[kvm-unit-tests PATCH v3 0/3] s390x: pv: Add test for large host pages backing

[kvm-unit-tests PATCH v3 0/3] s390x: pv: Add test for large host pages backing

[Claudio Imbrenda]

Add a new test to check that the host can use 1M large pages to back
protected guests when the corresponding feature is present.

v2->v3
* remove pointless timing measurements
* add two missing patches (oops!)
* minor fixes (thanks Christoph)

Claudio Imbrenda (3):
  lib: s390: add ptlb wrapper
  lib: s390x: add function to test available UV features
  s390x: pv: Add test for large host pages backing

 s390x/Makefile               |   2 +
 lib/s390x/asm/arch_def.h     |   1 +
 lib/s390x/asm/pgtable.h      |   5 +
 lib/s390x/asm/uv.h           |  18 ++
 lib/s390x/uv.h               |   1 +
 lib/s390x/uv.c               |   9 +
 s390x/pv-edat1.c             | 387 +++++++++++++++++++++++++++++++++++
 s390x/snippets/c/pv-memhog.c |  59 ++++++
 8 files changed, 482 insertions(+)
 create mode 100644 s390x/pv-edat1.c
 create mode 100644 s390x/snippets/c/pv-memhog.c

-- 
2.47.1

[kvm-unit-tests PATCH v3 1/3] lib: s390: add ptlb wrapper

[Claudio Imbrenda]

Add wrapper function for the Purge TLB instruction.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/asm/pgtable.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/s390x/asm/pgtable.h b/lib/s390x/asm/pgtable.h
index 7b556ad9..fcb30a1e 100644
--- a/lib/s390x/asm/pgtable.h
+++ b/lib/s390x/asm/pgtable.h
@@ -247,4 +247,9 @@ static inline void idte_pgdp(unsigned long vaddr, pgdval_t *pgdp)
 	idte((unsigned long)(pgdp - pgd_index(vaddr)) | ASCE_DT_REGION1, vaddr);
 }
 
+static inline void ptlb(void)
+{
+	asm volatile("ptlb" : : : "memory");
+}
+
 #endif /* _ASMS390X_PGTABLE_H_ */
-- 
2.47.1

[kvm-unit-tests PATCH v3 2/3] lib: s390x: add function to test available UV features

[Claudio Imbrenda]

Add uv_query_test_feature(), to test specific bits in the
uv_feature_indications bitmask, similar to uv_query_test_call().

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/uv.h | 1 +
 lib/s390x/uv.c | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/lib/s390x/uv.h b/lib/s390x/uv.h
index 00a37041..b0fbc478 100644
--- a/lib/s390x/uv.h
+++ b/lib/s390x/uv.h
@@ -10,6 +10,7 @@ bool uv_os_is_guest(void);
 bool uv_os_is_host(void);
 bool uv_host_requirement_checks(void);
 bool uv_query_test_call(unsigned int nr);
+bool uv_query_test_feature(unsigned int nr);
 const struct uv_cb_qui *uv_get_query_data(void);
 void uv_init(void);
 int uv_setup(void);
diff --git a/lib/s390x/uv.c b/lib/s390x/uv.c
index 723bb4f2..03499272 100644
--- a/lib/s390x/uv.c
+++ b/lib/s390x/uv.c
@@ -67,6 +67,15 @@ bool uv_query_test_call(unsigned int nr)
 	return test_bit_inv(nr, uvcb_qui.inst_calls_list);
 }
 
+bool uv_query_test_feature(unsigned int nr)
+{
+	/* Query needs to be called first */
+	assert(uvcb_qui.header.rc);
+	assert(nr < BITS_PER_LONG);
+
+	return test_bit_inv(nr, &uvcb_qui.uv_feature_indications);
+}
+
 const struct uv_cb_qui *uv_get_query_data(void)
 {
 	/* Query needs to be called first */
-- 
2.47.1

[kvm-unit-tests PATCH v3 3/3] s390x: pv: Add test for large host pages backing

[Claudio Imbrenda]

