[kvm-unit-tests GIT PULL 25/26] s390x: add a test for SIE without MSO/MSL

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

Since we now have the ability to run guests without MSO/MSL, add a test
to make sure this doesn't break.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20231106163738.1116942-8-nrb@linux.ibm.com
[ nrb: __pa -> virt_to_pte_phys to fix incompatiblity with 2g align ]
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 s390x/Makefile             |   2 +
 s390x/snippets/c/sie-dat.h |   2 +
 s390x/sie-dat.c            | 114 +++++++++++++++++++++++++++++++++++++
 s390x/snippets/c/sie-dat.c |  57 +++++++++++++++++++
 s390x/unittests.cfg        |   3 +
 5 files changed, 178 insertions(+)
 create mode 100644 s390x/snippets/c/sie-dat.h
 create mode 100644 s390x/sie-dat.c
 create mode 100644 s390x/snippets/c/sie-dat.c

diff --git a/s390x/Makefile b/s390x/Makefile
index 947a434..f79fd00 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -41,6 +41,7 @@ tests += $(TEST_DIR)/migration-sck.elf
 tests += $(TEST_DIR)/exittime.elf
 tests += $(TEST_DIR)/ex.elf
 tests += $(TEST_DIR)/topology.elf
+tests += $(TEST_DIR)/sie-dat.elf
 
 pv-tests += $(TEST_DIR)/pv-diags.elf
 pv-tests += $(TEST_DIR)/pv-icptcode.elf
@@ -123,6 +124,7 @@ snippet_lib = $(snippet_asmlib) lib/auxinfo.o
 # perquisites (=guests) for the snippet hosts.
 # $(TEST_DIR)/<snippet-host>.elf: snippets = $(SNIPPET_DIR)/<c/asm>/<snippet>.gbin
 $(TEST_DIR)/mvpg-sie.elf: snippets = $(SNIPPET_DIR)/c/mvpg-snippet.gbin
+$(TEST_DIR)/sie-dat.elf: snippets = $(SNIPPET_DIR)/c/sie-dat.gbin
 $(TEST_DIR)/spec_ex-sie.elf: snippets = $(SNIPPET_DIR)/c/spec_ex.gbin
 
