add VIRT_TEST support for qemu exit with exit_code, for CI autotest

os/src/boards/qemu.rs

@@ -1,9 +1,10 @@
 pub const CLOCK_FREQ: usize = 12500000;
 
 pub const MMIO: &[(usize, usize)] = &[
-    (0x1000_0000, 0x1000),
-    (0x1000_1000, 0x1000),
-    (0xC00_0000, 0x40_0000),
+    (0x1000_0000, 0x1000),        // VIRT_UART0 in virt machine
+    (0x1000_1000, 0x1000),        // VIRT_VIRTIO in virt machine 
+    (0x0C00_0000, 0x40_0000),  // VIRT_PLIC in virt machine
+    (0x0010_0000, 0x00_2000),  // VIRT_TEST/RTC  in virt machine
 ];
 
 pub type BlockDeviceImpl = crate::drivers::block::VirtIOBlock;
@@ -43,3 +44,84 @@ pub fn irq_handler() {
     }
     plic.complete(0, IntrTargetPriority::Supervisor, intr_src_id);
 }
+
+
+use core::arch::asm;
+
+const EXIT_SUCCESS: u32 = 0x5555; // Equals `exit(0)`. qemu successful exit
+
+const EXIT_FAILURE_FLAG: u32 = 0x3333;
+const EXIT_FAILURE: u32 = exit_code_encode(1); // Equals `exit(1)`. qemu failed exit 
+const EXIT_RESET: u32 = 0x7777;       // qemu reset
+
+pub trait QEMUExit {
+    /// Exit with specified return code.
+    ///
+    /// Note: For `X86`, code is binary-OR'ed with `0x1` inside QEMU.
+    fn exit(&self, code: u32) -> !;
+
+    /// Exit QEMU using `EXIT_SUCCESS`, aka `0`, if possible.
+    ///
+    /// Note: Not possible for `X86`.
+    fn exit_success(&self) -> !;
+
+    /// Exit QEMU using `EXIT_FAILURE`, aka `1`.
+    fn exit_failure(&self) -> !;
+}
+
+
+/// RISCV64 configuration
+pub struct RISCV64 {
+    /// Address of the sifive_test mapped device.
+    addr: u64,
+}
+
+/// Encode the exit code using EXIT_FAILURE_FLAG.
+const fn exit_code_encode(code: u32) -> u32 {
+    (code << 16) | EXIT_FAILURE_FLAG
+}
+
+impl RISCV64 {
+    /// Create an instance.
+    pub const fn new(addr: u64) -> Self {
+        RISCV64 { addr }
+    }
+}
+
+impl QEMUExit for RISCV64 {
+    /// Exit qemu with specified exit code.
+    fn exit(&self, code: u32) -> ! {
+        // If code is not a special value, we need to encode it with EXIT_FAILURE_FLAG.
+        let code_new = match code {
+            EXIT_SUCCESS | EXIT_FAILURE | EXIT_RESET => code,
+            _ => exit_code_encode(code),
+        };
+
+        unsafe {
+            asm!(
+                "sw {0}, 0({1})",
+                in(reg)code_new, in(reg)self.addr
+            );
+
+            // For the case that the QEMU exit attempt did not work, transition into an infinite
+            // loop. Calling `panic!()` here is unfeasible, since there is a good chance
+            // this function here is the last expression in the `panic!()` handler
+            // itself. This prevents a possible infinite loop.
+            loop {
+                asm!("wfi", options(nomem, nostack));
+            }
+        }
+    }
+
+    fn exit_success(&self) -> ! {
+        self.exit(EXIT_SUCCESS);
+    }
+
+    fn exit_failure(&self) -> ! {
+        self.exit(EXIT_FAILURE);
+    }
+}
+
+const VIRT_TEST: u64 =0x100000;
+
+pub const QEMU_EXIT_HANDLE: RISCV64 = RISCV64::new(VIRT_TEST); 

os/src/sbi.rs

@@ -39,7 +39,9 @@ pub fn console_getchar() -> usize {
     sbi_call(SBI_CONSOLE_GETCHAR, 0, 0, 0)
 }
 
+use crate::board::QEMUExit;
 pub fn shutdown(exit_code: usize) -> ! {
-    sbi_call(SBI_SHUTDOWN, exit_code, 0, 0);
+    //sbi_call(SBI_SHUTDOWN, exit_code, 0, 0);
+    crate::board::QEMU_EXIT_HANDLE.exit_failure();
     panic!("It should shutdown!");
 }

os/src/task/mod.rs

@@ -57,6 +57,8 @@ pub fn block_current_and_run_next() {
     schedule(task_cx_ptr);
 }
 
+use crate::board::QEMUExit;
+
 pub fn exit_current_and_run_next(exit_code: i32) {
     let task = take_current_task().unwrap();
     let mut task_inner = task.inner_exclusive_access();
@@ -79,9 +81,11 @@ pub fn exit_current_and_run_next(exit_code: i32) {
                 exit_code
             );
             if exit_code != 0 {
-                crate::sbi::shutdown(255); //255 == -1 for err hint
+                //crate::sbi::shutdown(255); //255 == -1 for err hint
+                crate::board::QEMU_EXIT_HANDLE.exit_failure();
             } else {
-                crate::sbi::shutdown(0); //0 for success hint
+                //crate::sbi::shutdown(0); //0 for success hint
+                crate::board::QEMU_EXIT_HANDLE.exit_success();
             }
         }
         remove_from_pid2process(pid);