Peter Xu <pet...@redhat.com> writes:
> On Wed, Feb 19, 2025 at 05:33:26AM +0000, Zhijian Li (Fujitsu) wrote:
>>
>>
>> On 19/02/2025 06:40, Peter Xu wrote:
>> > On Tue, Feb 18, 2025 at 06:03:48PM -0300, Fabiano Rosas wrote:
>> >> Li Zhijian via <qemu-devel@nongnu.org> writes:
>> >>
>> >>> This qtest requirs there is RXE link in the host.
>> >>>
>> >>> Here is an example to show how to add this RXE link:
>> >>> $ ./new-rdma-link.sh
>> >>> 192.168.22.93
>> >>>
>> >>> Signed-off-by: Li Zhijian <lizhij...@fujitsu.com>
>> >>> ---
>> >>> The RDMA migration was broken again...due to lack of sufficient
>> >>> test/qtest.
>> >>>
>> >>> It's urgly to add and execute a script to establish an RDMA link in
>> >>> the C program. If anyone has a better suggestion, please let me know.
>> >>>
>> >>> $ cat ./new-rdma-link.sh
>> >>> get_ipv4_addr() {
>> >>> ip -4 -o addr show dev "$1" |
>> >>> sed -n
>> >>> 's/.*[[:blank:]]inet[[:blank:]]*\([^[:blank:]/]*\).*/\1/p'
>> >>> }
>> >>>
>> >>> has_soft_rdma() {
>> >>> rdma link | grep -q " netdev $1[[:blank:]]*\$"
>> >>> }
>> >>>
>> >>> start_soft_rdma() {
>> >>> local type
>> >>>
>> >>> modprobe rdma_rxe || return $?
>> >>> type=rxe
>> >>> (
>> >>> cd /sys/class/net &&
>> >>> for i in *; do
>> >>> [ -e "$i" ] || continue
>> >>> [ "$i" = "lo" ] && continue
>> >>> [ "$(<"$i/addr_len")" = 6 ] || continue
>> >>> [ "$(<"$i/carrier")" = 1 ] || continue
>> >>> has_soft_rdma "$i" && break
>> >>> rdma link add "${i}_$type" type $type
>> >>> netdev "$i" && break
>> >>> done
>> >>> has_soft_rdma "$i" && echo $i
>> >>> )
>> >>>
>> >>> }
>> >>>
>> >>> rxe_link=$(start_soft_rdma)
>> >>> [[ "$rxe_link" ]] && get_ipv4_addr $rxe_link
>> >>>
>> >>> Signed-off-by: Li Zhijian <lizhij...@fujitsu.com>
>> >>> ---
>> >>> tests/qtest/migration/new-rdma-link.sh | 34 ++++++++
>> >>> tests/qtest/migration/precopy-tests.c | 103 +++++++++++++++++++++++++
>> >>> 2 files changed, 137 insertions(+)
>> >>> create mode 100644 tests/qtest/migration/new-rdma-link.sh
>> >>>
>> >>> diff --git a/tests/qtest/migration/new-rdma-link.sh
>> >>> b/tests/qtest/migration/new-rdma-link.sh
>> >>> new file mode 100644
>> >>> index 00000000000..ca20594eaae
>> >>> --- /dev/null
>> >>> +++ b/tests/qtest/migration/new-rdma-link.sh
>> >>> @@ -0,0 +1,34 @@
>> >>> +#!/bin/bash
>> >>> +
>> >>> +# Copied from blktests
>> >>> +get_ipv4_addr() {
>> >>> + ip -4 -o addr show dev "$1" |
>> >>> + sed -n
>> >>> 's/.*[[:blank:]]inet[[:blank:]]*\([^[:blank:]/]*\).*/\1/p'
>> >>> +}
>> >>> +
>> >>> +has_soft_rdma() {
>> >>> + rdma link | grep -q " netdev $1[[:blank:]]*\$"
>> >>> +}
>> >>> +
>> >>> +start_soft_rdma() {
>> >>> + local type
>> >>> +
>> >>> + modprobe rdma_rxe || return $?
