KVM: selftests: introduce P44V64 for z196 and EC12

Older machines like z196 and zEC12 do only support 44 bits of physical
addresses. Make this the default and check via IBC if we are on a later
machine. We then add P47V64 as an additional model.

Reviewed-by: David Hildenbrand <[e-mail]>
Reviewed-by: Thomas Huth <[e-mail]>
Reviewed-by: Cornelia Huck <[e-mail]>
Signed-off-by: Christian Borntraeger <[e-mail]>
Link: https://lore.kernel.org/kvm/[e-mail]/
Fixes: 1bc603af73dd ("KVM: selftests: introduce P47V64 for s390x")

tools/testing/selftests/kvm/include/kvm_util.h

···
 	VM_MODE_P40V48_64K,
 	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
 	VM_MODE_P47V64_4K,
+	VM_MODE_P44V64_4K,
 	NUM_VM_MODES,
 };
 
···
 
 #elif defined(__s390x__)
 
-#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
+#define VM_MODE_DEFAULT			VM_MODE_P44V64_4K
 #define MIN_PAGE_SHIFT			12U
 #define ptes_per_page(page_size)	((page_size) / 16)
 

tools/testing/selftests/kvm/lib/guest_modes.c

···
 		}
 	}
 #endif
+#ifdef __s390x__
+	{
+		int kvm_fd, vm_fd;
+		struct kvm_s390_vm_cpu_processor info;
+
+		kvm_fd = open_kvm_dev_path_or_exit();
+		vm_fd = ioctl(kvm_fd, KVM_CREATE_VM, 0);
+		kvm_device_access(vm_fd, KVM_S390_VM_CPU_MODEL,
+				  KVM_S390_VM_CPU_PROCESSOR, &info, false);
+		close(vm_fd);
+		close(kvm_fd);
+		/* Starting with z13 we have 47bits of physical address */
+		if (info.ibc >= 0x30)
+			guest_mode_append(VM_MODE_P47V64_4K, true, true);
+	}
+#endif
 }
 
 void for_each_guest_mode(void (*func)(enum vm_guest_mode, void *), void *arg)

tools/testing/selftests/kvm/lib/kvm_util.c

···
 		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
 		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
 		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
+		[VM_MODE_P44V64_4K]	= "PA-bits:44,  VA-bits:64,  4K pages",
 	};
 	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
 		       "Missing new mode strings?");
···
 	{ 40, 48, 0x10000, 16 },
 	{  0,  0,  0x1000, 12 },
 	{ 47, 64,  0x1000, 12 },
+	{ 44, 64,  0x1000, 12 },
 };
 _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
 	       "Missing new mode params?");
···
 #endif
 		break;
 	case VM_MODE_P47V64_4K:
+		vm->pgtable_levels = 5;
+		break;
+	case VM_MODE_P44V64_4K:
 		vm->pgtable_levels = 5;
 		break;
 	default: