Re: [PULL 8/8] migration: Add qtest for migration over RDMA

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi,

On 7/3/25 19:15, Fabiano Rosas wrote:
> From: Li Zhijian <lizhijian@fujitsu.com>
> 
> This qtest requires there is a RDMA(RoCE) link in the host.
> In order to make the test work smoothly, introduce a
> scripts/rdma-migration-helper.sh to
> - setup a new Soft-RoCE(aka RXE) if it's root
> - detect existing RoCE link
> 
> Test will be skipped if there is no available RoCE link.

Is it? Runing as user I'm getting:

   RDMA ERROR: RDMA host is not set!

Apparently called via:

qemu_start_incoming_migration()
   -> rdma_start_incoming_migration()
      -> qemu_rdma_dest_init()

>   # Start of rdma tests
>   # Running /x86_64/migration/precopy/rdma/plain
>   Command 'rdma' is not available, please install it first.
>   # To enable the test:
>   # (1) Run 'scripts/rdma-migration-helper.sh setup' with root and rerun the test
>   # or
>   # (2) Run the test with root privilege

Could this might be the issue, should we skip if not root, as calling
the script in "detect" mode makes the new_rdma_link() method to succeed.

>   #
>   ok 1 /x86_64/migration/precopy/rdma/plain # SKIP No rdma link available
>   # End of rdma tests
> 
> Note: Remove the newly added RXE link by executing 'modprobe -r rdma_rxe'
> or by specifying 'clean' within this script.

qtest_add() provides both setup() / teardown() methods.

Test leaving system in different state seems bogus to me.
More even if the information is buried in a commit description...

We shouldn't merge this patch as is IMHO.

Regards,

Phil.