Add a new test to check that the host can use 1M large pages to back
protected guests when the corresponding feature is present.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/Makefile               |   2 +
 lib/s390x/asm/arch_def.h     |   1 +
 lib/s390x/asm/uv.h           |  18 ++
 s390x/pv-edat1.c             | 387 +++++++++++++++++++++++++++++++++++
 s390x/snippets/c/pv-memhog.c |  59 ++++++
 5 files changed, 467 insertions(+)
 create mode 100644 s390x/pv-edat1.c
 create mode 100644 s390x/snippets/c/pv-memhog.c

diff --git a/s390x/Makefile b/s390x/Makefile
index 23342bd6..c5c6f92c 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -48,6 +48,7 @@ tests += $(TEST_DIR)/sie-dat.elf
 pv-tests += $(TEST_DIR)/pv-diags.elf
 pv-tests += $(TEST_DIR)/pv-icptcode.elf
 pv-tests += $(TEST_DIR)/pv-ipl.elf
+pv-tests += $(TEST_DIR)/pv-edat1.elf
 
 ifneq ($(HOST_KEY_DOCUMENT),)
 ifneq ($(GEN_SE_HEADER),)
@@ -137,6 +138,7 @@ $(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 += $(SNIPPET_DIR)/asm/pv-diag-308.gbin
+$(TEST_DIR)/pv-edat1.elf: pv-snippets += $(SNIPPET_DIR)/c/pv-memhog.gbin
 
 ifneq ($(GEN_SE_HEADER),)
 snippets += $(pv-snippets)
diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 745a3387..481ede8f 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -249,6 +249,7 @@ extern struct lowcore lowcore;
 #define PGM_INT_CODE_REGION_FIRST_TRANS		0x39
 #define PGM_INT_CODE_REGION_SECOND_TRANS	0x3a
 #define PGM_INT_CODE_REGION_THIRD_TRANS		0x3b
+#define PGM_INT_CODE_SECURE_PAGE_SIZE		0x3c
 #define PGM_INT_CODE_SECURE_STOR_ACCESS		0x3d
 #define PGM_INT_CODE_NON_SECURE_STOR_ACCESS	0x3e
 #define PGM_INT_CODE_SECURE_STOR_VIOLATION	0x3f
diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
index 611dcd3f..7527be48 100644
--- a/lib/s390x/asm/uv.h
+++ b/lib/s390x/asm/uv.h
@@ -35,6 +35,7 @@
 #define UVC_CMD_CONV_TO_SEC_STOR	0x0200
 #define UVC_CMD_CONV_FROM_SEC_STOR	0x0201
 #define UVC_CMD_DESTR_SEC_STOR		0x0202
+#define UVC_CMD_VERIFY_LARGE_FRAME	0x0203
 #define UVC_CMD_SET_SEC_CONF_PARAMS	0x0300
 #define UVC_CMD_UNPACK_IMG		0x0301
 #define UVC_CMD_VERIFY_IMG		0x0302
@@ -74,6 +75,11 @@ enum uv_cmds_inst {
 	BIT_UVC_CMD_PIN_PAGE_SHARED = 21,
 	BIT_UVC_CMD_UNPIN_PAGE_SHARED = 22,
 	BIT_UVC_CMD_ATTESTATION = 28,
+	BIT_UVC_CMD_VERIFY_LARGE_FRAME = 32,
+};
+
+enum uv_features {
+	BIT_UV_1M_BACKING = 6,
 };
 
 struct uv_cb_header {
@@ -312,6 +318,18 @@ static inline int uv_import(uint64_t handle, unsigned long gaddr)
 	return uv_call(0, (uint64_t)&uvcb);
 }
 
