Re: [PATCH 2/2] migration: add vsock as data channel support

["Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" <longpeng2@huawei.com>]

在 2020/8/12 17:52, Dr. David Alan Gilbert 写道:
> * Longpeng(Mike) (longpeng2@huawei.com) wrote:
>> The vsock channel is more widely use in some new features, for example,
>> the Nitro/Enclave. It can also be used as the migration channel.
>>
>> Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
> 
> OK; it might be worth adding some tests for this.
> 
OK, I'll try when I'm free.

> Can I ask what your use case is - is this migrating an L2 inside an L1
> or what?
> 
Yes, L2 migrationg is a potential use case for this. However, our use 
case is still focusing on the L1 migration.

There is no network stack in our platform ( [1] ), so we use the vsock 
channel to communicate between the QEMU (on x86/ARM) and an Agent (on a 
PCIe card), the source Agent will transport the data to the destination.

Links:
[1] 
https://kvmforum2019.sched.com/event/Tmzh/zero-next-generation-virtualization-platform-for-huawei-cloud-jinsong-liu-zhichao-huang-huawei

> 
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 
Thanks.

>> ---
>>   migration/migration.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/migration/migration.c b/migration/migration.c
>> index 3160b95..fcf7974 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -383,7 +383,8 @@ void qemu_start_incoming_migration(const char *uri, Error **errp)
>>       if (!strcmp(uri, "defer")) {
>>           deferred_incoming_migration(errp);
>>       } else if (strstart(uri, "tcp:", &p) ||
>> -               strstart(uri, "unix:", NULL)) {
>> +               strstart(uri, "unix:", NULL) ||
>> +               strstart(uri, "vsock:", NULL)) {
>>           socket_start_incoming_migration(p ? p : uri, errp);
>>   #ifdef CONFIG_RDMA
>>       } else if (strstart(uri, "rdma:", &p)) {
>> @@ -2072,7 +2073,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>>       }
>>   
>>       if (strstart(uri, "tcp:", &p) ||
>> -        strstart(uri, "unix:", NULL)) {
>> +        strstart(uri, "unix:", NULL) ||
>> +        strstart(uri, "vsock:", NULL)) {
>>           socket_start_outgoing_migration(s, p ? p : uri, &local_err);
>>   #ifdef CONFIG_RDMA
>>       } else if (strstart(uri, "rdma:", &p)) {
>> -- 
>> 1.8.3.1
>>