On 09/09/21 13:35, Richard W.M. Jones wrote: > On Thu, Sep 09, 2021 at 01:11:09PM +0200, Laszlo Ersek wrote: >> How does libguestfs deal with different QEMU versions / QEMU feature >> deprecation? Is there some kind of feature detection? > > Kind of, but it's only grepping the output of -help, -device \?, > and/or looking at QMP output of "query-qmp-schema" and "query-kvm". > > The code is in: > > https://github.com/libguestfs/libguestfs/blob/master/lib/qemu.c > > As qemu has settled down over time and libguestfs uses only a > well-established set of features, this kind of feature detection has > become less and less interesting. (So quite unlike libvirt where > they're always trying to catch up with the latest qemu features). At > some point we might just say "use qemu >= VERSION" and have done with > it.
OK! > >> For example, why would it be less good to implement the change as >> follows: >> >> if (g->verbose) { >> if (guestfs_int_qemu_supports_device(...) { >> arg ("-device", "sga"); >> } else { >> #if defined(__i386__) || defined(__x86_64__) >> arg ("-machine", "graphics=off"); >> #endif >> } > > I think in this case it's my understanding that the "new" (from RHEL > 7!) Ah, OK! I didn't check. > seabios graphics feature is just better than SGA, Agreed. > and so we might as well use it all the time even if SGA is available. > That was my understanding from talking to Gerd anyhow. So yes, my R-b stands. Thanks! Laszlo _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs