Re: [Qemu-devel] [PATCH] rdma: bugfix: make IPv6 support work

["Michael R. Hines" <mrhines@linux.vnet.ibm.com>]

On 07/30/2013 11:31 AM, Orit Wasserman wrote:
> On 07/30/2013 05:57 PM, Michael R. Hines wrote:
>> On 07/30/2013 04:14 AM, Orit Wasserman wrote:
>>> On 07/27/2013 05:23 AM, mrhines@linux.vnet.ibm.com wrote:
>>>> From: "Michael R. Hines" <mrhines@us.ibm.com>
>>>>
>>>> When testing with libvirt, a simple IPv6 migration test failed
>>>> because we were not using getaddrinfo() properly.
>>>> This makes IPv6 migration over RDMA work.
>>>>
>>>> Also, we forgot to turn the DPRINTF flag off =).
>>>>
>>>> Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
>>>> ---
>>>>    migration-rdma.c |   35 ++++++++++++++++++++++-------------
>>>>    1 file changed, 22 insertions(+), 13 deletions(-)
>>>>
>>>> diff --git a/migration-rdma.c b/migration-rdma.c
>>>> index d044830..3256c9b 100644
>>>> --- a/migration-rdma.c
>>>> +++ b/migration-rdma.c
>>>> @@ -27,7 +27,7 @@
>>>>    #include <string.h>
>>>>    #include <rdma/rdma_cma.h>
>>>>    -#define DEBUG_RDMA
>>>> +//#define DEBUG_RDMA
>>> Can you put this in a separate patch?
>> Acknowledged.
>>
>>>>    //#define DEBUG_RDMA_VERBOSE
>>>>    //#define DEBUG_RDMA_REALLY_VERBOSE
>>>>    @@ -392,6 +392,7 @@ typedef struct RDMAContext {
>>>>        uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX];
>>>>          GHashTable *blockmap;
>>>> +    bool ipv6;
>>>>    } RDMAContext;
>>>>      /*
>>>> @@ -744,6 +745,7 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
>>>>        char port_str[16];
>>>>        struct rdma_cm_event *cm_event;
>>>>        char ip[40] = "unknown";
>>>> +    int af = rdma->ipv6 ? PF_INET6 : PF_INET;
>>> We have code that handles ipv6 in utils/qemu-sockets.c, it also handle host
>>> and port parsing please take a look at inet_parse_connect_opts.
>>> I think it can be reused here and for the destination.
>> RDMA cannot use that function - it creates a socket and RDMA does not use sockets.
>>
>> RDMA is *already*, however, using inet_parse() which does exactly what you said.
>>
> You can update the function so it can be used for RDMA also.

The inet_parse() function does everything that we need -
it already understands IPv6 without opening an actual socket.

Any more than that would require CONFIG_RDMA to be
conditionalized inside of the utils/ source code,
and that seems like a lot of work for such a small reward.

- Michael

> Orit
>
>>> Regards,
>>> Orit
>>>>          if (rdma->host == NULL || !strcmp(rdma->host, "")) {
>>>>            ERROR(errp, "RDMA hostname has not been set\n");
>>>> @@ -773,7 +775,7 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
>>>>            goto err_resolve_get_addr;
>>>>        }
>>>>    -    inet_ntop(AF_INET, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
>>>> +    inet_ntop(af, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
>>>>                                    ip, sizeof ip);
>>>>        DPRINTF("%s => %s\n", rdma->host, ip);
>>>>    @@ -2236,9 +2238,12 @@ err_rdma_source_connect:
>>>>    static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp)
>>>>    {
>>>>        int ret = -EINVAL, idx;
>>>> +    int af = rdma->ipv6 ? PF_INET6 : PF_INET;
>>>>        struct sockaddr_in sin;
>>>>        struct rdma_cm_id *listen_id;
>>>>        char ip[40] = "unknown";
>>>> +    struct addrinfo *res;
>>>> +    char port_str[16];
>>>>          for (idx = 0; idx <= RDMA_WRID_MAX; idx++) {
>>>>            rdma->wr_data[idx].control_len = 0;
>>>> @@ -2266,27 +2271,30 @@ static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp)
>>>>        }
>>>>          memset(&sin, 0, sizeof(sin));
>>>> -    sin.sin_family = AF_INET;
>>>> +    sin.sin_family = af;
>>>>        sin.sin_port = htons(rdma->port);
>>>> +    snprintf(port_str, 16, "%d", rdma->port);
>>>> +    port_str[15] = '\0';
>>>>          if (rdma->host && strcmp("", rdma->host)) {
>>>> -        struct hostent *dest_addr;
>>>> -        dest_addr = gethostbyname(rdma->host);
>>>> -        if (!dest_addr) {
>>>> -            ERROR(errp, "migration could not gethostbyname!\n");
>>>> -            ret = -EINVAL;
>>>> +        ret = getaddrinfo(rdma->host, port_str, NULL, &res);
>>>> +        if (ret < 0) {
>>>> +            ERROR(errp, "could not getaddrinfo address %s\n", rdma->host);
>>>>                goto err_dest_init_bind_addr;
>>>>            }
>>>> -        memcpy(&sin.sin_addr.s_addr, dest_addr->h_addr,
>>>> -                dest_addr->h_length);
>>>> -        inet_ntop(AF_INET, dest_addr->h_addr, ip, sizeof ip);
>>>> +
>>>> +
>>>> +        inet_ntop(af, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
>>>> +                                    ip, sizeof ip);
>>>>        } else {
>>>> -        sin.sin_addr.s_addr = INADDR_ANY;
>>>> +        ERROR(errp, "migration host and port not specified!\n");
>>>> +        ret = -EINVAL;
>>>> +        goto err_dest_init_bind_addr;
>>>>        }
>>>>          DPRINTF("%s => %s\n", rdma->host, ip);
>>>>    -    ret = rdma_bind_addr(listen_id, (struct sockaddr *)&sin);
>>>> +    ret = rdma_bind_addr(listen_id, res->ai_addr);
>>>>        if (ret) {
>>>>            ERROR(errp, "Error: could not rdma_bind_addr!\n");
>>>>            goto err_dest_init_bind_addr;
>>>> @@ -2321,6 +2329,7 @@ static void *qemu_rdma_data_init(const char *host_port, Error **errp)
>>>>            if (addr != NULL) {
>>>>                rdma->port = atoi(addr->port);
>>>>                rdma->host = g_strdup(addr->host);
>>>> +            rdma->ipv6 = addr->ipv6;
>>>>            } else {
>>>>                ERROR(errp, "bad RDMA migration address '%s'", host_port);
>>>>                g_free(rdma);
>>>>