+static inline int uv_merge(uint64_t handle, unsigned long gaddr)
+{
+	struct uv_cb_cts uvcb = {
+		.header.cmd = UVC_CMD_VERIFY_LARGE_FRAME,
+		.header.len = sizeof(uvcb),
+		.guest_handle = handle,
+		.gaddr = gaddr,
+	};
+
+	return uv_call(0, (uint64_t)&uvcb);
+}
+
 static inline int uv_export(unsigned long paddr)
 {
 	struct uv_cb_cfs uvcb = {
diff --git a/s390x/pv-edat1.c b/s390x/pv-edat1.c
new file mode 100644
index 00000000..3f96c716
--- /dev/null
+++ b/s390x/pv-edat1.c
@@ -0,0 +1,387 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * PV huge page backing tests
+ *
+ * Copyright (c) 2024 IBM Corp
+ *
+ * Authors:
+ *  Claudio Imbrenda <imbrenda@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <asm/interrupt.h>
+#include <asm/facility.h>
+#include <asm/time.h>
+#include <asm/mem.h>
+#include <pv_icptdata.h>
+#include <vmalloc.h>
+#include <snippet.h>
+#include <sclp.h>
+#include <mmu.h>
+
+#define GUEST_ORDER	REGION3_SHIFT
+#define GUEST_SIZE	BIT_ULL(REGION3_SHIFT)
+#define N_ITER 		32
+#define MAGIC_ADDRESS	0x12a000
+
+#define FIRST		42
+#define SECOND		23
+
+#define STR(x)		((x) ? "1m" : "4k")
+#define STR3(x)		((x) != -1 ? STR(x) : "no")
+#define PARAM(n, step)	(((unsigned long)(n) << 32) | (step))
+
+static struct vm vm;
+static void *root;
+
+extern const char SNIPPET_NAME_START(c, pv_memhog)[];
+extern const char SNIPPET_NAME_END(c, pv_memhog)[];
+extern const char SNIPPET_HDR_START(c, pv_memhog)[];
+extern const char SNIPPET_HDR_END(c, pv_memhog)[];
+
+static void init_snippet(struct vm *vm) {
+	const unsigned long size_hdr = SNIPPET_HDR_LEN(c, pv_memhog);
+	const unsigned long size_gbin = SNIPPET_LEN(c, pv_memhog);
+
+	snippet_pv_init(vm, SNIPPET_NAME_START(c, pv_memhog),
+			SNIPPET_HDR_START(c, pv_memhog),
+			size_gbin, size_hdr, SNIPPET_UNPACK_OFF);
+}
+
+static inline uint64_t guest_start(struct vm *vm)
+{
+	return vm->sblk->mso;
+}
+
+static inline uint64_t guest_end(struct vm *vm)
+{
+	return vm->sblk->msl + SZ_1M;
+}
+
+static inline uint64_t guest_size(struct vm *vm)
+{
+	return guest_end(vm) - guest_start(vm);
+}
+
+static uint16_t uvc_merge(struct vm *vm, uint64_t addr)
+{
+	struct uv_cb_cts uvcb = {
+		.header.cmd = UVC_CMD_VERIFY_LARGE_FRAME,
+		.header.len = sizeof(uvcb),
+		.guest_handle = vm->uv.vm_handle,
+		.gaddr = addr,
+	};
+	int cc;
+
+	cc = uv_call(0, (uint64_t)&uvcb);
+	assert(cc ? uvcb.header.rc != 1 : uvcb.header.rc == 1);
+	return uvcb.header.rc;
+}
+
+static void map_identity_range(struct vm *vm, uint64_t start, uint64_t end, bool map1m)
+{
+	uint64_t mem = guest_start(vm);
+
+	if (map1m) {
+		for (start &= HPAGE_MASK; start < end; start += HPAGE_SIZE)
+			install_large_page(root, mem + start, (void *)(mem + start));
+	} else {
+		for (start &= PAGE_SIZE; start < end; start += PAGE_SIZE)
+			install_page(root, mem + start, (void *)(mem + start));
+	}
+}
+
+static inline void map_identity_all(struct vm *vm, bool map1m)
+{
+	map_identity_range(vm, 0, guest_size(vm), map1m);
+}
+
+static void import_range(struct vm *vm, uint64_t start, uint64_t end)
+{
+	for (start &= PAGE_MASK; start < end; start += PAGE_SIZE)
+		assert(uv_import(vm->uv.vm_handle, guest_start(vm) + start) == 0);
+}
+
+static inline void import_all(struct vm *vm)
+{
+	import_range(vm, 0, guest_size(vm));
+}
+
+static void export_range(struct vm *vm, uint64_t start, uint64_t end)
+{
+	for (start &= PAGE_MASK; start < end; start += PAGE_SIZE)
+		assert(uv_export(guest_start(vm) + start) == 0);
+}
+
+static void merge_range(struct vm *vm, uint64_t start, uint64_t end)
+{
+	for (start &= HPAGE_MASK; start < end; start += HPAGE_SIZE)
+		assert(uvc_merge(vm, guest_start(vm) + start) == 1);
+}
+
+static inline void merge_all(struct vm *vm)
+{
+	merge_range(vm, 0, guest_size(vm));
+}
+
+static inline bool pgm_3c_addr_is(struct vm *vm, uint64_t gaddr)
+{
+	union teid teid = { .val = lowcore.trans_exc_id };
+	bool res;
+
+	res = (lowcore.pgm_int_code == PGM_INT_CODE_SECURE_PAGE_SIZE) &&
+		(teid.addr == (guest_start(vm) + gaddr) >> PAGE_SHIFT);
