Re: [Qemu-devel] [PATCH v7 13/17] hw/arm/virt: Allocate device_memory

[Auger Eric]

Hi Igor,

On 2/22/19 2:48 PM, Igor Mammedov wrote:
> On Wed, 20 Feb 2019 23:39:59 +0100
> Eric Auger <address@hidden> wrote:
> 
>> The device memory region is located after the initial RAM.
>> its start/size are 1GB aligned.
>>
>> Signed-off-by: Eric Auger <address@hidden>
>> Signed-off-by: Kwangwoo Lee <address@hidden>
>>
>> ---
>> v6 -> v7:
>> - check the device memory top does not wrap
>> - check the device memory can fit the slots
>>
>> v4 -> v5:
>> - device memory set after the initial RAM
>>
>> v3 -> v4:
>> - remove bootinfo.device_memory_start/device_memory_size
>> - rename VIRT_HOTPLUG_MEM into VIRT_DEVICE_MEM
>> ---
>>  hw/arm/virt.c | 33 +++++++++++++++++++++++++++++++++
>>  1 file changed, 33 insertions(+)
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index 470ca0ce2d..33ad9b3f63 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -62,6 +62,7 @@
>>  #include "target/arm/internals.h"
>>  #include "hw/mem/pc-dimm.h"
>>  #include "hw/mem/nvdimm.h"
>> +#include "hw/acpi/acpi.h"
>>  
>>  #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
>>      static void virt_##major##_##minor##_class_init(ObjectClass *oc, \
>> @@ -1263,6 +1264,34 @@ static void create_secure_ram(VirtMachineState *vms,
>>      g_free(nodename);
>>  }
>>  
>> +static void create_device_memory(VirtMachineState *vms, MemoryRegion 
>> *sysmem)
>> +{
>> +    MachineState *ms = MACHINE(vms);
>> +
>> +    if (!vms->device_memory_size) {
> having vms->device_memory_size seems like duplicate, why not to reuse
> memory_region_size(MachineState::device_memory::mr) like we do elsewhere.
OK so you mean allocating the ms->device_memory in virt_setmmap? In that
case, I wonder if all that code shouldn't land in set_memmap directly?
> 
> Also it would be better to all device_memory allocation/initialization
> compact and close to each other like it's done in pc/spapr.
I am not sure I get your point here. alloc & init are done in this
function. Or do you mean I should rather move that into set_memmap?

Thanks

Eric
> 
>> +        return;
>> +    }
>> +
>> +    if (ms->ram_slots > ACPI_MAX_RAM_SLOTS) {
>> +        error_report("unsupported number of memory slots: %"PRIu64,
>> +                     ms->ram_slots);
>> +        exit(EXIT_FAILURE);
>> +    }
>> +
>> +    if (QEMU_ALIGN_UP(ms->maxram_size, GiB) != ms->maxram_size) {
>> +        error_report("maximum memory size must be GiB aligned");
>> +        exit(EXIT_FAILURE);
>> +    }
>> +
>> +    ms->device_memory = g_malloc0(sizeof(*ms->device_memory));
>> +    ms->device_memory->base = vms->device_memory_base;
>> +
>> +    memory_region_init(&ms->device_memory->mr, OBJECT(vms),
>> +                       "device-memory", vms->device_memory_size);
>> +    memory_region_add_subregion(sysmem, ms->device_memory->base,
>> +                                &ms->device_memory->mr);
>> +}
>> +
>>  static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
>>  {
>>      const VirtMachineState *board = container_of(binfo, VirtMachineState,
>> @@ -1610,6 +1639,10 @@ static void machvirt_init(MachineState *machine)
>>                                           machine->ram_size);
>>      memory_region_add_subregion(sysmem, vms->memmap[VIRT_MEM].base, ram);
>>  
>> +    if (vms->extended_memmap) {
>> +        create_device_memory(vms, sysmem);
>> +    }
>> +
>>      create_flash(vms, sysmem, secure_sysmem ? secure_sysmem : sysmem);
>>  
>>      create_gic(vms, pic);
>