diff mbox series

[v4,6/9] hw/i386/pc: Initialize ram_memory variable directly

Message ID 20230213162004.2797-7-shentey@gmail.com
State New
Headers show
Series PC cleanups | expand

Commit Message

Bernhard Beschow Feb. 13, 2023, 4:20 p.m. UTC 
Going through pc_memory_init() seems quite complicated for a simple
assignment.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/i386/pc.h | 1 -
 hw/i386/pc.c         | 2 --
 hw/i386/pc_piix.c    | 4 ++--
 hw/i386/pc_q35.c     | 6 ++----
 4 files changed, 4 insertions(+), 9 deletions(-)

Comments

Xiaoyao Li Feb. 22, 2023, 2:38 a.m. UTC | #1 
On 2/14/2023 12:20 AM, Bernhard Beschow wrote:
> Going through pc_memory_init() seems quite complicated for a simple
> assignment.
> 

...

> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 5bde4533cc..00ba725656 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -143,6 +143,7 @@ static void pc_init1(MachineState *machine,
>       if (xen_enabled()) {
>           xen_hvm_init_pc(pcms, &ram_memory);
>       } else {
> +        ram_memory = machine->ram;
>           if (!pcms->max_ram_below_4g) {
>               pcms->max_ram_below_4g = 0xe0000000; /* default: 3.5G */
>           }
> @@ -205,8 +206,7 @@ static void pc_init1(MachineState *machine,
>   
>       /* allocate ram and load rom/bios */
>       if (!xen_enabled()) {
> -        pc_memory_init(pcms, system_memory,
> -                       rom_memory, &ram_memory, hole64_size);

IMHO, it seems more proper to put

+        ram_memory = machine->ram;

here rather than above.

> +        pc_memory_init(pcms, system_memory, rom_memory, hole64_size);
>       } else {
>           pc_system_flash_cleanup_unused(pcms);
>           if (machine->kernel_filename != NULL) {
Bernhard Beschow Feb. 22, 2023, 8:21 a.m. UTC | #2 
Am 22. Februar 2023 02:38:04 UTC schrieb Xiaoyao Li <xiaoyao.li@intel.com>:
>On 2/14/2023 12:20 AM, Bernhard Beschow wrote:
>> Going through pc_memory_init() seems quite complicated for a simple
>> assignment.
>> 
>
>...
>
>> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
>> index 5bde4533cc..00ba725656 100644
>> --- a/hw/i386/pc_piix.c
>> +++ b/hw/i386/pc_piix.c
>> @@ -143,6 +143,7 @@ static void pc_init1(MachineState *machine,
>>       if (xen_enabled()) {
>>           xen_hvm_init_pc(pcms, &ram_memory);

In Xen mode, ram_memory is initialized here and machine->ram isn't used at all.

>>       } else {
>> +        ram_memory = machine->ram;

The idea of moving the assignment here is to make the code more symmetric to Xen and to establish the invariant of ram_memory being initialized after this if-else block. IOW one shouldn't need to use machine->ram directly after this point.

>>           if (!pcms->max_ram_below_4g) {
>>               pcms->max_ram_below_4g = 0xe0000000; /* default: 3.5G */
>>           }
>> @@ -205,8 +206,7 @@ static void pc_init1(MachineState *machine,
>>         /* allocate ram and load rom/bios */
>>       if (!xen_enabled()) {
>> -        pc_memory_init(pcms, system_memory,
>> -                       rom_memory, &ram_memory, hole64_size);
>
>IMHO, it seems more proper to put
>
>+        ram_memory = machine->ram;
>
>here rather than above.

This patch allowed for further cleanup (establishing above invariant) which I inlined for simplicity.

Do you still see issues here?

Thanks,
Bernhard
>
>> +        pc_memory_init(pcms, system_memory, rom_memory, hole64_size);
>>       } else {
>>           pc_system_flash_cleanup_unused(pcms);
>>           if (machine->kernel_filename != NULL) {
>
diff mbox series

Patch

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 66e3d059ef..b60b95921b 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -162,7 +162,6 @@  void xen_load_linux(PCMachineState *pcms);
 void pc_memory_init(PCMachineState *pcms,
                     MemoryRegion *system_memory,
                     MemoryRegion *rom_memory,
-                    MemoryRegion **ram_memory,
                     uint64_t pci_hole64_size);
 uint64_t pc_pci_hole64_start(void);
 DeviceState *pc_vga_init(ISABus *isa_bus, PCIBus *pci_bus);
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 6e592bd969..8898cc9961 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -936,7 +936,6 @@  static hwaddr pc_max_used_gpa(PCMachineState *pcms, uint64_t pci_hole64_size)
 void pc_memory_init(PCMachineState *pcms,
                     MemoryRegion *system_memory,
                     MemoryRegion *rom_memory,
-                    MemoryRegion **ram_memory,
                     uint64_t pci_hole64_size)
 {
     int linux_boot, i;
@@ -994,7 +993,6 @@  void pc_memory_init(PCMachineState *pcms,
      * Split single memory region and use aliases to address portions of it,
      * done for backwards compatibility with older qemus.
      */
-    *ram_memory = machine->ram;
     ram_below_4g = g_malloc(sizeof(*ram_below_4g));
     memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", machine->ram,
                              0, x86ms->below_4g_mem_size);
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 5bde4533cc..00ba725656 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -143,6 +143,7 @@  static void pc_init1(MachineState *machine,
     if (xen_enabled()) {
         xen_hvm_init_pc(pcms, &ram_memory);
     } else {
+        ram_memory = machine->ram;
         if (!pcms->max_ram_below_4g) {
             pcms->max_ram_below_4g = 0xe0000000; /* default: 3.5G */
         }
@@ -205,8 +206,7 @@  static void pc_init1(MachineState *machine,
 
     /* allocate ram and load rom/bios */
     if (!xen_enabled()) {
-        pc_memory_init(pcms, system_memory,
-                       rom_memory, &ram_memory, hole64_size);
+        pc_memory_init(pcms, system_memory, rom_memory, hole64_size);
     } else {
         pc_system_flash_cleanup_unused(pcms);
         if (machine->kernel_filename != NULL) {
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 8253b49296..455cbe11fa 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -129,7 +129,6 @@  static void pc_q35_init(MachineState *machine)
     MemoryRegion *system_io = get_system_io();
     MemoryRegion *pci_memory;
     MemoryRegion *rom_memory;
-    MemoryRegion *ram_memory;
     GSIState *gsi_state;
     ISABus *isa_bus;
     int i;
@@ -216,12 +215,11 @@  static void pc_q35_init(MachineState *machine)
     }
 
     /* allocate ram and load rom/bios */
-    pc_memory_init(pcms, system_memory, rom_memory, &ram_memory,
-                   pci_hole64_size);
+    pc_memory_init(pcms, system_memory, rom_memory, pci_hole64_size);
 
     object_property_add_child(OBJECT(machine), "q35", OBJECT(q35_host));
     object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_RAM_MEM,
-                             OBJECT(ram_memory), NULL);
+                             OBJECT(machine->ram), NULL);
     object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_PCI_MEM,
                              OBJECT(pci_memory), NULL);
     object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_SYSTEM_MEM,