Re: [PATCH REBASE 5/7] qemu: Introduce QEMU_CAPS_MACHINE_MEMORY_BACKEND

On a Tuesday in 2020, Michal Privoznik wrote: > This capability corresponds to '-machine memory-backend=' command > line argument. Unfortunately, it is not possible for us to detect > the capability via QMP and therefore we have to have a version > check. > The QEMU capability was introduced in v5.1.0-3-gc556600598. > Please rephrase this or drop the period at the end, e.g.: QEMU commit v5.1.0-3-gc556600598 introduced the capability. (to make it easier to select) > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > src/qemu/qemu_capabilities.c                     | 7 +++++++ > src/qemu/qemu_capabilities.h                     | 3 +++ > tests/qemucapabilitiesdata/caps_5.2.0.x86_64.xml | 1 + > 3 files changed, 11 insertions(+) > > diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c > index dcfd7cdd4e..d0a7c7b30e 100644 > --- a/src/qemu/qemu_capabilities.c > +++ b/src/qemu/qemu_capabilities.c > @@ -597,6 +597,9 @@ VIR_ENUM_IMPL(virQEMUCaps, >               "spapr-tpm-proxy", >               "numa.hmat", >               "blockdev-hostdev-scsi", > + > +              /* 380 */ > +              "machine.memory-backend", >     ); > > > @@ -5104,6 +5107,10 @@ virQEMUCapsInitQMPVersionCaps(virQEMUCapsPtr > qemuCaps) >     /* TCG couldn't be disabled nor queried until QEMU 2.10 */ >     if (qemuCaps->version < 2010000) >         virQEMUCapsSet(qemuCaps, QEMU_CAPS_TCG); > + > +    /* no way to query for -machine memory-backend */ > +    if (qemuCaps->version >= 5001050) That's a git version. Also, the above mentioned commit introduces the 'default-ram-id' property, which does show up in our capability replies file. Can't we safely assume that its presence also means that -machine memory-backend is supported?