[Qemu-devel] [RESEND PATCH v4 00/10] QEmu memory hot unplug support.

[Qemu-devel] [RESEND PATCH v4 00/10] QEmu memory hot unplug support.

[Tang Chen]

This patch-set implements memory hot-remove for QEmu. 

Rebased on Igor's asynchronize hotplug framework (qemu v2.1.2, the latest).

Approach: QEmu sets GPE status bit, then triggers SCI to notify guest os.
Guest os checks device status, and free memory resource if possible,
then generate OST.

NOTE: In this version, memory hot-remove is independent from _OST, 
      following Igor's comments. Will implement _OST for memory hot-remove
      soon if this part is OK.

Change log v3 -> v4 (RESEND):
1. Add new patch 1 ~ 4, fix some small problems in coding.
2. In patch 9, make memory hot-remove independent from _OST.
3. In patch 9, add comment for is_removing flag to document.
4. In patch 10, use macro instead of number.
5. Remove original patch 8 and 12 to coincident with asynchronize
   hotplug framework.

Hu Tao (4):
  acpi, piix4: Add memory hot unplug support for piix4.
  pc: Add memory hot unplug support for pc machine.
  pc-dimm: Add pc_dimm_unrealize() for memory hot unplug support.
  pc, acpi bios: Add memory hot unplug interface.

Tang Chen (6):
  acpi, mem-hotplug: Use PC_DIMM_SLOT_PROP in acpi_memory_plug_cb().
  acpi, mem-hotplug: Add acpi_memory_get_slot_status_descriptor() to get
    MemStatus.
  acpi, mem-hotplug: Add acpi_memory_hotplug_sci() to rise sci for
    memory hotplug.
  acpi, mem-hotplug: Add acpi_memory_unplug_cb() to implement memory
    unplug.
  acpi, ich9: Add memory hot unplug support for ich9.
  acpi: Add hardware implementation for memory hot unplug.

 docs/specs/acpi_mem_hotplug.txt  |  8 +++--
 hw/acpi/ich9.c                   | 12 +++++++
 hw/acpi/memory_hotplug.c         | 71 +++++++++++++++++++++++++++++++---------
 hw/acpi/piix4.c                  |  6 +++-
 hw/i386/pc.c                     | 31 ++++++++++++++++++
 hw/i386/ssdt-mem.dsl             |  5 +++
 hw/i386/ssdt-misc.dsl            | 13 +++++++-
 hw/isa/lpc_ich9.c                |  5 +--
 hw/mem/pc-dimm.c                 | 10 ++++++
 include/hw/acpi/ich9.h           |  2 ++
 include/hw/acpi/memory_hotplug.h |  3 ++
 include/hw/acpi/pc-hotplug.h     |  2 ++
 12 files changed, 146 insertions(+), 22 deletions(-)

-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 01/10] acpi, mem-hotplug: Use PC_DIMM_SLOT_PROP in acpi_memory_plug_cb().

[Tang Chen]

Replace string "slot" in acpi_memory_plug_cb() with MACRO PC_DIMM_SLOT_PROP.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/acpi/memory_hotplug.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index ed39241..c6580da 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -168,7 +168,8 @@ void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
 {
     MemStatus *mdev;
     Error *local_err = NULL;
-    int slot = object_property_get_int(OBJECT(dev), "slot", &local_err);
+    int slot = object_property_get_int(OBJECT(dev), PC_DIMM_SLOT_PROP,
+                                       &local_err);
 
     if (local_err) {
         error_propagate(errp, local_err);
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 02/10] acpi, mem-hotplug: Add acpi_memory_get_slot_status_descriptor() to get MemStatus.

[Tang Chen]

Add a new API named acpi_memory_get_slot_status_descriptor() to obtain
a single memory slot status. Doing this is because this procedure will
be used by other functions in the next coming patches.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/acpi/memory_hotplug.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index c6580da..ef56bf6 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -163,29 +163,40 @@ void acpi_memory_hotplug_init(MemoryRegion *as, Object *owner,
     memory_region_add_subregion(as, ACPI_MEMORY_HOTPLUG_BASE, &state->io);
 }
 
-void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
-                         DeviceState *dev, Error **errp)
+static MemStatus *
+acpi_memory_get_slot_status_descriptor(MemHotplugState *mem_st,
+                                       DeviceState *dev, Error **errp)
 {
-    MemStatus *mdev;
     Error *local_err = NULL;
     int slot = object_property_get_int(OBJECT(dev), PC_DIMM_SLOT_PROP,
                                        &local_err);
 
     if (local_err) {
         error_propagate(errp, local_err);
-        return;
+        return NULL;
     }
 
     if (slot >= mem_st->dev_count) {
         char *dev_path = object_get_canonical_path(OBJECT(dev));
-        error_setg(errp, "acpi_memory_plug_cb: "
+        error_setg(errp, "acpi_memory_get_slot_status_descriptor: "
                    "device [%s] returned invalid memory slot[%d]",
-                    dev_path, slot);
+                   dev_path, slot);
         g_free(dev_path);
-        return;
+        return NULL;
     }
 