+	clear_pgm_int();
+	return res;
+}
+
+static inline void assert_diag500_val(struct vm *vm, uint64_t val)
+{
+	assert(pv_icptdata_check_diag(vm, 0x500));
+	assert(vm->save_area.guest.grs[2] == val);
+}
+
+
+static void do_one_test(struct vm *vm, bool init1m, bool import1m, int merge, bool run1m)
+{
+	map_identity_all(vm, init1m);
+	init_snippet(vm);
+
+	map_identity_all(vm, import1m);
+	import_all(vm);
+
+	if (merge >= 0) {
+		map_identity_all(vm, merge);
+		merge_all(vm);
+	}
+
+	map_identity_all(vm, run1m);
+	if ((merge == -1) && run1m) {
+		sie(vm);
+		report(vm->sblk->icptcode == ICPT_PV_PREF, "ICPT 112");
+		merge_range(vm, 0, SZ_1M);
+		expect_pgm_int();
+		sie(vm);
+		report(pgm_3c_addr_is(vm, MAGIC_ADDRESS), "PGM 3C at address %#x", MAGIC_ADDRESS);
+		map_identity_all(vm, false);
+	}
+
+	sie(vm);
+	assert_diag500_val(vm, FIRST);
+	vm->save_area.guest.grs[2] = PARAM(4096, 1);
+	sie(vm);
+	assert_diag500_val(vm, 23);
+
+	uv_destroy_guest(vm);
+}
+
+
+static void test_run(void)
+{
+	int init1m, import1m, merge, run1m;
+
+	report_prefix_push("test run");
+
+	for (init1m = 0; init1m < 1; init1m++) {
+		for (import1m = 0; import1m < 2; import1m++) {
+			for (merge = -1; merge < 2; merge++) {
+				for (run1m = 0; run1m < 2; run1m++) {
+					report_prefix_pushf("init %s, import %s, merge %s, run %s",
+						STR(init1m), STR(import1m), STR3(merge), STR(run1m));
+
+					do_one_test(&vm, init1m, import1m, merge, run1m);
+					report_pass("Execution successful");
+
+					report_prefix_pop();
+				}
+			}
+		}
+	}
+
+	report_prefix_pop();
+}
+
+static void test_merge(void)
+{
+	uint64_t tmp, mem;
+	int cc;
+
+	report_prefix_push("merge");
+	init_snippet(&vm);
+
+	mem = guest_start(&vm);
+
+	map_identity_all(&vm, false);
+	install_page(root, mem + 0x101000, (void *)(mem + 0x102000));
+	install_page(root, mem + 0x102000, (void *)(mem + 0x101000));
+	install_page(root, mem + 0x205000, (void *)(mem + 0x305000));
+	install_page(root, mem + 0x305000, (void *)(mem + 0x205000));
+	import_range(&vm, 0, 0x400000);
+	import_range(&vm, 0x401000, 0x501000);
+	import_range(&vm, 0x600000, 0x700000);
+
+	/* Address lower than MSO */
+	report(uvc_merge(&vm, 0) == 0x103, "Address below MSO");
+	report(uvc_merge(&vm, mem - SZ_1M) == 0x103, "Address below MSO");
+
+	/* Address higher than MSL */
+	install_large_page(root, guest_end(&vm), (void *)guest_end(&vm));
+	report(uvc_merge(&vm, guest_end(&vm)) == 0x103, "Address above MSL");
+
+	/* Not all pages are imported */
+	report(uvc_merge(&vm, mem + 0x400000) == 0x106, "First page not imported");
+	report(uvc_merge(&vm, mem + 0x500000) == 0x106, "Only first page imported");
+
+	/* Large 2G page used */
+	tmp = mem & REGION3_ENTRY_RFAA;
+	install_huge_page(root, tmp, (void *)tmp);
+	report(uvc_merge(&vm, mem) == 0x108, "Large region-3 table entry (2G page)");
+	map_identity_range(&vm, 0, SZ_2G, false);
+
+	/* Not all pages are aligned correctly */
+	report(uvc_merge(&vm, mem + 0x100000) == 0x104, "Pages not consecutive");
+	report(uvc_merge(&vm, mem + 0x200000) == 0x104, "Pages not in the same 1M frame");
+
+	/* Invalid host virtual to host aboslute mapping */
+	install_large_page(root, get_ram_size(), (void *)(mem + 0x600000));
+	report(uvc_merge(&vm, mem + 0x600000) == 0x107, "Invalid mapping");
+	map_identity_range(&vm, 0x600000, 0x700000, false);
+
+	/* Success */
+	report(uvc_merge(&vm, mem) == 1, "Successful merge");
+
+	cc = uv_export(mem + 0xff000);
+	report(cc == 0, "Successful export of merged page");
+
+	uv_destroy_guest(&vm);
+	report_prefix_pop();
+}
+
+static void test_one_export(struct vm *vm, int pre1m, bool exportfirst, int page, bool post1m)
+{
+	uint64_t addr = SZ_1M + page * PAGE_SIZE;
+	int expected = FIRST;
+
+	report_prefix_pushf("page %d", page);
+
+	map_identity_all(vm, pre1m == 1);
+	init_snippet(vm);
+	import_all(vm);
+	merge_all(vm);
+
+	if (pre1m != -1) {
+		sie(vm);
+		assert_diag500_val(vm, expected);
+		vm->save_area.guest.grs[2] = PARAM(4, 256 + 42);
+		expected = SECOND;
+	}
+
+	if (exportfirst) {
+		export_range(vm, addr, addr + PAGE_SIZE);
+		if (pre1m != 1)
+			map_identity_all(vm, true);
+	} else {
+		if (pre1m != 1)
+			map_identity_all(vm, true);
+		export_range(vm, addr, addr + PAGE_SIZE);
+	}
+	expect_pgm_int();
+	sie(vm);
+	assert(pgm_3c_addr_is(vm, MAGIC_ADDRESS));
+
+	import_range(vm, addr, addr + PAGE_SIZE);
+	if (post1m) {
+		merge_range(vm, SZ_1M, 2 * SZ_1M);
+	} else {
+		map_identity_all(vm, false);
+	}
+	sie(vm);
+	assert_diag500_val(vm, expected);
+	report_pass("Successful");
+
+	uv_destroy_guest(vm);
+	ptlb();
+	report_prefix_pop();
+}
+
+static void test_export(void)
+{
+	int pre1m, post1m, exportfirst;
+
+	report_prefix_push("export");
+
+	for (pre1m = -1; pre1m < 2; pre1m++) {
+		for (post1m = 0; post1m < 2; post1m++) {
+			for (exportfirst = 0; exportfirst < 2; exportfirst++) {
+				report_prefix_pushf("%s pre-run, %s post-run, export %s remap",
+						    STR3(pre1m), STR(post1m), exportfirst ? "before" : "after");
+
+				test_one_export(&vm, pre1m, exportfirst, 0, post1m);
+				test_one_export(&vm, pre1m, exportfirst, 1, post1m);
+				test_one_export(&vm, pre1m, exportfirst, 42, post1m);
+				test_one_export(&vm, pre1m, exportfirst, 128, post1m);
+				test_one_export(&vm, pre1m, exportfirst, 254, post1m);
+				test_one_export(&vm, pre1m, exportfirst, 255, post1m);
+
+				report_prefix_pop();
+			}
+		}
+	}
+
+	report_prefix_pop();
+}
+
+static bool check_facilities(void)
+{
+	if (!uv_host_requirement_checks())
+		return false;
+	if (!test_facility(8) || !test_facility(78)) {
+		report_skip("EDAT2 not available in the host.");
+		return false;
+	}
+	if (!uv_query_test_call(BIT_UVC_CMD_VERIFY_LARGE_FRAME)) {
+		report_skip("Verify Large Frame UVC not supported.");
+		return false;
+	}
+	if (!uv_query_test_feature(BIT_UV_1M_BACKING)) {
+		report_skip("Large frames not supported for Secure Execution.");
+		return false;
+	}
+	return true;
+}
+
+static void init(void)
+{
+	uint8_t *guest_memory;
+
+	setup_vm();
+
+	root = (void *)(stctg(1) & PAGE_MASK);
+	ctl_set_bit(0, CTL0_EDAT);
+
+	guest_memory = alloc_pages(GUEST_ORDER - PAGE_SHIFT);
+	if (!guest_memory)
+		report_abort("Could not allocate 2^%d MiB for guest memory.",
+			GUEST_ORDER - 20);
+	sie_guest_create(&vm, (uint64_t)guest_memory, GUEST_SIZE);
+	sie_guest_sca_create(&vm);
+	uv_init();
+	uv_setup_asces();
+}
+
+int main(void)
+{
+	report_prefix_push("uv-edat1-host");
+
+	if (check_facilities()) {
+		init();
+
+		test_merge();
+		test_export();
+		test_run();
+
+		sie_guest_destroy(&vm);
+	}
+
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/snippets/c/pv-memhog.c b/s390x/snippets/c/pv-memhog.c
new file mode 100644
index 00000000..43f0c2b1
--- /dev/null
+++ b/s390x/snippets/c/pv-memhog.c
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Snippet used by the pv-edat1.c test.
+ * This snippet expects to run with at least 2G or memory.
+ *
+ * Copyright (c) 2024 IBM Corp
+ *
+ * Authors:
+ *  Claudio Imbrenda <imbrenda@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <asm-generic/page.h>
+#include <asm/mem.h>
+
+#define N_PAGES		(SZ_2G / PAGE_SIZE)
+#define MID_OF_PAGE	(PAGE_SIZE / 2)
+#define MASK_2G		(SZ_2G - 1)
+#define MIDPAGE_PTR(x)	((uint64_t *)((x) + MID_OF_PAGE))
+
+static inline void sie_exit(void)
+{
+	asm volatile("diag	0,0,0x44\n" : : : "memory");
+}
+
+static inline uint64_t get_value(uint64_t res)
+{
+	asm volatile("lgr	%%r2, %[res]\n"
+		"	diag	0, 0, 0x500\n"
+		"	lgr	%[res], %%r2\n"
+		     : [res] "+d"(res)
+		     :
+		     : "2", "memory"
+	);
+	return res;
+}
+
+int main(void)
+{
+	uint64_t param, addr, i, n;
+
+	READ_ONCE(*MIDPAGE_PTR(SZ_1M + 42 * PAGE_SIZE));
+	param = get_value(42);
+
+	n = (param >> 32) & 0x1fffffff;
+	n = n ? n : N_PAGES;
+	param &= 0x7fffffff;
+
+	while (true) {
+		for (i = 0; i < n; i++) {
+			addr = ((param ? i * param : i * i * i) * PAGE_SIZE) & MASK_2G;
+			WRITE_ONCE(*MIDPAGE_PTR(addr), addr);
+		}
+
+		i = get_value(23);
+		if (i != 42)
+			sie_exit();
+	}
+	return 0;
+}
-- 
2.47.1

