Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/qemu/docs/specs/acpi_mem_hotplug.txt b/qemu/docs/specs/acpi_mem_hotplug.txt
new file mode 100644
index 000000000..3df3620ce
--- /dev/null
+++ b/qemu/docs/specs/acpi_mem_hotplug.txt
@@ -0,0 +1,94 @@
+QEMU<->ACPI BIOS memory hotplug interface
+--------------------------------------
+
+ACPI BIOS GPE.3 handler is dedicated for notifying OS about memory hot-add
+and hot-remove events.
+
+Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
+---------------------------------------------------------------
+0xa00:
+  read access:
+      [0x0-0x3] Lo part of memory device phys address
+      [0x4-0x7] Hi part of memory device phys address
+      [0x8-0xb] Lo part of memory device size in bytes
+      [0xc-0xf] Hi part of memory device size in bytes
+      [0x10-0x13] Memory device proximity domain
+      [0x14] Memory device status fields
+          bits:
+              0: Device is enabled and may be used by guest
+              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: Device remove event, used to distinguish device for which
+                 no device eject request to OSPM was issued.
+              3-7: reserved and should be ignored by OSPM
+      [0x15-0x17] reserved
+
+  write access:
+      [0x0-0x3] Memory device slot selector, selects active memory device.
+                All following accesses to other registers in 0xa00-0xa17
+                region will read/store data from/to selected memory device.
+      [0x4-0x7] OST event code reported by OSPM
+      [0x8-0xb] OST status code reported by OSPM
+      [0xc-0x13] reserved, writes into it are ignored
+      [0x14] Memory device control fields
+          bits:
+              0: reserved, OSPM must clear it before writing to register.
+                 Due to BUG in versions prior 2.4 that field isn't cleared
+                 when other fields are written. Keep it reserved and don't
+                 try to reuse it.
+              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: if set to 1 clears device remove event, set by OSPM
+                 after it has emitted device eject request for the
+                 selected memory device
+              3: if set to 1 initiates device eject, set by OSPM when it
+                 triggers memory device removal and calls _EJ0 method
+              4-7: 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
+     ignored
+   - read accesses to memory hot-plug registers not documented above return
+     all bits set to 1.
+
+Memory hot remove process diagram:
+----------------------------------
+ +-------------+     +-----------------------+      +------------------+     
+ |  1. QEMU    |     | 2. QEMU               |      |3. QEMU           |     
+ |  device_del +---->+ device unplug request +----->+Send SCI to guest,|     
+ |             |     |         cb            |      |return control to |     
+ +-------------+     +-----------------------+      |management        |     
+                                                    +------------------+     
+                                                                             
+ +---------------------------------------------------------------------+     
+                                                                             
+ +---------------------+              +-------------------------+            
+ | OSPM:               | remove event | OSPM:                   |            
+ | send Eject Request, |              | Scan memory devices     |            
+ | clear remove event  +<-------------+ for event flags         |            
+ |                     |              |                         |            
+ +---------------------+              +-------------------------+            
+           |                                                                 
+           |                                                                 
+ +---------v--------+            +-----------------------+                   
+ | Guest OS:        |  success   | OSPM:                 |                   
+ | process Ejection +----------->+ Execute _EJ0 method,  |                   
+ | request          |            | set eject bit in flags|                   
+ +------------------+            +-----------------------+                   
+           |failure                         |                                
+           v                                v                                
+ +------------------------+      +-----------------------+                   
+ | OSPM:                  |      | QEMU:                 |                   
+ | set OST event & status |      | call device unplug cb |                   
+ | fields                 |      |                       |                   
+ +------------------------+      +-----------------------+                   
+          |                                  |                               
+          v                                  v                               
+ +------------------+              +-------------------+                     
+ |QEMU:             |              |QEMU:              |                     
+ |Send OST QMP event|              |Send device deleted|                     
+ |                  |              |QMP event          |                     
+ +------------------+              |                   |                     
+                                   +-------------------+