-    mdev = &mem_st->devs[slot];
+    return &mem_st->devs[slot];
+}
+
+void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
+                         DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_get_slot_status_descriptor(mem_st, dev, errp);
+    if (!mdev)
+        return;
+
     mdev->dimm = dev;
     mdev->is_enabled = true;
     mdev->is_inserting = true;
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 03/10] acpi, mem-hotplug: Add acpi_memory_hotplug_sci() to rise sci for memory hotplug.

[Tang Chen]

Add a new API named acpi_memory_hotplug_sci() to send memory hotplug SCI.
Doing this is because this procedure will be used by other functions in the
next coming patches.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/acpi/memory_hotplug.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index ef56bf6..9839963 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -188,6 +188,12 @@ acpi_memory_get_slot_status_descriptor(MemHotplugState *mem_st,
     return &mem_st->devs[slot];
 }
 
+static void acpi_memory_hotplug_sci(ACPIREGS *ar, qemu_irq irq)
+{
+    ar->gpe.sts[0] |= ACPI_MEMORY_HOTPLUG_STATUS;
+    acpi_update_sci(ar, irq);
+}
+
 void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
                          DeviceState *dev, Error **errp)
 {
@@ -201,10 +207,8 @@ void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
     mdev->is_enabled = true;
     mdev->is_inserting = true;
 
-    /* do ACPI magic */
-    ar->gpe.sts[0] |= ACPI_MEMORY_HOTPLUG_STATUS;
-    acpi_update_sci(ar, irq);
-    return;
+    /* Do ACPI magic */
+    acpi_memory_hotplug_sci(ar, irq);
 }
 
 static const VMStateDescription vmstate_memhp_sts = {
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 04/10] acpi, mem-hotplug: Add acpi_memory_unplug_cb() to implement memory unplug.

[Tang Chen]

Add a new bool member named is_removing to MemStatus indicating that
the memory solt is being removed. Set it to true in acpi_memory_unplug_cb(),
and send SCI to guest.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/acpi/memory_hotplug.c         | 15 +++++++++++++++
 include/hw/acpi/memory_hotplug.h |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index 9839963..01dea6c 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -211,6 +211,21 @@ void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
     acpi_memory_hotplug_sci(ar, irq);
 }
 
+void acpi_memory_unplug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
+                           DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_get_slot_status_descriptor(mem_st, dev, errp);
+    if (!mdev)
+        return;
+
+    mdev->is_removing = true;
+
+    /* Do ACPI magic */
+    acpi_memory_hotplug_sci(ar, irq);
+}
+
 static const VMStateDescription vmstate_memhp_sts = {
     .name = "memory hotplug device state",
     .version_id = 1,
diff --git a/include/hw/acpi/memory_hotplug.h b/include/hw/acpi/memory_hotplug.h
index 7bbf8a0..fe41268 100644
--- a/include/hw/acpi/memory_hotplug.h
+++ b/include/hw/acpi/memory_hotplug.h
@@ -11,6 +11,7 @@ typedef struct MemStatus {
     DeviceState *dimm;
     bool is_enabled;
     bool is_inserting;
+    bool is_removing;
     uint32_t ost_event;
     uint32_t ost_status;
 } MemStatus;
@@ -28,6 +29,8 @@ void acpi_memory_hotplug_init(MemoryRegion *as, Object *owner,
 
 void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
                          DeviceState *dev, Error **errp);
+void acpi_memory_unplug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
+                           DeviceState *dev, Error **errp);
 
 extern const VMStateDescription vmstate_memory_hotplug;
 #define VMSTATE_MEMORY_HOTPLUG(memhp, state) \
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 05/10] acpi, piix4: Add memory hot unplug support for piix4.

[Tang Chen]

From: Hu Tao <hutao@cn.fujitsu.com>

Implement acpi_memory_unplug_cb(), sending an sci to guest to trigger
memory hot-remove, and call it in piix4_device_unplug_cb().

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/acpi/piix4.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index 78c0a6d..92b29b7 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -360,7 +360,11 @@ static void piix4_device_unplug_request_cb(HotplugHandler *hotplug_dev,
 {
     PIIX4PMState *s = PIIX4_PM(hotplug_dev);
 
-    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+    if (s->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_cb(&s->ar, s->irq, &s->acpi_memory_hotplug, dev,
+                              errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         acpi_pcihp_device_unplug_cb(&s->ar, s->irq, &s->acpi_pci_hotplug, dev,
                                     errp);
     } else {
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 06/10] acpi, ich9: Add memory hot unplug support for ich9.

