add a boot parameter to set reboot timeout

Added an option to let qemu transfer a configuration file to bios,
"etc/boot-fail-wait", which could be specified by command
    -boot reboot-timeout=T
T have a max value of 0xffff, unit is ms.

With this option, guest will wait for a given time if not find
bootabled device, then reboot. If reboot-timeout is '-1', guest
will not reboot, qemu passes '-1' to bios by default.

This feature need the new seabios's support.

Seabios pulls the value from the fwcfg "file" interface, this
interface is used because SeaBIOS needs a reliable way of
obtaining a name, value size, and value. It in no way requires
that there be a real file on the user's host machine.

Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/hw/fw_cfg.c b/hw/fw_cfg.c
index 7b3b576..dcde1a9 100644
--- a/hw/fw_cfg.c
+++ b/hw/fw_cfg.c
@@ -183,6 +183,30 @@ static void fw_cfg_bootsplash(FWCfgState *s)
     }
 }
 
+static void fw_cfg_reboot(FWCfgState *s)
+{
+    int reboot_timeout = -1;
+    char *p;
+    const char *temp;
+
+    /* get user configuration */
+    QemuOptsList *plist = qemu_find_opts("boot-opts");
+    QemuOpts *opts = QTAILQ_FIRST(&plist->head);
+    if (opts != NULL) {
+        temp = qemu_opt_get(opts, "reboot-timeout");
+        if (temp != NULL) {
+            p = (char *)temp;
+            reboot_timeout = strtol(p, (char **)&p, 10);
+        }
+    }
+    /* validate the input */
+    if (reboot_timeout > 0xffff) {
+        error_report("reboot timeout is larger than 65535, force it to 65535.");
+        reboot_timeout = 0xffff;
+    }
+    fw_cfg_add_file(s, "etc/boot-fail-wait", g_memdup(&reboot_timeout, 4), 4);
+}
+
 static void fw_cfg_write(FWCfgState *s, uint8_t value)
 {
     int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
@@ -497,6 +521,7 @@ FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
     fw_cfg_add_i16(s, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
     fw_cfg_add_i16(s, FW_CFG_BOOT_MENU, (uint16_t)boot_menu);
     fw_cfg_bootsplash(s);
+    fw_cfg_reboot(s);
 
     s->machine_ready.notify = fw_cfg_machine_ready;
     qemu_add_machine_init_done_notifier(&s->machine_ready);