[Xen-devel] [RFC QEMU PATCH v2 09/10] xen-hvm: create hotplug memory region on Xen

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

The current QEMU implementation allocates guest physical address for
vNVDIMM in the hotplug memory region, which was not created when QEMU
is used as Xen device model. Reuse existing code in i386/pc.c to
create the hotplug memory region for HVM domain on Xen, so that we can
reuse other parts of NVDIMM implementation with minor modifications.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Eduardo Habkost <ehabkost@xxxxxxxxxx>
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Anthony Perard <anthony.perard@xxxxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
---
 hw/i386/pc.c         | 82 ++++++++++++++++++++++++++++------------------------
 include/hw/i386/pc.h |  1 +
 xen-hvm.c            |  2 ++
 3 files changed, 47 insertions(+), 38 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 6b76720c35..4ea6baa613 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1356,6 +1356,49 @@ void xen_load_linux(PCMachineState *pcms)
     pcms->fw_cfg = fw_cfg;
 }
 
+void pc_memory_hotplug_init(PCMachineState *pcms, MemoryRegion *system_memory)
+{
+    MachineState *machine = MACHINE(pcms);
+    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
+    ram_addr_t hotplug_mem_size = machine->maxram_size - machine->ram_size;;
+
+    if (!pcmc->has_reserved_memory || machine->ram_size >= 
machine->maxram_size)
+        return;
+
+    if (machine->ram_slots > ACPI_MAX_RAM_SLOTS) {
+        error_report("unsupported amount of memory slots: %"PRIu64,
+                     machine->ram_slots);
+        exit(EXIT_FAILURE);
+    }
+
+    if (QEMU_ALIGN_UP(machine->maxram_size,
+                      TARGET_PAGE_SIZE) != machine->maxram_size) {
+        error_report("maximum memory size must by aligned to multiple of "
+                     "%d bytes", TARGET_PAGE_SIZE);
+        exit(EXIT_FAILURE);
+    }
+
+    pcms->hotplug_memory.base =
+        ROUND_UP(0x100000000ULL + pcms->above_4g_mem_size, 1ULL << 30);
+
+    if (pcmc->enforce_aligned_dimm) {
+        /* size hotplug region assuming 1G page max alignment per slot */
+        hotplug_mem_size += (1ULL << 30) * machine->ram_slots;
+    }
+
+    if ((pcms->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(&pcms->hotplug_memory.mr, OBJECT(pcms),
+                       "hotplug-memory", hotplug_mem_size);
+    memory_region_add_subregion(system_memory, pcms->hotplug_memory.base,
+                                &pcms->hotplug_memory.mr);
+}
+
 void pc_memory_init(PCMachineState *pcms,
                     MemoryRegion *system_memory,
                     MemoryRegion *rom_memory,
@@ -1407,44 +1450,7 @@ void pc_memory_init(PCMachineState *pcms,
     }
 
     /* initialize hotplug memory address space */
-    if (pcmc->has_reserved_memory &&
-        (machine->ram_size < machine->maxram_size)) {
-        ram_addr_t hotplug_mem_size =
-            machine->maxram_size - machine->ram_size;
-
-        if (machine->ram_slots > ACPI_MAX_RAM_SLOTS) {
-            error_report("unsupported amount of memory slots: %"PRIu64,
-                         machine->ram_slots);
-            exit(EXIT_FAILURE);
-        }
-
-        if (QEMU_ALIGN_UP(machine->maxram_size,
-                          TARGET_PAGE_SIZE) != machine->maxram_size) {
-            error_report("maximum memory size must by aligned to multiple of "
-                         "%d bytes", TARGET_PAGE_SIZE);
-            exit(EXIT_FAILURE);
-        }
-
-        pcms->hotplug_memory.base =
-            ROUND_UP(0x100000000ULL + pcms->above_4g_mem_size, 1ULL << 30);
-
-        if (pcmc->enforce_aligned_dimm) {
-            /* size hotplug region assuming 1G page max alignment per slot */
-            hotplug_mem_size += (1ULL << 30) * machine->ram_slots;
-        }
-
-        if ((pcms->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(&pcms->hotplug_memory.mr, OBJECT(pcms),
-                           "hotplug-memory", hotplug_mem_size);
-        memory_region_add_subregion(system_memory, pcms->hotplug_memory.base,
-                                    &pcms->hotplug_memory.mr);
-    }
+    pc_memory_hotplug_init(pcms, system_memory);
 
     /* Initialize PC system firmware */
     pc_system_firmware_init(rom_memory, !pcmc->pci_enabled);
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index f278b3ae89..7f0b3bc648 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -259,6 +259,7 @@ void pc_memory_init(PCMachineState *pcms,
                     MemoryRegion *system_memory,
                     MemoryRegion *rom_memory,
                     MemoryRegion **ram_memory);
+void pc_memory_hotplug_init(PCMachineState *pcms, MemoryRegion *system_memory);
 qemu_irq pc_allocate_cpu_irq(void);
 DeviceState *pc_vga_init(ISABus *isa_bus, PCIBus *pci_bus);
 void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
diff --git a/xen-hvm.c b/xen-hvm.c
index 0c36dd11da..79cf871a53 100644
--- a/xen-hvm.c
+++ b/xen-hvm.c
@@ -252,6 +252,8 @@ static void xen_ram_init(PCMachineState *pcms,
                                  pcms->above_4g_mem_size);
         memory_region_add_subregion(sysmem, 0x100000000ULL, &ram_hi);
     }
+
+    pc_memory_hotplug_init(pcms, sysmem);
 }
 
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
-- 
2.12.0


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