Initial stab at a driver for virtual disks found on sun4v logical domains.

Still needs some work, but reading from and writing to a disk image works.

1 files changed, 1077 insertions, 0 deletions

diff --git a/sys/arch/sparc64/dev/vdsk.c b/sys/arch/sparc64/dev/vdsk.c
new file mode 100644
index 00000000000..8e4860b6264
--- /dev/null
+++ b/sys/arch/sparc64/dev/vdsk.c
@@ -0,0 +1,1077 @@
+/*	$OpenBSD: vdsk.c,v 1.1 2009/01/12 20:11:13 kettenis Exp $	*/
+/*
+ * Copyright (c) 2009 Mark Kettenis
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/buf.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+
+#include <machine/autoconf.h>
+#include <machine/hypervisor.h>
+
+#include <uvm/uvm.h>
+
+#include <scsi/scsi_all.h>
+#include <scsi/scsi_disk.h>
+#include <scsi/scsiconf.h>
+
+#include <sparc64/dev/cbusvar.h>
+#include <sparc64/dev/ldcvar.h>
+#include <sparc64/dev/viovar.h>
+
+#ifdef VDSK_DEBUG
+#define DPRINTF(x)	printf x
+#else
+#define DPRINTF(x)
+#endif
+
+#define VDSK_TX_ENTRIES		32
+#define VDSK_RX_ENTRIES		32
+
+struct vd_attr_info {
+	struct vio_msg_tag	tag;
+	uint8_t			xfer_mode;
+	uint8_t			vd_type;
+	uint8_t			vd_mtype;
+	uint8_t			_reserved1;
+	uint32_t		vdisk_block_size;
+	uint64_t		operations;
+	uint64_t		vdisk_size;
+	uint64_t		max_xfer_sz;
+	uint64_t		reserved2[2];
+};
+
+#define VD_DISK_TYPE_SLICE	0x01
+#define VD_DISK_TYPE_DISK	0x02
+
+#define VD_MEDIA_TYPE_FIXED	0x01
+#define VD_MEDIA_TYPE_CD	0x02
+#define VD_MEDIA_TYPE_DVD	0x03
+
+/* vDisk version 1.0. */
+#define VD_OP_BREAD		0x01
+#define VD_OP_BWRITE		0x02
+#define VD_OP_FLUSH		0x03
+#define VD_OP_GET_WCE		0x04
+#define VD_OP_SET_WCE		0x05
+#define VD_OP_GET_VTOC		0x06
+#define VD_OP_SET_VTOC		0x07
+#define VD_OP_GET_DISKGEOM	0x08
+#define VD_OP_SET_DISKGEOM	0x09
+#define VD_OP_GET_DEVID		0x0b
+#define VD_OP_GET_EFI		0x0c
+#define VD_OP_SET_EFI		0x0d
+
+/* vDisk version 1.1 */
+#define VD_OP_SCSICMD		0x0a
+#define VD_OP_RESET		0x0e
+#define VD_OP_GET_ACCESS	0x0f
+#define VD_OP_SET_ACCESS	0x10
+#define VD_OP_GET_CAPACITY	0x11
+
+struct vd_desc {
+	struct vio_dring_hdr	hdr;
+	uint64_t		req_id;
+	uint8_t			operation;
+	uint8_t			slice;
+	uint16_t		_reserved1;
+	uint32_t		status;
+	uint64_t		offset;
+	uint64_t		size;
+	uint32_t		ncookies;
+	uint32_t		_reserved2;
+	struct ldc_cookie	cookie[MAXPHYS / PAGE_SIZE];
+};
+
+#define VD_SLICE_NONE		0xff
+
+struct vdsk_dring {
+	bus_dmamap_t		vd_map;
+	bus_dma_segment_t	vd_seg;
+	struct vd_desc		*vd_desc;
+	int			vd_nentries;
+};
+
+struct vdsk_dring *vdsk_dring_alloc(bus_dma_tag_t, int);
+void	vdsk_dring_free(bus_dma_tag_t, struct vdsk_dring *);
+
+/*
+ * For now, we only support vDisk 1.0.
