From 8aca9eb12fdc81adce98af7c1183f7ea8cb019a6 Mon Sep 17 00:00:00 2001
From: Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
Date: Thu, 29 Aug 2024 07:55:04 +0000
Subject: [PATCH] dm: uart: add escape sequence Ctrl-a x to exit dm

When guest console is redirected to stdio, Ctrl-c is also passed to
guest. Add escape sequence Ctrl-a x to send SIGINT to exit acrn-dm
in such case.

Tracked-On: #8731
Signed-off-by: Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
Reviewed-by: Jian Jun Chen <jian.jun.chen@intel.com>
---
 devicemodel/hw/uart_core.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/devicemodel/hw/uart_core.c b/devicemodel/hw/uart_core.c
index d001b9800..5ec35c3ed 100644
--- a/devicemodel/hw/uart_core.c
+++ b/devicemodel/hw/uart_core.c
@@ -29,6 +29,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <signal.h>
 #include <fcntl.h>
 #include <termios.h>
 #include <unistd.h>
@@ -94,6 +95,8 @@ static struct {
 	{ COM5_BASE, COM5_IRQ, false},
 };
 
+static bool stdio_ctrl_a_pressed = false;
+
 #define	UART_NLDEVS	(ARRAY_SIZE(uart_lres))
 
 enum uart_be_type {
@@ -717,6 +720,18 @@ uart_backend_read(struct uart_backend *be)
 
 	switch (be->be_type) {
 	case UART_BE_STDIO:
+		rc = read(be->fd, &rb, 1);
+		if (rb == 0x01) {  // Ctrl-a
+			DPRINTF(("%s: Got Ctrl-a\n", __func__));
+			stdio_ctrl_a_pressed = true;
+		} else if (stdio_ctrl_a_pressed) {
+			if (rb == 'x') {
+				DPRINTF(("%s: Got Ctrl-a x\n", __func__));
+				kill(getpid(), SIGINT);
+			}
+			stdio_ctrl_a_pressed = false;
+		}
+		break;
 	case UART_BE_TTY:
 		/* fd is used to read */
 		rc = read(be->fd, &rb, 1);