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

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 20 Feb 2019 23:39:59 +0100
Eric Auger <eric.auger@redhat.com> wrote:

> The device memory region is located after the initial RAM.
> its start/size are 1GB aligned.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Kwangwoo Lee <kwangwoo.lee@sk.com>
> 
> ---
> 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.

Also it would be better to all device_memory allocation/initialization
compact and close to each other like it's done in pc/spapr.

> +        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);