>> >>> + type=rxe
>> >>> + (
>> >>> + cd /sys/class/net &&
>> >>> + for i in *; do
>> >>> + [ -e "$i" ] || continue
>> >>> + [ "$i" = "lo" ] && continue
>> >>> + [ "$(<"$i/addr_len")" = 6 ] || continue
>> >>> + [ "$(<"$i/carrier")" = 1 ] || continue
>> >>> + has_soft_rdma "$i" && break
>> >>> + rdma link add "${i}_$type" type $type
>> >>> netdev "$i" && break
>> >>> + done
>> >>> + has_soft_rdma "$i" && echo $i
>> >>> + )
>> >>> +
>> >>> +}
>> >>> +
>> >>> +rxe_link=$(start_soft_rdma)
>> >>> +[[ "$rxe_link" ]] && get_ipv4_addr $rxe_link
>> >>> diff --git a/tests/qtest/migration/precopy-tests.c
>> >>> b/tests/qtest/migration/precopy-tests.c
>> >>> index 162fa695318..d2a1c9c9438 100644
>> >>> --- a/tests/qtest/migration/precopy-tests.c
>> >>> +++ b/tests/qtest/migration/precopy-tests.c
>> >>> @@ -98,6 +98,105 @@ static void test_precopy_unix_dirty_ring(void)
>> >>> test_precopy_common(&args);
>> >>> }
>> >>>
>> >>> +static int new_rdma_link(char *buffer) {
>> >>> + // Copied from blktests
>> >>> + const char *script =
>> >>> + "#!/bin/bash\n"
>> >>> + "\n"
>> >>> + "get_ipv4_addr() {\n"
>> >>> + " ip -4 -o addr show dev \"$1\" |\n"
>> >>> + " sed -n
>> >>> 's/.*[[:blank:]]inet[[:blank:]]*\\([^[:blank:]/]*\\).*/\\1/p'\n"
>> >>> + "}\n"
>> >>> + "\n"
>> >>> + "has_soft_rdma() {\n"
>> >>> + " rdma link | grep -q \" netdev $1[[:blank:]]*\\$\"\n"
>> >>> + "}\n"
>> >>> + "\n"
>> >>> + "start_soft_rdma() {\n"
>> >>> + " local type\n"
>> >>> + "\n"
>> >>> + " modprobe rdma_rxe || return $?\n"
>> >>> + " type=rxe\n"
>> >>> + " (\n"
>> >>> + " cd /sys/class/net &&\n"
>> >>> + " for i in *; do\n"
>> >>> + " [ -e \"$i\" ] || continue\n"
>> >>> + " [ \"$i\" = \"lo\" ] && continue\n"
>> >>> + " [ \"$(<$i/addr_len)\" = 6 ] || continue\n"
>> >>> + " [ \"$(<$i/carrier)\" = 1 ] || continue\n"
>> >>> + " has_soft_rdma \"$i\" && break\n"
>> >>> + " rdma link add \"${i}_$type\" type $type netdev
>> >>> \"$i\" && break\n"
>> >>> + " done\n"
>> >>> + " has_soft_rdma \"$i\" && echo $i\n"
>> >>> + " )\n"
>> >>> + "}\n"
>> >>> + "\n"
>> >>> + "rxe_link=$(start_soft_rdma)\n"
>> >>> + "[[ \"$rxe_link\" ]] && get_ipv4_addr $rxe_link\n";
>> >>> +
>> >>> + char script_filename[] = "/tmp/temp_scriptXXXXXX";
>> >>> + int fd = mkstemp(script_filename);
>> >>> + if (fd == -1) {
>> >>> + perror("Failed to create temporary file");
>> >>> + return 1;
>> >>> + }
>> >>> +
>> >>> + FILE *fp = fdopen(fd, "w");
>> >>> + if (fp == NULL) {
>> >>> + perror("Failed to open file stream");
>> >>> + close(fd);
>> >>> + return 1;
>> >>> + }
>> >>> + fprintf(fp, "%s", script);
>> >>> + fclose(fp);
>> >>> +
>> >>> + if (chmod(script_filename, 0700) == -1) {
>> >>> + perror("Failed to set execute permission");
>> >>> + return 1;
>> >>> + }
>> >>> +
>> >>> + FILE *pipe = popen(script_filename, "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);
>> >>> + }
>> >>> + if (buffer[idx - 1] == '\n')
>> >>> + buffer[idx - 1] = 0;
>> >>> +
>> >>> + int status = pclose(pipe);
>> >>> + if (status == -1) {
>> >>> + perror("Error reported by pclose()");
>> >>> + } else if (!WIFEXITED(status)) {
>> >>> + printf("Script did not terminate normally\n");
>> >>> + }
>> >>> +
>> >>> + remove(script_filename);
>> >
>> > The script can be put separately instead if hard-coded here, right?
