Patchwork [5/5] target-i386: implement machine->hot_add_cpu hook

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Submitter Igor Mammedov
Date April 30, 2013, 4 p.m.
Message ID <1367337653-557-1-git-send-email-imammedo@redhat.com>
Download mbox | patch
Permalink /patch/240664/
State New
Headers show

Comments

Igor Mammedov - April 30, 2013, 4 p.m.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v3:
  * use local static variable for saving cpu_model

v2:
  * override .hot_add_cpu statically starting with 1.5 machine
---
 hw/i386/pc.c         |   26 ++++++++++++++++++++++++++
 hw/i386/pc_piix.c    |    1 +
 hw/i386/pc_q35.c     |    1 +
 include/hw/i386/pc.h |    1 +
 4 files changed, 29 insertions(+), 0 deletions(-)
Andreas Färber - May 1, 2013, 7:32 p.m.
Am 30.04.2013 18:00, schrieb Igor Mammedov:
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> v3:
>   * use local static variable for saving cpu_model
> 
> v2:
>   * override .hot_add_cpu statically starting with 1.5 machine

Thanks, applied to qom-cpu:
https://github.com/afaerber/qemu-cpu/commits/qom-cpu

I verified it's working as expected in Windows 2012 Datacenter, but
neither in openSUSE 12.3 nor in Fedora 18 Live DVD did I see any change
in /proc/cpuinfo or GNOME System Monitor.

Andreas
Igor Mammedov - May 2, 2013, 7:18 a.m.
On Wed, 01 May 2013 21:32:59 +0200
Andreas Färber <afaerber@suse.de> wrote:

> Am 30.04.2013 18:00, schrieb Igor Mammedov:
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> > v3:
> >   * use local static variable for saving cpu_model
> > 
> > v2:
> >   * override .hot_add_cpu statically starting with 1.5 machine
> 
> Thanks, applied to qom-cpu:
> https://github.com/afaerber/qemu-cpu/commits/qom-cpu
> 
> I verified it's working as expected in Windows 2012 Datacenter, but
> neither in openSUSE 12.3 nor in Fedora 18 Live DVD did I see any change
> in /proc/cpuinfo or GNOME System Monitor.
Right after hot-add a new CPU entry should appear in /sys/devices/system/cpu
then kernel doesn't online hot-added CPUs automatically, one needs online
a new CPU manually, for example issuing following command:
 echo 1 > /sys/devices/system/cpu/cpuXX/online




> Andreas
> 
> -- 
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
Andreas Färber - May 2, 2013, 11:46 a.m.
Am 02.05.2013 09:18, schrieb Igor Mammedov:
> On Wed, 01 May 2013 21:32:59 +0200
> Andreas Färber <afaerber@suse.de> wrote:
> 
>> I verified it's working as expected in Windows 2012 Datacenter, but
>> neither in openSUSE 12.3 nor in Fedora 18 Live DVD did I see any change
>> in /proc/cpuinfo or GNOME System Monitor.
> Right after hot-add a new CPU entry should appear in /sys/devices/system/cpu
> then kernel doesn't online hot-added CPUs automatically, one needs online
> a new CPU manually, for example issuing following command:
>  echo 1 > /sys/devices/system/cpu/cpuXX/online

Ah thanks, that works for both then!

Andreas

Patch

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 28f958d..197d218 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -54,6 +54,7 @@ 
 #include "qemu/config-file.h"
 #include "hw/acpi/acpi.h"
 #include "hw/cpu/icc_bus.h"
+#include "hw/boards.h"
 
 /* debug PC/ISA interrupts */
 //#define DEBUG_IRQ
@@ -919,6 +920,30 @@  static X86CPU *pc_new_cpu(const char *cpu_model, int64_t apic_id,
     return cpu;
 }
 
+static const char *current_cpu_model;
+
+void pc_hot_add_cpu(const int64_t id, Error **errp)
+{
+    DeviceState *icc_bridge;
+    int64_t apic_id = x86_cpu_apic_id_from_index(id);
+
+    if (cpu_exists(apic_id)) {
+        error_setg(errp, "Unable to add CPU: %" PRIi64
+                   ", it already exists", id);
+        return;
+    }
+
+    if (id >= max_cpus) {
+        error_setg(errp, "Unable to add CPU: %" PRIi64
+                   ", max allowed: %d", id, max_cpus - 1);
+        return;
+    }
+
+    icc_bridge = DEVICE(object_resolve_path_type("icc-bridge",
+                                                 TYPE_ICC_BRIDGE, NULL));
+    pc_new_cpu(current_cpu_model, apic_id, icc_bridge, errp);
+}
+
 void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
 {
     int i;
@@ -933,6 +958,7 @@  void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
         cpu_model = "qemu32";
 #endif
     }
+    current_cpu_model = cpu_model;
 
     for (i = 0; i < smp_cpus; i++) {
         cpu = pc_new_cpu(cpu_model, x86_cpu_apic_id_from_index(i),
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 3717796..1727fb5 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -322,6 +322,7 @@  static QEMUMachine pc_i440fx_machine_v1_5 = {
     .alias = "pc",
     .desc = "Standard PC (i440FX + PIIX, 1996)",
     .init = pc_init_pci,
+    .hot_add_cpu = pc_hot_add_cpu,
     .max_cpus = 255,
     .is_default = 1,
     DEFAULT_MACHINE_OPTIONS,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 073543e..dbf6930 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -213,6 +213,7 @@  static QEMUMachine pc_q35_machine_v1_5 = {
     .alias = "q35",
     .desc = "Standard PC (Q35 + ICH9, 2009)",
     .init = pc_q35_init,
+    .hot_add_cpu = pc_hot_add_cpu,
     .max_cpus = 255,
     DEFAULT_MACHINE_OPTIONS,
 };
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 8a6e76c..0bbb7b4 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -79,6 +79,7 @@  void pc_register_ferr_irq(qemu_irq irq);
 void pc_acpi_smi_interrupt(void *opaque, int irq, int level);
 
 void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge);
+void pc_hot_add_cpu(const int64_t id, Error **errp);
 void pc_acpi_init(const char *default_dsdt);
 void *pc_memory_init(MemoryRegion *system_memory,
                     const char *kernel_filename,