--- /sys/src/9k/386/sdvirtio10.c
+++ /sys/src/9k/386/sdvirtio10.c
@@ -0,0 +1,813 @@
+/*
+ * virtio 1.0 disk driver
+ * http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html
+ *
+ * In contrast to sdvirtio.c, this driver handles the non-legacy
+ * interface for virtio disk which uses mmio for all register accesses
+ * and requires a laborate pci capability structure dance to get working.
+ *
+ * It is kind of pointless as it is most likely slower than
+ * port i/o (harder to emulate on the pc platform).
+ *
+ * The reason why this driver is needed it is that vultr set the
+ * disable-legacy=on option in the -device parameter for qemu
+ * on their hypervisor.
+ */
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+#include "ureg.h"
+#include "../port/error.h"
+
+#include "../port/sd.h"
+
+typedef struct Vscsidev Vscsidev;
+typedef struct Vblkdev Vblkdev;
+
+typedef struct Vconfig Vconfig;
+typedef struct Vring Vring;
+typedef struct Vdesc Vdesc;
+typedef struct Vused Vused;
+typedef struct Vqueue Vqueue;
+typedef struct Vdev Vdev;
+
+
+/* device types */
+enum {
+	TypBlk	= 2,
+	TypSCSI	= 8,
+};
+
+/* status flags */
+enum {
+	Acknowledge = 1,
+	Driver = 2,
+	FeaturesOk = 8,
+	DriverOk = 4,
+	Failed = 0x80,
+};
+
+/* descriptor flags */
+enum {
+	_Next = 1,
+	Write = 2,
+	Indirect = 4,
+};
+
+/* struct sizes */
+enum {
+	VringSize = 4,
+};
+
+enum {
+	CDBSIZE		= 32,
+	SENSESIZE	= 96,
+};
+
+
+struct Vscsidev
+{
+	u32int	num_queues;
+	u32int	seg_max;
+	u32int	max_sectors;
+	u32int	cmd_per_lun;
+	u32int	event_info_size;
+	u32int	sense_size;
+	u32int	cdb_size;
+	u16int	max_channel;
+	u16int	max_target;
+	u32int	max_lun;
+};
+
+struct Vblkdev
+{
+	u64int	capacity;
+};
+
+struct Vconfig {
+	u32int	devfeatsel;
+	u32int	devfeat;
+	u32int	drvfeatsel;
+	u32int	drvfeat;
+
+	u16int	msixcfg;
+	u16int	nqueues;
+
+	u8int	status;
+	u8int	cfggen;
+	u16int	queuesel;
+
+	u16int	queuesize;
+	u16int	queuemsixvect;
+
+	u16int	queueenable;
+	u16int	queuenotifyoff;
+
+	u64int	queuedesc;
+	u64int	queueavail;
+	u64int	queueused;
+};
+
+struct Vring
+{
+	u16int	flags;
+	u16int	idx;
+};
+
+struct Vdesc
+{
+	u64int	addr;
+	u32int	len;
+	u16int	flags;
+	u16int	next;
+};
+
+struct Vused
+{
+	u32int	id;
+	u32int	len;
+};
+
+struct Vqueue
+{
+	Lock;
+
+	Vdev	*dev;
+	void	*notify;
+	int	idx;
+
+	int	size;
+
+	int	free;
+	int	nfree;
+
+	Vdesc	*desc;
+
+	Vring	*avail;
+	u16int	*availent;
+	u16int	*availevent;
+
+	Vring	*used;
+	Vused	*usedent;
+	u16int	*usedevent;
+	u16int	lastused;
+
+	void	*rock[];
+};
+
+struct Vdev
+{
+	int	typ;
+
+	Pcidev	*pci;
+	void*	vector;
+
+	uvlong	port;
+	ulong	feat[2];
+
+	int	nqueue;
+	Vqueue	*queue[16];
+
+	void	*dev;	/* device specific config (for scsi) */
+
+	/* registers */
+	Vconfig	*cfg;
+	u8int	*isr;
+	u8int	*notify;
+	u32int	notifyoffmult;
+
+	Vdev	*next;
+};
+
+static Vqueue*
+mkvqueue(int size)
+{
+	Vqueue *q;
