kvm: selftest: unify the guest port macros

Most of the tests are using the same way to do guest to host sync but
the code is mostly duplicated.  Generalize the guest port macros into
the common header file and use it in different tests.

Meanwhile provide "struct guest_args" and a helper "guest_args_read()"
to hide the register details when playing with these port operations on
RDI and RSI.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index d32632f71ab8..d8ca48687e35 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -144,4 +144,43 @@ allocate_kvm_dirty_log(struct kvm_userspace_memory_region *region);
 
 int vm_create_device(struct kvm_vm *vm, struct kvm_create_device *cd);
 
+#define GUEST_PORT_SYNC         0x1000
+#define GUEST_PORT_ABORT        0x1001
+#define GUEST_PORT_DONE         0x1002
+
+static inline void __exit_to_l0(uint16_t port, uint64_t arg0, uint64_t arg1)
+{
+	__asm__ __volatile__("in %[port], %%al"
+			     :
+			     : [port]"d"(port), "D"(arg0), "S"(arg1)
+			     : "rax");
+}
+
+/*
+ * Allows to pass three arguments to the host: port is 16bit wide,
+ * arg0 & arg1 are 64bit wide
+ */
+#define GUEST_SYNC_ARGS(_port, _arg0, _arg1) \
+	__exit_to_l0(_port, (uint64_t) (_arg0), (uint64_t) (_arg1))
+
+#define GUEST_ASSERT(_condition) do {				\
+		if (!(_condition))				\
+			GUEST_SYNC_ARGS(GUEST_PORT_ABORT,	\
+					"Failed guest assert: "	\
+					#_condition, __LINE__);	\
+	} while (0)
+
+#define GUEST_SYNC(stage)  GUEST_SYNC_ARGS(GUEST_PORT_SYNC, "hello", stage)
+
+#define GUEST_DONE()  GUEST_SYNC_ARGS(GUEST_PORT_DONE, 0, 0)
+
+struct guest_args {
+	uint64_t arg0;
+	uint64_t arg1;
+	uint16_t port;
+} __attribute__ ((packed));
+
+void guest_args_read(struct kvm_vm *vm, uint32_t vcpu_id,
+		     struct guest_args *args);
+
 #endif /* SELFTEST_KVM_UTIL_H */