The capabilities will have a <drivediscard/> feature if you are allowed to use the qemu attribute: <driver name='qemu' ... discard='unmap|ignore' /> The new capabilities XML looks like this: <capabilities> ... <guest> <os_type>hvm</os_type> ... <features> <drivediscard/> </features> </guest> </capabilities> --- src/conf/capabilities.c | 3 ++- src/qemu/qemu_capabilities.c | 4 ++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/src/conf/capabilities.c b/src/conf/capabilities.c index c1c4ab8..ff5912a 100644 --- a/src/conf/capabilities.c +++ b/src/conf/capabilities.c @@ -947,7 +947,8 @@ virCapabilitiesFormatXML(virCapsPtr caps) STREQ(caps->guests[i]->features[j]->name, "nonpae") || STREQ(caps->guests[i]->features[j]->name, "ia64_be") || STREQ(caps->guests[i]->features[j]->name, "cpuselection") || - STREQ(caps->guests[i]->features[j]->name, "deviceboot")) { + STREQ(caps->guests[i]->features[j]->name, "deviceboot") || + STREQ(caps->guests[i]->features[j]->name, "drivediscard")) { virBufferAsprintf(&xml, " <%s/>\n", caps->guests[i]->features[j]->name); } else { diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index cae25e0..b755fb2 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -778,6 +778,10 @@ virQEMUCapsInitGuest(virCapsPtr caps, !virCapabilitiesAddGuestFeature(guest, "deviceboot", 1, 0)) goto error; + if (virQEMUCapsGet(qemubinCaps, QEMU_CAPS_DRIVE_DISCARD) && + !virCapabilitiesAddGuestFeature(guest, "drivediscard", 0, 0)) + goto error; + if (virCapabilitiesAddGuestDomain(guest, "qemu", NULL, -- 1.8.5.3