Author: bryanv
Date: Thu Jul 4 17:53:02 2013
New Revision: 252703
URL: http://svnweb.freebsd.org/changeset/base/252703
Log:
Merge several virtio_blk changes from projects/virtio
The notable changes of this commit are support for disk resizing
and chases updates to the spec regarding write caching.
Contains projects/virtio commits:
r245713:
virtio_blk: Replace __FUNCTION__ with __func__
r245714:
virtio_blk: Use more consistent mutex name
r245715:
virtio_blk: Print device name too if failed to reinit during dump
r245716:
virtio_blk: Remove an unuseful ASSERT
r245723:
virtio_blk: Record the vendor and device information
r245724:
virtio_blk: Add resize support
r245726:
virtio_blk: More verbose ASSERT messages
r245730:
virtio_blk: Tweak resize announcement message
r246061:
virtio_blk: Do not always read entire config
r246062:
virtio_blk: Use topology to set the stripe size/offset
r246307:
virtio_blk: Correct stripe offset calculation
r246063:
virtio_blk: Add support for write cache enable feature
r246303:
virtio_blk: Expand a comment
r252529:
virtio_blk: Improve write cache handling
r252681:
virtio_blk: Remove unneeded curly braces
MFC after: 1 month
Modified:
head/share/man/man4/virtio_blk.4
head/sys/dev/virtio/block/virtio_blk.c
head/sys/dev/virtio/block/virtio_blk.h
Modified: head/share/man/man4/virtio_blk.4
==============================================================================
--- head/share/man/man4/virtio_blk.4 Thu Jul 4 17:50:11 2013
(r252702)
+++ head/share/man/man4/virtio_blk.4 Thu Jul 4 17:53:02 2013
(r252703)
@@ -24,7 +24,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd January 22, 2012
+.Dd July 2, 2013
.Dt VIRTIO_BLK 4
.Os
.Sh NAME
@@ -53,11 +53,33 @@ Tunables can be set at the
.Xr loader 8
prompt before booting the kernel or stored in
.Xr loader.conf 5 .
-.Bl -tag -width "xxxxxx"
+.Bl -tag -width indent
.It Va hw.vtblk.no_ident
-This tunable disables retrieving the device identification string
-from the hypervisor.
+.It Va hw.vtblk. Ns Ar X Ns Va .no_ident
+.Pp
+These tunables disable retrieving the device identification string
+from the hypervisor either globally or per-device.
The default value is 0.
+.It Va hw.vtblk.writecache_mode
+.It Va hw.vtblk. Ns Ar X Ns Va .writecache_mode
+.Pp
+These tunables determine the write cache mode globally or per-device.
+The mode can changed only if the ConfigWCE feature is negotiated.
+Set to 0 for writethrough mode, 1 for writeback mode, and -1 to leave
+it as-is.
+The default value is to leave as-is.
+.El
+.Sh SYSCTL VARIABLES
+The following variables are available as
+.Xr sysctl 8
+variables.
+.Bl -tag -width indent
+.It Va dev.vtblk. Ns Ar X Ns Va .writecache_mode
+.Pp
+The write cache mode of the device can be either writethrough (0) or
+writeback (1).
+If the ConfigWCE feature is negotiated, the write cache mode can
+be toggled between writethrough and writeback.
