diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
new file mode 100644
index 0000000..14ab5cc
--- /dev/null
+++ b/lib/s390x/asm/uv.h
@@ -0,0 +1,68 @@
+/*
+ * s390x Ultravisor related definitions
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ *
+ * 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
+
+#define UVC_RC_EXECUTED		0x0001
+#define UVC_RC_INV_CMD		0x0002
+#define UVC_RC_INV_STATE	0x0003
+#define UVC_RC_INV_LEN		0x0005
+#define UVC_RC_NO_RESUME	0x0007
+
+#define UVC_CMD_QUI			0x0001
+#define UVC_CMD_SET_SHARED_ACCESS	0x1000
+#define UVC_CMD_REMOVE_SHARED_ACCESS	0x1001
+
+/* Bits in installed uv calls */
+enum uv_cmds_inst {
+	BIT_UVC_CMD_QUI = 0,
+	BIT_UVC_CMD_SET_SHARED_ACCESS = 8,
+	BIT_UVC_CMD_REMOVE_SHARED_ACCESS = 9,
+};
+
+struct uv_cb_header {
+	u16 len;
+	u16 cmd;	/* Command Code */
+	u16 rc;		/* Response Code */
+	u16 rrc;	/* Return Reason Code */
+} __attribute__((packed))  __attribute__((aligned(8)));
+
+struct uv_cb_qui {
+	struct uv_cb_header header;
+	u64 reserved08;
+	u64 inst_calls_list[4];
+	u64 reserved30[15];
+} __attribute__((packed))  __attribute__((aligned(8)));
+
+struct uv_cb_share {
+	struct uv_cb_header header;
+	u64 reserved08[3];
+	u64 paddr;
+	u64 reserved28;
+} __attribute__((packed))  __attribute__((aligned(8)));
+
+static inline int uv_call(unsigned long r1, unsigned long r2)
+{
+	int cc;
+
+	asm volatile(
+		"0:	.insn rrf,0xB9A40000,%[r1],%[r2],0,0\n"
+		"		brc	3,0b\n"
+		"		ipm	%[cc]\n"
+		"		srl	%[cc],28\n"
+		: [cc] "=d" (cc)
+		: [r1] "a" (r1), [r2] "a" (r2)
+		: "memory", "cc");
+	return cc;
+}
+
+#endif
diff --git a/s390x/Makefile b/s390x/Makefile
index 0f54bf4..c2213ad 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -18,6 +18,7 @@ tests += $(TEST_DIR)/skrf.elf
 tests += $(TEST_DIR)/smp.elf
 tests += $(TEST_DIR)/sclp.elf
 tests += $(TEST_DIR)/css.elf
+tests += $(TEST_DIR)/uv-guest.elf
 tests_binary = $(patsubst %.elf,%.bin,$(tests))
 
 all: directories test_cases test_cases_binary
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index b35269b..6d50c63 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -92,3 +92,6 @@ extra_params = -device virtio-net-ccw
 [skrf]
 file = skrf.elf
 smp = 2
+
+[uv-guest]
+file = uv-guest.elf
diff --git a/s390x/uv-guest.c b/s390x/uv-guest.c
new file mode 100644
index 0000000..15720a9
--- /dev/null
+++ b/s390x/uv-guest.c
@@ -0,0 +1,159 @@
+/*
+ * Guest Ultravisor Call tests
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <libcflat.h>
+#include <alloc_page.h>
+#include <asm/page.h>
+#include <asm/asm-offsets.h>
+#include <asm/interrupt.h>
+#include <asm/facility.h>
+#include <asm/uv.h>
+
+static unsigned long page;
+
+static inline int share(unsigned long addr, u16 cmd)
+{
+	struct uv_cb_share uvcb = {
+		.header.cmd = cmd,
+		.header.len = sizeof(uvcb),
+		.paddr = addr
+	};
+
+	uv_call(0, (u64)&uvcb);
+	return uvcb.header.rc;
+}
+
+static inline int uv_set_shared(unsigned long addr)
+{
+	return share(addr, UVC_CMD_SET_SHARED_ACCESS);
+}