+ */
+#define VDSK_MAJOR	1
+#define VDSK_MINOR	0
+
+struct vdsk_soft_desc {
+	int		vsd_map_idx[MAXPHYS / PAGE_SIZE];
+	struct scsi_xfer *vsd_xs;
+};
+
+struct vdsk_softc {
+	struct device	sc_dv;
+	bus_space_tag_t	sc_bustag;
+	bus_dma_tag_t	sc_dmatag;
+
+	void		*sc_tx_ih;
+	void		*sc_rx_ih;
+
+	struct ldc_conn	sc_lc;
+
+	uint8_t		sc_vio_state;
+#define VIO_ESTABLISHED	8
+
+	uint32_t	sc_local_sid;
+	uint64_t	sc_dring_ident;
+	uint64_t	sc_seq_no;
+
+	int		sc_tx_cnt;
+	int		sc_tx_prod;
+	int		sc_tx_cons;
+
+	struct ldc_map	*sc_lm;
+	struct vdsk_dring *sc_vd;
+	struct vdsk_soft_desc *sc_vsd;
+
+	struct scsi_adapter sc_switch;
+	struct scsi_link sc_link;
+
+	uint32_t	sc_vdisk_block_size;
+	uint64_t	sc_vdisk_size;
+};
+
+int	vdsk_match(struct device *, void *, void *);
+void	vdsk_attach(struct device *, struct device *, void *);
+
+struct cfattach vdsk_ca = {
+	sizeof(struct vdsk_softc), vdsk_match, vdsk_attach
+};
+
+struct cfdriver vdsk_cd = {
+	NULL, "vdsk", DV_IFNET
+};
+
+struct scsi_device vdsk_device = {
+	NULL, NULL, NULL, NULL
+};
+
+int	vdsk_tx_intr(void *);
+int	vdsk_rx_intr(void *);
+
+void	vdsk_rx_data(struct ldc_conn *, struct ldc_pkt *);
+void	vdsk_rx_vio_ctrl(struct vdsk_softc *, struct vio_msg *);
+void	vdsk_rx_vio_ver_info(struct vdsk_softc *, struct vio_msg_tag *);
+void	vdsk_rx_vio_attr_info(struct vdsk_softc *, struct vio_msg_tag *);
+void	vdsk_rx_vio_dring_reg(struct vdsk_softc *, struct vio_msg_tag *);
+void	vdsk_rx_vio_rdx(struct vdsk_softc *sc, struct vio_msg_tag *);
+void	vdsk_rx_vio_data(struct vdsk_softc *sc, struct vio_msg *);
+void	vdsk_rx_vio_dring_data(struct vdsk_softc *sc, struct vio_msg_tag *);
+
+void	vdsk_reset(struct ldc_conn *);
+void	vdsk_start(struct ldc_conn *);
+
+void	vdsk_sendmsg(struct vdsk_softc *, void *, size_t);
+void	vdsk_send_ver_info(struct vdsk_softc *, uint16_t, uint16_t);
+void	vdsk_send_attr_info(struct vdsk_softc *);
+void	vdsk_send_dring_reg(struct vdsk_softc *);
+void	vdsk_send_rdx(struct vdsk_softc *);
+
+int	vdsk_scsi_cmd(struct scsi_xfer *);
+int	vdsk_dev_probe(struct scsi_link *);
+void	vdsk_dev_free(struct scsi_link *);
+int	vdsk_ioctl(struct scsi_link *, u_long, caddr_t, int, struct proc *);
+
+int	vdsk_scsi_inq(struct scsi_xfer *);
+int	vdsk_scsi_inquiry(struct scsi_xfer *);
+int	vdsk_scsi_capacity(struct scsi_xfer *);
+int	vdsk_scsi_done(struct scsi_xfer *, int);
+
+int
+vdsk_match(struct device *parent, void *match, void *aux)
+{
+	struct cbus_attach_args *ca = aux;
+
+	if (strcmp(ca->ca_name, "disk") == 0)
+		return (1);
+
+	return (0);
+}
+
+void
+vdsk_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct vdsk_softc *sc = (struct vdsk_softc *)self;
+	struct cbus_attach_args *ca = aux;
+	struct scsibus_attach_args saa;
+	struct ldc_conn *lc;
+	uint64_t sysino[2];
+	int err, s;
+	int timeout;
+
+	sc->sc_bustag = ca->ca_bustag;
+	sc->sc_dmatag = ca->ca_dmatag;
+
+	if (cbus_intr_map(ca->ca_node, ca->ca_tx_ino, &sysino[0]) ||
+	    cbus_intr_map(ca->ca_node, ca->ca_rx_ino, &sysino[1])) {
+		printf(": can't map interrupt\n");
+		return;
+	}
+	printf(": ivec 0x%lx, 0x%lx", sysino[0], sysino[1]);
+
+	/*
+	 * Un-configure queues before registering interrupt handlers,
+	 * such that we dont get any stale LDC packets or events.
