[CentOS-virt] KVM virtio block layer - is TRIM/DISCARD supported?

Hi,

One question please:

If I use SSD as a storage on a host machine, does KVM's virtio I/O layer
pass the TRIM/DISCARD commands to the SSD?

I guess the question would be twofold:
1) is TRIM supported/forwarded if only one LVM'ed partition of SSD is
forwarded?
2) is TRIM supported/forwarded if full SSD is forwarded (i.e. /dev/sdX)

-- 
Best regards,
        Dmitry Mikhailov