+
+static inline int uv_remove_shared(unsigned long addr)
+{
+	return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS);
+}
+
+static void test_priv(void)
+{
+	struct uv_cb_header uvcb = {};
+
+	report_prefix_push("privileged");
+
+	report_prefix_push("query");
+	expect_pgm_int();
+	uvcb.cmd = UVC_CMD_QUI;
+	uvcb.len = sizeof(struct uv_cb_qui);
+	enter_pstate();
+	uv_call(0, (u64)&uvcb);
+	check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
+	report_prefix_pop();
+
+	report_prefix_push("share");
+	expect_pgm_int();
+	enter_pstate();
+	uv_set_shared((unsigned long)page);
+	check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
+	report_prefix_pop();
+
+	report_prefix_push("unshare");
+	expect_pgm_int();
+	enter_pstate();
+	uv_remove_shared((unsigned long)page);
+	check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
+	report_prefix_pop();
+
+	report_prefix_pop();
+}
+
+static void test_query(void)
+{
+	struct uv_cb_qui uvcb = {
+		.header.cmd = UVC_CMD_QUI,
+		.header.len = sizeof(uvcb) - 8,
+	};
+
+	report_prefix_push("query");
+	uv_call(0, (u64)&uvcb);
+	report(uvcb.header.rc == UVC_RC_INV_LEN, "length");
+
+	uvcb.header.len = sizeof(uvcb);
+	uv_call(0, (u64)&uvcb);
+	report(uvcb.header.rc == UVC_RC_EXECUTED, "successful query");
+
+	/*
+	 * These bits have been introduced with the very first
+	 * Ultravisor version and are expected to always be available
+	 * because they are basic building blocks.
+	 */
+	report(uvcb.inst_calls_list[0] & (1UL << (63 - BIT_UVC_CMD_QUI)),
+	       "query indicated");
+	report(uvcb.inst_calls_list[0] & (1UL << (63 - BIT_UVC_CMD_SET_SHARED_ACCESS)),
+	       "share indicated");
+	report(uvcb.inst_calls_list[0] & (1UL << (63 - BIT_UVC_CMD_REMOVE_SHARED_ACCESS)),
+	       "unshare indicated");
+	report_prefix_pop();
+}
+
+static void test_sharing(void)
+{
+	struct uv_cb_share uvcb = {
+		.header.cmd = UVC_CMD_SET_SHARED_ACCESS,
+		.header.len = sizeof(uvcb) - 8,
+	};
+
+	report_prefix_push("share");
+	uv_call(0, (u64)&uvcb);
+	report(uvcb.header.rc == UVC_RC_INV_LEN, "length");
+	report(uv_set_shared(page) == UVC_RC_EXECUTED, "share");
+	report_prefix_pop();
+
+	report_prefix_push("unshare");
+	uvcb.header.cmd = UVC_CMD_REMOVE_SHARED_ACCESS;
+	uv_call(0, (u64)&uvcb);
+	report(uvcb.header.rc == UVC_RC_INV_LEN, "length");
+	report(uv_remove_shared(page) == UVC_RC_EXECUTED, "unshare");
+	report_prefix_pop();
+
+	report_prefix_pop();
+}
+
+static void test_invalid(void)
+{
+	struct uv_cb_header uvcb = {
+		.len = 16,
+		.cmd = 0x4242,
+	};
+
+	uv_call(0, (u64)&uvcb);
+	report(uvcb.rc == UVC_RC_INV_CMD, "invalid command");
+}
+
+int main(void)
+{
+	bool has_uvc = test_facility(158);
+
+	report_prefix_push("uvc");
+	if (!has_uvc) {
+		report_skip("Ultravisor call facility is not available");
+		goto done;
+	}
+
+	page = (unsigned long)alloc_page();
+	test_priv();
+	test_invalid();
+	test_query();
+	test_sharing();
+	free_page((void *)page);
+done:
+	report_prefix_pop();
+	return report_summary();
+}