+	 */
+	hv_ldc_tx_qconf(ca->ca_id, 0, 0);
+	hv_ldc_rx_qconf(ca->ca_id, 0, 0);
+
+	sc->sc_tx_ih = bus_intr_establish(ca->ca_bustag, sysino[0], IPL_BIO,
+	    0, vdsk_tx_intr, sc, sc->sc_dv.dv_xname);
+	sc->sc_rx_ih = bus_intr_establish(ca->ca_bustag, sysino[1], IPL_BIO,
+	    0, vdsk_rx_intr, sc, sc->sc_dv.dv_xname);
+	if (sc->sc_tx_ih == NULL || sc->sc_rx_ih == NULL) {
+		printf(", can't establish interrupt\n");
+		return;
+	}
+
+	lc = &sc->sc_lc;
+	lc->lc_id = ca->ca_id;
+	lc->lc_sc = sc;
+	lc->lc_reset = vdsk_reset;
+	lc->lc_start = vdsk_start;
+	lc->lc_rx_data = vdsk_rx_data;
+
+	lc->lc_txq = ldc_queue_alloc(sc->sc_dmatag, VDSK_TX_ENTRIES);
+	if (lc->lc_txq == NULL) {
+		printf(", can't allocate tx queue\n");
+		return;
+	}
+
+	lc->lc_rxq = ldc_queue_alloc(sc->sc_dmatag, VDSK_RX_ENTRIES);
+	if (lc->lc_rxq == NULL) {
+		printf(", can't allocate rx queue\n");
+		goto free_txqueue;
+	}
+
+	sc->sc_lm = ldc_map_alloc(sc->sc_dmatag, 2048);
+	if (sc->sc_lm == NULL) {
+		printf(", can't allocate LDC mapping table\n");
+		goto free_rxqueue;
+	}
+
+	err = hv_ldc_set_map_table(lc->lc_id,
+	    sc->sc_lm->lm_map->dm_segs[0].ds_addr, sc->sc_lm->lm_nentries);
+	if (err != H_EOK) {
+		printf("hv_ldc_set_map_table %d\n", err);
+		goto free_map;
+	}
+
+	sc->sc_vd = vdsk_dring_alloc(sc->sc_dmatag, 32);
+	if (sc->sc_vd == NULL) {
+		printf(", can't allocate dring\n");
+		goto free_map;
+	}
+	sc->sc_vsd = malloc(32 * sizeof(*sc->sc_vsd), M_DEVBUF, M_NOWAIT);
+	if (sc->sc_vsd == NULL) {
+		printf(", can't allocate software ring\n");
+		goto free_dring;
+	}
+
+	sc->sc_lm->lm_slot[0].entry = sc->sc_vd->vd_map->dm_segs[0].ds_addr;
+	sc->sc_lm->lm_slot[0].entry &= LDC_MTE_RA_MASK;
+	sc->sc_lm->lm_slot[0].entry |= LDC_MTE_CPR | LDC_MTE_CPW;
+	sc->sc_lm->lm_slot[0].entry |= LDC_MTE_R | LDC_MTE_W;
+	sc->sc_lm->lm_next = 1;
+	sc->sc_lm->lm_count = 1;
+
+	err = hv_ldc_tx_qconf(lc->lc_id,
+	    lc->lc_txq->lq_map->dm_segs[0].ds_addr, lc->lc_txq->lq_nentries);
+	if (err != H_EOK)
+		printf("hv_ldc_tx_qconf %d\n", err);
+
+	err = hv_ldc_rx_qconf(lc->lc_id,
+	    lc->lc_rxq->lq_map->dm_segs[0].ds_addr, lc->lc_rxq->lq_nentries);
+	if (err != H_EOK)
+		printf("hv_ldc_rx_qconf %d\n", err);
+
+	ldc_send_vers(lc);
+
+	printf("\n");
+
+	/*
+	 * Interrupts aren't enabled during autoconf, so poll for VIO
+	 * peer-to-peer hanshake completion.
+	 */
+	s = splbio();
+	timeout = 1000;
+	do {
+		if (vdsk_rx_intr(sc) && sc->sc_vio_state == VIO_ESTABLISHED)
+			break;
+
+		delay(1000);
+	} while(--timeout > 0);
+	splx(s);
+
+	if (sc->sc_vio_state != VIO_ESTABLISHED)
+		return;
+
+	sc->sc_switch.scsi_cmd = vdsk_scsi_cmd;
+	sc->sc_switch.scsi_minphys = minphys;
+	sc->sc_switch.dev_probe = vdsk_dev_probe;
+	sc->sc_switch.dev_free = vdsk_dev_free;
+	sc->sc_switch.ioctl = vdsk_ioctl;
+
+	sc->sc_link.device = &vdsk_device;
+	sc->sc_link.adapter = &sc->sc_switch;
+	sc->sc_link.adapter_softc = self;
+	sc->sc_link.adapter_buswidth = 2;
+	sc->sc_link.luns = 1; /* XXX slices should be presented as luns? */
+	sc->sc_link.adapter_target = 2;
+	sc->sc_link.openings = 32;
+
+	bzero(&saa, sizeof(saa));
+	saa.saa_sc_link = &sc->sc_link;
+	config_found(self, &saa, scsiprint);
+
+	return;
+
+free_dring:
+	vdsk_dring_free(sc->sc_dmatag, sc->sc_vd);
+free_map:
+	hv_ldc_set_map_table(lc->lc_id, 0, 0);
