[kvm-unit-tests PATCH v5 7/8] s390x: pv: Add IPL reset tests

[Janosch Frank <frankja@linux.ibm.com>]

The diag308 requires extensive cooperation between the hypervisor and
the Ultravisor so the Ultravisor can make sure all necessary reset
steps have been done.

Let's check if we get the correct validity errors.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
---
 s390x/Makefile                   |   2 +
 s390x/pv-ipl.c                   | 143 +++++++++++++++++++++++++++++++
 s390x/snippets/asm/pv-diag-308.S |  51 +++++++++++
 s390x/unittests.cfg              |   5 ++
 4 files changed, 201 insertions(+)
 create mode 100644 s390x/pv-ipl.c
 create mode 100644 s390x/snippets/asm/pv-diag-308.S

diff --git a/s390x/Makefile b/s390x/Makefile
index 67be5360..b5b94810 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -43,6 +43,7 @@ tests += $(TEST_DIR)/ex.elf
 
 pv-tests += $(TEST_DIR)/pv-diags.elf
 pv-tests += $(TEST_DIR)/pv-icptcode.elf
+pv-tests += $(TEST_DIR)/pv-ipl.elf
 
 ifneq ($(HOST_KEY_DOCUMENT),)
 ifneq ($(GEN_SE_HEADER),)
@@ -130,6 +131,7 @@ $(TEST_DIR)/pv-icptcode.elf: pv-snippets += $(SNIPPET_DIR)/asm/pv-icpt-112.gbin
 $(TEST_DIR)/pv-icptcode.elf: pv-snippets += $(SNIPPET_DIR)/asm/icpt-loop.gbin
 $(TEST_DIR)/pv-icptcode.elf: pv-snippets += $(SNIPPET_DIR)/asm/loop.gbin
 $(TEST_DIR)/pv-icptcode.elf: pv-snippets += $(SNIPPET_DIR)/asm/pv-icpt-vir-timing.gbin
+$(TEST_DIR)/pv-ipl.elf: pv-snippets += $(SNIPPET_DIR)/asm/pv-diag-308.gbin
 