[Tang Chen]

Implement ich9_pm_device_unplug_cb() to support memory hot-remove,
calling acpi_memory_unplug_cb(). And itself will be called in
ich9_device_unplug_cb().

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/acpi/ich9.c         | 12 ++++++++++++
 hw/isa/lpc_ich9.c      |  5 +++--
 include/hw/acpi/ich9.h |  2 ++
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
index ea991a3..68cc169 100644
--- a/hw/acpi/ich9.c
+++ b/hw/acpi/ich9.c
@@ -301,6 +301,18 @@ void ich9_pm_device_plug_cb(ICH9LPCPMRegs *pm, DeviceState *dev, Error **errp)
     }
 }
 
+void ich9_pm_device_unplug_cb(ICH9LPCPMRegs *pm, DeviceState *dev, Error **errp)
+{
+    if (pm->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_cb(&pm->acpi_regs, pm->irq, &pm->acpi_memory_hotplug,
+                              dev, errp);
+    } else {
+        error_setg(errp, "acpi: device unplug request for not supported device"
+                   " type: %s", object_get_typename(OBJECT(dev)));
+    }
+}
+
 void ich9_pm_ospm_status(AcpiDeviceIf *adev, ACPIOSTInfoList ***list)
 {
     ICH9LPCState *s = ICH9_LPC_DEVICE(adev);
diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
index 530b074..75f28d1 100644
--- a/hw/isa/lpc_ich9.c
+++ b/hw/isa/lpc_ich9.c
@@ -610,8 +610,9 @@ static void ich9_device_plug_cb(HotplugHandler *hotplug_dev,
 static void ich9_device_unplug_request_cb(HotplugHandler *hotplug_dev,
                                           DeviceState *dev, Error **errp)
 {
-    error_setg(errp, "acpi: device unplug request for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    ICH9LPCState *lpc = ICH9_LPC_DEVICE(hotplug_dev);
+
+    ich9_pm_device_unplug_cb(&lpc->pm, dev, errp);
 }
 
 static bool ich9_rst_cnt_needed(void *opaque)
diff --git a/include/hw/acpi/ich9.h b/include/hw/acpi/ich9.h
index fe975e6..92f19de 100644
--- a/include/hw/acpi/ich9.h
+++ b/include/hw/acpi/ich9.h
@@ -59,6 +59,8 @@ extern const VMStateDescription vmstate_ich9_pm;
 void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs *pm, Error **errp);
 
 void ich9_pm_device_plug_cb(ICH9LPCPMRegs *pm, DeviceState *dev, Error **errp);
+void ich9_pm_device_unplug_cb(ICH9LPCPMRegs *pm, DeviceState *dev,
+                              Error **errp);
 
 void ich9_pm_ospm_status(AcpiDeviceIf *adev, ACPIOSTInfoList ***list);
 #endif /* HW_ACPI_ICH9_H */
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 07/10] pc: Add memory hot unplug support for pc machine.

[Tang Chen]

From: Hu Tao <hutao@cn.fujitsu.com>

Implement device unplug callback for PCMachine. And it now only support
pc-dimm hot-remove. The callback will call piix4 or ich9 callbacks introduced
in previous patches.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/i386/pc.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 1205db8..2c26749 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -61,6 +61,8 @@
 #include "hw/mem/pc-dimm.h"
 #include "trace.h"
 #include "qapi/visitor.h"
+#include "hw/acpi/piix4.h"
+#include "hw/i386/ich9.h"
 
 /* debug PC/ISA interrupts */
 //#define DEBUG_IRQ
@@ -1637,6 +1639,26 @@ out:
     error_propagate(errp, local_err);
 }
 
+static void pc_dimm_unplug(HotplugHandler *hotplug_dev,
+                           DeviceState *dev, Error **errp)
+{
+    HotplugHandlerClass *hhc;
+    Error *local_err = NULL;
+    PCMachineState *pcms = PC_MACHINE(hotplug_dev);
+
+    if (!pcms->acpi_dev) {
+        error_setg(&local_err,
+                   "memory hotplug is not enabled: missing acpi device");
+	goto out;
+    }
+
+    hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
+    hhc->unplug_request(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
+
+out:
+    error_propagate(errp, local_err);
+}
+
 static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
                                       DeviceState *dev, Error **errp)
 {
@@ -1647,6 +1669,14 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
     }
 }
 
+static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
+                                        DeviceState *dev, Error **errp)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        pc_dimm_unplug(hotplug_dev, dev, errp);
+    }
+}
+
 static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
                                              DeviceState *dev)
 {
@@ -1753,6 +1783,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     pcmc->get_hotplug_handler = mc->get_hotplug_handler;
     mc->get_hotplug_handler = pc_get_hotpug_handler;
     hc->plug = pc_machine_device_plug_cb;
+    hc->unplug = pc_machine_device_unplug_cb;
 }
 
 static const TypeInfo pc_machine_info = {
-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 08/10] pc-dimm: Add pc_dimm_unrealize() for memory hot unplug support.

[Tang Chen]

From: Hu Tao <hutao@cn.fujitsu.com>

Implement unrealize function for pc-dimm device. It remove subregion from
hotplug region, and delete ram address range from guest ram list.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/mem/pc-dimm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index ee802bb..b105871 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -270,12 +270,22 @@ static MemoryRegion *pc_dimm_get_memory_region(PCDIMMDevice *dimm)
     return host_memory_backend_get_memory(dimm->hostmem, &error_abort);
 }
 
+static void pc_dimm_unrealize(DeviceState *dev, Error **errp)
+{
+    PCDIMMDevice *dimm = PC_DIMM(dev);
+    MemoryRegion *mr = pc_dimm_get_memory_region(dimm);
+
+    memory_region_del_subregion(mr->container, mr);
+    vmstate_unregister_ram(mr, dev);
+}
+
 static void pc_dimm_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
     PCDIMMDeviceClass *ddc = PC_DIMM_CLASS(oc);
 
     dc->realize = pc_dimm_realize;
+    dc->unrealize = pc_dimm_unrealize;
     dc->props = pc_dimm_properties;
 
     ddc->get_memory_region = pc_dimm_get_memory_region;
-- 
1.8.4.2

Re: [Qemu-devel] [RESEND PATCH v4 08/10] pc-dimm: Add pc_dimm_unrealize() for memory hot unplug support.

[Igor Mammedov]

On Wed, 5 Nov 2014 13:49:53 +0800
Tang Chen <tangchen@cn.fujitsu.com> wrote:

> From: Hu Tao <hutao@cn.fujitsu.com>
> 
> Implement unrealize function for pc-dimm device. It remove subregion from
> hotplug region, and delete ram address range from guest ram list.
This still doesn't address comments made in V3

looks like there isn't any need for unrealize so far
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> ---
>  hw/mem/pc-dimm.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index ee802bb..b105871 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -270,12 +270,22 @@ static MemoryRegion *pc_dimm_get_memory_region(PCDIMMDevice *dimm)
>      return host_memory_backend_get_memory(dimm->hostmem, &error_abort);
>  }
>  
> +static void pc_dimm_unrealize(DeviceState *dev, Error **errp)
> +{
> +    PCDIMMDevice *dimm = PC_DIMM(dev);
> +    MemoryRegion *mr = pc_dimm_get_memory_region(dimm);
> +
> +    memory_region_del_subregion(mr->container, mr);
you wouldn't need to access fields if it's done in unplug handler
and you shouldn't access MemoryRegion fields directly in the first place

> +    vmstate_unregister_ram(mr, dev);


all above should be done unplug handler by pc-machine

> +}
> +
>  static void pc_dimm_class_init(ObjectClass *oc, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(oc);
>      PCDIMMDeviceClass *ddc = PC_DIMM_CLASS(oc);
>  
>      dc->realize = pc_dimm_realize;
> +    dc->unrealize = pc_dimm_unrealize;
>      dc->props = pc_dimm_properties;
>  
>      ddc->get_memory_region = pc_dimm_get_memory_region;

[Qemu-devel] [RESEND PATCH v4 09/10] acpi: Add hardware implementation for memory hot unplug.

[Tang Chen]

This patch adds a new bit to memory hotplug IO port indicating that
memory device is be removed. And set MemStatus->is_removing to false
when the bit is written.

NOTE: MemStatus->is_removing is set to true in acpi_memory_unplug_cb()
when doing memory hot-remove with device_del command.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 docs/specs/acpi_mem_hotplug.txt |  8 ++++++--
 hw/acpi/memory_hotplug.c        | 14 +++++++++++---
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/docs/specs/acpi_mem_hotplug.txt b/docs/specs/acpi_mem_hotplug.txt
index 1290994..5524c30 100644
--- a/docs/specs/acpi_mem_hotplug.txt
+++ b/docs/specs/acpi_mem_hotplug.txt
@@ -19,7 +19,9 @@ Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
               1: Device insert event, used to distinguish device for which
                  no device check event to OSPM was issued.
                  It's valid only when bit 1 is set.
-              2-7: reserved and should be ignored by OSPM
+              2: Device remove event, used to indicate that device is being
+		 removed.
+              3-7: reserved and should be ignored by OSPM
       [0x15-0x17] reserved
 
   write access:
@@ -35,7 +37,9 @@ Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
               1: if set to 1 clears device insert event, set by OSPM
                  after it has emitted device check event for the
                  selected memory device
-              2-7: reserved, OSPM must clear them before writing to register
+              2: set by hardware after it has emitted devive eject event for
+		 selected memory device
+              3-7: reserved, OSPM must clear them before writing to register
 