Re: [kvm-unit-tests PATCH v3 3/3] s390x: pv: Add test for large host pages backing

[Nico Boehr]

On Wed Dec 18, 2024 at 2:51 PM CET, Claudio Imbrenda wrote:
[...]
> diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
> index 611dcd3f..7527be48 100644
> --- a/lib/s390x/asm/uv.h
> +++ b/lib/s390x/asm/uv.h
[...]
> +static inline int uv_merge(uint64_t handle, unsigned long gaddr)
> +{
> +	struct uv_cb_cts uvcb = {
> +		.header.cmd = UVC_CMD_VERIFY_LARGE_FRAME,
> +		.header.len = sizeof(uvcb),
> +		.guest_handle = handle,
> +		.gaddr = gaddr,
> +	};
> +
> +	return uv_call(0, (uint64_t)&uvcb);
> +}

This function seems unused and uvc_merge() below looks very similar.

[...]

> diff --git a/s390x/pv-edat1.c b/s390x/pv-edat1.c
> new file mode 100644
> index 00000000..3f96c716
> --- /dev/null
> +++ b/s390x/pv-edat1.c
[...]
> +#define FIRST		42
> +#define SECOND		23

It was not obvious to me what these mean. It would be easier for me to
understand if they had some name like GUEST_READ_DONE_GET_PARAM and
SHOULD_EXIT_LOOP (or so) and share the define with the guest or at least have
defines with the same name in the guest (see also below).

[...]
> +static inline void assert_diag500_val(struct vm *vm, uint64_t val)
> +{
> +	assert(pv_icptdata_check_diag(vm, 0x500));
> +	assert(vm->save_area.guest.grs[2] == val);
> +}

I would appreciate it if you could base on Ninas STFLE series and use
snippet_check_force_exit_value() here. See
https://lore.kernel.org/kvm/20240620141700.4124157-6-nsg@linux.ibm.com/
See also below.

[...]
> +static void test_run(void)
> +{
> +	int init1m, import1m, merge, run1m;
> +
> +	report_prefix_push("test run");
> +
> +	for (init1m = 0; init1m < 1; init1m++) {

Are you sure this does what you want it to do?

