On Mon, Dec 06, 2021 at 10:02:44 +0100, Thomas Huth wrote: > On 06/12/2021 09.57, Peter Krempa wrote: > > On Mon, Dec 06, 2021 at 09:47:58 +0100, Thomas Huth wrote: > > > On 06/12/2021 09.40, Thomas Huth wrote: > > > > The HPET setting has been turned into a machine property a while ago > > > > already, so we should finally do the next step and deprecate the > > > > legacy CLI option, too. > > > > While we're at it, add a proper help text for the machine property, too. > > > > > > > > Signed-off-by: Thomas Huth <th...@redhat.com> > > > > --- > > > > docs/about/deprecated.rst | 6 ++++++ > > > > hw/i386/pc.c | 2 ++ > > > > qemu-options.hx | 2 +- > > > > softmmu/vl.c | 1 + > > > > 4 files changed, 10 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > > > > index 5693abb663..1dfe69aa6a 100644 > > > > --- a/docs/about/deprecated.rst > > > > +++ b/docs/about/deprecated.rst > > > > @@ -198,6 +198,12 @@ form is preferred. > > > > Using ``-drive if=none`` to configure the OTP device of the sifive_u > > > > RISC-V machine is deprecated. Use ``-drive if=pflash`` instead. > > > > +``-no-hpet`` (since 7.0) > > > > +'''''''''''''''''''''''' > > > > + > > > > +The HPET setting has been turned into a machine property. > > > > +Use ``-machine hpet=off`` instead. > > > [...] > > > > > > Forgot to CC: the libvirt folks, doing so now. > > > > > > Seems like libvirt is still using -no-hpet in some few spots, so I guess > > > these would need to be changed first, before we could finally remove this > > > option in QEMU? > > > > Yes we need to switch to the new property first. > > > > Is the new way via -machine property by any chance usable with > > qemu-2.11? If yes, then we can do it unconditionally, otherwise we'll > > need a witness to detect the support for the new flag as a qemu > > capability. > > The machine property has been added just a year ago: > > https://gitlab.com/qemu-project/qemu/-/commit/0259c78ca79 > > So it's just available on QEMU v5.2.0 and newer.
Okay, so we can't unfortunately always use the new way. I had a brief look in what libvirt queries to build the capability list and unfortunately neither query-command-line-options nor query-machines list anything which we could detect. Since only the config knob is changing the presence in qom-list-types doesn't help either. So if qemu want's to deprecate the '-no-hpet' spelling we need something which we can detect by one of the above means or other probe command to use the new spelling.
