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, 69 insertions, 0 deletions

diff --git a/accel/tcg/tb-hash.h b/accel/tcg/tb-hash.h
new file mode 100644
index 000000000..0a273d960
--- /dev/null
+++ b/accel/tcg/tb-hash.h
@@ -0,0 +1,69 @@
+/*
+ * internal execution defines for qemu
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ * 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/>.
+ */
+
+#ifndef EXEC_TB_HASH_H
+#define EXEC_TB_HASH_H
+
+#include "exec/cpu-defs.h"
+#include "exec/exec-all.h"
+#include "qemu/xxhash.h"
+
+#ifdef CONFIG_SOFTMMU
+
+/* Only the bottom TB_JMP_PAGE_BITS of the jump cache hash bits vary for
+   addresses on the same page.  The top bits are the same.  This allows
+   TLB invalidation to quickly clear a subset of the hash table.  */
+#define TB_JMP_PAGE_BITS (TB_JMP_CACHE_BITS / 2)
+#define TB_JMP_PAGE_SIZE (1 << TB_JMP_PAGE_BITS)
+#define TB_JMP_ADDR_MASK (TB_JMP_PAGE_SIZE - 1)
+#define TB_JMP_PAGE_MASK (TB_JMP_CACHE_SIZE - TB_JMP_PAGE_SIZE)
+
+static inline unsigned int tb_jmp_cache_hash_page(target_ulong pc)
+{
+    target_ulong tmp;
+    tmp = pc ^ (pc >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS));
+    return (tmp >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS)) & TB_JMP_PAGE_MASK;
+}
+
+static inline unsigned int tb_jmp_cache_hash_func(target_ulong pc)
+{
+    target_ulong tmp;
+    tmp = pc ^ (pc >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS));
+    return (((tmp >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS)) & TB_JMP_PAGE_MASK)
+           | (tmp & TB_JMP_ADDR_MASK));
+}
+
+#else
+
+/* In user-mode we can get better hashing because we do not have a TLB */
+static inline unsigned int tb_jmp_cache_hash_func(target_ulong pc)
+{
+    return (pc ^ (pc >> TB_JMP_CACHE_BITS)) & (TB_JMP_CACHE_SIZE - 1);
+}
+
+#endif /* CONFIG_SOFTMMU */
+
+static inline
+uint32_t tb_hash_func(tb_page_addr_t phys_pc, target_ulong pc, uint32_t flags,
+                      uint32_t cf_mask, uint32_t trace_vcpu_dstate)
+{
+    return qemu_xxhash7(phys_pc, pc, flags, cf_mask, trace_vcpu_dstate);
+}
+
+#endif