 $(TEST_DIR)/pv-diags.elf: pv-snippets += $(SNIPPET_DIR)/asm/pv-diag-yield.gbin
diff --git a/s390x/snippets/c/sie-dat.h b/s390x/snippets/c/sie-dat.h
new file mode 100644
index 0000000..ed3f99f
--- /dev/null
+++ b/s390x/snippets/c/sie-dat.h
@@ -0,0 +1,2 @@
+#define GUEST_TEST_PAGE_COUNT 10
+#define GUEST_TOTAL_PAGE_COUNT 256
diff --git a/s390x/sie-dat.c b/s390x/sie-dat.c
new file mode 100644
index 0000000..f025777
--- /dev/null
+++ b/s390x/sie-dat.c
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Tests SIE with paging.
+ *
+ * Copyright 2023 IBM Corp.
+ *
+ * Authors:
+ *    Nico Boehr <nrb@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <vmalloc.h>
+#include <asm/pgtable.h>
+#include <mmu.h>
+#include <asm/page.h>
+#include <asm/interrupt.h>
+#include <alloc_page.h>
+#include <sclp.h>
+#include <sie.h>
+#include <snippet.h>
+#include "snippets/c/sie-dat.h"
+
+static struct vm vm;
+static pgd_t *guest_root;
+
+static void test_sie_dat(void)
+{
+	uint64_t test_page_gpa, test_page_hpa;
+	uint8_t *test_page_hva, expected_val;
+	bool contents_match;
+	uint8_t r1;
+
+	/* guest will tell us the guest physical address of the test buffer */
+	sie(&vm);
+	assert(vm.sblk->icptcode == ICPT_INST &&
+	       (vm.sblk->ipa & 0xff00) == 0x8300 && vm.sblk->ipb == 0x9c0000);
+
+	r1 = (vm.sblk->ipa & 0xf0) >> 4;
+	test_page_gpa = vm.save_area.guest.grs[r1];
+	test_page_hpa = virt_to_pte_phys(guest_root, (void*)test_page_gpa);
+	test_page_hva = __va(test_page_hpa);
+	report_info("test buffer gpa=0x%lx hva=%p", test_page_gpa, test_page_hva);
+
+	/* guest will now write to the test buffer and we verify the contents */
+	sie(&vm);
+	assert(vm.sblk->icptcode == ICPT_INST &&
+	       vm.sblk->ipa == 0x8300 && vm.sblk->ipb == 0x440000);
+
+	contents_match = true;
+	for (unsigned int i = 0; i < GUEST_TEST_PAGE_COUNT; i++) {
+		expected_val = 42 + i;
+		if (test_page_hva[i * PAGE_SIZE] != expected_val) {
+			report_fail("page %u mismatch actual_val=%x expected_val=%x",
+				    i, test_page_hva[i], expected_val);
+			contents_match = false;
+		}
+	}
+	report(contents_match, "test buffer contents match");
+
+	/* the guest will now write to an unmapped address and we check that this causes a segment translation exception */
+	report_prefix_push("guest write to unmapped");
+	expect_pgm_int();
+	sie(&vm);
+	check_pgm_int_code(PGM_INT_CODE_SEGMENT_TRANSLATION);
+	report((lowcore.trans_exc_id & PAGE_MASK) == (GUEST_TOTAL_PAGE_COUNT * PAGE_SIZE), "TEID address match");
+	report_prefix_pop();
+}
+
+static void setup_guest(void)
+{
+	extern const char SNIPPET_NAME_START(c, sie_dat)[];
+	extern const char SNIPPET_NAME_END(c, sie_dat)[];
+	uint64_t guest_max_addr;
+	pgd_t *root;
+
+	setup_vm();
+	root = (pgd_t *)(stctg(1) & PAGE_MASK);
+
+	snippet_setup_guest(&vm, false);
+
+	/* allocate a region-1 table */
+	guest_root = pgd_alloc_one();
+
+	/* map guest memory 1:1 */
+	guest_max_addr = GUEST_TOTAL_PAGE_COUNT * PAGE_SIZE;
+	for (uint64_t i = 0; i < guest_max_addr; i += PAGE_SIZE)
+		install_page(guest_root, virt_to_pte_phys(root, vm.guest_mem + i), (void *)i);
+
+	/* set up storage limit supression - leave mso and msl intact they are ignored anyways */
+	vm.sblk->cpuflags |= CPUSTAT_SM;
+
+	/* set up the guest asce */
+	vm.save_area.guest.asce = __pa(guest_root) | ASCE_DT_REGION1 | REGION_TABLE_LENGTH;
+
+	snippet_init(&vm, SNIPPET_NAME_START(c, sie_dat),
+		     SNIPPET_LEN(c, sie_dat), SNIPPET_UNPACK_OFF);
+}
+
+int main(void)
+{
+	report_prefix_push("sie-dat");
+	if (!sclp_facilities.has_sief2) {
+		report_skip("SIEF2 facility unavailable");
+		goto done;
+	}
+
+	setup_guest();
+	test_sie_dat();
+	sie_guest_destroy(&vm);
+
+done:
+	report_prefix_pop();
+	return report_summary();
+
+}
diff --git a/s390x/snippets/c/sie-dat.c b/s390x/snippets/c/sie-dat.c
new file mode 100644
index 0000000..ecfcb60
--- /dev/null
+++ b/s390x/snippets/c/sie-dat.c
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Snippet used by the sie-dat.c test to verify paging without MSO/MSL
+ *
+ * Copyright (c) 2023 IBM Corp
+ *
+ * Authors:
+ *  Nico Boehr <nrb@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <asm-generic/page.h>
+#include "sie-dat.h"
+
+static uint8_t test_pages[GUEST_TEST_PAGE_COUNT * PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+
+static inline void force_exit(void)
+{
+	asm volatile("diag	0,0,0x44\n"
+		     :
+		     :
+		     : "memory"
+	);
+}
+
+static inline void force_exit_value(uint64_t val)
+{
+	asm volatile("diag	%[val],0,0x9c\n"
+		     :
+		     : [val] "d"(val)
+		     : "memory"
+	);
+}
+
+int main(void)
+{
+	uint8_t *invalid_ptr;
+
+	memset(test_pages, 0, sizeof(test_pages));
+	/* tell the host the page's physical address (we're running DAT off) */
+	force_exit_value((uint64_t)test_pages);
+
+	/* write some value to the page so the host can verify it */
+	for (size_t i = 0; i < GUEST_TEST_PAGE_COUNT; i++)
+		test_pages[i * PAGE_SIZE] = 42 + i;
+
+	/* indicate we've written all pages */
+	force_exit();
+
+	/* the first unmapped address */
+	invalid_ptr = (uint8_t *)(GUEST_TOTAL_PAGE_COUNT * PAGE_SIZE);
+	*invalid_ptr = 42;
+
+	/* indicate we've written the non-allowed page (should never get here) */
+	force_exit();
+
+	return 0;
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index b08b0fb..f5024b6 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -380,3 +380,6 @@ extra_params = """-cpu max,ctop=on -smp cpus=1,drawers=2,books=2,sockets=2,cores
 -device max-s390x-cpu,core-id=97,drawer-id=1,book-id=1,socket-id=1,entitlement=high,dedicated=true \
 -device max-s390x-cpu,core-id=111,drawer-id=1,book-id=1,socket-id=1,entitlement=medium,dedicated=false \
 """
+
+[sie-dat]
+file = sie-dat.elf
-- 
2.41.0