Re: [Qemu-devel] [RFC v1] Add declarations for hierarchical memory region API

[Avi Kivity <avi@redhat.com>]

On 05/20/2011 12:04 AM, Stefan Weil wrote:
> Am 19.05.2011 16:12, schrieb Avi Kivity:
>> The memory API separates the attributes of a memory region (its size, 
>> how
>> reads or writes are handled, dirty logging, and coalescing) from 
>> where it
>> is mapped and whether it is enabled. This allows a device to configure
>> a memory region once, then hand it off to its parent bus to map it 
>> according
>> to the bus configuration.
>>
>> Hierarchical registration also allows a device to compose a region 
>> out of
>> a number of sub-regions with different properties; for example some 
>> may be
>> RAM while others may be MMIO.

>> --- /dev/null
>> +++ b/memory.h
>> @@ -0,0 +1,142 @@
>> +#ifndef MEMORY_H
>> +#define MEMORY_H
>> +
>> +#include <stdint.h>
>> +#include <stdbool.h>
>
> stdbool.h is already included in qemu-common.h,
> stdint.h (indirectly) too.
>
> Therefore both include statements can be removed.

We shouldn't rely on indirect includes, it makes updating headers very 
hard.  Each header should #include what it directly needs and no more.

>> +typedef struct CoalescedMemoryRange CoalescedMemoryRange;
>> +
>> +struct CoalescedMemoryRange {
>> + target_phys_addr_t start;
>> + target_phys_addr_t size;
>> + QTAILQ_ENTRY(coalesced_ranges) link;
>> +};
>> +
>> +struct MemoryRegion {
>> + /* All fields are private - violators will be prosecuted */
>
> Is it possible to move this private declaration into the implementation
> file (or a private header file if the declaration is needed by more than
> one file)?


No, the structure size is needed by clients.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.