s390: Add test case for GS

- Add new test "s390x_gs_threads" for GS with broadcast command for the
s390_guarded_storage() system call.

 - Add GS control blocks in test s390x_regs_check.c

The original test case for GS has been provided by
Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Alice Frosi <alice@linux.vnet.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

test/zdtm/static/Makefile

@@ -187,7 +187,8 @@ endif
 endif
 
 ifeq ($(SRCARCH),s390)
-        TST_NOFILE += s390x_regs_check
+        TST_NOFILE +=	s390x_regs_check	\
+			s390x_gs_threads
 endif
 
 TST_FILE	=				\
@@ -471,6 +472,7 @@ pty-console:		CFLAGS += -D ZDTM_DEV_CONSOLE
 shm-unaligned:		CFLAGS += -DZDTM_SHM_UNALIGNED
 
 s390x_regs_check:	LDFLAGS += -pthread
+s390x_gs_threads:	LDFLAGS += -pthread
 
 thread_different_uid_gid:	LDLIBS += -pthread -lcap
 

test/zdtm/static/s390x_gs_threads.c

+#include <linux/types.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "lock.h"
+#include "zdtmtst.h"
+
+#define NR_THREADS	4
+#define GS_ENABLE	0
+#define GS_SET_BC_CB	2
+#define GS_BROADCAST	4
+
+#ifndef __NR_guarded_storage
+#define __NR_guarded_storage   378
+#endif
+
+const char *test_doc = "Check the guarded storage broadcast";
+/* Original test provided by Martin Schwidefsky <schwidefsky@de.ibm.com> */
+const char *test_author = "Alice Frosi <alice@linux.vnet.ibm.com>";
+
+static unsigned long main_thread_tid;
+
+/*
+ * This test case executes the following procedure:
+ *
+ * 1) The parent thread creates NR_THREADS child threads
+ *
+ * 2) For each thread (including the parent thread):
+ *    - Enable guarded-storage
+ *    - Set the guarded-storage broadcast control block and
+ *      specify gs_handler as Guarded-Storage-Event Parameter-List
+ *      address
+ *
+ * 3) Dump and restore
+ *
+ * 4) Guarded-storage broadcast event
+ *    - Child threads: Wait until main thread does GS broadcast
+ *    - Parent thread: Trigger GS broadcast
+ *
+ * 5) Verify that all GS works as expected and all threads have been
+ *    executed the gs_handler
+ */
+
+struct gs_cb {
+	__u64 reserved;
+	__u64 gsd;
+	__u64 gssm;
+	__u64 gs_epl_a;
+};
+
+static futex_t futex;
+static futex_t futex2;
+
+/*
+ * Load guarded-storage
+ */
+void load_guarded(unsigned long *mem);
+asm(
+	".global load_guarded\n"
+	"load_guarded:\n"
+	"	.insn rxy,0xe3000000004c,%r2,0(%r2)\n"
+	"	br %r14\n"
+	"	.size load_guarded,.-load_guarded\n");
+
+/*
+ * Inline assembly to deal with interrupted context to the call of
+ * the GS handler. Load guarded can be turned into a branch to this
+ * function.
+ */
+void gs_handler_asm(void);
+asm(
+	".globl gs_handler_asm\n"
+	"gs_handler_asm:\n"
+	"	lgr	%r14,%r15\n"
+	"	aghi	%r15,-320\n"
+	"	stmg	%r0,%r14,192(%r15)\n"
+	"	stg	%r14,312(%r14)\n"
+	"	la	%r2,160(%r15)\n"
+	"	.insn	rxy,0xe30000000049,0,160(%r15)\n"
+	"	lg	%r14,24(%r2)\n"
+	"	lg	%r14,40(%r14)\n"
+	"	la	%r14,6(%r14)\n"
+	"	stg	%r14,304(%r15)\n"
+	"	brasl	%r14,gs_handler\n"
+	"	lmg	%r0,%r15,192(%r15)\n"
+	"	br	%r14\n"
+	"	.size gs_handler_asm,.-gs_handler_asm\n");
+
+/*
+ * GS handler called when GS event occurs
+ */
+void gs_handler(struct gs_cb *this_cb)
+{
+	unsigned long tid = syscall(SYS_gettid);
+	test_msg("gs_handler for thread %016lx\n", tid);
+	futex_dec_and_wake(&futex2);
+}
+
+/*
+ * Entry point for threads
+ */
+static void *thread_run(void *param)
+{
+	unsigned long test = 0x1234000000;
+	unsigned long *gs_epl;
+	struct gs_cb *gs_cb;
+
+	/* Enable guarded-storage */
+	if (syscall(__NR_guarded_storage, GS_ENABLE) != 0) {
+		fail("Unable to enable guarded storage");
+		exit(1);
+	}
+	gs_epl = malloc(sizeof(unsigned long) * 6);
+	gs_cb = malloc(sizeof(*gs_cb));
+	if (gs_epl == NULL || gs_cb == NULL) {
+		fail("Error allocating memory\n");
+		exit(1);
+	}
+	gs_cb->gsd = 0x1234000000UL | 26;
+	gs_cb->gssm = -1UL;
+	gs_cb->gs_epl_a = (unsigned long) gs_epl;
+	gs_epl[1] = (unsigned long) gs_handler_asm;
+	/* Set the GS broadcast control block */
+	syscall(__NR_guarded_storage, GS_SET_BC_CB, gs_cb);
+	futex_dec_and_wake(&futex);
+	/* Wait for all threads to set the GS broadcast control block */
+	futex_wait_until(&futex, 0);
+	test_msg("Thread %016lx staring loop\n",  syscall(SYS_gettid));
+	/*
+	 * Designate a guarded-storage section until the main task
+	 * performs the GS_BROADCAST action and the following load_guarded
+	 * will provoke the switch to the gs handler
+	 */
+	while (1)
+		load_guarded(&test);
+}
+
+int main(int argc, char *argv[])
+{
+	pthread_t tids[NR_THREADS];
+	int i;
+
+	main_thread_tid = syscall(SYS_gettid);
+	test_init(argc, argv);
+	/* Enable guarded-storage */
+	if (syscall(__NR_guarded_storage, GS_ENABLE) != 0) {
+		if (errno == ENOSYS) {
+			test_daemon();
+			test_waitsig();
+			skip("No guarded storage support");
+			pass();
+			return 0;
+		}
+		fail("Unable to enable guarded storage");
+		return 1;
+	}
+
+	futex_set(&futex, NR_THREADS);
+
+	for (i = 0; i < NR_THREADS; i++)
+		pthread_create(tids + i, NULL, thread_run, NULL);
+
+	test_msg("Waiting for thread startup\n");
+	/* Wait for all threads to set the GS broadcast control block */
+	futex_wait_until(&futex, 0);
+
+	test_daemon();
+	test_waitsig();
+
+	test_msg("Doing broadcast\n");
+	futex_set(&futex2, NR_THREADS);
+	/*
+	 * Triggers a GS event and force all the threads to execute
+	 * the gs handler
+	 */
+	syscall(__NR_guarded_storage, GS_BROADCAST);
+
+	test_msg("Waiting for thread completion\n");
+	futex_wait_until(&futex2, 0);
+	pass();
+	return 0;
+}