.El
.Sh SEE ALSO
.Xr virtio 4
Modified: head/sys/dev/virtio/block/virtio_blk.c
==============================================================================
--- head/sys/dev/virtio/block/virtio_blk.c Thu Jul 4 17:50:11 2013
(r252702)
+++ head/sys/dev/virtio/block/virtio_blk.c Thu Jul 4 17:53:02 2013
(r252703)
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sglist.h>
+#include <sys/sysctl.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/queue.h>
@@ -61,6 +62,12 @@ struct vtblk_request {
TAILQ_ENTRY(vtblk_request) vbr_link;
};
+enum vtblk_cache_mode {
+ VTBLK_CACHE_WRITETHROUGH,
+ VTBLK_CACHE_WRITEBACK,
+ VTBLK_CACHE_MAX
+};
+
struct vtblk_softc {
device_t vtblk_dev;
struct mtx vtblk_mtx;
@@ -72,6 +79,7 @@ struct vtblk_softc {
#define VTBLK_FLAG_SUSPEND 0x0008
#define VTBLK_FLAG_DUMPING 0x0010
#define VTBLK_FLAG_BARRIER 0x0020
+#define VTBLK_FLAG_WC_CONFIG 0x0040
struct virtqueue *vtblk_vq;
struct sglist *vtblk_sglist;
@@ -86,6 +94,7 @@ struct vtblk_softc {
int vtblk_max_nsegs;
int vtblk_request_count;
+ enum vtblk_cache_mode vtblk_write_cache;
struct vtblk_request vtblk_dump_request;
};
@@ -98,8 +107,9 @@ static struct virtio_feature_desc vtblk_
{ VIRTIO_BLK_F_RO, "ReadOnly" },
{ VIRTIO_BLK_F_BLK_SIZE, "BlockSize" },
{ VIRTIO_BLK_F_SCSI, "SCSICmds" },
- { VIRTIO_BLK_F_FLUSH, "FlushCmd" },
+ { VIRTIO_BLK_F_WCE, "WriteCache" },
{ VIRTIO_BLK_F_TOPOLOGY, "Topology" },
+ { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" },
{ 0, NULL }
};
@@ -112,6 +122,7 @@ static int vtblk_detach(device_t);
static int vtblk_suspend(device_t);
static int vtblk_resume(device_t);
static int vtblk_shutdown(device_t);
+static int vtblk_config_change(device_t);
static int vtblk_open(struct disk *);
static int vtblk_close(struct disk *);
@@ -124,6 +135,11 @@ static void vtblk_negotiate_features(str
static int vtblk_maximum_segments(struct vtblk_softc *,
struct virtio_blk_config *);
static int vtblk_alloc_virtqueue(struct vtblk_softc *);
+static void vtblk_resize_disk(struct vtblk_softc *, uint64_t);
+static void vtblk_set_write_cache(struct vtblk_softc *, int);
+static int vtblk_write_cache_enabled(struct vtblk_softc *sc,
+ struct virtio_blk_config *);
+static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS);
static void vtblk_alloc_disk(struct vtblk_softc *,
struct virtio_blk_config *);
static void vtblk_create_disk(struct vtblk_softc *);
@@ -138,6 +154,8 @@ static void vtblk_vq_intr(void *);
static void vtblk_stop(struct vtblk_softc *);
+static void vtblk_read_config(struct vtblk_softc *,
+ struct virtio_blk_config *);
static void vtblk_get_ident(struct vtblk_softc *);
static void vtblk_prepare_dump(struct vtblk_softc *);
static int vtblk_write_dump(struct vtblk_softc *, void *, off_t, size_t);
@@ -162,9 +180,14 @@ static void vtblk_enqueue_ready(struct v
static int vtblk_request_error(struct vtblk_request *);
static void vtblk_finish_bio(struct bio *, int);
+static void vtblk_setup_sysctl(struct vtblk_softc *);
+static int vtblk_tunable_int(struct vtblk_softc *, const char *, int);
+
/* Tunables. */
static int vtblk_no_ident = 0;
TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident);
+static int vtblk_writecache_mode = -1;
+TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode);
/* Features desired/implemented by this driver. */
#define VTBLK_FEATURES \
@@ -174,13 +197,14 @@ TUNABLE_INT("hw.vtblk.no_ident", &vtblk_
VIRTIO_BLK_F_GEOMETRY | \
VIRTIO_BLK_F_RO | \
VIRTIO_BLK_F_BLK_SIZE | \
- VIRTIO_BLK_F_FLUSH | \
+ VIRTIO_BLK_F_WCE | \
+ VIRTIO_BLK_F_CONFIG_WCE | \
