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-rw-r--r--block/qcow2.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index e28ea47d3d..ef8a2cac39 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -295,6 +295,22 @@ static QemuOptsList qcow2_runtime_opts = {
.type = QEMU_OPT_BOOL,
.help = "Postpone refcount updates",
},
+ {
+ .name = QCOW2_OPT_DISCARD_REQUEST,
+ .type = QEMU_OPT_BOOL,
+ .help = "Pass guest discard requests to the layer below",
+ },
+ {
+ .name = QCOW2_OPT_DISCARD_SNAPSHOT,
+ .type = QEMU_OPT_BOOL,
+ .help = "Generate discard requests when snapshot related space "
+ "is freed",
+ },
+ {
+ .name = QCOW2_OPT_DISCARD_OTHER,
+ .type = QEMU_OPT_BOOL,
+ .help = "Generate discard requests when other clusters are freed",
+ },
{ /* end of list */ }
},
};
@@ -532,6 +548,16 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
(s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
+ s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
+ s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
+ s->discard_passthrough[QCOW2_DISCARD_REQUEST] =
+ qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,
+ flags & BDRV_O_UNMAP);
+ s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =
+ qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
+ s->discard_passthrough[QCOW2_DISCARD_OTHER] =
+ qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
+
qemu_opts_del(opts);
if (s->use_lazy_refcounts && s->qcow_version < 3) {