ref: 8bf1e5b77521d94876a58989a434ef1a08d6d509
dir: /sys/src/9/pc/sdvirtio10.c/
/*
* 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 "../port/pci.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;
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(
PGROUND(sizeof(Vdesc)*size +
VringSize +
sizeof(u16int)*size +
sizeof(u16int)) +
PGROUND(VringSize +
sizeof(Vused)*size +
sizeof(u16int)),
BY2PG, 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*)PGROUND((uintptr)p);
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;
pcienable(p);
vd->isr = virtiomapregs(p, virtiocap(p, 3), 0);
if(vd->isr == nil){
Baddev:
pcidisable(p);
/* 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;
}
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)) != 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);
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)
{
char name[32];
Vdev *vd;
vd = sd->ctlr;
snprint(name, sizeof(name), "%s (%s)", sd->name, sd->ifc->name);
intrdisable(vd->pci->intl, viointerrupt, vd, vd->pci->tbdf, name);
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 */
};