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/mips/msa.c b/target/mips/msa.c
new file mode 100644
index 000000000..61f1a9a59
--- /dev/null
+++ b/target/mips/msa.c
@@ -0,0 +1,60 @@
+/*
+ * MIPS SIMD Architecture Module Instruction emulation helpers for QEMU.
+ *
+ * Copyright (c) 2014 Imagination Technologies
+ *
+ * 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 "internal.h"
+#include "fpu/softfloat.h"
+#include "fpu_helper.h"
+
+void msa_reset(CPUMIPSState *env)
+{
+    if (!ase_msa_available(env)) {
+        return;
+    }
+
+#ifdef CONFIG_USER_ONLY
+    /* MSA access enabled */
+    env->CP0_Config5 |= 1 << CP0C5_MSAEn;
+    env->CP0_Status |= (1 << CP0St_CU1) | (1 << CP0St_FR);
+#endif
+
+    /*
+     * MSA CSR:
+     * - non-signaling floating point exception mode off (NX bit is 0)
+     * - Cause, Enables, and Flags are all 0
+     * - round to nearest / ties to even (RM bits are 0)
+     */
+    env->active_tc.msacsr = 0;
+
+    restore_msa_fp_status(env);
+
+    /* tininess detected after rounding.*/
+    set_float_detect_tininess(float_tininess_after_rounding,
+                              &env->active_tc.msa_fp_status);
+
+    /* clear float_status exception flags */
+    set_float_exception_flags(0, &env->active_tc.msa_fp_status);
+
+    /* clear float_status nan mode */
+    set_default_nan_mode(0, &env->active_tc.msa_fp_status);
+
+    /* set proper signanling bit meaning ("1" means "quiet") */
+    set_snan_bit_is_one(0, &env->active_tc.msa_fp_status);
+}