+	ldc_map_free(sc->sc_dmatag, sc->sc_lm);
+free_rxqueue:
+	ldc_queue_free(sc->sc_dmatag, lc->lc_rxq);
+free_txqueue:
+	ldc_queue_free(sc->sc_dmatag, lc->lc_txq);
+	return;
+}
+
+int
+vdsk_tx_intr(void *arg)
+{
+	struct vdsk_softc *sc = arg;
+	struct ldc_conn *lc = &sc->sc_lc;
+	uint64_t tx_head, tx_tail, tx_state;
+
+	hv_ldc_tx_get_state(lc->lc_id, &tx_head, &tx_tail, &tx_state);
+	if (tx_state != lc->lc_tx_state) {
+		switch (tx_state) {
+		case LDC_CHANNEL_DOWN:
+			DPRINTF(("Tx link down\n"));
+			break;
+		case LDC_CHANNEL_UP:
+			DPRINTF(("Tx link up\n"));
+			break;
+		case LDC_CHANNEL_RESET:
+			DPRINTF(("Tx link reset\n"));
+			break;
+		}
+		lc->lc_tx_state = tx_state;
+	}
+
+	return (1);
+}
+
+int
+vdsk_rx_intr(void *arg)
+{
+	struct vdsk_softc *sc = arg;
+	struct ldc_conn *lc = &sc->sc_lc;
+	uint64_t rx_head, rx_tail, rx_state;
+	struct ldc_pkt *lp;
+	uint64_t *msg;
+	int err;
+
+	err = hv_ldc_rx_get_state(lc->lc_id, &rx_head, &rx_tail, &rx_state);
+	if (err == H_EINVAL)
+		return (0);
+	if (err != H_EOK) {
+		printf("hv_ldc_rx_get_state %d\n", err);
+		return (0);
+	}
+
+	if (rx_state != lc->lc_rx_state) {
+		sc->sc_tx_cnt = sc->sc_tx_prod = sc->sc_tx_cons = 0;
+		sc->sc_vio_state = 0;
+		lc->lc_tx_seqid = 0;
+		lc->lc_state = 0;
+		switch (rx_state) {
+		case LDC_CHANNEL_DOWN:
+			DPRINTF(("Rx link down\n"));
+			break;
+		case LDC_CHANNEL_UP:
+			DPRINTF(("Rx link up\n"));
+			ldc_send_vers(lc);
+			break;
+		case LDC_CHANNEL_RESET:
+			DPRINTF(("Rx link reset\n"));
+			break;
+		}
+		lc->lc_rx_state = rx_state;
+		hv_ldc_rx_set_qhead(lc->lc_id, rx_tail);
+		return (1);
+	}
+
+	if (rx_head == rx_tail)
+		return (0);
+
+	msg = (uint64_t *)(lc->lc_rxq->lq_va + rx_head);
+#if 0
+{
+	int i;
+
+	printf("%s: rx intr, head %lx, tail %lx\n", sc->sc_dv.dv_xname,
+	    rx_head, rx_tail);
+	for (i = 0; i < 8; i++)
+		printf("word %d: 0x%016lx\n", i, msg[i]);
+}
+#endif
+	lp = (struct ldc_pkt *)(lc->lc_rxq->lq_va + rx_head);
+	switch (lp->type) {
+	case LDC_CTRL:
+		ldc_rx_ctrl(lc, lp);
+		break;
+
+	case LDC_DATA:
+		ldc_rx_data(lc, lp);
+		break;
+
+	default:
+		DPRINTF(("%0x02/%0x02/%0x02\n", lp->type, lp->stype,
+		    lp->ctrl));
+		ldc_reset(lc);
+		break;
+	}
+
+	if (lc->lc_state == 0)
+		return (1);
+
+	rx_head += sizeof(*lp);
+	rx_head &= ((lc->lc_rxq->lq_nentries * sizeof(*lp)) - 1);
+	err = hv_ldc_rx_set_qhead(lc->lc_id, rx_head);
+	if (err != H_EOK)
+		printf("%s: hv_ldc_rx_set_qhead %d\n", __func__, err);
+
+	return (1);
+}
+
+void
+vdsk_rx_data(struct ldc_conn *lc, struct ldc_pkt *lp)
+{
+	struct vio_msg *vm = (struct vio_msg *)lp;
+
+	switch (vm->type) {
+	case VIO_TYPE_CTRL:
+		if ((lp->env & LDC_FRAG_START) == 0 &&
+		    (lp->env & LDC_FRAG_STOP) == 0)
+			return;
+		vdsk_rx_vio_ctrl(lc->lc_sc, vm);
+		break;
+
+	case VIO_TYPE_DATA:
+		if((lp->env & LDC_FRAG_START) == 0)
+			return;
+		vdsk_rx_vio_data(lc->lc_sc, vm);
+		break;
+
+	default:
+		DPRINTF(("Unhandled packet type 0x%02x\n", vm->type));
+		ldc_reset(lc);
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_ctrl(struct vdsk_softc *sc, struct vio_msg *vm)
+{
+	struct vio_msg_tag *tag = (struct vio_msg_tag *)&vm->type;
+
+	switch (tag->stype_env) {
+	case VIO_VER_INFO:
+		vdsk_rx_vio_ver_info(sc, tag);
+		break;
+	case VIO_ATTR_INFO:
