[Qemu-devel] [PATCH v4 02/16] pc: delay setting number of boot CPUs to machine_done time

[Igor Mammedov]

currently present CPUs counter in CMOS only contains
smp_cpus (i.e. initial CPUs specified with -smp X) and
doesn't account for CPUs created with -device.
If VM is started with additional CPUs added with
 -device, it will hang in BIOS waiting for condition
   smp_cpus == counted_cpus
forever as counted_cpus will include -device CPUs as well
and be more than smp_cpus.

make present CPUs counter in CMOS to count all CPUs
(initial and coldplugged with -device) by delaying
it to machine done time when it possible to count
CPUs added with -device.

Signed-off-by: Igor Mammedov <address@hidden>
---
v4:
 - extract present cpus count into a separate function
     pc_present_cpus_count()
---
 hw/i386/pc.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 31b502c..d83fde4 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -471,9 +471,6 @@ void pc_cmos_init(PCMachineState *pcms,
     rtc_set_memory(s, 0x5c, val >> 8);
     rtc_set_memory(s, 0x5d, val >> 16);
 
-    /* set the number of CPU */
-    rtc_set_memory(s, 0x5f, smp_cpus - 1);
-
     object_property_add_link(OBJECT(pcms), "rtc_state",
                              TYPE_ISA_DEVICE,
                              (Object **)&pcms->rtc,
@@ -1039,6 +1036,17 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int 
level)
     }
 }
 
+static int pc_present_cpus_count(PCMachineState *pcms)
+{
+    int i, boot_cpus = 0;
+    for (i = 0; i < pcms->possible_cpus->len; i++) {
+        if (pcms->possible_cpus->cpus[i].cpu) {
+            boot_cpus++;
+        }
+    }
+    return boot_cpus;
+}
+
 static X86CPU *pc_new_cpu(const char *typename, int64_t apic_id,
                           Error **errp)
 {
@@ -1189,6 +1197,9 @@ void pc_machine_done(Notifier *notifier, void *data)
                                         PCMachineState, machine_done);
     PCIBus *bus = pcms->bus;
 
+    /* set the number of CPUs */
+    rtc_set_memory(pcms->rtc, 0x5f, pc_present_cpus_count(pcms) - 1);
+
     if (bus) {
         int extra_hosts = 0;
 
-- 
2.7.4