Re: [Qemu-devel] [PATCH 29/29] memory: strengthen assertions on mr->terminates

[Fam Zheng]

On Mon, 04/27 18:28, Paolo Bonzini wrote:
> mr->terminates alone doesn't guarantee that we are looking at a RAM region.
> mr->ram_addr also has to be checked, in order to distinguish RAM and I/O
> regions.
> 
> IOMMU regions were not setting mr->ram_addr to a bogus value, do it now
> so that the assertions would fire for IOMMU regions as well.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>

It would be nicer to introduce a memory_region_is_ram(MemoryRegion *mr), the
~(ram_addr_t) duplications are too many.

Fam

> ---
>  memory.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/memory.c b/memory.c
> index bb86b4b..82d9df6 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1242,6 +1242,7 @@ void memory_region_init_iommu(MemoryRegion *mr,
>      memory_region_init(mr, owner, name, size);
>      mr->iommu_ops = ops,
>      mr->terminates = true;  /* then re-forwards */
> +    mr->ram_addr = ~(ram_addr_t)0;
>      notifier_list_init(&mr->iommu_notify);
>  }
>  
> @@ -1382,14 +1383,14 @@ void memory_region_set_log(MemoryRegion *mr, bool 
> log, unsigned client)
>  bool memory_region_get_dirty(MemoryRegion *mr, hwaddr addr,
>                               hwaddr size, unsigned client)
>  {
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>      return cpu_physical_memory_get_dirty(mr->ram_addr + addr, size, client);
>  }
>  
>  void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
>                               hwaddr size)
>  {
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>      cpu_physical_memory_set_dirty_range(mr->ram_addr + addr, size,
>                                          
> memory_region_get_dirty_log_mask(mr));
>  }
> @@ -1397,7 +1398,7 @@ void memory_region_set_dirty(MemoryRegion *mr, hwaddr 
> addr,
>  bool memory_region_test_and_clear_dirty(MemoryRegion *mr, hwaddr addr,
>                                          hwaddr size, unsigned client)
>  {
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>      return cpu_physical_memory_test_and_clear_dirty(mr->ram_addr + addr,
>                                                      size, client);
>  }
> @@ -1442,7 +1443,7 @@ void memory_region_rom_device_set_romd(MemoryRegion 
> *mr, bool romd_mode)
>  void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
>                                 hwaddr size, unsigned client)
>  {
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>      cpu_physical_memory_test_and_clear_dirty(mr->ram_addr + addr, size,
>                                               client);
>  }
> @@ -1453,7 +1454,7 @@ int memory_region_get_fd(MemoryRegion *mr)
>          return memory_region_get_fd(mr->alias);
>      }
>  
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>  
>      return qemu_get_ram_fd(mr->ram_addr & TARGET_PAGE_MASK);
>  }
> @@ -1464,14 +1465,14 @@ void *memory_region_get_ram_ptr(MemoryRegion *mr)
>          return memory_region_get_ram_ptr(mr->alias) + mr->alias_offset;
>      }
>  
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>  
>      return qemu_get_ram_ptr(mr->ram_addr & TARGET_PAGE_MASK);
>  }
>  
>  void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize, Error 
> **errp)
>  {
> -    assert(mr->terminates);
> +    assert(mr->terminates && mr->ram_addr != ~(ram_addr_t)0);
>  
>      qemu_ram_resize(mr->ram_addr, newsize, errp);
>  }
> -- 
> 1.8.3.1
>