K 10
svn:author
V 9
allanjude
K 8
svn:date
V 27
2020-07-16T16:32:16.454435Z
K 7
svn:log
V 463
Add VIRTIO_BLK_T_DISCARD support to the virtio-blk driver

If the hypervisor advertises support for the DISCARD command then the
guest can perform TRIM commands, freeing space on the backing store.

If VIRTIO_BLK_F_DISCARD is enabled, advertise DISKFLAG_CANDELETE

Tested with FreeBSD guests on bhyve and KVM

Reviewed by:	jhb
Tested by:	freqlabs
MFC after:	1 month
Relnotes:	yes
Sponsored by:	Klara Inc.
Differential Revision:	https://reviews.freebsd.org/D21708

END