+		vdsk_rx_vio_attr_info(sc, tag);
+		break;
+	case VIO_DRING_REG:
+		vdsk_rx_vio_dring_reg(sc, tag);
+		break;
+	case VIO_RDX:
+		vdsk_rx_vio_rdx(sc, tag);
+		break;
+	default:
+		DPRINTF(("CTRL/0x%02x/0x%04x\n", tag->stype, tag->stype_env));
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_ver_info(struct vdsk_softc *sc, struct vio_msg_tag *tag)
+{
+	struct vio_ver_info *vi = (struct vio_ver_info *)tag;
+
+	switch (vi->tag.stype) {
+	case VIO_SUBTYPE_INFO:
+		DPRINTF(("CTRL/INFO/VER_INFO\n"));
+		break;
+
+	case VIO_SUBTYPE_ACK:
+		DPRINTF(("CTRL/ACK/VER_INFO\n"));
+		vdsk_send_attr_info(sc);
+		break;
+
+	default:
+		DPRINTF(("CTRL/0x%02x/VER_INFO\n", vi->tag.stype));
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_attr_info(struct vdsk_softc *sc, struct vio_msg_tag *tag)
+{
+	struct vd_attr_info *ai = (struct vd_attr_info *)tag;
+
+	switch (ai->tag.stype) {
+	case VIO_SUBTYPE_INFO:
+		DPRINTF(("CTRL/INFO/ATTR_INFO\n"));
+		break;
+
+	case VIO_SUBTYPE_ACK:
+		DPRINTF(("CTRL/ACK/ATTR_INFO\n"));
+		sc->sc_vdisk_block_size = ai->vdisk_block_size;
+		sc->sc_vdisk_size = ai->vdisk_size;
+		vdsk_send_dring_reg(sc);
+		break;
+
+	default:
+		DPRINTF(("CTRL/0x%02x/ATTR_INFO\n", ai->tag.stype));
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_dring_reg(struct vdsk_softc *sc, struct vio_msg_tag *tag)
+{
+	struct vio_dring_reg *dr = (struct vio_dring_reg *)tag;
+
+	switch (dr->tag.stype) {
+	case VIO_SUBTYPE_INFO:
+		DPRINTF(("CTRL/INFO/DRING_REG\n"));
+		break;
+
+	case VIO_SUBTYPE_ACK:
+		DPRINTF(("CTRL/ACK/DRING_REG\n"));
+
+		sc->sc_dring_ident = dr->dring_ident;
+		sc->sc_seq_no = 1;
+
+		vdsk_send_rdx(sc);
+		break;
+
+	default:
+		DPRINTF(("CTRL/0x%02x/DRING_REG\n", dr->tag.stype));
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_rdx(struct vdsk_softc *sc, struct vio_msg_tag *tag)
+{
+	switch(tag->stype) {
+	case VIO_SUBTYPE_INFO:
+		DPRINTF(("CTRL/INFO/RDX\n"));
+		break;
+
+	case VIO_SUBTYPE_ACK:
+		DPRINTF(("CTRL/ACK/RDX\n"));
+
+		/* Link is up! */
+		sc->sc_vio_state = VIO_ESTABLISHED;
+		break;
+
+	default:
+		DPRINTF(("CTRL/0x%02x/RDX (VIO)\n", tag->stype));
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_data(struct vdsk_softc *sc, struct vio_msg *vm)
+{
+	struct vio_msg_tag *tag = (struct vio_msg_tag *)&vm->type;
+
+	if (sc->sc_vio_state != VIO_ESTABLISHED) {
+		DPRINTF(("Spurious DATA/0x%02x/0x%04x\n", tag->stype,
+		    tag->stype_env));
+		return;
+	}
+
+	switch(tag->stype_env) {
+	case VIO_DRING_DATA:
+		vdsk_rx_vio_dring_data(sc, tag);
+		break;
+
+	default:
+		DPRINTF(("DATA/0x%02x/0x%04x\n", tag->stype, tag->stype_env));
+		break;
+	}
+}
+
+void
+vdsk_rx_vio_dring_data(struct vdsk_softc *sc, struct vio_msg_tag *tag)
+{
+	switch(tag->stype) {
+	case VIO_SUBTYPE_INFO:
+		DPRINTF(("DATA/INFO/DRING_DATA\n"));
+		break;
+
+	case VIO_SUBTYPE_ACK:
+	{
+		struct scsi_xfer *xs;
+		struct ldc_map *map = sc->sc_lm;
+		int cons, error;
+		int cookie, idx;
+		int len;
+
+		cons = sc->sc_tx_cons;
+		while (sc->sc_vd->vd_desc[cons].hdr.dstate == VIO_DESC_DONE) {
+			xs = sc->sc_vsd[cons].vsd_xs;
+
+			cookie = 0;
+			len = xs->datalen;
+			while (len > 0) {
+				idx = sc->sc_vsd[cons].vsd_map_idx[cookie++];
+				map->lm_slot[idx].entry = 0;
+				map->lm_count--;
+				len -= PAGE_SIZE;
