On Wed, Feb 19, 2025 at 10:20:21AM -0300, Fabiano Rosas wrote:
> 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.
Yes, if we want to have the test being able to trigger the script, we can
put it under tests/qtest/migration/.
>
> >>
> >>
> >> > 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.
Looks good here. We can also keep all the rdma stuff into one file, taking
parameters.
./rdma-helper.sh setup
./rdma-helper.sh detect-ip
>
> 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.
For misterious reasons I seem to have all the libs needed, probably I tried
to build RDMA at some point and do something with it. So I gave it a shot
quickly, I can reproduce Zhijian's failure, and patch 1 fixes it.
--
Peter Xu
