On Thu, Jul 13, 2023 at 07:10:47PM +0200, Laszlo Ersek wrote: > We generate the <interface type="user"> element on libvirt 3.8.0+ already. > > For selecting passt rather than SLIRP, we only need to insert the child > element <backend type='passt'>. Make that child element conditional on > libvirt 9.0.0+, plus "passt --help" being executable. > > For the latter, place the new helper function guestfs_int_passt_runnable() > in "lib/launch.c" -- we're going to use the same function for the direct > backend as well. > > This change exposes a number of (perceived) shortcomings in libvirt; I've > filed <https://bugzilla.redhat.com/show_bug.cgi?id=2222766> about those. > > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2184967 > Signed-off-by: Laszlo Ersek <ler...@redhat.com> > --- > lib/guestfs-internal.h | 1 + > lib/launch-libvirt.c | 11 ++++++++ > lib/launch.c | 28 ++++++++++++++++++++ > 3 files changed, 40 insertions(+) > > diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h > index 4be351e3d3cc..a6c4266ad3fe 100644 > --- a/lib/guestfs-internal.h > +++ b/lib/guestfs-internal.h > @@ -703,6 +703,7 @@ extern void guestfs_int_unblock_sigterm (void); > extern int guestfs_int_create_socketname (guestfs_h *g, const char > *filename, char (*sockname)[UNIX_PATH_MAX]); > extern void guestfs_int_register_backend (const char *name, const struct > backend_ops *); > extern int guestfs_int_set_backend (guestfs_h *g, const char *method); > +extern bool guestfs_int_passt_runnable (guestfs_h *g); > > /* Close all file descriptors matching the condition. */ > #define close_file_descriptors(cond) do { \ > diff --git a/lib/launch-libvirt.c b/lib/launch-libvirt.c > index d4bf1a8ff242..994909a35f2d 100644 > --- a/lib/launch-libvirt.c > +++ b/lib/launch-libvirt.c > @@ -1414,6 +1414,17 @@ construct_libvirt_xml_devices (guestfs_h *g, > guestfs_int_version_ge (¶ms->data->libvirt_version, 3, 8, 0)) { > start_element ("interface") { > attribute ("type", "user"); > + /* If libvirt is 9.0.0+ and "passt" is available, ask for passt > rather > + * than SLIRP (RHBZ#2184967). Note that this causes some > + * appliance-visible changes (although network connectivity is > certainly > + * functional); refer to RHBZ#2222766 about those. > + */ > + if (guestfs_int_version_ge (¶ms->data->libvirt_version, 9, 0, 0) > && > + guestfs_int_passt_runnable (g)) { > + start_element ("backend") { > + attribute ("type", "passt"); > + } end_element (); > + } > start_element ("model") { > attribute ("type", "virtio"); > } end_element (); > diff --git a/lib/launch.c b/lib/launch.c > index 6e08b12006da..94c8f676d8bd 100644 > --- a/lib/launch.c > +++ b/lib/launch.c > @@ -36,6 +36,7 @@ > #include <signal.h> > #include <sys/stat.h> > #include <sys/types.h> > +#include <sys/wait.h> > #include <errno.h> > #include <assert.h> > #include <libintl.h> > @@ -414,6 +415,33 @@ guestfs_int_set_backend (guestfs_h *g, const char > *method) > return 0; > } > > +/** > + * Return C<true> if we can call S<C<passt --help>>, and it exits with status > + * C<0> or C<1>. > + * > + * (At least C<passt-0^20230222.g4ddbcb9-2.el9_2.x86_64> terminates with > status > + * C<1> in response to "--help", which is arguably wrong, and potentially > + * subject to change, but it doesn't really matter.) > + */ > +bool > +guestfs_int_passt_runnable (guestfs_h *g) > +{ > + CLEANUP_CMD_CLOSE struct command *cmd = NULL; > + int r, ex; > + > + cmd = guestfs_int_new_command (g); > + if (cmd == NULL) > + return false; > + > + guestfs_int_cmd_add_string_unquoted (cmd, "passt --help");
Do we need " >/dev/null 2>&1" here to avoid unnecessary messages being printed when libguestfs is not in verbose mode? Apart from that: Reviewed-by: Richard W.M. Jones <rjo...@redhat.com> Rich. > + r = guestfs_int_cmd_run (cmd); > + if (r == -1 || !WIFEXITED (r)) > + return false; > + > + ex = WEXITSTATUS (r); > + return ex == 0 || ex == 1; > +} > + > /* This hack is only required to make static linking work. See: > * > https://stackoverflow.com/questions/1202494/why-doesnt-attribute-constructor-work-in-a-static-library > */ > > _______________________________________________ > Libguestfs mailing list > Libguestfs@redhat.com > https://listman.redhat.com/mailman/listinfo/libguestfs -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