VIRTIO_RING_F_INDIRECT_DESC)
#define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx
#define VTBLK_LOCK_INIT(_sc, _name) \
mtx_init(VTBLK_MTX((_sc)), (_name), \
- "VTBLK Lock", MTX_DEF)
+ "VirtIO Block Lock", MTX_DEF)
#define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc)))
#define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc)))
#define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc)))
@@ -206,6 +230,9 @@ static device_method_t vtblk_methods[] =
DEVMETHOD(device_resume, vtblk_resume),
DEVMETHOD(device_shutdown, vtblk_shutdown),
+ /* VirtIO methods. */
+ DEVMETHOD(virtio_config_change, vtblk_config_change),
+
DEVMETHOD_END
};
@@ -279,10 +306,13 @@ vtblk_attach(device_t dev)
sc->vtblk_flags |= VTBLK_FLAG_READONLY;
if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER))
sc->vtblk_flags |= VTBLK_FLAG_BARRIER;
+ if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE))
+ sc->vtblk_flags |= VTBLK_FLAG_WC_CONFIG;
+
+ vtblk_setup_sysctl(sc);
/* Get local copy of config. */
- virtio_read_device_config(dev, 0, &blkcfg,
- sizeof(struct virtio_blk_config));
+ vtblk_read_config(sc, &blkcfg);
/*
* With the current sglist(9) implementation, it is not easy
@@ -418,6 +448,26 @@ vtblk_shutdown(device_t dev)
}
static int
+vtblk_config_change(device_t dev)
+{
+ struct vtblk_softc *sc;
+ struct virtio_blk_config blkcfg;
+ uint64_t capacity;
+
+ sc = device_get_softc(dev);
+
+ vtblk_read_config(sc, &blkcfg);
+
+ /* Capacity is always in 512-byte units. */
+ capacity = blkcfg.capacity * 512;
+
+ if (sc->vtblk_disk->d_mediasize != capacity)
+ vtblk_resize_disk(sc, capacity);
+
+ return (0);
+}
+
+static int
vtblk_open(struct disk *dp)
{
struct vtblk_softc *sc;
@@ -518,8 +568,8 @@ vtblk_strategy(struct bio *bp)
max_nsegs = sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS;
KASSERT(nsegs <= max_nsegs,
- ("bio %p spanned too many segments: %d, max: %d",
- bp, nsegs, max_nsegs));
+ ("%s: bio %p spanned too many segments: %d, max: %d",
+ __func__, bp, nsegs, max_nsegs));
}
#endif
@@ -583,6 +633,84 @@ vtblk_alloc_virtqueue(struct vtblk_softc
}
static void
+vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity)
+{
+ device_t dev;
+ struct disk *dp;
+ int error;
+
+ dev = sc->vtblk_dev;
+ dp = sc->vtblk_disk;
+
+ dp->d_mediasize = new_capacity;
+ if (bootverbose) {
+ device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n",
+ (uintmax_t) dp->d_mediasize >> 20,
+ (uintmax_t) dp->d_mediasize / dp->d_sectorsize,
+ dp->d_sectorsize);
+ }
+
+ error = disk_resize(dp, M_NOWAIT);
+ if (error) {
+ device_printf(dev,
+ "disk_resize(9) failed, error: %d\n", error);
+ }
+}
+
+static void
+vtblk_set_write_cache(struct vtblk_softc *sc, int wc)
+{
+
+ /* Set either writeback (1) or writethrough (0) mode. */
+ virtio_write_dev_config_1(sc->vtblk_dev,
+ offsetof(struct virtio_blk_config, writeback), wc);
+}
+
+static int
+vtblk_write_cache_enabled(struct vtblk_softc *sc,
+ struct virtio_blk_config *blkcfg)
+{
+ int wc;
+
+ if (sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) {
+ wc = vtblk_tunable_int(sc, "writecache_mode",
+ vtblk_writecache_mode);
+ if (wc >= 0 && wc < VTBLK_CACHE_MAX)
+ vtblk_set_write_cache(sc, wc);
+ else
+ wc = blkcfg->writeback;
+ } else
+ wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_WCE);
+
+ return (wc);
+}
+
+static int
+vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS)
+{
+ struct vtblk_softc *sc;
+ int wc, error;
+
+ sc = oidp->oid_arg1;
+ wc = sc->vtblk_write_cache;
+
+ error = sysctl_handle_int(oidp, &wc, 0, req);
