[Qemu-devel] [RESEND PATCH v4 2/6] acpi, mem-hotplug: Add unplug request cb for memory device

[Zhu Guihua]

From: Tang Chen <address@hidden>

Memory hot unplug are both asynchronous procedures.
When the unplug operation happens, unplug request cb is called first.
And when guest OS finished handling unplug, unplug cb will be called
to do the real removal of device.

This patch adds unplug request cb for memory device, and adds the
is_removing boolean field to MemStatus. This field is used to indicate
whether the memory slot is being removed. This field is set to true in
acpi_memory_unplug_request_cb().

Signed-off-by: Tang Chen <address@hidden>
Signed-off-by: Zhu Guihua <address@hidden>
---
 hw/acpi/ich9.c                   | 10 ++++++++--
 hw/acpi/memory_hotplug.c         | 19 +++++++++++++++++++
 hw/acpi/piix4.c                  |  6 +++++-
 include/hw/acpi/memory_hotplug.h |  4 ++++
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
index 5352e19..b85eed4 100644
--- a/hw/acpi/ich9.c
+++ b/hw/acpi/ich9.c
@@ -400,8 +400,14 @@ void ich9_pm_device_plug_cb(ICH9LPCPMRegs *pm, DeviceState 
*dev, Error **errp)
 void ich9_pm_device_unplug_request_cb(ICH9LPCPMRegs *pm, DeviceState *dev,
                                       Error **errp)
 {
-    error_setg(errp, "acpi: device unplug request for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    if (pm->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_request_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_device_unplug_cb(ICH9LPCPMRegs *pm, DeviceState *dev,
diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index 0efc357..2ef6a94 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:
@@ -208,6 +209,24 @@ void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, 
MemHotplugState *mem_st,
     return;
 }
 
+void acpi_memory_unplug_request_cb(ACPIREGS *ar, qemu_irq irq,
+                                   MemHotplugState *mem_st,
+                                   DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_slot_status(mem_st, dev, errp);
+    if (!mdev) {
+        return;
+    }
+
+    mdev->is_removing = true;
+
+    /* Do ACPI magic */
+    ar->gpe.sts[0] |= ACPI_MEMORY_HOTPLUG_STATUS;
+    acpi_update_sci(ar, irq);
+}
+
 static const VMStateDescription vmstate_memhp_sts = {
     .name = "memory hotplug device state",
     .version_id = 1,
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index d1f1179..f716e91 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -361,7 +361,11 @@ 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_request_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 {
diff --git a/include/hw/acpi/memory_hotplug.h b/include/hw/acpi/memory_hotplug.h
index 7bbf8a0..c437a85 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 +29,9 @@ 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_request_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) \
-- 
1.9.3