[PATCH 2/2] tests/tcg/s390x: Test PRNO TRNG interruptibility

[Ilya Leoshkevich <iii@linux.ibm.com>]

Add a small test that issues a large PRNO TRNG request while a timer is
running, and checks that the timer interrupts it several times.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tests/tcg/s390x/Makefile.target |  1 +
 tests/tcg/s390x/prno-trng.c     | 67 +++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 tests/tcg/s390x/prno-trng.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 0ca030ded01..48cba4cdfa4 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -75,6 +75,7 @@ Z13_TESTS+=vcksm
 Z13_TESTS+=vstl
 Z13_TESTS+=vrep
 Z13_TESTS+=precise-smc-user
+Z13_TESTS+=prno-trng
 $(Z13_TESTS): CFLAGS+=-march=z13 -O2
 TESTS+=$(Z13_TESTS)
 
diff --git a/tests/tcg/s390x/prno-trng.c b/tests/tcg/s390x/prno-trng.c
new file mode 100644
index 00000000000..43eea5db1dc
--- /dev/null
+++ b/tests/tcg/s390x/prno-trng.c
@@ -0,0 +1,67 @@
+/*
+ * Test that PERFORM RANDOM NUMBER OPERATION TRNG is interruptible.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <asm/ucontext.h>
+
+static unsigned char buf1[16 * 1024 * 1024];
+static unsigned char buf2[16 * 1024 * 1024];
+
+static volatile sig_atomic_t interrupted;
+
+static void sigprof_handler(int sig, siginfo_t *info, void *ucontext)
+{
+    struct ucontext *uc = ucontext;
+    unsigned long addr = uc->uc_mcontext.regs.psw.addr;
+
+    if (*(unsigned short *)(addr - 4) == 0xb93c) {
+        interrupted++;
+    }
+}
+
+static void prno_trng(void *b1, unsigned long l1, void *b2, unsigned long l2)
+{
+    register unsigned long r0 asm("r0") = 114;  /* TRNG */
+    register unsigned long r2 asm("r2") = (unsigned long)b1;
+    register unsigned long r3 asm("r3") = l1;
+    register unsigned long r4 asm("r4") = (unsigned long)b2;
+    register unsigned long r5 asm("r5") = l2;
+
+    asm volatile("0: ppno %[r2],%[r4]\n"  /* prno alias for old toolchains */
+                 "   jo 0b"
+                 : [r2] "+r" (r2), [r3] "+r" (r3)
+                 , [r4] "+r" (r4), [r5] "+r" (r5)
+                 : "r" (r0)
+                 : "cc", "memory");
+}
+
+int main(void)
+{
+    struct itimerval it = {
+        .it_interval = { .tv_usec = 10000 },  /* 0.01s */
+        .it_value = { .tv_usec = 10000 },
+    };
+    struct sigaction act = {
+        .sa_sigaction = sigprof_handler,
+        .sa_flags = SA_SIGINFO,
+    };
+    int err;
+
+    err = sigaction(SIGPROF, &act, NULL);
+    assert(err == 0);
+    err = setitimer(ITIMER_PROF, &it, NULL);
+    assert(err == 0);
+
+    prno_trng(buf1, sizeof(buf1), buf2, sizeof(buf2));
+    printf("interrupted %d times\n", interrupted);
+    assert(interrupted >= 3);
+
+    return EXIT_SUCCESS;
+}
-- 
2.55.0