+	uchar *p;
+	int i;
+
+	q = malloc(sizeof(*q) + sizeof(void*)*size);
+	p = mallocalign(
+		ROUNDUP(sizeof(Vdesc)*size +
+			VringSize +
+			sizeof(u16int)*size +
+			sizeof(u16int),
+			4*KiB) +
+		ROUNDUP(VringSize +
+			sizeof(Vused)*size +
+			sizeof(u16int),
+			4*KiB),
+		PGSZ, 0, 0);
+	if(p == nil || q == nil){
+		print("virtio: no memory for Vqueue\n");
+		free(p);
+		free(q);
+		return nil;
+	}
+
+	q->desc = (void*)p;
+	p += sizeof(Vdesc)*size;
+	q->avail = (void*)p;
+	p += VringSize;
+	q->availent = (void*)p;
+	p += sizeof(u16int)*size;
+	q->availevent = (void*)p;
+	p += sizeof(u16int);
+
+	p = (uchar*)ROUNDUP((uintptr)p, 4*KiB);
+	q->used = (void*)p;
+	p += VringSize;
+	q->usedent = (void*)p;
+	p += sizeof(Vused)*size;
+	q->usedevent = (void*)p;
+
+	q->free = -1;
+	q->nfree = q->size = size;
+	for(i=0; i<size; i++){
+		q->desc[i].next = q->free;
+		q->free = i;
+	}
+
+	return q;
+}
+
+static int
+matchvirtiocfgcap(Pcidev *p, int cap, int off, int typ)
+{
+	int bar;
+
+	if(cap != 9 || pcicfgr8(p, off+3) != typ)
+		return 1;
+
+	/* skip invalid or non memory bars */
+	bar = pcicfgr8(p, off+4);
+	if(bar < 0 || bar >= nelem(p->mem)
+	|| p->mem[bar].size == 0
+	|| (p->mem[bar].bar & 3) != 0)
+		return 1;
+
+	return 0;
+}
+
+static int
+virtiocap(Pcidev *p, int typ)
+{
+	return pcienumcaps(p, matchvirtiocfgcap, typ);
+}
+
+static void*
+virtiomapregs(Pcidev *p, int cap, int size)
+{
+	int bar, len;
+	uvlong addr;
+
+	if(cap < 0)
+		return nil;
+	bar = pcicfgr8(p, cap+4) % nelem(p->mem);
+	addr = pcicfgr32(p, cap+8);
+	len = pcicfgr32(p, cap+12);
+	if(size <= 0)
+		size = len;
+	else if(len < size)
+		return nil;
+	if(addr+len > p->mem[bar].size)
+		return nil;
+	addr += p->mem[bar].bar & ~0xFULL;
+	return vmap(addr, size);
+}
+
+static Vdev*
+viopnpdevs(int typ)
+{
+	Vdev *vd, *h, *t;
+	Vconfig *cfg;
+	Vqueue *q;
+	Pcidev *p;
+	int cap, bar;
+	int n, i;
+
+	h = t = nil;
+	for(p = nil; p = pcimatch(p, 0x1AF4, 0x1040+typ);){
+		if(p->rid == 0)
+			continue;
+		if((cap = virtiocap(p, 1)) < 0)
+			continue;
+		bar = pcicfgr8(p, cap+4) % nelem(p->mem);
+		cfg = virtiomapregs(p, cap, sizeof(Vconfig));
+		if(cfg == nil)
+			continue;
+		if((vd = malloc(sizeof(*vd))) == nil){
+			print("virtio: no memory for Vdev\n");
+			break;
+		}
+		vd->port = p->mem[bar].bar & ~0xFULL;
+		vd->typ = typ;
+		vd->pci = p;
+		vd->cfg = cfg;
+
+		vd->isr = virtiomapregs(p, virtiocap(p, 3), 0);
+		if(vd->isr == nil){
+Baddev:
+			/* TODO: vunmap */
+			free(vd);
+			continue;
+		}
+		cap = virtiocap(p, 2);
+		vd->notify = virtiomapregs(p, cap, 0);
+		if(vd->notify == nil)
+			goto Baddev;
+		vd->notifyoffmult = pcicfgr32(p, cap+16);
+
+		/* reset */
+		cfg->status = 0;
+		while(cfg->status != 0)
+			delay(1);
+		cfg->status = Acknowledge|Driver;
+
+		/* negotiate feature bits */
+		cfg->devfeatsel = 1;
+		vd->feat[1] = cfg->devfeat;
+		cfg->devfeatsel = 0;