+			}
+
+			error = XS_NOERROR;
+			if (sc->sc_vd->vd_desc[cons].status != 0)
+				error = XS_DRIVER_STUFFUP;
+			xs->resid = xs->datalen -
+			    sc->sc_vd->vd_desc[cons].size;
+			vdsk_scsi_done(xs, error);
+
+			sc->sc_vd->vd_desc[cons++].hdr.dstate = VIO_DESC_FREE;
+			cons &= (sc->sc_vd->vd_nentries - 1);
+			sc->sc_tx_cnt--;
+		}
+		sc->sc_tx_cons = cons;
+		break;
+	}
+
+	case VIO_SUBTYPE_NACK:
+		DPRINTF(("DATA/NACK/DRING_DATA\n"));
+		printf("state 0x%02x\n", sc->sc_vd->vd_desc[0].hdr.dstate);
+		printf("status 0x%04x\n", sc->sc_vd->vd_desc[0].status);
+		printf("size 0x%04x\n", sc->sc_vd->vd_desc[0].size);
+		break;
+
+	default:
+		DPRINTF(("DATA/0x%02x/DRING_DATA\n", tag->stype));
+		break;
+	}
+}
+
+void
+vdsk_reset(struct ldc_conn *lc)
+{
+	struct vdsk_softc *sc = lc->lc_sc;
+
+	sc->sc_tx_cnt = sc->sc_tx_prod = sc->sc_tx_cons = 0;
+	sc->sc_vio_state = 0;
+}
+
+void
+vdsk_start(struct ldc_conn *lc)
+{
+	struct vdsk_softc *sc = lc->lc_sc;
+
+	vdsk_send_ver_info(sc, VDSK_MAJOR, VDSK_MINOR);
+}
+
+void
+vdsk_sendmsg(struct vdsk_softc *sc, void *msg, size_t len)
+{
+	struct ldc_conn *lc = &sc->sc_lc;
+	struct ldc_pkt *lp;
+	uint64_t tx_head, tx_tail, tx_state;
+	int err;
+
+	err = hv_ldc_tx_get_state(lc->lc_id, &tx_head, &tx_tail, &tx_state);
+	if (err != H_EOK)
+		return;
+
+	lp = (struct ldc_pkt *)(lc->lc_txq->lq_va + tx_tail);
+	bzero(lp, sizeof(struct ldc_pkt));
+	lp->type = LDC_DATA;
+	lp->stype = LDC_INFO;
+	KASSERT((len & ~LDC_LEN_MASK) == 0);
+	lp->env = len | LDC_FRAG_STOP | LDC_FRAG_START;
+	lp->seqid = lc->lc_tx_seqid++;
+	bcopy(msg, &lp->major, len);
+
+	tx_tail += sizeof(*lp);
+	tx_tail &= ((lc->lc_txq->lq_nentries * sizeof(*lp)) - 1);
+	err = hv_ldc_tx_set_qtail(lc->lc_id, tx_tail);
+	if (err != H_EOK)
+		printf("hv_ldc_tx_set_qtail: %d\n", err);
+}
+
+void
+vdsk_send_ver_info(struct vdsk_softc *sc, uint16_t major, uint16_t minor)
+{
+	struct vio_ver_info vi;
+
+	/* Allocate new session ID. */
+	sc->sc_local_sid = tick();
+
+	bzero(&vi, sizeof(vi));
+	vi.tag.type = VIO_TYPE_CTRL;
+	vi.tag.stype = VIO_SUBTYPE_INFO;
+	vi.tag.stype_env = VIO_VER_INFO;
+	vi.tag.sid = sc->sc_local_sid;
+	vi.major = major;
+	vi.minor = minor;
+	vi.dev_class = VDEV_DISK;
+	vdsk_sendmsg(sc, &vi, sizeof(vi));
+}
+
+void
+vdsk_send_attr_info(struct vdsk_softc *sc)
+{
+	struct vd_attr_info ai;
+
+	bzero(&ai, sizeof(ai));
+	ai.tag.type = VIO_TYPE_CTRL;
+	ai.tag.stype = VIO_SUBTYPE_INFO;
+	ai.tag.stype_env = VIO_ATTR_INFO;
+	ai.tag.sid = sc->sc_local_sid;
+	ai.xfer_mode = VIO_DRING_MODE;
+	ai.vdisk_block_size = DEV_BSIZE;
+	ai.max_xfer_sz = MAXPHYS / DEV_BSIZE;
+	vdsk_sendmsg(sc, &ai, sizeof(ai));
+}
+
+void
+vdsk_send_dring_reg(struct vdsk_softc *sc)
+{
+	struct vio_dring_reg dr;
+
+	bzero(&dr, sizeof(dr));
+	dr.tag.type = VIO_TYPE_CTRL;
+	dr.tag.stype = VIO_SUBTYPE_INFO;
+	dr.tag.stype_env = VIO_DRING_REG;
+	dr.tag.sid = sc->sc_local_sid;
+	dr.dring_ident = 0;
+	dr.num_descriptors = sc->sc_vd->vd_nentries;
+	dr.descriptor_size = sizeof(struct vd_desc);
+	dr.options = VIO_TX_RING | VIO_RX_RING;
+	dr.ncookies = 1;
+	dr.cookie[0].addr = 0;
+	dr.cookie[0].size = PAGE_SIZE;
+	vdsk_sendmsg(sc, &dr, sizeof(dr));
+};
+
+void
+vdsk_send_rdx(struct vdsk_softc *sc)
+{
+	struct vio_rdx rdx;
+
+	bzero(&rdx, sizeof(rdx));
+	rdx.tag.type = VIO_TYPE_CTRL;
