untrusted comment: verify with openbsd-69-base.pub
RWQQsAemppS46PrjUAfqh4/+SdZ4HyTSGfpLLLMB2UHNoFXr4x1JTg4MxBE5RfjYyTNjfEEqYGr/LNUBxDrJxHzr3aAK4gGvcA4=

OpenBSD 6.9 errata 001, May 4, 2021:

vmd guests can trigger excessive log messages on the host by sending
certain network packets.

Apply by doing:
    signify -Vep /etc/signify/openbsd-69-base.pub -x 001_vmd.patch.sig \
        -m - | (cd /usr/src && patch -p0)

And then rebuild and install vmd(8):
    cd /usr/src/usr.sbin/vmd
    make obj
    make
    make install

Index: usr.sbin/vmd/virtio.c
===================================================================
RCS file: /cvs/src/usr.sbin/vmd/virtio.c,v
retrieving revision 1.84
diff -u -p -r1.84 virtio.c
--- usr.sbin/vmd/virtio.c	29 Mar 2021 23:37:01 -0000	1.84
+++ usr.sbin/vmd/virtio.c	2 May 2021 15:49:26 -0000
@@ -1394,7 +1394,7 @@ vionet_notify_tx(struct vionet_dev *dev)
 	uint32_t vr_sz;
 	uint16_t idx, pkt_desc_idx, hdr_desc_idx, dxx;
 	size_t pktsz;
-	ssize_t dhcpsz;
+	ssize_t dhcpsz = 0;
 	int ret, num_enq, ofs, spc;
 	char *vr, *pkt, *dhcppkt;
 	struct vring_desc *desc, *pkt_desc, *hdr_desc;