> Reviewed-by: Peter Xu <peterx@redhat.com>
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> Message-ID: <20250305062825.772629-7-lizhijian@fujitsu.com>
> [reformated the message to be under 90 characters]
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>   MAINTAINERS                           |  1 +
>   scripts/rdma-migration-helper.sh      | 48 +++++++++++++++++++
>   tests/qtest/migration/precopy-tests.c | 69 +++++++++++++++++++++++++++
>   3 files changed, 118 insertions(+)
>   create mode 100755 scripts/rdma-migration-helper.sh
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5df6020ed5..56e85adcfb 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3517,6 +3517,7 @@ R: Li Zhijian <lizhijian@fujitsu.com>
>   R: Peter Xu <peterx@redhat.com>
>   S: Odd Fixes
>   F: migration/rdma*
> +F: scripts/rdma-migration-helper.sh
>   
>   Migration dirty limit and dirty page rate
>   M: Hyman Huang <yong.huang@smartx.com>
> diff --git a/scripts/rdma-migration-helper.sh b/scripts/rdma-migration-helper.sh
> new file mode 100755
> index 0000000000..08e29a52eb
> --- /dev/null
> +++ b/scripts/rdma-migration-helper.sh
> @@ -0,0 +1,48 @@
> +#!/bin/bash
> +
> +# Copied from blktests
> +get_ipv4_addr()
> +{
> +    ip -4 -o addr show dev "$1" |
> +        sed -n 's/.*[[:blank:]]inet[[:blank:]]*\([^[:blank:]/]*\).*/\1/p' |
> +        tr -d '\n'
> +}
> +
> +has_soft_rdma()
> +{
> +    rdma link | grep -q " netdev $1[[:blank:]]*\$"
> +}
> +
> +rdma_rxe_setup_detect()
> +{
> +    (
> +        cd /sys/class/net &&
> +            for i in *; do
> +                [ -e "$i" ] || continue
> +                [ "$i" = "lo" ] && continue
> +                [ "$(<"$i/addr_len")" = 6 ] || continue
> +                [ "$(<"$i/carrier")" = 1 ] || continue
> +
> +                has_soft_rdma "$i" && break
> +                [ "$operation" = "setup" ] &&
> +                    rdma link add "${i}_rxe" type rxe netdev "$i" && break
> +            done
> +        has_soft_rdma "$i" || return
> +        get_ipv4_addr "$i"
> +    )
> +}
> +
> +operation=${1:-setup}
> +
> +command -v rdma >/dev/null || {
> +    echo "Command 'rdma' is not available, please install it first." >&2
> +    exit 1
> +}
> +
> +if [ "$operation" == "setup" ] || [ "$operation" == "detect" ]; then
> +    rdma_rxe_setup_detect
> +elif [ "$operation" == "clean" ]; then
> +    modprobe -r rdma_rxe
> +else
> +    echo "Usage: $0 [setup | detect | clean]"
> +fi
> diff --git a/tests/qtest/migration/precopy-tests.c b/tests/qtest/migration/precopy-tests.c
> index ba273d10b9..f1fe34020d 100644
> --- a/tests/qtest/migration/precopy-tests.c
> +++ b/tests/qtest/migration/precopy-tests.c
> @@ -99,6 +99,71 @@ static void test_precopy_unix_dirty_ring(void)
>       test_precopy_common(&args);
>   }
>   
> +#ifdef CONFIG_RDMA
> +
> +#define RDMA_MIGRATION_HELPER "scripts/rdma-migration-helper.sh"
> +static int new_rdma_link(char *buffer, bool verbose)
> +{
> +    const char *argument = (geteuid() == 0) ? "setup" : "detect";
> +    char cmd[1024];
> +
> +    snprintf(cmd, sizeof(cmd), "%s %s %s", RDMA_MIGRATION_HELPER, argument,
> +             verbose ? "" : "2>/dev/null");
> +
> +    FILE *pipe = popen(cmd, "r");
> +    if (pipe == NULL) {
> +        perror("Failed to run script");
> +        return -1;
> +    }
> +
> +    int idx = 0;
> +    while (fgets(buffer + idx, 128 - idx, pipe) != NULL) {
> +        idx += strlen(buffer);
> +    }
> +
> +    int status = pclose(pipe);
> +    if (status == -1) {
> +        perror("Error reported by pclose()");
> +        return -1;
> +    } else if (WIFEXITED(status)) {
> +        return WEXITSTATUS(status);
> +    }
> +
> +    return -1;
> +}
> +
> +static void test_precopy_rdma_plain(void)
> +{
> +    char buffer[128] = {};
> +    bool verbose = g_getenv("QTEST_LOG");
> +
> +    if (new_rdma_link(buffer, verbose)) {
> +        g_test_skip("No rdma link available");
> +        if (verbose) {
> +            g_test_message(
> +                "To enable the test:\n"
> +                "(1) Run \'" RDMA_MIGRATION_HELPER
> +                " setup\' with root and rerun the test\n"
> +                "or\n(2) Run the test with root privilege");
> +        }
> +        return;
> +    }
> +
> +    /*
> +     * TODO: query a free port instead of hard code.
> +     * 29200=('R'+'D'+'M'+'A')*100
> +     **/
> +    g_autofree char *uri = g_strdup_printf("rdma:%s:29200", buffer);
> +
> +    MigrateCommon args = {
> +        .listen_uri = uri,
> +        .connect_uri = uri,
> +    };
> +
> +    test_precopy_common(&args);
> +}
> +#endif
> +
>   static void test_precopy_tcp_plain(void)
>   {
>       MigrateCommon args = {
> @@ -1124,6 +1189,10 @@ static void migration_test_add_precopy_smoke(MigrationTestEnv *env)
>                          test_multifd_tcp_uri_none);
>       migration_test_add("/migration/multifd/tcp/plain/cancel",
>                          test_multifd_tcp_cancel);
> +#ifdef CONFIG_RDMA
> +    migration_test_add("/migration/precopy/rdma/plain",
> +                       test_precopy_rdma_plain);
> +#endif
>   }
>   
>   void migration_test_add_precopy(MigrationTestEnv *env)