[...]
> +static void test_merge(void)
> +{
> +	uint64_t tmp, mem;
> +	int cc;
> +
> +	report_prefix_push("merge");
> +	init_snippet(&vm);
> +
> +	mem = guest_start(&vm);
> +
> +	map_identity_all(&vm, false);
> +	install_page(root, mem + 0x101000, (void *)(mem + 0x102000));
> +	install_page(root, mem + 0x102000, (void *)(mem + 0x101000));
> +	install_page(root, mem + 0x205000, (void *)(mem + 0x305000));

(see below)

[...]
> +	/* Not all pages are aligned correctly */
> +	report(uvc_merge(&vm, mem + 0x100000) == 0x104, "Pages not consecutive");
> +	report(uvc_merge(&vm, mem + 0x200000) == 0x104, "Pages not in the same 1M frame");

It would be easier for me to understand if the regions were named, e.g. with a
variable for each region, for example:

uint64_t non_consecutive = mem + 0x100000

and then above

install_page(root, mem + 0x101000, (void *)(non_consecutive + 0x2000));
install_page(root, mem + 0x102000, (void *)(non_consecutive + 0x1000));

[...]
> diff --git a/s390x/snippets/c/pv-memhog.c b/s390x/snippets/c/pv-memhog.c
> new file mode 100644
> index 00000000..43f0c2b1
> --- /dev/null
> +++ b/s390x/snippets/c/pv-memhog.c
> @@ -0,0 +1,59 @@
[...]
> +int main(void)
> +{
> +	uint64_t param, addr, i, n;
> +
> +	READ_ONCE(*MIDPAGE_PTR(SZ_1M + 42 * PAGE_SIZE));
> +	param = get_value(42);

(see below)

> +	n = (param >> 32) & 0x1fffffff;
> +	n = n ? n : N_PAGES;
> +	param &= 0x7fffffff;
> +
> +	while (true) {
> +		for (i = 0; i < n; i++) {
> +			addr = ((param ? i * param : i * i * i) * PAGE_SIZE) & MASK_2G;
> +			WRITE_ONCE(*MIDPAGE_PTR(addr), addr);
> +		}
> +
> +		i = get_value(23);
> +		if (i != 42)

I would like some defines for 23 and 42 and possibly share them with the host.

Re: [kvm-unit-tests PATCH v3 3/3] s390x: pv: Add test for large host pages backing

[Christoph Schlameuss]

On Wed Dec 18, 2024 at 2:51 PM CET, Claudio Imbrenda wrote:
> Add a new test to check that the host can use 1M large pages to back
> protected guests when the corresponding feature is present.
>
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

LGTM

Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>

Re: [kvm-unit-tests PATCH v3 3/3] s390x: pv: Add test for large host pages backing

[Claudio Imbrenda]

On Fri, 20 Dec 2024 16:22:31 +0100
"Nico Boehr" <nrb@linux.ibm.com> wrote:

> On Wed Dec 18, 2024 at 2:51 PM CET, Claudio Imbrenda wrote:
> [...]
> > diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
> > index 611dcd3f..7527be48 100644
> > --- a/lib/s390x/asm/uv.h
> > +++ b/lib/s390x/asm/uv.h  
> [...]
> > +static inline int uv_merge(uint64_t handle, unsigned long gaddr)
> > +{
> > +	struct uv_cb_cts uvcb = {
> > +		.header.cmd = UVC_CMD_VERIFY_LARGE_FRAME,
> > +		.header.len = sizeof(uvcb),
> > +		.guest_handle = handle,
> > +		.gaddr = gaddr,
> > +	};
> > +
> > +	return uv_call(0, (uint64_t)&uvcb);
> > +}  
> 
> This function seems unused and uvc_merge() below looks very similar.

it's a leftover, will remove

> 
> [...]
> 
> > diff --git a/s390x/pv-edat1.c b/s390x/pv-edat1.c
> > new file mode 100644
> > index 00000000..3f96c716
> > --- /dev/null
> > +++ b/s390x/pv-edat1.c  
> [...]
> > +#define FIRST		42
> > +#define SECOND		23  
> 
> It was not obvious to me what these mean. It would be easier for me to
> understand if they had some name like GUEST_READ_DONE_GET_PARAM and
> SHOULD_EXIT_LOOP (or so) and share the define with the guest or at least have
> defines with the same name in the guest (see also below).

will do

> 
> [...]
> > +static inline void assert_diag500_val(struct vm *vm, uint64_t val)
> > +{
> > +	assert(pv_icptdata_check_diag(vm, 0x500));
> > +	assert(vm->save_area.guest.grs[2] == val);
> > +}  
> 
> I would appreciate it if you could base on Ninas STFLE series and use
> snippet_check_force_exit_value() here. See
> https://lore.kernel.org/kvm/20240620141700.4124157-6-nsg@linux.ibm.com/
> See also below.
> 
> [...]
> > +static void test_run(void)
> > +{
> > +	int init1m, import1m, merge, run1m;
> > +
> > +	report_prefix_push("test run");
> > +
> > +	for (init1m = 0; init1m < 1; init1m++) {  
> 
> Are you sure this does what you want it to do?