 Selecting memory device slot beyond present range has no effect on platform:
    - write accesses to memory hot-plug registers not documented above are
diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index 01dea6c..a745bb0 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -75,6 +75,7 @@ static uint64_t acpi_memory_hotplug_read(void *opaque, hwaddr addr,
     case 0x14: /* pack and return is_* fields */
         val |= mdev->is_enabled   ? 1 : 0;
         val |= mdev->is_inserting ? 2 : 0;
+        val |= mdev->is_removing  ? 4 : 0;
         trace_mhp_acpi_read_flags(mem_st->selector, val);
         break;
     default:
@@ -121,21 +122,28 @@ static void acpi_memory_hotplug_write(void *opaque, hwaddr addr, uint64_t data,
         mdev = &mem_st->devs[mem_st->selector];
         mdev->ost_status = data;
         trace_mhp_acpi_write_ost_status(mem_st->selector, mdev->ost_status);
-        /* TODO: implement memory removal on guest signal */
 
         info = acpi_memory_device_status(mem_st->selector, mdev);
         qapi_event_send_acpi_device_ost(info, &error_abort);
         qapi_free_ACPIOSTInfo(info);
         break;
-    case 0x14:
+    case 0x14: /* set is_* fields */
         mdev = &mem_st->devs[mem_st->selector];
+
         if (data & 2) { /* clear insert event */
             mdev->is_inserting  = false;
             trace_mhp_acpi_clear_insert_evt(mem_st->selector);
+        } else if (data & 4) { /* request removal of device */
+            mdev->is_enabled = false;
+            mdev->is_removing = false;
+            object_unparent(OBJECT(mdev->dimm));
+            mdev->dimm = NULL;
         }
+
+        break;
+    default:
         break;
     }
-
 }
 static const MemoryRegionOps acpi_memory_hotplug_ops = {
     .read = acpi_memory_hotplug_read,
-- 
1.8.4.2

Re: [Qemu-devel] [RESEND PATCH v4 09/10] acpi: Add hardware implementation for memory hot unplug.

[Hu Tao]

On Wed, Nov 05, 2014 at 01:49:54PM +0800, Tang Chen wrote:

<...>

> -              2-7: reserved, OSPM must clear them before writing to register
> +              2: set by hardware after it has emitted devive eject event for

s/devive/device/

Regards,
Hu

[Qemu-devel] [RESEND PATCH v4 10/10] pc, acpi bios: Add memory hot unplug interface.

[Tang Chen]

From: Hu Tao <hutao@cn.fujitsu.com>

This patch implements MEMORY_SLOT_EJECT_METHOD according to ACPI spec.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 hw/i386/ssdt-mem.dsl         |  5 +++++
 hw/i386/ssdt-misc.dsl        | 13 ++++++++++++-
 include/hw/acpi/pc-hotplug.h |  2 ++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/hw/i386/ssdt-mem.dsl b/hw/i386/ssdt-mem.dsl
index 22ff5dd..1416639 100644
--- a/hw/i386/ssdt-mem.dsl
+++ b/hw/i386/ssdt-mem.dsl
@@ -43,6 +43,7 @@ DefinitionBlock ("ssdt-mem.aml", "SSDT", 0x02, "BXPC", "CSSDT", 0x1)
     External(\_SB.PCI0.MEMORY_HOTPLUG_DEVICE.MEMORY_SLOT_STATUS_METHOD, MethodObj)
     External(\_SB.PCI0.MEMORY_HOTPLUG_DEVICE.MEMORY_SLOT_OST_METHOD, MethodObj)
     External(\_SB.PCI0.MEMORY_HOTPLUG_DEVICE.MEMORY_SLOT_PROXIMITY_METHOD, MethodObj)
+    External(\_SB.PCI0.MEMORY_HOTPLUG_DEVICE.MEMORY_SLOT_EJECT_METHOD, MethodObj)
 
