Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc, virtio enhancements

Memory hot-unplug support for pc, MSI-X
mapping update speedup for virtio-pci,
misc refactorings and bugfixes.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Mon May 11 08:23:43 2015 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream: (28 commits)
  acpi: update expected files for memory unplug
  virtio-scsi: Move DEFINE_VIRTIO_SCSI_FEATURES to virtio-scsi
  virtio-net: Move DEFINE_VIRTIO_NET_FEATURES to virtio-net
  pci: Merge pci_nic_init() into pci_nic_init_nofail()
  acpi: add a missing backslash to the \_SB scope.
  qmp-event: add event notification for memory hot unplug error
  acpi: add hardware implementation for memory hot unplug
  acpi: fix "Memory device control fields" register
  acpi: extend aml_field() to support UpdateRule
  acpi, mem-hotplug: add unplug cb for memory device
  acpi, mem-hotplug: add unplug request cb for memory device
  acpi, mem-hotplug: add acpi_memory_slot_status() to get MemStatus
  docs: update documentation for memory hot unplug
  virtio: coding style tweak
  pci: remove hard-coded bar size in msix_init_exclusive_bar()
  virtio-pci: speedup MSI-X masking and unmasking
  virtio: introduce vector to virtqueues mapping
  virtio-ccw: using VIRTIO_NO_VECTOR instead of 0 for invalid virtqueue
  monitor: check return value of qemu_find_net_clients_except()
  monitor: replace the magic number 255 with MAX_QUEUE_NUM
  ...

Conflicts:
	hw/s390x/s390-virtio-bus.c

[PMM: fixed conflict in s390_virtio_scsi_properties and
s390_virtio_net_properties arrays; since the result of the
two conflicting patches is to empty the property arrays
completely, the conflict resolution is to remove them entirely.]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 91 insertions, 7 deletions

diff --git a/docs/memory-hotplug.txt b/docs/memory-hotplug.txt
index f70571df0c..56bdd0a47b 100644
--- a/docs/memory-hotplug.txt
+++ b/docs/memory-hotplug.txt
@@ -4,9 +4,7 @@ QEMU memory hotplug
 This document explains how to use the memory hotplug feature in QEMU,
 which is present since v2.1.0.
 
-Please, note that memory hotunplug is not supported yet. This means
-that you're able to add memory, but you're not able to remove it.
-Also, proper guest support is required for memory hotplug to work.
+Guest support is required for memory hotplug to work.
 
 Basic RAM hotplug
 -----------------
@@ -74,3 +72,22 @@ comes from regular RAM, 1GB is a 1GB hugepage page and 256MB is from
    -device pc-dimm,id=dimm1,memdev=mem1 \
    -object memory-backend-file,id=mem2,size=256M,mem-path=/mnt/hugepages-2MB \
    -device pc-dimm,id=dimm2,memdev=mem2
+
+
+RAM hot-unplug
+---------------
+
+In order to be able to hot unplug pc-dimm device, QEMU has to be told the ids
+of pc-dimm device and memory backend object. The ids were assigned when you hot
+plugged memory.
+
+Two monitor commands are used to hot unplug memory:
+
+ - "device_del": deletes a front-end pc-dimm device
+ - "object_del": deletes a memory backend object
+
+For example, assuming that the pc-dimm device with id "dimm1" exists, and its memory
+backend is "mem1", the following commands tries to remove it.
+
+  (qemu) device_del dimm1
+  (qemu) object_del mem1
diff --git a/docs/qmp/qmp-events.txt b/docs/qmp/qmp-events.txt
index 64ba46c769..6dc2cca7de 100644
--- a/docs/qmp/qmp-events.txt
+++ b/docs/qmp/qmp-events.txt
@@ -232,6 +232,23 @@ Example:
 { "event": "GUEST_PANICKED",
      "data": { "action": "pause" } }
 
+MEM_HOT_UNPLUG_ERROR
+--------------------
+Emitted when memory hot unplug error occurs.
+
+Data:
+
+- "device": device name (json-string)
+- "msg": Informative message (e.g., reason for the error) (json-string)
+
+Example:
+
+{ "event": "MEM_HOT_UNPLUG_ERROR"
+  "data": { "device": "dimm1",
+            "msg": "acpi: device unplug for unsupported device"
+  },
+  "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
+
 NIC_RX_FILTER_CHANGED
 ---------------------
 
diff --git a/docs/specs/acpi_mem_hotplug.txt b/docs/specs/acpi_mem_hotplug.txt
index 12909940cc..3df3620ce4 100644
--- a/docs/specs/acpi_mem_hotplug.txt
+++ b/docs/specs/acpi_mem_hotplug.txt
@@ -2,7 +2,7 @@ QEMU<->ACPI BIOS memory hotplug interface
 --------------------------------------
 
 ACPI BIOS GPE.3 handler is dedicated for notifying OS about memory hot-add
-events.
+and hot-remove events.
 
 Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
 ---------------------------------------------------------------
@@ -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 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:
@@ -31,14 +33,62 @@ Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
       [0xc-0x13] reserved, writes into it are ignored
       [0x14] Memory device control fields
           bits:
-              0: reserved, OSPM must clear it before writing to register
+              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
-              2-7: reserved, OSPM must clear them before writing to register
+              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          |                     
+ +------------------+              |                   |                     
+                                   +-------------------+