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

2 files changed, 78 insertions, 0 deletions

diff --git a/linux-user/host/sparc/host-signal.h b/linux-user/host/sparc/host-signal.h
new file mode 100644
index 000000000..734293607
--- /dev/null
+++ b/linux-user/host/sparc/host-signal.h
@@ -0,0 +1,63 @@
+/*
+ * host-signal.h: signal info dependent on the host architecture
+ *
+ * Copyright (c) 2003-2005 Fabrice Bellard
+ * Copyright (c) 2021 Linaro Limited
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef SPARC_HOST_SIGNAL_H
+#define SPARC_HOST_SIGNAL_H
+
+static inline uintptr_t host_signal_pc(ucontext_t *uc)
+{
+#ifdef __arch64__
+    return uc->uc_mcontext.mc_gregs[MC_PC];
+#else
+    return uc->uc_mcontext.gregs[REG_PC];
+#endif
+}
+
+static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc)
+{
+#ifdef __arch64__
+    uc->uc_mcontext.mc_gregs[MC_PC] = pc;
+#else
+    uc->uc_mcontext.gregs[REG_PC] = pc;
+#endif
+}
+
+static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc)
+{
+    uint32_t insn = *(uint32_t *)host_signal_pc(uc);
+
+    if ((insn >> 30) == 3) {
+        switch ((insn >> 19) & 0x3f) {
+        case 0x05: /* stb */
+        case 0x15: /* stba */
+        case 0x06: /* sth */
+        case 0x16: /* stha */
+        case 0x04: /* st */
+        case 0x14: /* sta */
+        case 0x07: /* std */
+        case 0x17: /* stda */
+        case 0x0e: /* stx */
+        case 0x1e: /* stxa */
+        case 0x24: /* stf */
+        case 0x34: /* stfa */
+        case 0x27: /* stdf */
+        case 0x37: /* stdfa */
+        case 0x26: /* stqf */
+        case 0x36: /* stqfa */
+        case 0x25: /* stfsr */
+        case 0x3c: /* casa */
+        case 0x3e: /* casxa */
+            return true;
+        }
+    }
+    return false;
+}
+
+#endif
diff --git a/linux-user/host/sparc/hostdep.h b/linux-user/host/sparc/hostdep.h
new file mode 100644
index 000000000..391ad923c
--- /dev/null
+++ b/linux-user/host/sparc/hostdep.h
@@ -0,0 +1,15 @@
+/*
+ * hostdep.h : things which are dependent on the host architecture
+ *
+ *  * Written by Peter Maydell <peter.maydell@linaro.org>
+ *
+ * Copyright (C) 2016 Linaro Limited
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef SPARC_HOSTDEP_H
+#define SPARC_HOSTDEP_H
+
+#endif