diff mbox series

[kvm-unit-tests,v7,7/8] s390x: add a test for SIE without MSO/MSL

Message ID 20231103092954.238491-8-nrb@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: Add support for running guests without MSO/MSL | expand

Commit Message

Nico Boehr Nov. 3, 2023, 9:29 a.m. UTC
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>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 s390x/Makefile             |   2 +
 s390x/sie-dat.c            | 110 +++++++++++++++++++++++++++++++++++++
 s390x/snippets/c/sie-dat.c |  52 ++++++++++++++++++
 s390x/snippets/c/sie-dat.h |   2 +
 s390x/unittests.cfg        |   3 +
 5 files changed, 169 insertions(+)
 create mode 100644 s390x/sie-dat.c
 create mode 100644 s390x/snippets/c/sie-dat.c
 create mode 100644 s390x/snippets/c/sie-dat.h

Comments

Claudio Imbrenda Nov. 3, 2023, 2:12 p.m. UTC | #1
On Fri,  3 Nov 2023 10:29:36 +0100
Nico Boehr <nrb@linux.ibm.com> wrote:

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

[...]

> +	/* 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);

can you also check that the faulting address is the one we expect?

> +	report_prefix_pop();
> +}
> +

[...]

> diff --git a/s390x/snippets/c/sie-dat.c b/s390x/snippets/c/sie-dat.c
> new file mode 100644
> index 000000000000..e07136bf7430
> --- /dev/null
> +++ b/s390x/snippets/c/sie-dat.c
> @@ -0,0 +1,52 @@
> +/* 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_page[GUEST_TEST_PAGE_COUNT * PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));

I would call it test_pages

[...]
Janosch Frank Nov. 3, 2023, 2:16 p.m. UTC | #2
On 11/3/23 10:29, Nico Boehr wrote:
> 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>
> Reviewed-by: Thomas Huth <thuth@redhat.com>

Two small nits below

> +
> +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);
> +
> +	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);
> +	assert(vm.sblk->icptcode == ICPT_INST &&
> +	       (vm.sblk->ipa & 0xff00) == 0x8300 && vm.sblk->ipb == 0x9c0000);

Move the assert right under the sie() call.

> +	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);
> +

[...]

> +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 */

0:guest_max_addr

> +	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);
> +}
> +
Heiko Carstens Nov. 6, 2023, 10:39 a.m. UTC | #3
On Fri, Nov 03, 2023 at 10:29:36AM +0100, Nico Boehr wrote:
> 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>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>  s390x/Makefile             |   2 +
>  s390x/sie-dat.c            | 110 +++++++++++++++++++++++++++++++++++++
>  s390x/snippets/c/sie-dat.c |  52 ++++++++++++++++++
>  s390x/snippets/c/sie-dat.h |   2 +
>  s390x/unittests.cfg        |   3 +
>  5 files changed, 169 insertions(+)
>  create mode 100644 s390x/sie-dat.c
>  create mode 100644 s390x/snippets/c/sie-dat.c
>  create mode 100644 s390x/snippets/c/sie-dat.h
...
> +static uint8_t test_page[GUEST_TEST_PAGE_COUNT * PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
> +
> +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)
> +	);
> +}
> +
> +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 < GUEST_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 *)(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;
> +}

The compiler will not necessarily generate the expected code here, since
there is no data dependency between the used inline assemblies and the
memory locations that are changed. That is: the compiler may move the
inline assemblies and/or memory assignments around.

In order to prevent that you could simply add a compiler barrier to both
inline assemblies (add "memory" to the clobber list).
Nico Boehr Nov. 6, 2023, 3:51 p.m. UTC | #4
Quoting Janosch Frank (2023-11-03 15:16:36)
[...]
> > +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 */
> 
> 0:guest_max_addr

Sorry, I don't get what you mean.
diff mbox series

Patch

diff --git a/s390x/Makefile b/s390x/Makefile
index 947a4344738f..f79fd0098312 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/sie-dat.c b/s390x/sie-dat.c
new file mode 100644
index 000000000000..89e2c4c13db2
--- /dev/null
+++ b/s390x/sie-dat.c
@@ -0,0 +1,110 @@ 
+/* 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);
+
+	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);
+	assert(vm.sblk->icptcode == ICPT_INST &&
+	       (vm.sblk->ipa & 0xff00) == 0x8300 && vm.sblk->ipb == 0x9c0000);
+	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_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..e07136bf7430
--- /dev/null
+++ b/s390x/snippets/c/sie-dat.c
@@ -0,0 +1,52 @@ 
+/* 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_page[GUEST_TEST_PAGE_COUNT * PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+
+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)
+	);
+}
+
+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 < GUEST_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 *)(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/snippets/c/sie-dat.h b/s390x/snippets/c/sie-dat.h
new file mode 100644
index 000000000000..ed3f99f75f9c
--- /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/unittests.cfg b/s390x/unittests.cfg
index 68e119e4fcaa..184658ff7d8d 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -247,3 +247,6 @@  file = topology.elf
 [topology-2]
 file = topology.elf
 extra_params = -cpu max,ctop=on -smp sockets=31,cores=8,maxcpus=248  -append '-sockets 31 -cores 8'
+
+[sie-dat]
+file = sie-dat.elf