+	rdx.tag.stype = VIO_SUBTYPE_INFO;
+	rdx.tag.stype_env = VIO_RDX;
+	rdx.tag.sid = sc->sc_local_sid;
+	vdsk_sendmsg(sc, &rdx, sizeof(rdx));
+}
+
+struct vdsk_dring *
+vdsk_dring_alloc(bus_dma_tag_t t, int nentries)
+{
+	struct vdsk_dring *vd;
+	bus_size_t size;
+	caddr_t va;
+	int nsegs;
+	int i;
+
+	vd = malloc(sizeof(struct vdsk_dring), M_DEVBUF, M_NOWAIT);
+	if (vd == NULL)
+		return NULL;
+
+	size = roundup(nentries * sizeof(struct vd_desc), PAGE_SIZE);
+
+	if (bus_dmamap_create(t, size, 1, size, 0,
+	    BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW, &vd->vd_map) != 0)
+		return (NULL);
+
+	if (bus_dmamem_alloc(t, size, PAGE_SIZE, 0, &vd->vd_seg, 1,
+	    &nsegs, BUS_DMA_NOWAIT) != 0)
+		goto destroy;
+
+	if (bus_dmamem_map(t, &vd->vd_seg, 1, size, &va,
+	    BUS_DMA_NOWAIT) != 0)
+		goto free;
+
+	if (bus_dmamap_load(t, vd->vd_map, va, size, NULL,
+	    BUS_DMA_NOWAIT) != 0)
+		goto unmap;
+
+	vd->vd_desc = (struct vd_desc *)va;
+	vd->vd_nentries = nentries;
+	bzero(vd->vd_desc, nentries * sizeof(struct vd_desc));
+	for (i = 0; i < vd->vd_nentries; i++)
+		vd->vd_desc[i].hdr.dstate = VIO_DESC_FREE;
+	return (vd);
+
+unmap:
+	bus_dmamem_unmap(t, va, size);
+free:
+	bus_dmamem_free(t, &vd->vd_seg, 1);
+destroy:
+	bus_dmamap_destroy(t, vd->vd_map);
+
+	return (NULL);
+}
+
+void
+vdsk_dring_free(bus_dma_tag_t t, struct vdsk_dring *vd)
+{
+	bus_size_t size;
+
+	size = vd->vd_nentries * sizeof(struct vd_desc);
+	size = roundup(size, PAGE_SIZE);
+
+	bus_dmamap_unload(t, vd->vd_map);
+	bus_dmamem_unmap(t, (caddr_t)vd->vd_desc, size);
+	bus_dmamem_free(t, &vd->vd_seg, 1);
+	bus_dmamap_destroy(t, vd->vd_map);
+	free(vd, M_DEVBUF);
+}
+
+int
+vdsk_scsi_cmd(struct scsi_xfer *xs)
+{
+	struct scsi_rw *rw;
+	struct scsi_rw_big *rwb;
+	u_int64_t lba;
+	u_int32_t sector_count;
+	uint8_t operation;
+
+	switch (xs->cmd->opcode) {
+	case READ_BIG:
+	case READ_COMMAND:
+		operation = VD_OP_BREAD;
+		break;
+	case WRITE_BIG:
+	case WRITE_COMMAND:
+		operation = VD_OP_BWRITE;
+		break;
+
+	case INQUIRY:
+		return (vdsk_scsi_inq(xs));
+	case READ_CAPACITY:
+		return (vdsk_scsi_capacity(xs));
+
+	case TEST_UNIT_READY:
+	case START_STOP:
+	case PREVENT_ALLOW:
+		return (vdsk_scsi_done(xs, XS_NOERROR));
+
+	default:
+		printf("%s cmd 0x%02x\n", __func__, xs->cmd->opcode);
+	case MODE_SENSE:
+	case MODE_SENSE_BIG:
+	case REPORT_LUNS:
+		return (vdsk_scsi_done(xs, XS_DRIVER_STUFFUP));
+	}
+
+	if (xs->cmdlen == 6) {
+		rw = (struct scsi_rw *)xs->cmd;
+		lba = _3btol(rw->addr) & (SRW_TOPADDR << 16 | 0xffff);
+		sector_count = rw->length ? rw->length : 0x100;
+	} else {
+		rwb = (struct scsi_rw_big *)xs->cmd;
+		lba = _4btol(rwb->addr);
+		sector_count = _2btol(rwb->length);
+	}
+
+{
+	struct vdsk_softc *sc = xs->sc_link->adapter_softc;
+	struct ldc_map *map = sc->sc_lm;
+	struct vio_dring_msg dm;
+	vaddr_t va;
+	paddr_t pa;
+	int len, ncookies;
+	int desc;
+
+	desc = sc->sc_tx_prod;
+
+	ncookies = 0;
+	len = xs->datalen;
+	va = (vaddr_t)xs->data;
+	while (len > 0) {
+		pmap_extract(pmap_kernel(), va, &pa);
+		while (map->lm_slot[map->lm_next].entry != 0) {
+			map->lm_next++;
+			map->lm_next &= (map->lm_nentries - 1);
+		}
+		/* Don't take slot 0; it's used by our descriptor ring. */
+		if (map->lm_next == 0)
