[Qemu-devel] [RFC PATCH v1 11/13] spapr: Initialize hotplug memory address space

[Bharata B Rao]

Initialize a hotplug memory region under which all the hotplugged
memory is accommodated. Also enable memory hotplug by setting
CONFIG_MEM_HOTPLUG.

Modelled on i386 memory hotplug.

Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>
---
 default-configs/ppc64-softmmu.mak |  1 +
 hw/ppc/spapr.c                    | 26 ++++++++++++++++++++++++++
 include/hw/ppc/spapr.h            |  3 +++
 3 files changed, 30 insertions(+)

diff --git a/default-configs/ppc64-softmmu.mak 
b/default-configs/ppc64-softmmu.mak
index bd30d69..03210de 100644
--- a/default-configs/ppc64-softmmu.mak
+++ b/default-configs/ppc64-softmmu.mak
@@ -60,3 +60,4 @@ CONFIG_I82374=y
 CONFIG_I8257=y
 CONFIG_MC146818RTC=y
 CONFIG_ISA_TESTDEV=y
+CONFIG_MEM_HOTPLUG=y
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 44405b2..9ff08ff 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -120,6 +120,8 @@ struct sPAPRMachineState {
 
     /*< public >*/
     char *kvm_type;
+    ram_addr_t hotplug_memory_base;
+    MemoryRegion hotplug_memory;
 };
 
 sPAPREnvironment *spapr;
@@ -1403,6 +1405,7 @@ static void ppc_spapr_init(MachineState *machine)
     bool kernel_le = false;
     char *filename;
     int smt = kvmppc_smt_threads();
+    sPAPRMachineState *ms = SPAPR_MACHINE(machine);
 
     msi_supported = true;
 
@@ -1492,6 +1495,29 @@ static void ppc_spapr_init(MachineState *machine)
         memory_region_add_subregion(sysmem, 0, rma_region);
     }
 
+    if (machine->ram_size < machine->maxram_size) {
+        ram_addr_t hotplug_mem_size = machine->maxram_size - machine->ram_size;
+
+        if (machine->ram_slots > SPAPR_MAX_RAM_SLOTS) {
+            error_report("unsupported amount of memory slots: %"PRIu64,
+                         machine->ram_slots);
+            exit(EXIT_FAILURE);
+        }
+
+        ms->hotplug_memory_base = ROUND_UP(machine->ram_size, 1ULL << 30);
+
+        if ((ms->hotplug_memory_base + hotplug_mem_size) < hotplug_mem_size) {
+            error_report("unsupported amount of maximum memory: " RAM_ADDR_FMT,
+                         machine->maxram_size);
+            exit(EXIT_FAILURE);
+        }
+
+        memory_region_init(&ms->hotplug_memory, OBJECT(ms),
+                           "hotplug-memory", hotplug_mem_size);
+        memory_region_add_subregion(sysmem, ms->hotplug_memory_base,
+                                    &ms->hotplug_memory);
+    }
+
     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, "spapr-rtas.bin");
     spapr->rtas_size = get_image_size(filename);
     spapr->rtas_blob = g_malloc(spapr->rtas_size);
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index ae8b4e1..64681c4 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -482,6 +482,9 @@ struct sPAPRTCETable {
 #define TIMEBASE_FREQ           512000000ULL
 #define SPAPR_MIN_MEMORY_BLOCK_SIZE (1 << 28) /* 256MB */
 
+/* Support a min of 1TB hotplug memory assuming 256MB per slot */
+#define SPAPR_MAX_RAM_SLOTS     (1ULL << 12)
+
 void spapr_events_init(sPAPREnvironment *spapr);
 void spapr_events_fdt_skel(void *fdt, uint32_t epow_irq);
 int spapr_h_cas_compose_response(target_ulong addr, target_ulong size);
-- 
2.1.0