+		vd->feat[0] = cfg->devfeat;
+		cfg->drvfeatsel = 1;
+		cfg->drvfeat = vd->feat[1] & 1;
+		cfg->drvfeatsel = 0;
+		cfg->drvfeat = 0;
+		cfg->status |= FeaturesOk;
+
+		for(i=0; i<nelem(vd->queue); i++){
+			cfg->queuesel = i;
+			n = cfg->queuesize;
+			if(n == 0 || (n & (n-1)) != 0)
+				break;
+			if((q = mkvqueue(n)) == nil)
+				break;
+			q->notify = vd->notify + vd->notifyoffmult * cfg->queuenotifyoff;
+			q->dev = vd;
+			q->idx = i;
+			vd->queue[i] = q;
+			coherence();
+			cfg->queuedesc = PADDR(q->desc);
+			cfg->queueavail = PADDR(q->avail);
+			cfg->queueused = PADDR(q->used);
+		}
+		vd->nqueue = i;
+
+		if(h == nil)
+			h = vd;
+		else
+			t->next = vd;
+		t = vd;
+	}
+
+	return h;
+}
+
+struct Rock {
+	int done;
+	Rendez *sleep;
+};
+
+static void
+vqinterrupt(Vqueue *q)
+{
+	int id, free, m;
+	struct Rock *r;
+	Rendez *z;
+
+	m = q->size-1;
+
+	ilock(q);
+	while((q->lastused ^ q->used->idx) & m){
+		id = q->usedent[q->lastused++ & m].id;
+		if(r = q->rock[id]){
+			q->rock[id] = nil;
+			z = r->sleep;
+			r->done = 1;	/* hands off */
+			if(z != nil)
+				wakeup(z);
+		}
+		do {
+			free = id;
+			id = q->desc[free].next;
+			q->desc[free].next = q->free;
+			q->free = free;
+			q->nfree++;
+		} while(q->desc[free].flags & _Next);
+	}
+	iunlock(q);
+}
+
+static void
+viointerrupt(Ureg *, void *arg)
+{
+	Vdev *vd = arg;
+
+	if(vd->isr[0] & 1)
+		vqinterrupt(vd->queue[vd->typ == TypSCSI ? 2 : 0]);
+}
+
+static int
+viodone(void *arg)
+{
+	return ((struct Rock*)arg)->done;
+}
+
+static void
+vqio(Vqueue *q, int head)
+{
+	struct Rock rock;
+
+	rock.done = 0;
+	rock.sleep = &up->sleep;
+	q->rock[head] = &rock;
+	q->availent[q->avail->idx & (q->size-1)] = head;
+	coherence();
+	q->avail->idx++;
+	iunlock(q);
+	if((q->used->flags & 1) == 0)
+		*((u16int*)q->notify) = q->idx;
+	while(!rock.done){
+		while(waserror())
+			;
+		tsleep(rock.sleep, viodone, &rock, 1000);
+		poperror();
+
+		if(!rock.done)
+			vqinterrupt(q);
+	}
+}
+
+static int
+vioblkreq(Vdev *vd, int typ, void *a, long count, long secsize, uvlong lba)
+{
+	int need, free, head;
+	Vqueue *q;
+	Vdesc *d;
+
+	u8int status;
+	struct Vioblkreqhdr {
+		u32int	typ;
+		u32int	prio;
+		u64int	lba;
+	} req;
+
+	need = 2;
+	if(a != nil)
+		need = 3;
+
+	status = -1;
+	req.typ = typ;
+	req.prio = 0;
+	req.lba = lba;
+
+	q = vd->queue[0];
+	ilock(q);
+	while(q->nfree < need){
+		iunlock(q);
+
+		if(!waserror())
+			tsleep(&up->sleep, return0, 0, 500);
+		poperror();
+
+		ilock(q);
+	}
+
+	head = free = q->free;
+
+	d = &q->desc[free]; free = d->next;
+	d->addr = PADDR(&req);
+	d->len = sizeof(req);
+	d->flags = _Next;
+
+	if(a != nil){
+		d = &q->desc[free]; free = d->next;
+		d->addr = PADDR(a);
+		d->len = secsize*count;
+		d->flags = typ ? _Next : (Write|_Next);
+	}
+
+	d = &q->desc[free]; free = d->next;
+	d->addr = PADDR(&status);
+	d->len = sizeof(status);
