Re: [Qemu-devel] [PATCH v2 04/20] memory-device: get_region_size()/get_plugged_size() might fail

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 29 Aug 2018 17:36:08 +0200
David Hildenbrand <david@redhat.com> wrote:

> Let's properly forward the error, so errors from get_region_size() /
> get_plugged_size(), can be handled.
> 
> Users right now call both functions after the device has been realized,
> which is guaranteed to no fail (we'll document this behavior in a
> follow-up patch).
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/mem/memory-device.c         | 6 +++---
>  hw/mem/pc-dimm.c               | 5 +++--
>  include/hw/mem/memory-device.h | 4 ++--
>  3 files changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
> index 0d9892b715..d87599c280 100644
> --- a/hw/mem/memory-device.c
> +++ b/hw/mem/memory-device.c
> @@ -60,7 +60,7 @@ static int memory_device_used_region_size(Object *obj, void *opaque)
>          const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj);
>  
>          if (dev->realized) {
> -            *size += mdc->get_region_size(md);
> +            *size += mdc->get_region_size(md, &error_abort);
>          }
>      }
>  
> @@ -167,7 +167,7 @@ uint64_t memory_device_get_free_addr(MachineState *ms, const uint64_t *hint,
>          uint64_t md_size, md_addr;
>  
>          md_addr = mdc->get_addr(md);
> -        md_size = mdc->get_region_size(md);
> +        md_size = mdc->get_region_size(md, &error_abort);
s/error_abort/errp/, so it won't crash on hotplug?

>          if (*errp) {
>              goto out;
is this ever reachable?

>          }
> @@ -233,7 +233,7 @@ static int memory_device_plugged_size(Object *obj, void *opaque)
>          const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj);
>  
>          if (dev->realized) {
> -            *size += mdc->get_plugged_size(md);
> +            *size += mdc->get_plugged_size(md, &error_abort);
>          }
>      }
>  
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index fb6bcaedc4..4bf1a0acc9 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -236,14 +236,15 @@ static uint64_t pc_dimm_md_get_addr(const MemoryDeviceState *md)
>      return dimm->addr;
>  }
>  
> -static uint64_t pc_dimm_md_get_region_size(const MemoryDeviceState *md)
> +static uint64_t pc_dimm_md_get_region_size(const MemoryDeviceState *md,
> +                                           Error **errp)
>  {
>      /* dropping const here is fine as we don't touch the memory region */
>      PCDIMMDevice *dimm = PC_DIMM(md);
>      const PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(md);
>      MemoryRegion *mr;
>  
> -    mr = ddc->get_memory_region(dimm, &error_abort);
> +    mr = ddc->get_memory_region(dimm, errp);
>      if (!mr) {
>          return 0;
>      }
> diff --git a/include/hw/mem/memory-device.h b/include/hw/mem/memory-device.h
> index 2853b084b5..f02b229837 100644
> --- a/include/hw/mem/memory-device.h
> +++ b/include/hw/mem/memory-device.h
> @@ -33,8 +33,8 @@ typedef struct MemoryDeviceClass {
>      InterfaceClass parent_class;
>  
>      uint64_t (*get_addr)(const MemoryDeviceState *md);
> -    uint64_t (*get_plugged_size)(const MemoryDeviceState *md);
> -    uint64_t (*get_region_size)(const MemoryDeviceState *md);
> +    uint64_t (*get_plugged_size)(const MemoryDeviceState *md, Error **errp);
> +    uint64_t (*get_region_size)(const MemoryDeviceState *md, Error **errp);
>      void (*fill_device_info)(const MemoryDeviceState *md,
>                               MemoryDeviceInfo *info);
>  } MemoryDeviceClass;