Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 60 insertions, 0 deletions

diff --git a/target/openrisc/exception_helper.c b/target/openrisc/exception_helper.c
new file mode 100644
index 000000000..d02a1cf0a
--- /dev/null
+++ b/target/openrisc/exception_helper.c
@@ -0,0 +1,60 @@
+/*
+ * OpenRISC exception helper routines
+ *
+ * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+#include "exception.h"
+
+void HELPER(exception)(CPUOpenRISCState *env, uint32_t excp)
+{
+    OpenRISCCPU *cpu = env_archcpu(env);
+
+    raise_exception(cpu, excp);
+}
+
+static void QEMU_NORETURN do_range(CPUOpenRISCState *env, uintptr_t pc)
+{
+    CPUState *cs = env_cpu(env);
+
+    cs->exception_index = EXCP_RANGE;
+    cpu_loop_exit_restore(cs, pc);
+}
+
+void HELPER(ove_cy)(CPUOpenRISCState *env)
+{
+    if (env->sr_cy) {
+        do_range(env, GETPC());
+    }
+}
+
+void HELPER(ove_ov)(CPUOpenRISCState *env)
+{
+    if (env->sr_ov < 0) {
+        do_range(env, GETPC());
+    }
+}
+
+void HELPER(ove_cyov)(CPUOpenRISCState *env)
+{
+    if (env->sr_cy || env->sr_ov < 0) {
+        do_range(env, GETPC());
+    }
+}