     Scope(\_SB) {
 /*  v------------------ DO NOT EDIT ------------------v */
@@ -72,6 +73,10 @@ DefinitionBlock ("ssdt-mem.aml", "SSDT", 0x02, "BXPC", "CSSDT", 0x1)
             Method(_OST, 3) {
                 \_SB.PCI0.MEMORY_HOTPLUG_DEVICE.MEMORY_SLOT_OST_METHOD(_UID, Arg0, Arg1, Arg2)
             }
+
+            Method(_EJ0, 1) {
+                \_SB.PCI0.MEMORY_HOTPLUG_DEVICE.MEMORY_SLOT_EJECT_METHOD(_UID, Arg0)
+            }
         }
     }
 }
diff --git a/hw/i386/ssdt-misc.dsl b/hw/i386/ssdt-misc.dsl
index 0fd4480..7b29539 100644
--- a/hw/i386/ssdt-misc.dsl
+++ b/hw/i386/ssdt-misc.dsl
@@ -156,6 +156,7 @@ DefinitionBlock ("ssdt-misc.aml", "SSDT", 0x01, "BXPC", "BXSSDTSUSP", 0x1)
                 Offset(20),
                 MEMORY_SLOT_ENABLED,  1, // 1 if enabled, read only
                 MEMORY_SLOT_INSERT_EVENT, 1, // (read) 1 if has a insert event. (write) 1 to clear event
+                MEMORY_SLOT_REMOVE_EVENT, 1, // 1 if DIMM has a remove request, read only
             }
 
             Mutex (MEMORY_SLOT_LOCK, 0)
@@ -174,11 +175,14 @@ DefinitionBlock ("ssdt-misc.aml", "SSDT", 0x01, "BXPC", "BXSSDTSUSP", 0x1)
                 Acquire(MEMORY_SLOT_LOCK, 0xFFFF)
                 while (LLess(Local0, MEMORY_SLOTS_NUMBER)) {
                     Store(Local0, MEMORY_SLOT_SLECTOR) // select Local0 DIMM
+
                     If (LEqual(MEMORY_SLOT_INSERT_EVENT, One)) { // Memory device needs check
                         MEMORY_SLOT_NOTIFY_METHOD(Local0, 1)
                         Store(1, MEMORY_SLOT_INSERT_EVENT)
+                    } Elseif (LEqual(MEMORY_SLOT_REMOVE_EVENT, One)) { // Ejection request
+                        MEMORY_SLOT_NOTIFY_METHOD(Local0, 3)
                     }
-                    // TODO: handle memory eject request
+
                     Add(Local0, One, Local0) // goto next DIMM
                 }
                 Release(MEMORY_SLOT_LOCK)
@@ -278,6 +282,13 @@ DefinitionBlock ("ssdt-misc.aml", "SSDT", 0x01, "BXPC", "BXSSDTSUSP", 0x1)
                 Store(Arg2, MEMORY_SLOT_OST_STATUS)
                 Release(MEMORY_SLOT_LOCK)
             }
+
+            Method(MEMORY_SLOT_EJECT_METHOD, 2) {
+                Acquire(MEMORY_SLOT_LOCK, 0xFFFF)
+                Store(ToInteger(Arg0), MEMORY_SLOT_SLECTOR) // select DIMM
+                Store(One, MEMORY_SLOT_REMOVE_EVENT)
+                Release(MEMORY_SLOT_LOCK)
+            }
         } // Device()
     } // Scope()
 }
diff --git a/include/hw/acpi/pc-hotplug.h b/include/hw/acpi/pc-hotplug.h
index b9db295..b61b6ea 100644
--- a/include/hw/acpi/pc-hotplug.h
+++ b/include/hw/acpi/pc-hotplug.h
@@ -42,6 +42,7 @@
 #define MEMORY_SLOT_PROXIMITY        MPX
 #define MEMORY_SLOT_ENABLED          MES
 #define MEMORY_SLOT_INSERT_EVENT     MINS
+#define MEMORY_SLOT_REMOVE_EVENT     MRMV
 #define MEMORY_SLOT_SLECTOR          MSEL
 #define MEMORY_SLOT_OST_EVENT        MOEV
 #define MEMORY_SLOT_OST_STATUS       MOSC
@@ -50,6 +51,7 @@
 #define MEMORY_SLOT_CRS_METHOD       MCRS
 #define MEMORY_SLOT_OST_METHOD       MOST
 #define MEMORY_SLOT_PROXIMITY_METHOD MPXM
+#define MEMORY_SLOT_EJECT_METHOD     MEJ0
 #define MEMORY_SLOT_NOTIFY_METHOD    MTFY
 #define MEMORY_SLOT_SCAN_METHOD      MSCN
 
-- 
1.8.4.2

Re: [Qemu-devel] [RESEND PATCH v4 00/10] QEmu memory hot unplug support.

