Re: [Qemu-devel] qemu physical address

[Xin Tong]

but should not the address be within 1 - 4G-1 even with PAE. is not
the PAE just using 64bits addresses as supposed to 32 bit ? what does
the physical address bigger than 4G mean ?  is not the physical
address starting from 0 from the prospective of the processor ?

Xin


On Wed, Apr 18, 2012 at 4:03 PM, Blue Swirl <address@hidden> wrote:
> On Wed, Apr 18, 2012 at 01:28, Xin Tong <address@hidden> wrote:
>> I am reading how qemu refill TLB working.
>>
>> target-i386/helper.c
>>
>>    pte = pte & env->a20_mask;
>>
>>    /* Even if 4MB pages, we map only one 4KB page in the cache to
>>       avoid filling it too fast */
>>    page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1);
>>    paddr = (pte & TARGET_PAGE_MASK) + page_offset;
>>    vaddr = virt_addr + page_offset;
>>
>>
>> How can the paddr be bigger than 4G even though i gave the machine
>> 4096 MB of memory ( i.e. qemu -m 4096 ...). should not paddr be within
>> 0 - 4G-1 ?
>
> No. There's PAE and the same code is used by both i386 and x86_64.
>
>>
>> Thanks
>>
>> Xin
>>