On Tue, Apr 17, 2018 at 01:16:42PM +0200, Michal Privoznik wrote: > https://bugzilla.redhat.com/show_bug.cgi?id=1480668 > > The cases when we cannot enable this optimization are: > 1) nvdimms > 2) if memAccess='shared' The specific use case for discard-data=on uses share=on, see: https://bugzilla.redhat.com/show_bug.cgi?id=1460848#c4 It looks like this will require a explicit XML element, after all. > > Otherwise it is safe to enable it. > > Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> > --- > src/qemu/qemu_command.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 527a35779d..b920f5c3e4 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -3121,6 +3121,13 @@ qemuBuildMemoryBackendStr(virJSONValuePtr *backendProps, > NULL) < 0) > goto cleanup; > > + if (!mem->nvdimmPath && memAccess != VIR_DOMAIN_MEMORY_ACCESS_SHARED && > + virQEMUCapsGet(qemuCaps, QEMU_CAPS_OBJECT_MEMORY_FILE_DISCARD) && > + virJSONValueObjectAdd(props, > + "B:discard-data", true, > + NULL) < 0) > + goto cleanup; > + > switch (memAccess) { > case VIR_DOMAIN_MEMORY_ACCESS_SHARED: > if (virJSONValueObjectAdd(props, "b:share", true, NULL) < 0) > -- > 2.16.1 > -- Eduardo -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