[Igor Mammedov]

On Wed, 5 Nov 2014 13:49:45 +0800
Tang Chen <tangchen@cn.fujitsu.com> wrote:

> This patch-set implements memory hot-remove for QEmu. 
> 
> Rebased on Igor's asynchronize hotplug framework (qemu v2.1.2, the latest).
As I've wrote before, there were hot-unplug patches merged last month,
see for reference http://lists.nongnu.org/archive/html/qemu-devel/2014-09/msg05195.html
and this series could benefit from them.

So please look take in account not addressed yet comments on V3
and rebase on current master instead of stable 2.1.2.

> 
> Approach: QEmu sets GPE status bit, then triggers SCI to notify guest os.
> Guest os checks device status, and free memory resource if possible,
> then generate OST.
> 
> NOTE: In this version, memory hot-remove is independent from _OST, 
>       following Igor's comments. Will implement _OST for memory hot-remove
>       soon if this part is OK.
> 
> Change log v3 -> v4 (RESEND):
> 1. Add new patch 1 ~ 4, fix some small problems in coding.
> 2. In patch 9, make memory hot-remove independent from _OST.
> 3. In patch 9, add comment for is_removing flag to document.
> 4. In patch 10, use macro instead of number.
> 5. Remove original patch 8 and 12 to coincident with asynchronize
>    hotplug framework.
> 
> Hu Tao (4):
>   acpi, piix4: Add memory hot unplug support for piix4.
>   pc: Add memory hot unplug support for pc machine.
>   pc-dimm: Add pc_dimm_unrealize() for memory hot unplug support.
>   pc, acpi bios: Add memory hot unplug interface.
> 
> Tang Chen (6):
>   acpi, mem-hotplug: Use PC_DIMM_SLOT_PROP in acpi_memory_plug_cb().
>   acpi, mem-hotplug: Add acpi_memory_get_slot_status_descriptor() to get
>     MemStatus.
>   acpi, mem-hotplug: Add acpi_memory_hotplug_sci() to rise sci for
>     memory hotplug.
>   acpi, mem-hotplug: Add acpi_memory_unplug_cb() to implement memory
>     unplug.
>   acpi, ich9: Add memory hot unplug support for ich9.
>   acpi: Add hardware implementation for memory hot unplug.
> 
>  docs/specs/acpi_mem_hotplug.txt  |  8 +++--
>  hw/acpi/ich9.c                   | 12 +++++++
>  hw/acpi/memory_hotplug.c         | 71 +++++++++++++++++++++++++++++++---------
>  hw/acpi/piix4.c                  |  6 +++-
>  hw/i386/pc.c                     | 31 ++++++++++++++++++
>  hw/i386/ssdt-mem.dsl             |  5 +++
>  hw/i386/ssdt-misc.dsl            | 13 +++++++-
>  hw/isa/lpc_ich9.c                |  5 +--
>  hw/mem/pc-dimm.c                 | 10 ++++++
>  include/hw/acpi/ich9.h           |  2 ++
>  include/hw/acpi/memory_hotplug.h |  3 ++
>  include/hw/acpi/pc-hotplug.h     |  2 ++
>  12 files changed, 146 insertions(+), 22 deletions(-)
> 

[Qemu-devel] [RESEND PATCH v4 00/10] QEmu memory hot unplug support.

[Tang Chen]

This patch-set implements memory hot-remove for QEmu. 

Rebased on Igor's asynchronize hotplug framework (qemu v2.1.2, the latest).

Approach: QEmu sets GPE status bit, then triggers SCI to notify guest os.
Guest os checks device status, and free memory resource if possible,
then generate OST.

NOTE: In this version, memory hot-remove is independent from _OST, 
      following Igor's comments.
      Patches _OST handling for platforms supporting _OST will come 
      soon when Igor finishes his refacting for framework of hotplug.

Change log v3 -> v4 (RESEND):
1. Add new patch 1 ~ 4, fix some small problems in coding.
2. In patch 9, make memory hot-remove independent from _OST.
3. In patch 9, add comment for is_removing flag to document.
4. In patch 10, use macro instead of number.
5. Remove original patch 8 and 12 to coincident with asynchronize
   hotplug framework.

Hu Tao (4):
  acpi, piix4: Add memory hot unplug support for piix4.
  pc: Add memory hot unplug support for pc machine.
  pc-dimm: Add pc_dimm_unrealize() for memory hot unplug support.
  pc, acpi bios: Add memory hot unplug interface.

