applicable to PowerKVM, hence the reason for extending the notification
framework to support hotplug events.
-Note that these events are not yet formally part of the PAPR+ specification,
-but support for this format has already been implemented in DR-related
-guest tools such as powerpc-utils/librtas, as well as kernel patches that have
-been submitted to handle in-kernel processing of memory/cpu-related hotplug
-events[1], and is planned for formal inclusion is PAPR+ specification. The
-hotplug-specific payload is QEMU implemented as follows (with all values
+The format for these EPOW-signalled events is described below under
+"hotplug/unplug event structure". Note that these events are not
+formally part of the PAPR+ specification, and have been superseded by a
+newer format, also described below under "hotplug/unplug event structure",
+and so are now deemed a "legacy" format. The formats are similar, but the
+"modern" format contains additional fields/flags, which are denoted for the
+purposes of this documentation with "#ifdef GUEST_SUPPORTS_MODERN" guards.
+
+QEMU should assume support only for "legacy" fields/flags unless the guest
+advertises support for the "modern" format via ibm,client-architecture-support
+hcall by setting byte 5, bit 6 of it's ibm,architecture-vec-5 option vector
+structure (as described by LoPAPR v11, B.6.2.3). As with "legacy" format events,
+"modern" format events are surfaced to the guest via check-exception RTAS calls,
+but use a dedicated event source to signal the guest. This event source is
+advertised to the guest by the addition of a "hot-plug-events" node under
+"/event-sources" node of the guest's device tree using the standard format
+described in LoPAPR v11, B.6.12.1.
+
+== hotplug/unplug event structure ==
+
+The hotplug-specific payload in QEMU is implemented as follows (with all values
encoded in big-endian format):
struct rtas_event_log_v6_hp {
#define RTAS_LOG_V6_HP_ACTION_ADD 1
#define RTAS_LOG_V6_HP_ACTION_REMOVE 2
uint8_t hotplug_action; /* action (add/remove) */
-#define RTAS_LOG_V6_HP_ID_DRC_NAME 1
-#define RTAS_LOG_V6_HP_ID_DRC_INDEX 2
-#define RTAS_LOG_V6_HP_ID_DRC_COUNT 3
+#define RTAS_LOG_V6_HP_ID_DRC_NAME 1
+#define RTAS_LOG_V6_HP_ID_DRC_INDEX 2
+#define RTAS_LOG_V6_HP_ID_DRC_COUNT 3
+#ifdef GUEST_SUPPORTS_MODERN
+#define RTAS_LOG_V6_HP_ID_DRC_COUNT_INDEXED 4
+#endif
uint8_t hotplug_identifier; /* type of the resource identifier,
* which serves as the discriminator
* for the 'drc' union field below
*/
+#ifdef GUEST_SUPPORTS_MODERN
+ uint8_t capabilities; /* capability flags, currently unused
+ * by QEMU
+ */
+#else
uint8_t reserved;
+#endif
union {
uint32_t index; /* DRC index of resource to take action
* on
uint32_t count; /* number of DR resources to take
* action on (guest chooses which)
*/
+#ifdef GUEST_SUPPORTS_MODERN
+ struct {
+ uint32_t count; /* number of DR resources to take
+ * action on
+ */
+ uint32_t index; /* DRC index of first resource to take
+ * action on. guest will take action
+ * on DRC index <index> through
+ * DRC index <index + count - 1> in
+ * sequential order
+ */
+ } count_indexed;
+#endif
char name[1]; /* string representing the name of the
* DRC to take action on
*/
pseries guests use this property to note the maximum allowed CPUs for the
guest.
+== ibm,dynamic-reconfiguration-memory ==
+
+ibm,dynamic-reconfiguration-memory is a device tree node that represents
+dynamically reconfigurable logical memory blocks (LMB). This node
+is generated only when the guest advertises the support for it via
+ibm,client-architecture-support call. Memory that is not dynamically
+reconfigurable is represented by /memory nodes. The properties of this
+node that are of interest to the sPAPR memory hotplug implementation
+in QEMU are described here.
+
+ibm,lmb-size
+
+This 64bit integer defines the size of each dynamically reconfigurable LMB.
+
+ibm,associativity-lookup-arrays
+
+This property defines a lookup array in which the NUMA associativity
+information for each LMB can be found. It is a property encoded array
+that begins with an integer M, the number of associativity lists followed
+by an integer N, the number of entries per associativity list and terminated
+by M associativity lists each of length N integers.
+
+This property provides the same information as given by ibm,associativity
+property in a /memory node. Each assigned LMB has an index value between
+0 and M-1 which is used as an index into this table to select which
+associativity list to use for the LMB. This index value for each LMB
+is defined in ibm,dynamic-memory property.
+
+ibm,dynamic-memory
+
+This property describes the dynamically reconfigurable memory. It is a
+property encoded array that has an integer N, the number of LMBs followed
+by N LMB list entires.
+
+Each LMB list entry consists of the following elements:
+
+- Logical address of the start of the LMB encoded as a 64bit integer. This
+ corresponds to reg property in /memory node.
+- DRC index of the LMB that corresponds to ibm,my-drc-index property
+ in a /memory node.
+- Four bytes reserved for expansion.
+- Associativity list index for the LMB that is used as an index into
+ ibm,associativity-lookup-arrays property described earlier. This
+ is used to retrieve the right associativity list to be used for this
+ LMB.
+- A 32bit flags word. The bit at bit position 0x00000008 defines whether
+ the LMB is assigned to the the partition as of boot time.
+
+ibm,dynamic-memory-v2
+
+This property describes the dynamically reconfigurable memory. This is
+an alternate and newer way to describe dyanamically reconfigurable memory.
+It is a property encoded array that has an integer N (the number of
+LMB set entries) followed by N LMB set entries. There is an LMB set entry
+for each sequential group of LMBs that share common attributes.
+
+Each LMB set entry consists of the following elements:
+
+- Number of sequential LMBs in the entry represented by a 32bit integer.
+- Logical address of the first LMB in the set encoded as a 64bit integer.
+- DRC index of the first LMB in the set.
+- Associativity list index that is used as an index into
+ ibm,associativity-lookup-arrays property described earlier. This
+ is used to retrieve the right associativity list to be used for all
+ the LMBs in this set.
+- A 32bit flags word that applies to all the LMBs in the set.
+
[1] http://thread.gmane.org/gmane.linux.ports.ppc.embedded/75350/focus=106867