test/zdtm/static/s390x_regs_check.c

@@ -182,6 +182,50 @@ struct reg_set reg_set_vxrs_high = {
 	.optional	= true,
 };
 
+/*
+ * s390 guarded-storage registers
+ */
+#define NT_S390_GS_CB		0x30b
+#define NT_S390_GS_BC		0x30c
+
+struct gs_cb {
+	uint64_t regs[4];
+};
+
+struct gs_cb gs_cb_data = {
+	.regs = {
+		0x0000000000000000,
+		0x000000123400001a,
+		0x5555555555555555,
+		0x000000014b58a010,
+	}
+};
+
+struct reg_set reg_set_gs_cb = {
+	.name		= "GS_CB",
+	.nr		= NT_S390_GS_CB,
+	.data		= &gs_cb_data,
+	.len		= sizeof(gs_cb_data),
+	.optional	= true,
+};
+
+struct gs_cb gs_bc_data = {
+	.regs = {
+		0x0000000000000000,
+		0x000000123400001a,
+		0xffffffffffffffff,
+		0x0000000aaaaaaaaa,
+	}
+};
+
+struct reg_set reg_set_gs_bc = {
+	.name		= "GS_BC_CB",
+	.nr		= NT_S390_GS_BC,
+	.data		= &gs_bc_data,
+	.len		= sizeof(gs_bc_data),
+	.optional	= true,
+};
+
 /*
  * Vector with all regsets
  */
@@ -189,6 +233,8 @@ struct reg_set *reg_set_vec[] = {
 	&reg_set_prfpreg,
 	&reg_set_vxrs_low,
 	&reg_set_vxrs_high,
+	&reg_set_gs_cb,
+	&reg_set_gs_bc,
 	NULL,
 };
 
@@ -246,6 +292,7 @@ static int set_regset(pid_t pid, struct reg_set *reg_set)
 	}
 	if (reg_set->optional) {
 		switch (errno) {
+		case EOPNOTSUPP:
 		case ENODEV:
 			test_msg(" REGSET: %12s -> not supported by machine\n",
 				 reg_set->name);