+			map->lm_next++;
+		map->lm_slot[map->lm_next].entry = (pa & LDC_MTE_RA_MASK);
+		map->lm_slot[map->lm_next].entry |= LDC_MTE_CPR | LDC_MTE_CPW;
+		map->lm_slot[map->lm_next].entry |= LDC_MTE_IOR | LDC_MTE_IOW;
+		map->lm_slot[map->lm_next].entry |= LDC_MTE_R | LDC_MTE_W;
+		map->lm_count++;
+
+		sc->sc_vd->vd_desc[desc].cookie[ncookies].addr =
+		    map->lm_next << PAGE_SHIFT | (pa & PAGE_MASK);
+		sc->sc_vd->vd_desc[desc].cookie[ncookies].size =
+		    min(len, PAGE_SIZE);
+
+		sc->sc_vsd[desc].vsd_map_idx[ncookies] = map->lm_next;
+		va += PAGE_SIZE;
+		len -= PAGE_SIZE;
+	}
+
+	sc->sc_vd->vd_desc[desc].hdr.ack = 1;
+	sc->sc_vd->vd_desc[desc].operation = operation;
+	sc->sc_vd->vd_desc[desc].slice = VD_SLICE_NONE;
+	sc->sc_vd->vd_desc[desc].status = 0xffffffff;
+	sc->sc_vd->vd_desc[desc].offset = lba;
+	sc->sc_vd->vd_desc[desc].size = xs->datalen;
+	sc->sc_vd->vd_desc[desc].ncookies = 1;
+	membar(Sync);
+	sc->sc_vd->vd_desc[desc].hdr.dstate = VIO_DESC_READY;
+
+	sc->sc_vsd[desc].vsd_xs = xs;
+
+	desc++;
+	desc &= (sc->sc_vd->vd_nentries - 1);
+	sc->sc_tx_cnt++;
+
+	bzero(&dm, sizeof(dm));
+	dm.tag.type = VIO_TYPE_DATA;
+	dm.tag.stype = VIO_SUBTYPE_INFO;
+	dm.tag.stype_env = VIO_DRING_DATA;
+	dm.tag.sid = sc->sc_local_sid;
+	dm.seq_no = sc->sc_seq_no++;
+	dm.dring_ident = sc->sc_dring_ident;
+	dm.start_idx = sc->sc_tx_prod;
+	dm.end_idx = sc->sc_tx_prod;
+	vdsk_sendmsg(sc, &dm, sizeof(dm));
+
+	sc->sc_tx_prod = desc;
+}
+
+	return (SUCCESSFULLY_QUEUED);
+}
+
+int
+vdsk_scsi_inq(struct scsi_xfer *xs)
+{
+	struct scsi_inquiry *inq = (struct scsi_inquiry *)xs->cmd;
+
+	if (ISSET(inq->flags, SI_EVPD))
+		return (vdsk_scsi_done(xs, XS_DRIVER_STUFFUP));
+
+	return (vdsk_scsi_inquiry(xs));
+}
+
+int
+vdsk_scsi_inquiry(struct scsi_xfer *xs)
+{
+	struct scsi_inquiry_data inq;
+
+	bzero(&inq, sizeof(inq));
+
+	inq.device = T_DIRECT;
+	inq.version = 0x05; /* SPC-3 */
+	inq.response_format = 2;
+	inq.additional_length = 32;
+	bcopy("SUN     ", inq.vendor, sizeof(inq.vendor));
+	bcopy("Virtual Disk    ", inq.product, sizeof(inq.product));
+	bcopy("1.0 ", inq.revision, sizeof(inq.revision));
+
+	bcopy(&inq, xs->data, MIN(sizeof(inq), xs->datalen));
+
+	return (vdsk_scsi_done(xs, XS_NOERROR));
+}
+
+int
+vdsk_scsi_capacity(struct scsi_xfer *xs)
+{
+	struct vdsk_softc *sc = xs->sc_link->adapter_softc;
+	struct scsi_read_cap_data rcd;
+	uint64_t capacity;
+
+	bzero(&rcd, sizeof(rcd));
+
+	capacity = sc->sc_vdisk_size;
+	if (capacity > 0xffffffff)
+		capacity = 0xffffffff;
+
+	_lto4b(capacity - 1, rcd.addr);
+	_lto4b(sc->sc_vdisk_block_size, rcd.length);
+
+	bcopy(&rcd, xs->data, MIN(sizeof(rcd), xs->datalen));
+
+	return (vdsk_scsi_done(xs, XS_NOERROR));
+}
+
+int
+vdsk_scsi_done(struct scsi_xfer *xs, int error)
+{
+	int s;
+
+	xs->error = error;
+	xs->flags |= ITSDONE;
+
+	s = splbio();
+	scsi_done(xs);
+	splx(s);
+	return (COMPLETE);
+}
+
+int
+vdsk_dev_probe(struct scsi_link *link)
+{
+	KASSERT(link->scsibus == 0);
+	KASSERT(link->lun == 0);
+
+	if (link->target == 0)
+		return (0);
+
+	return (ENODEV);
+}
+
+void
+vdsk_dev_free(struct scsi_link *link)
+{
+	printf("%s\n", __func__);
+}
+
+int
+vdsk_ioctl(struct scsi_link *link, u_long cmd, caddr_t addr, int flags,
+    struct proc *p)
+{
+	printf("%s\n", __func__);
+	return (ENOTTY);
+}
+