Re: [PULL 11/38] tests/qtest: migration-test: Add tests for file-based migration

[Fabiano Rosas]

Juan Quintela <quintela@redhat.com> writes:

> Fabiano Rosas <farosas@suse.de> wrote:
> D> Juan Quintela <quintela@redhat.com> writes:
>>
>>> From: Fabiano Rosas <farosas@suse.de>
>>>
>>> Add basic tests for file-based migration.
>>>
>>> Note that we cannot use test_precopy_common because that routine
>>> expects it to be possible to run the migration live. With the file
>>> transport there is no live migration because we must wait for the
>>> source to finish writing the migration data to the file before the
>>> destination can start reading. Add a new migration function
>>> specifically to handle the file migration.
>>>
>>> Reviewed-by: Peter Xu <peterx@redhat.com>
>>> Reviewed-by: Juan Quintela <quintela@redhat.com>
>>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>>> Message-ID: <20230712190742.22294-7-farosas@suse.de>
>
>>> +static void file_offset_finish_hook(QTestState *from, QTestState *to,
>>> +                                    void *opaque)
>>> +{
>>> +#if defined(__linux__)
>>> +    g_autofree char *path = g_strdup_printf("%s/%s", tmpfs, 
>>> FILE_TEST_FILENAME);
>>> +    size_t size = FILE_TEST_OFFSET + sizeof(QEMU_VM_FILE_MAGIC);
>>> +    uintptr_t *addr, *p;
>>> +    int fd;
>>> +
>>> +    fd = open(path, O_RDONLY);
>>> +    g_assert(fd != -1);
>>> +    addr = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
>>> +    g_assert(addr != MAP_FAILED);
>>> +
>>> +    /*
>>> +     * Ensure the skipped offset contains zeros and the migration
>>> +     * stream starts at the right place.
>>> +     */
>>> +    p = addr;
>>> +    while (p < addr + FILE_TEST_OFFSET / sizeof(uintptr_t)) {
>>> +        g_assert(*p == 0);
>>> +        p++;
>>> +    }
>>> +    g_assert_cmpint(cpu_to_be32(*p), ==, QEMU_VM_FILE_MAGIC);
>>
>> This truncates to 32-bits, so it breaks on a BE host. We need this:
>>
>> -->8--
>> From ea0c2d1c988add48d9754891a9fc7f6854a9718a Mon Sep 17 00:00:00 2001
>> From: Fabiano Rosas <farosas@suse.de>
>> Date: Mon, 16 Oct 2023 15:21:49 -0300
>> Subject: [PATCH] fixup! tests/qtest: migration-test: Add tests for file-based
>>  migration
>>
>> ---
>>  tests/qtest/migration-test.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
>> index da02b6d692..e1c110537b 100644
>> --- a/tests/qtest/migration-test.c
>> +++ b/tests/qtest/migration-test.c
>> @@ -1966,7 +1966,7 @@ static void file_offset_finish_hook(QTestState *from, 
>> QTestState *to,
>>          g_assert(*p == 0);
>>          p++;
>>      }
>> -    g_assert_cmpint(cpu_to_be32(*p), ==, QEMU_VM_FILE_MAGIC);
>> +    g_assert_cmpint(cpu_to_be64(*p) >> 32, ==, QEMU_VM_FILE_MAGIC);
>>  
>>      munmap(addr, size);
>>      close(fd);
>
> I am resubmitting with this change.
>
> But I think we need to change this:
>
>>> +    g_autofree char *path = g_strdup_printf("%s/%s", tmpfs, 
>>> FILE_TEST_FILENAME);
>>> +    size_t size = FILE_TEST_OFFSET + sizeof(QEMU_VM_FILE_MAGIC);
>>> +    uintptr_t *addr, *p;
>
> I think we should change the test so the file is 64 bits on every
> architecture.
> Then we can cast to void * or uintptr_t as needed.

Hm, I don't get what you mean here. What needs to be 64 bits?