[PATCH v4 2/2] KVM: s390: selftests: memop: add a simple AR test

Eric Farman
2024-02-20T21:12:24Z

There is a selftest that checks for an (expected) error when an
invalid AR is specified, but not one that exercises the AR path.

Add a simple test that mirrors the vanilla write/read test while
providing an AR. An AR that contains zero will direct the CPU to
use the primary address space normally used anyway. AR[1] is
selected for this test because the host AR[1] is usually non-zero,
and KVM needs to correctly swap those values.

Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
tools/testing/selftests/kvm/s390x/memop.c | 31 +++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
index bb3ca9a5d731..b6da8f71ea19 100644
--- a/tools/testing/selftests/kvm/s390x/memop.c
+++ b/tools/testing/selftests/kvm/s390x/memop.c
@@ -375,6 +375,32 @@ static void test_copy(void)
kvm_vm_free(t.kvm_vm);
}

+static void test_copy_access_register(void)
+{
+ struct test_default t = test_default_init(guest_copy);
+
+ HOST_SYNC(t.vcpu, STAGE_INITED);
+
+ prepare_mem12();
+ t.run->psw_mask &= ~(3UL << (63 - 17));
+ t.run->psw_mask |= 1UL << (63 - 17); /* Enable AR mode */
+
+ /*
+ * Primary address space gets used if an access register
+ * contains zero. The host makes use of AR[1] so is a good
+ * candidate to ensure the guest AR (of zero) is used.
+ */
+ CHECK_N_DO(MOP, t.vcpu, LOGICAL, WRITE, mem1, t.size,
+ GADDR_V(mem1), AR(1));
+ HOST_SYNC(t.vcpu, STAGE_COPIED);
+
+ CHECK_N_DO(MOP, t.vcpu, LOGICAL, READ, mem2, t.size,
+ GADDR_V(mem2), AR(1));
+ ASSERT_MEM_EQ(mem1, mem2, t.size);
+
+ kvm_vm_free(t.kvm_vm);
+}
+
static void set_storage_key_range(void *addr, size_t len, uint8_t key)
{
uintptr_t _addr, abs, i;
@@ -1101,6 +1127,11 @@ int main(int argc, char *argv[])
.test = test_copy_key_fetch_prot_override,
.requirements_met = extension_cap > 0,
},
+ {
+ .name = "copy with access register mode",
+ .test = test_copy_access_register,
+ .requirements_met = true,
+ },
{
.name = "error checks with key",
.test = test_errors_key,
--
2.40.1