */
diff --git a/s390x/Makefile b/s390x/Makefile
index b92de9c5..bbf177fa 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -67,6 +67,7 @@ cflatobjs += lib/s390x/vm.o
 cflatobjs += lib/s390x/css_dump.o
 cflatobjs += lib/s390x/css_lib.o
 cflatobjs += lib/s390x/malloc_io.o
+cflatobjs += lib/s390x/uv.o
 
 OBJDIRS += lib/s390x
 
-- 
2.27.0