KVM: s390: selftests: memop: add a simple AR test

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>
Link: https://lore.kernel.org/r/20240220211211.3102609-3-farman@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
index bb3ca9a5d7318ebe88fbe9f5a7ebfaaf0c2235b6..b6da8f71ea191e82a3cc68632bf61b6938f60c73 100644 (file)
--- 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,