>>
>>
>> Sure, If so, I wonder whether the migration-test program is able to know
>> where is this script?
>>
>>
>> >
>> >>> +
>> >>> + return 0;
>> >>> +}
>> >>> +
>> >>> +static void test_precopy_rdma_plain(void)
>> >>> +{
>> >>> + char buffer[128] = {};
>> >>> +
>> >>> + if (new_rdma_link(buffer))
>> >>> + return;
>> >>> +
>> >>> + g_autofree char *uri = g_strdup_printf("rdma:%s:7777", buffer);
>> >>> +
>> >>> + MigrateCommon args = {
>> >>> + .listen_uri = uri,
>> >>> + .connect_uri = uri,
>> >>> + };
>> >>> +
>> >>> + test_precopy_common(&args);
>> >>> +}
>> >>> +
>> >>> static void test_precopy_tcp_plain(void)
>> >>> {
>> >>> MigrateCommon args = {
>> >>> @@ -968,6 +1067,10 @@ 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)
>> >>
>> >> Thanks, that's definitely better than nothing. I'll experiment with this
>> >> locally, see if I can at least run it before sending a pull request.
>> >
>> > With your newly added --full, IIUC we can add whatever we want there.
>> > E.g. we can add --rdma and iff specified, migration-test adds the rdma
>> > test.
>> >
>> > Or.. skip the test when the rdma link isn't available.
>> >
>> > If we could separate the script into a file, it'll be better. We could
>> > create scripts/migration dir and put all migration scripts over there,
>>
>> We have any other existing script? I didn't find it in current QEMU tree.
>
> We have a few that I'm aware of:
>
> - analyze-migration.py
> - vmstate-static-checker.py
> - userfaultfd-wrlat.py
>
If it cannot be reached from there for some reason, we could copy it to
build/tests/qtest/migration during the build. As a last resort I'm fine
with just having it directly at tests/qtest/migration like this patch
does.
>>
>>
>> > then
>> > in the test it tries to detect rdma link and fetch the ip only
>>
>> It should work without root permission if we just *detect* and *fetch ip*.
>>
>> Do you also mean we can split new-rdma-link.sh to 2 separate scripts
>> - add-rdma-link.sh # optionally, execute by user before the test (require
>> root permission)
>> - detect-fetch-rdma.sh # execute from the migration-test
>
> Hmm indeed we still need a script to scan over all the ports..
>
> If having --rdma is a good idea, maybe we can further make it a parameter
> to --rdma?
>
> $ migration-test --rdma $RDMA_IP
>
> Or:
>
> $ migration-test --rdma-ip $RDMA_IP
I think --rdma only makes sense if it's going to do something
special. The optmimal scenario is that it always runs the test when it
can and sets up/tears down anything it needs.
If it needs root, I'd prefer the test informs about this and does the
work itself.
It would also be good to have the add + detect separate so we have more
flexibility, maybe we manage to enable this in CI even.
So:
./add.sh
migration-test
(runs detect.sh + runs rdma test)
(leaves stuff behind)
migration-test
(skips rdma test with message that it needs root)
sudo migration-test
(runs add.sh + detect.sh + runs rdma test)
(cleans itself up)
Does that make sense to you? I hope it's not too much work.
If you'd like to limit the usage of sudo for running the tests, then we
could indeed add the --rdma option and this would be even more
strict. The good thing of not having --rdma is that I could call add.sh
and then run the full make check afterwards, but that's not a huge deal.
> Then maybe migration-test can directly take that IP and run the tests,
> assuming the admin setup the rdma link. Then we keep that one script.
>
> Or I assume it's still ok that the test requires root only for --rdma, then
> invoke the script directly in the test. If so, we'd better also remove the
> rdma link after test finished, so no side effect of the test (modprobe is
> probably fine).
>
> We can wait and see how far Fabiano went with this, and also his opinion.
I haven't got the chance to try the script yet. I still need to figure
out what packages I need from the distro.
