[kvm-unit-tests PATCH v3 6/6] s390x: add a test for SIE without MSO/MSL

Nico Boehr
2023-06-01T07:02:35Z

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

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
s390x/Makefile | 2 +
s390x/sie-dat.c | 120 +++++++++++++++++++++++++++++++++++++
s390x/snippets/c/sie-dat.c | 58 ++++++++++++++++++
s390x/unittests.cfg | 3 +
4 files changed, 183 insertions(+)
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 a80db538810e..4921669ee4c3 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -40,6 +40,7 @@ tests += $(TEST_DIR)/panic-loop-pgm.elf
tests += $(TEST_DIR)/migration-sck.elf
tests += $(TEST_DIR)/exittime.elf
tests += $(TEST_DIR)/ex.elf
+tests += $(TEST_DIR)/sie-dat.elf

pv-tests += $(TEST_DIR)/pv-diags.elf

@@ -120,6 +121,7 @@ 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/snippet-pv-diag-yield.gbin
diff --git a/s390x/sie-dat.c b/s390x/sie-dat.c
new file mode 100644
index 000000000000..c490a2aa825c
--- /dev/null
+++ b/s390x/sie-dat.c
@@ -0,0 +1,120 @@
+/* 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/asm-offsets.h>
+#include <asm-generic/barrier.h>
+#include <asm/pgtable.h>
+#include <mmu.h>
+#include <asm/page.h>
+#include <asm/facility.h>
+#include <asm/interrupt.h>
+#include <asm/mem.h>
+#include <alloc_page.h>
+#include <sclp.h>
+#include <sie.h>
+#include <snippet.h>
+
+static struct vm vm;
+static pgd_t *guest_root;
+
+/* keep in sync with TEST_PAGE_COUNT in s390x/snippets/c/sie-dat.c */
+#define GUEST_TEST_PAGE_COUNT 10
+
+/* keep in sync with TOTAL_PAGE_COUNT in s390x/snippets/c/sie-dat.c */
+#define GUEST_TOTAL_PAGE_COUNT 256
+
+static void test_sie_dat(void)
+{
+ uint8_t r1;
+ bool contents_match;
+ uint64_t test_page_gpa, test_page_hpa;
+ uint8_t *test_page_hva;
+
+ /* guest will tell us the guest physical address of the test buffer */
+ sie(&vm);
+
+ 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(vm.sblk->icptcode == ICPT_INST &&
+ (vm.sblk->ipa & 0xFF00) == 0x8300 && vm.sblk->ipb == 0x9c0000,
+ "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);
+ report(vm.sblk->icptcode == ICPT_INST &&
+ vm.sblk->ipa == 0x8300 && vm.sblk->ipb == 0x440000,
+ "guest wrote to test buffer");
+
+ contents_match = true;
+ for (unsigned int i = 0; i < GUEST_TEST_PAGE_COUNT; i++) {
+ uint8_t 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_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;
+
+ setup_vm();
+ 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, __pa(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 000000000000..e156d0c36c4c
--- /dev/null
+++ b/s390x/snippets/c/sie-dat.c
@@ -0,0 +1,58 @@
+/* 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 <stddef.h>
+#include <inttypes.h>
+#include <string.h>
+#include <asm-generic/page.h>
+
+/* keep in sync with GUEST_TEST_PAGE_COUNT in s390x/sie-dat.c */
+#define TEST_PAGE_COUNT 10
+static uint8_t test_page[TEST_PAGE_COUNT * PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+
+/* keep in sync with GUEST_TOTAL_PAGE_COUNT in s390x/sie-dat.c */
+#define TOTAL_PAGE_COUNT 256
+
+static inline void force_exit(void)
+{
+ asm volatile("diag 0,0,0x44\n");
+}
+
+static inline void force_exit_value(uint64_t val)
+{
+ asm volatile(
+ "diag %[val],0,0x9c\n"
+ : : [val] "d"(val)
+ );
+}
+
+__attribute__((section(".text"))) int main(void)
+{
+ uint8_t *invalid_ptr;
+
+ memset(test_page, 0, sizeof(test_page));
+ /* tell the host the page's physical address (we're running DAT off) */
+ force_exit_value((uint64_t)test_page);
+
+ /* write some value to the page so the host can verify it */
+ for (size_t i = 0; i < TEST_PAGE_COUNT; i++)
+ test_page[i * PAGE_SIZE] = 42 + i;
+
+ /* indicate we've written all pages */
+ force_exit();
+
+ /* the first unmapped address */
+ invalid_ptr = (uint8_t *)(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 b61faf0737c3..24cd27202a08 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -218,3 +218,6 @@ extra_params = -append '--parallel'

[execute]
file = ex.elf
+
+[sie-dat]
+file = sie-dat.elf
--
2.39.1