 ifneq ($(GEN_SE_HEADER),)
 snippets += $(pv-snippets)
diff --git a/s390x/pv-ipl.c b/s390x/pv-ipl.c
new file mode 100644
index 00000000..cc46e7f7
--- /dev/null
+++ b/s390x/pv-ipl.c
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * PV diagnose 308 (IPL) tests
+ *
+ * Copyright (c) 2023 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <sie.h>
+#include <sclp.h>
+#include <snippet.h>
+#include <pv_icptdata.h>
+#include <asm/facility.h>
+#include <asm/uv.h>
+
+static struct vm vm;
+
+static void test_diag_308(int subcode)
+{
+	extern const char SNIPPET_NAME_START(asm, pv_diag_308)[];
+	extern const char SNIPPET_NAME_END(asm, pv_diag_308)[];
+	extern const char SNIPPET_HDR_START(asm, pv_diag_308)[];
+	extern const char SNIPPET_HDR_END(asm, pv_diag_308)[];
+	int size_hdr = SNIPPET_HDR_LEN(asm, pv_diag_308);
+	int size_gbin = SNIPPET_LEN(asm, pv_diag_308);
+	uint16_t rc, rrc;
+	int cc;
+
+	report_prefix_pushf("subcode %d", subcode);
+	snippet_pv_init(&vm, SNIPPET_NAME_START(asm, pv_diag_308),
+			SNIPPET_HDR_START(asm, pv_diag_308),
+			size_gbin, size_hdr, SNIPPET_UNPACK_OFF);
+
+	/* First exit is a diag 0x500 */
+	sie(&vm);
+	assert(pv_icptdata_check_diag(&vm, 0x500));
+
+	/*
+	 * The snippet asked us for the subcode and we answer by
+	 * putting the value in gr2.
+	 * SIE will copy gr2 to the guest
+	 */
+	vm.save_area.guest.grs[2] = subcode;
+
+	/* Continue after diag 0x500, next icpt should be the 0x308 */
+	sie(&vm);
+	assert(pv_icptdata_check_diag(&vm, 0x308));
+	assert(vm.save_area.guest.grs[2] == subcode);
+
+	/*
+	 * We need to perform several UV calls to emulate the subcode
+	 * 0/1. Failing to do that should result in a validity.
+	 *
+	 * - Mark all cpus as stopped
+	 * - Unshare all memory
+	 * - Prepare the reset
+	 * - Reset the cpus
+	 * - Load the reset PSW
+	 */
+	sie_expect_validity(&vm);
+	sie(&vm);
+	report(uv_validity_check(&vm), "validity, no action");
+
+	/* Mark the CPU as stopped so we can unshare and reset */
+	cc = uv_set_cpu_state(vm.sblk->pv_handle_cpu, PV_CPU_STATE_STP);
+	report(!cc, "Set cpu stopped");
+
+	sie_expect_validity(&vm);
+	sie(&vm);
+	report(uv_validity_check(&vm), "validity, stopped");
+
+	/* Unshare all memory */
+	cc = uv_cmd_nodata(vm.sblk->pv_handle_config,
+			   UVC_CMD_SET_UNSHARED_ALL, &rc, &rrc);
+	report(cc == 0 && rc == 1, "Unshare all");
+
+	sie_expect_validity(&vm);
+	sie(&vm);
+	report(uv_validity_check(&vm), "validity, stopped, unshared");
+
+	/* Prepare the CPU reset */
+	cc = uv_cmd_nodata(vm.sblk->pv_handle_config,
+			   UVC_CMD_PREPARE_RESET, &rc, &rrc);
+	report(cc == 0 && rc == 1, "Prepare reset call");
+
+	sie_expect_validity(&vm);
+	sie(&vm);
+	report(uv_validity_check(&vm), "validity, stopped, unshared, prep reset");
+
+	/*
+	 * Do the reset on the initiating cpu
+	 *
+	 * Reset clear for subcode 0
+	 * Reset initial for subcode 1
+	 */
+	if (subcode == 0) {
+		cc = uv_cmd_nodata(vm.sblk->pv_handle_cpu,
+				   UVC_CMD_CPU_RESET_CLEAR, &rc, &rrc);
+		report(cc == 0 && rc == 1, "Clear reset cpu");
+	} else {
+		cc = uv_cmd_nodata(vm.sblk->pv_handle_cpu,
+				   UVC_CMD_CPU_RESET_INITIAL, &rc, &rrc);
+		report(cc == 0 && rc == 1, "Initial reset cpu");
+	}
+
+	sie_expect_validity(&vm);
+	sie(&vm);
+	report(uv_validity_check(&vm), "validity, stopped, unshared, prep reset, cpu reset");
+
+	/* Load the PSW from 0x0 */
+	cc = uv_set_cpu_state(vm.sblk->pv_handle_cpu, PV_CPU_STATE_OPR_LOAD);
+	report(!cc, "Set cpu load");
+
+	/*
+	 * Check if we executed the iaddr of the reset PSW, we should
+	 * see a diagnose 0x9c PV instruction notification.
+	 */
+	sie(&vm);
+	report(pv_icptdata_check_diag(&vm, 0x9c) &&
+	       vm.save_area.guest.grs[0] == 42,
+	       "continue after load");
+
+	uv_destroy_guest(&vm);
+	report_prefix_pop();
+}
+
+int main(void)
+{
+	report_prefix_push("uv-sie");
+	if (!uv_host_requirement_checks())
+		goto done;
+
+	snippet_setup_guest(&vm, true);
+	test_diag_308(0);
+	test_diag_308(1);
+	sie_guest_destroy(&vm);
+
+done:
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/snippets/asm/pv-diag-308.S b/s390x/snippets/asm/pv-diag-308.S
new file mode 100644
index 00000000..70aea589
--- /dev/null
+++ b/s390x/snippets/asm/pv-diag-308.S
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Diagnose 0x308 snippet used for PV IPL and reset testing
+ *
+ * Copyright (c) 2023 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ */
+#include <asm/asm-offsets.h>
+.section .text
+
+/*
+ * Entry
+ * Execute the diag500 which will set the diag 308 subcode in gr2
+ */
+diag	0, 0, 0x500
+
+/*
+ * A valid PGM new PSW can be a real problem since we never fall out
+ * of SIE and therefore effectively loop forever. 0 is a valid PSW
+ * therefore we re-use the reset_psw as this has the short PSW
+ * bit set which is invalid for a long PSW like the exception new
+ * PSWs.
+ *
+ * For subcode 0/1 there are no PGMs to consider.
+ */
+lgrl   %r5, reset_psw
+stg    %r5, GEN_LC_PGM_NEW_PSW
+
+/* Set up the reset psw at 0x0 */
+lgrl	%r5, reset_psw
+larl	%r6, done
+ogr	%r5, %r6
+stg	%r5, 0
+
+/* Diag 308, subcode is in gr2 */
+diag	%r0, %r2, 0x308
+
+/* Should never be executed because of the reset PSW */
+diag	0, 0, 0x44
+
+/* Pass on a special value indicating success */
+done:
+lghi	%r1, 42
+diag	%r1, 0, 0x9c
+
+
+	.align	8
+reset_psw:
+	.quad	0x0008000180000000
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index df25b483..26bab34a 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -224,3 +224,8 @@ file = pv-icptcode.elf
 smp = 3
 groups = pv-host
 extra_params = -m 2200
+
+[pv-ipl]
+file = pv-ipl.elf
+groups = pv-host
+extra_params = -m 2200
-- 
2.34.1