I'm quite sure it does __not__ do what I want it to :D
I'll fix it

> 
> [...]
> > +static void test_merge(void)
> > +{
> > +	uint64_t tmp, mem;
> > +	int cc;
> > +
> > +	report_prefix_push("merge");
> > +	init_snippet(&vm);
> > +
> > +	mem = guest_start(&vm);
> > +
> > +	map_identity_all(&vm, false);
> > +	install_page(root, mem + 0x101000, (void *)(mem + 0x102000));
> > +	install_page(root, mem + 0x102000, (void *)(mem + 0x101000));
> > +	install_page(root, mem + 0x205000, (void *)(mem + 0x305000));  
> 
> (see below)
> 
> [...]
> > +	/* Not all pages are aligned correctly */
> > +	report(uvc_merge(&vm, mem + 0x100000) == 0x104, "Pages not consecutive");
> > +	report(uvc_merge(&vm, mem + 0x200000) == 0x104, "Pages not in the same 1M frame");  
> 
> It would be easier for me to understand if the regions were named, e.g. with a
> variable for each region, for example:
> 
> uint64_t non_consecutive = mem + 0x100000
> 
> and then above
> 
> install_page(root, mem + 0x101000, (void *)(non_consecutive + 0x2000));
> install_page(root, mem + 0x102000, (void *)(non_consecutive + 0x1000));

hmmm ok I'll do that

> 
> [...]
> > diff --git a/s390x/snippets/c/pv-memhog.c b/s390x/snippets/c/pv-memhog.c
> > new file mode 100644
> > index 00000000..43f0c2b1
> > --- /dev/null
> > +++ b/s390x/snippets/c/pv-memhog.c
> > @@ -0,0 +1,59 @@  
> [...]
> > +int main(void)
> > +{
> > +	uint64_t param, addr, i, n;
> > +
> > +	READ_ONCE(*MIDPAGE_PTR(SZ_1M + 42 * PAGE_SIZE));
> > +	param = get_value(42);  
> 
> (see below)
> 
> > +	n = (param >> 32) & 0x1fffffff;
> > +	n = n ? n : N_PAGES;
> > +	param &= 0x7fffffff;
> > +
> > +	while (true) {
> > +		for (i = 0; i < n; i++) {
> > +			addr = ((param ? i * param : i * i * i) * PAGE_SIZE) & MASK_2G;
> > +			WRITE_ONCE(*MIDPAGE_PTR(addr), addr);
> > +		}
> > +
> > +		i = get_value(23);
> > +		if (i != 42)  
> 
> I would like some defines for 23 and 42 and possibly share them with the host.

not sure what's the easiest way to share with the host, but I can just
copy the defines

Re: [kvm-unit-tests PATCH v3 3/3] s390x: pv: Add test for large host pages backing

[Nico Boehr]

On Fri Dec 20, 2024 at 4:52 PM CET, Claudio Imbrenda wrote:
[...]
> > > diff --git a/s390x/snippets/c/pv-memhog.c b/s390x/snippets/c/pv-memhog.c
> > > new file mode 100644
> > > index 00000000..43f0c2b1
> > > --- /dev/null
> > > +++ b/s390x/snippets/c/pv-memhog.c
> > > @@ -0,0 +1,59 @@  
> > [...]
> > > +int main(void)
> > > +{
> > > +	uint64_t param, addr, i, n;
> > > +
> > > +	READ_ONCE(*MIDPAGE_PTR(SZ_1M + 42 * PAGE_SIZE));
> > > +	param = get_value(42);  
> > 
> > (see below)
> > 
> > > +	n = (param >> 32) & 0x1fffffff;
> > > +	n = n ? n : N_PAGES;
> > > +	param &= 0x7fffffff;
> > > +
> > > +	while (true) {
> > > +		for (i = 0; i < n; i++) {
> > > +			addr = ((param ? i * param : i * i * i) * PAGE_SIZE) & MASK_2G;
> > > +			WRITE_ONCE(*MIDPAGE_PTR(addr), addr);
> > > +		}
> > > +
> > > +		i = get_value(23);
> > > +		if (i != 42)  
> > 
> > I would like some defines for 23 and 42 and possibly share them with the host.
>
> not sure what's the easiest way to share with the host, but I can just
> copy the defines

The sie-dat.c test does this, there's a header file

s390x/snippets/c/sie-dat.h

which is included in the host:

#include "snippets/c/sie-dat.h"

Not the most beautiful way, but works.