+	d->flags = Write;
+
+	q->free = free;
+	q->nfree -= need;
+
+	/* queue io, unlock and wait for completion */
+	vqio(q, head);
+
+	return status;
+}
+
+static int
+vioscsireq(SDreq *r)
+{
+	u8int resp[4+4+2+2+SENSESIZE];
+	u8int req[8+8+3+CDBSIZE];
+	int free, head;
+	u32int len;
+	Vqueue *q;
+	Vdesc *d;
+	Vdev *vd;
+	SDunit *u;
+	Vscsidev *scsi;
+
+	u = r->unit;
+	vd = u->dev->ctlr;
+	scsi = vd->dev;
+
+	memset(resp, 0, sizeof(resp));
+	memset(req, 0, sizeof(req));
+	req[0] = 1;
+	req[1] = u->subno;
+	req[2] = r->lun>>8;
+	req[3] = r->lun&0xFF;
+	*(u64int*)(&req[8]) = (uintptr)r;
+
+	memmove(&req[8+8+3], r->cmd, r->clen);
+
+	q = vd->queue[2];
+	ilock(q);
+	while(q->nfree < 3){
+		iunlock(q);
+
+		if(!waserror())
+			tsleep(&up->sleep, return0, 0, 500);
+		poperror();
+
+		ilock(q);
+	}
+
+	head = free = q->free;
+
+	d = &q->desc[free]; free = d->next;
+	d->addr = PADDR(req);
+	d->len = 8+8+3+scsi->cdb_size;
+	d->flags = _Next;
+
+	if(r->write && r->dlen > 0){
+		d = &q->desc[free]; free = d->next;
+		d->addr = PADDR(r->data);
+		d->len = r->dlen;
+		d->flags = _Next;
+	}
+
+	d = &q->desc[free]; free = d->next;
+	d->addr = PADDR(resp);
+	d->len = 4+4+2+2+scsi->sense_size;
+	d->flags = Write;
+
+	if(!r->write && r->dlen > 0){
+		d->flags |= _Next;
+
+		d = &q->desc[free]; free = d->next;
+		d->addr = PADDR(r->data);
+		d->len = r->dlen;
+		d->flags = Write;
+	}
+
+	q->free = free;
+	q->nfree -= 2 + (r->dlen > 0);
+
+	/* queue io, unlock and wait for completion */
+	vqio(q, head);
+
+	/* response+status */
+	r->status = resp[10];
+	if(resp[11] != 0)
+		r->status = SDcheck;
+
+	/* sense_len */
+	len = *((u32int*)&resp[0]);
+	if(len > 0){
+		if(len > sizeof(r->sense))
+			len = sizeof(r->sense);
+		memmove(r->sense, &resp[4+4+2+2], len);
+		r->flags |= SDvalidsense;
+	}
+
+	/* data residue */
+	len = *((u32int*)&resp[4]);
+	if(len > r->dlen)
+		r->rlen = 0;
+	else
+		r->rlen = r->dlen - len;
+
+	return r->status;
+
+}
+
+static long
+viobio(SDunit *u, int lun, int write, void *a, long count, uvlong lba)
+{
+	long ss, cc, max, ret;
+	Vdev *vd;
+
+	vd = u->dev->ctlr;
+	if(vd->typ == TypSCSI)
+		return scsibio(u, lun, write, a, count, lba);
+
+	max = 32;
+	ss = u->secsize;
+	ret = 0;
+	while(count > 0){
+		if((cc = count) > max)
+			cc = max;
+		if(vioblkreq(vd, write != 0, (uchar*)a + ret, cc, ss, lba) != 0)
+			error(Eio);
+		ret += cc*ss;
+		count -= cc;
+		lba += cc;
+	}
+	return ret;
+}
+
+enum {
+	SDread,
+	SDwrite,
+};
+
+static int
+viorio(SDreq *r)
+{
+	int i, count, rw;
+	uvlong lba;
+	SDunit *u;
+	Vdev *vd;
+
+	u = r->unit;
+	vd = u->dev->ctlr;
+	if(vd->typ == TypSCSI)
+		return vioscsireq(r);
+	if(r->cmd[0] == 0x35 || r->cmd[0] == 0x91){
+		if(vioblkreq(vd, 4, nil, 0, 0, 0) != 0)
+			return sdsetsense(r, SDcheck, 3, 0xc, 2);
+		return sdsetsense(r, SDok, 0, 0, 0);
+	}
+	if((i = sdfakescsi(r, nil, 0)) != SDnostatus)
