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, 62 insertions, 0 deletions

diff --git a/linux-user/riscv/target_syscall.h b/linux-user/riscv/target_syscall.h
new file mode 100644
index 000000000..dc597c897
--- /dev/null
+++ b/linux-user/riscv/target_syscall.h
@@ -0,0 +1,62 @@
+/*
+ * This struct defines the way the registers are stored on the
+ *  stack during a system call.
+ *
+ * Reference: linux/arch/riscv/include/uapi/asm/ptrace.h
+ */
+
+#ifndef LINUX_USER_RISCV_TARGET_SYSCALL_H
+#define LINUX_USER_RISCV_TARGET_SYSCALL_H
+
+struct target_pt_regs {
+    abi_long sepc;
+    abi_long ra;
+    abi_long sp;
+    abi_long gp;
+    abi_long tp;
+    abi_long t0;
+    abi_long t1;
+    abi_long t2;
+    abi_long s0;
+    abi_long s1;
+    abi_long a0;
+    abi_long a1;
+    abi_long a2;
+    abi_long a3;
+    abi_long a4;
+    abi_long a5;
+    abi_long a6;
+    abi_long a7;
+    abi_long s2;
+    abi_long s3;
+    abi_long s4;
+    abi_long s5;
+    abi_long s6;
+    abi_long s7;
+    abi_long s8;
+    abi_long s9;
+    abi_long s10;
+    abi_long s11;
+    abi_long t3;
+    abi_long t4;
+    abi_long t5;
+    abi_long t6;
+};
+
+#ifdef TARGET_RISCV32
+#define UNAME_MACHINE "riscv32"
+#else
+#define UNAME_MACHINE "riscv64"
+#endif
+#define UNAME_MINIMUM_RELEASE "4.15.0"
+
+#define TARGET_MINSIGSTKSZ 2048
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
+
+/* clone(flags, newsp, ptidptr, tls, ctidptr) for RISC-V */
+/* This comes from linux/kernel/fork.c, CONFIG_CLONE_BACKWARDS */
+#define TARGET_CLONE_BACKWARDS
+
+#endif