[Qemu-devel] [PATCH 06/16] target-i386: pc: update rtc_cmos on CPU hot-plug

[Igor Mammedov]

... so that on reboot BIOS could read current available CPU count

Signed-off-by: Igor Mammedov <address@hidden>
---
 hw/i386/pc.c                   | 20 ++++++++++++++++++++
 hw/timer/mc146818rtc.c         |  7 +++++++
 include/hw/timer/mc146818rtc.h |  1 +
 3 files changed, 28 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 8d75b34..dc1a78b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -337,6 +337,21 @@ static void pc_cmos_init_late(void *opaque)
     qemu_unregister_reset(pc_cmos_init_late, opaque);
 }
 
+typedef struct rtc_cpu_hotplug_arg {
+    ISADevice *rtc_state;
+    Notifier cpu_added_notifier;
+} rtc_cpu_hotplug_arg;
+
+static void rtc_notify_cpu_added(Notifier *notifier, void *data)
+{
+    rtc_cpu_hotplug_arg *arg = container_of(notifier, rtc_cpu_hotplug_arg,
+                                           cpu_added_notifier);
+    ISADevice *s = arg->rtc_state;
+
+    /* increment the number of CPUs */
+    rtc_set_memory(s, 0x5f, rtc_get_memory(s, 0x5f) + 1);
+}
+
 void pc_cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
                   const char *boot_device,
                   ISADevice *floppy, BusState *idebus0, BusState *idebus1,
@@ -345,6 +360,7 @@ void pc_cmos_init(ram_addr_t ram_size, ram_addr_t 
above_4g_mem_size,
     int val, nb, i;
     FDriveType fd_type[2] = { FDRIVE_DRV_NONE, FDRIVE_DRV_NONE };
     static pc_cmos_init_late_arg arg;
+    static rtc_cpu_hotplug_arg cpu_hotplug_cb;
 
     /* various important CMOS locations needed by PC/Bochs bios */
 
@@ -383,6 +399,10 @@ void pc_cmos_init(ram_addr_t ram_size, ram_addr_t 
above_4g_mem_size,
 
     /* set the number of CPU */
     rtc_set_memory(s, 0x5f, smp_cpus - 1);
+    /* init CPU hotplug notifier */
+    cpu_hotplug_cb.rtc_state = s;
+    cpu_hotplug_cb.cpu_added_notifier.notify = rtc_notify_cpu_added;
+    qemu_register_cpu_added_notifier(&cpu_hotplug_cb.cpu_added_notifier);
 
     /* set boot devices, and disable floppy signature check if requested */
     if (set_boot_dev(s, boot_device, fd_bootchk)) {
diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index 69e6844..e639942 100644
--- a/hw/timer/mc146818rtc.c
+++ b/hw/timer/mc146818rtc.c
@@ -677,6 +677,13 @@ void rtc_set_memory(ISADevice *dev, int addr, int val)
         s->cmos_data[addr] = val;
 }
 
+int rtc_get_memory(ISADevice *dev, int addr)
+{
+    RTCState *s = DO_UPCAST(RTCState, dev, dev);
+    assert(addr >= 0 && addr <= 127);
+    return s->cmos_data[addr];
+}
+
 static void rtc_set_date_from_host(ISADevice *dev)
 {
     RTCState *s = DO_UPCAST(RTCState, dev, dev);
diff --git a/include/hw/timer/mc146818rtc.h b/include/hw/timer/mc146818rtc.h
index 854ea3f..09f37b7 100644
--- a/include/hw/timer/mc146818rtc.h
+++ b/include/hw/timer/mc146818rtc.h
@@ -6,6 +6,7 @@
 
 ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq);
 void rtc_set_memory(ISADevice *dev, int addr, int val);
+int rtc_get_memory(ISADevice *dev, int addr);
 void rtc_set_date(ISADevice *dev, const struct tm *tm);
 
 #endif /* !MC146818RTC_H */
-- 
1.8.2