+		return r->status = i;
+	if((i = sdfakescsirw(r, &lba, &count, &rw)) != SDnostatus)
+		return i;
+	r->rlen = viobio(u, r->lun, rw == SDwrite, r->data, count, lba);
+	return r->status = SDok;
+}
+
+static int
+vioonline(SDunit *u)
+{
+	Vdev *vd;
+	Vblkdev *blk;
+	uvlong cap;
+
+	vd = u->dev->ctlr;
+	if(vd->typ == TypSCSI)
+		return scsionline(u);
+
+	blk = vd->dev;
+	cap = blk->capacity;
+	if(u->sectors != cap){
+		u->sectors = cap;
+		u->secsize = 512;
+		return 2;
+	}
+	return 1;
+}
+
+static int
+vioverify(SDunit *u)
+{
+	Vdev *vd;
+
+	vd = u->dev->ctlr;
+	if(vd->typ == TypSCSI)
+		return scsiverify(u);
+
+	return 1;
+}
+
+SDifc sdvirtio10ifc;
+
+static int
+vioenable(SDev *sd)
+{
+	char name[32];
+	Vdev *vd;
+	int i;
+
+	vd = sd->ctlr;
+	pcisetbme(vd->pci);
+	snprint(name, sizeof(name), "%s (%s)", sd->name, sd->ifc->name);
+	vd->vector = intrenable(vd->pci->intl, viointerrupt, vd, vd->pci->tbdf, name);
+	coherence();
+
+	for(i = 0; i < vd->nqueue; i++){
+		vd->cfg->queuesel = i;
+		vd->cfg->queueenable = 1;
+	}
+	vd->cfg->status |= DriverOk;
+
+	return 1;
+}
+
+static int
+viodisable(SDev *sd)
+{
+	Vdev *vd;
+
+	vd = sd->ctlr;
+	intrdisable(vd->vector);
+	pciclrbme(vd->pci);
+	return 1;
+}
+
+static SDev*
+viopnp(void)
+{
+	SDev *s, *h, *t;
+	Vdev *vd;
+	int id;
+
+	h = t = nil;
+
+	id = 'F';
+	for(vd =  viopnpdevs(TypBlk); vd; vd = vd->next){
+		if(vd->nqueue == 0)
+			continue;
+
+		if((vd->dev = virtiomapregs(vd->pci, virtiocap(vd->pci, 4), sizeof(Vblkdev))) == nil)
+			break;
+		if((s = malloc(sizeof(*s))) == nil)
+			break;
+		s->ctlr = vd;
+		s->idno = id++;
+		s->ifc = &sdvirtio10ifc;
+		s->nunit = 1;
+		if(h)
+			t->next = s;
+		else
+			h = s;
+		t = s;
+	}
+
+	id = '0';
+	for(vd = viopnpdevs(TypSCSI); vd; vd = vd->next){
+		Vscsidev *scsi;
+
+		if(vd->nqueue < 3)
+			continue;
+
+		if((scsi = virtiomapregs(vd->pci, virtiocap(vd->pci, 4), sizeof(Vscsidev))) == nil)
+			break;
+		if(scsi->max_target == 0){
+			vunmap(scsi, sizeof(Vscsidev));
+			continue;
+		}
+		if((scsi->cdb_size > CDBSIZE) || (scsi->sense_size > SENSESIZE)){
+			print("sdvirtio: cdb %ud or sense size %ud too big\n",
+				scsi->cdb_size, scsi->sense_size);
+			vunmap(scsi, sizeof(Vscsidev));
+			continue;
+		}
+		vd->dev = scsi;
+
+		if((s = malloc(sizeof(*s))) == nil)
+			break;
+		s->ctlr = vd;
+		s->idno = id++;
+		s->ifc = &sdvirtio10ifc;
+		s->nunit = scsi->max_target;
+
+		if(h)
+			t->next = s;
+		else
+			h = s;
+		t = s;
+	}
+	return h;
+}
+
+SDifc sdvirtio10ifc = {
+	"virtio10",			/* name */
+
+	viopnp,				/* pnp */
+	nil,				/* legacy */
+	vioenable,			/* enable */
+	viodisable,			/* disable */
+
+	vioverify,			/* verify */
+	vioonline,			/* online */
+	viorio,				/* rio */
+	nil,				/* rctl */
+	nil,				/* wctl */
+
+	viobio,				/* bio */
+	nil,				/* probe */
+	nil,				/* clear */
+	nil,				/* rtopctl */
+	nil,				/* wtopctl */
+};