Re: [PATCH v4 7/9] migration: Simplify alignment and alignment checks

[David Hildenbrand <david@redhat.com>]

On 03.09.21 12:07, David Hildenbrand wrote:
> On 03.09.21 10:47, David Hildenbrand wrote:
>> On 03.09.21 00:32, Peter Xu wrote:
>>> On Thu, Sep 02, 2021 at 03:14:30PM +0200, David Hildenbrand wrote:
>>>> diff --git a/migration/migration.c b/migration/migration.c
>>>> index bb909781b7..ae97c2c461 100644
>>>> --- a/migration/migration.c
>>>> +++ b/migration/migration.c
>>>> @@ -391,7 +391,7 @@ int migrate_send_rp_message_req_pages(MigrationIncomingState *mis,
>>>>     int migrate_send_rp_req_pages(MigrationIncomingState *mis,
>>>>                                   RAMBlock *rb, ram_addr_t start, uint64_t haddr)
>>>>     {
>>>> -    void *aligned = (void *)(uintptr_t)(haddr & (-qemu_ram_pagesize(rb)));
>>>> +    void *aligned = (void *)QEMU_ALIGN_DOWN(haddr, qemu_ram_pagesize(rb));
>>>
>>> Is uintptr_t still needed?  I thought it would generate a warning otherwise but
>>> not sure.
>>
>> It doesn't in my setup, but maybe it will on 32bit archs ...
>>
>> I discussed this with Phil in
>>
>> https://lkml.kernel.org/r/2c8d80ad-f171-7d5f-3235-92f02fa174b3@redhat.com
>>
>> Maybe
>>
>> QEMU_ALIGN_PTR_DOWN((void *)haddr, qemu_ram_pagesize(rb)));
>>
>> Is really what we want.
> 
> ... but it would suffer the same issue I think. I just ran it trough the
> gitlab pipeline, including "i386-fedora-cross-compile" ... and it seems
> to compile just fine, which is weird, because I'd also expect

[I know, talking to my self] Some 32bit tests actually did fail later, 
so the CI is able to catch this properly.

-- 
Thanks,

David / dhildenb