Tang Chen (6):
  acpi, mem-hotplug: Use PC_DIMM_SLOT_PROP in acpi_memory_plug_cb().
  acpi, mem-hotplug: Add acpi_memory_get_slot_status_descriptor() to get
    MemStatus.
  acpi, mem-hotplug: Add acpi_memory_hotplug_sci() to rise sci for
    memory hotplug.
  acpi, mem-hotplug: Add acpi_memory_unplug_cb() to implement memory
    unplug.
  acpi, ich9: Add memory hot unplug support for ich9.
  acpi: Add hardware implementation for memory hot unplug.

 docs/specs/acpi_mem_hotplug.txt  |  8 +++--
 hw/acpi/ich9.c                   | 12 +++++++
 hw/acpi/memory_hotplug.c         | 71 +++++++++++++++++++++++++++++++---------
 hw/acpi/piix4.c                  |  6 +++-
 hw/i386/pc.c                     | 31 ++++++++++++++++++
 hw/i386/ssdt-mem.dsl             |  5 +++
 hw/i386/ssdt-misc.dsl            | 13 +++++++-
 hw/isa/lpc_ich9.c                |  5 +--
 hw/mem/pc-dimm.c                 | 10 ++++++
 include/hw/acpi/ich9.h           |  2 ++
 include/hw/acpi/memory_hotplug.h |  3 ++
 include/hw/acpi/pc-hotplug.h     |  2 ++
 12 files changed, 146 insertions(+), 22 deletions(-)

-- 
1.8.4.2

[Qemu-devel] [RESEND PATCH v4 09/10] acpi: Add hardware implementation for memory hot unplug.

[Tang Chen]

This patch adds a new bit to memory hotplug IO port indicating that
memory device is be removed. And set MemStatus->is_removing to false
when the bit is written.

NOTE: MemStatus->is_removing is set to true in acpi_memory_unplug_cb()
when doing memory hot-remove with device_del command.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 docs/specs/acpi_mem_hotplug.txt |  8 ++++++--
 hw/acpi/memory_hotplug.c        | 14 +++++++++++---
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/docs/specs/acpi_mem_hotplug.txt b/docs/specs/acpi_mem_hotplug.txt
index 1290994..5524c30 100644
--- a/docs/specs/acpi_mem_hotplug.txt
+++ b/docs/specs/acpi_mem_hotplug.txt
@@ -19,7 +19,9 @@ Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
               1: Device insert event, used to distinguish device for which
                  no device check event to OSPM was issued.
                  It's valid only when bit 1 is set.
-              2-7: reserved and should be ignored by OSPM
+              2: Device remove event, used to indicate that device is being
+		 removed.
+              3-7: reserved and should be ignored by OSPM
       [0x15-0x17] reserved
 
   write access:
@@ -35,7 +37,9 @@ Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
               1: if set to 1 clears device insert event, set by OSPM
                  after it has emitted device check event for the
                  selected memory device
-              2-7: reserved, OSPM must clear them before writing to register
+              2: set by hardware after it has emitted devive eject event for
+		 selected memory device
+              3-7: reserved, OSPM must clear them before writing to register
 
 Selecting memory device slot beyond present range has no effect on platform:
    - write accesses to memory hot-plug registers not documented above are
diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index 01dea6c..a745bb0 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -75,6 +75,7 @@ static uint64_t acpi_memory_hotplug_read(void *opaque, hwaddr addr,
     case 0x14: /* pack and return is_* fields */
         val |= mdev->is_enabled   ? 1 : 0;
         val |= mdev->is_inserting ? 2 : 0;
+        val |= mdev->is_removing  ? 4 : 0;
         trace_mhp_acpi_read_flags(mem_st->selector, val);
         break;
     default:
@@ -121,21 +122,28 @@ static void acpi_memory_hotplug_write(void *opaque, hwaddr addr, uint64_t data,
         mdev = &mem_st->devs[mem_st->selector];
         mdev->ost_status = data;
         trace_mhp_acpi_write_ost_status(mem_st->selector, mdev->ost_status);
-        /* TODO: implement memory removal on guest signal */
 
         info = acpi_memory_device_status(mem_st->selector, mdev);
         qapi_event_send_acpi_device_ost(info, &error_abort);
         qapi_free_ACPIOSTInfo(info);
         break;
-    case 0x14:
+    case 0x14: /* set is_* fields */
         mdev = &mem_st->devs[mem_st->selector];
+
         if (data & 2) { /* clear insert event */
             mdev->is_inserting  = false;
             trace_mhp_acpi_clear_insert_evt(mem_st->selector);
+        } else if (data & 4) { /* request removal of device */
+            mdev->is_enabled = false;
+            mdev->is_removing = false;
+            object_unparent(OBJECT(mdev->dimm));
+            mdev->dimm = NULL;
         }
+
+        break;
+    default:
         break;
     }
-
 }
 static const MemoryRegionOps acpi_memory_hotplug_ops = {
     .read = acpi_memory_hotplug_read,
-- 
1.8.4.2