diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 30afbad36cd5516509beae779c03d7ab4c0bfd3c..1b9c257fca5e042bc28a451177c00959f1520514 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -36,7 +36,7 @@ endif
LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c
LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c
LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
-LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c
+LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..b0ed71302722ae8f4efd41356dc38dd3b9a935a9
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * Test handler for the s390x DIAGNOSE 0x0318 instruction.
+ *
+ * Copyright (C) 2020, IBM
+ */
+
+#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER
+#define SELFTEST_KVM_DIAG318_TEST_HANDLER
+
+uint64_t get_diag318_info(void);
+
+#endif
diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
new file mode 100644
index 0000000000000000000000000000000000000000..86b9e611ad8713d2f42e8b1bc06d78b5a999b87b
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Test handler for the s390x DIAGNOSE 0x0318 instruction.
+ *
+ * Copyright (C) 2020, IBM
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+
+#define VCPU_ID 6
+
+#define ICPT_INSTRUCTION 0x04
+#define IPA0_DIAG 0x8300
+
+static void guest_code(void)
+{
+ uint64_t diag318_info = 0x12345678;
+
+ asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info));
+}
+
+/*
+ * The DIAGNOSE 0x0318 instruction call must be handled via userspace. As such,
+ * we create an ad-hoc VM here to handle the instruction then extract the
+ * necessary data. It is up to the caller to decide what to do with that data.
+ */
+static uint64_t diag318_handler(void)
+{
+ struct kvm_vm *vm;
+ struct kvm_run *run;
+ uint64_t reg;
+ uint64_t diag318_info;
+
+ vm = vm_create_default(VCPU_ID, 0, guest_code);
+ vcpu_run(vm, VCPU_ID);
+ run = vcpu_state(vm, VCPU_ID);
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
+ "DIAGNOSE 0x0318 instruction was not intercepted");
+ TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION,
+ "Unexpected intercept code: 0x%x", run->s390_sieic.icptcode);
+ TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG,
+ "Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00));
+
+ reg = (run->s390_sieic.ipa & 0x00f0) >> 4;
+ diag318_info = run->s.regs.gprs[reg];
+
+ TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set");
+
+ kvm_vm_free(vm);
+
+ return diag318_info;
+}
+
+uint64_t get_diag318_info(void)
+{
+ static uint64_t diag318_info;
+ static bool printed_skip;
+
+ /*
+ * If KVM does not support diag318, then return 0 to
+ * ensure tests do not break.
+ */
+ if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) {
+ if (!printed_skip) {
+ fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. "
+ "Skipping diag318 test.\n");
+ printed_skip = true;
+ }
+ return 0;
+ }
+
+ /*
+ * If a test has previously requested the diag318 info,
+ * then don't bother spinning up a temporary VM again.
+ */
+ if (!diag318_info)
+ diag318_info = diag318_handler();
+
+ return diag318_info;
+}
diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
index 5731ccf34917f2c51955b0897c60c6f3182a5f12..caf7b8859a94a5b999e15d00364028bd151e6695 100644
--- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -20,6 +20,7 @@
#include "test_util.h"
#include "kvm_util.h"
+#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS)
+#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318)
#define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[])
@@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS;
run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS;
+
+ if (get_diag318_info() > 0) {
+ run->s.regs.diag318 = get_diag318_info();
+ run->kvm_dirty_regs |= KVM_SYNC_DIAG318;
+ }
+
rv = _vcpu_run(vm, VCPU_ID);
TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -164,6 +171,9 @@ int main(int argc, char *argv[])
TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11,
"acr0 sync regs value incorrect 0x%x.",
run->s.regs.acrs[0]);
+ TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(),
+ "diag318 sync regs value incorrect 0x%llx.",
+ run->s.regs.diag318);
vcpu_regs_get(vm, VCPU_ID, ®s);
compare_regs(®s, &run->s.regs);
@@ -177,6 +187,7 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS;
run->kvm_dirty_regs = 0;
run->s.regs.gprs[11] = 0xDEADBEEF;
+ run->s.regs.diag318 = 0x4B1D;
rv = _vcpu_run(vm, VCPU_ID);
TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -186,6 +197,9 @@ int main(int argc, char *argv[])
TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF,
"r11 sync regs value incorrect 0x%llx.",
run->s.regs.gprs[11]);
+ TEST_ASSERT(run->s.regs.diag318 != 0x4B1D,
+ "diag318 sync regs value incorrect 0x%llx.",
+ run->s.regs.diag318);
kvm_vm_free(vm);