+ if (error || req->newptr == NULL)
+ return (error);
+ if ((sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) == 0)
+ return (EPERM);
+ if (wc < 0 || wc >= VTBLK_CACHE_MAX)
+ return (EINVAL);
+
+ VTBLK_LOCK(sc);
+ sc->vtblk_write_cache = wc;
+ vtblk_set_write_cache(sc, sc->vtblk_write_cache);
+ VTBLK_UNLOCK(sc);
+
+ return (0);
+}
+
+static void
vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg)
{
device_t dev;
@@ -598,6 +726,11 @@ vtblk_alloc_disk(struct vtblk_softc *sc,
dp->d_name = VTBLK_DISK_NAME;
dp->d_unit = device_get_unit(dev);
dp->d_drv1 = sc;
+ dp->d_flags = DISKFLAG_CANFLUSHCACHE;
+ dp->d_hba_vendor = virtio_get_vendor(dev);
+ dp->d_hba_device = virtio_get_device(dev);
+ dp->d_hba_subvendor = virtio_get_subvendor(dev);
+ dp->d_hba_subdevice = virtio_get_subdevice(dev);
if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0)
dp->d_dump = vtblk_dump;
@@ -633,8 +766,18 @@ vtblk_alloc_disk(struct vtblk_softc *sc,
dp->d_fwheads = blkcfg->geometry.heads;
}
- if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH))
- dp->d_flags |= DISKFLAG_CANFLUSHCACHE;
+ if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY)) {
+ dp->d_stripesize = dp->d_sectorsize *
+ (1 << blkcfg->topology.physical_block_exp);
+ dp->d_stripeoffset = (dp->d_stripesize -
+ blkcfg->topology.alignment_offset * dp->d_sectorsize) %
+ dp->d_stripesize;
+ }
+
+ if (vtblk_write_cache_enabled(sc, blkcfg) != 0)
+ sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK;
+ else
+ sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH;
}
static void
@@ -742,8 +885,7 @@ vtblk_bio_request(struct vtblk_softc *sc
req->vbr_hdr.sector = bp->bio_offset / 512;
break;
default:
- panic("%s: bio with unhandled cmd: %d", __FUNCTION__,
- bp->bio_cmd);
+ panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd);
}
return (req);
@@ -786,14 +928,13 @@ vtblk_execute_request(struct vtblk_softc
}
sglist_reset(sg);
-
sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr));
if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
error = sglist_append(sg, bp->bio_data, bp->bio_bcount);
if (error || sg->sg_nseg == sg->sg_maxseg)
panic("%s: data buffer too big bio:%p error:%d",
- __FUNCTION__, bp, error);
+ __func__, bp, error);
/* BIO_READ means the host writes into our buffer. */
if (bp->bio_cmd == BIO_READ)
@@ -851,6 +992,37 @@ vtblk_stop(struct vtblk_softc *sc)
virtio_stop(sc->vtblk_dev);
}
+#define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \
+ if (virtio_with_feature(_dev, _feature)) { \
+ virtio_read_device_config(_dev, \
+ offsetof(struct virtio_blk_config, _field), \
+ &(_cfg)->_field, sizeof((_cfg)->_field)); \
+ }
+
+static void
+vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg)
+{
+ device_t dev;
+
+ dev = sc->vtblk_dev;
+
+ bzero(blkcfg, sizeof(struct virtio_blk_config));
+
+ /* The capacity is always available. */
+ virtio_read_device_config(dev, offsetof(struct virtio_blk_config,
+ capacity), &blkcfg->capacity, sizeof(blkcfg->capacity));
+
+ /* Read the configuration if the feature was negotiated. */
+ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg);
+ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg);
+ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, geometry, blkcfg);
+ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg);
+ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, topology, blkcfg);
+ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, writeback, blkcfg);
+}
+
+#undef VTBLK_GET_CONFIG
+
static void
vtblk_get_ident(struct vtblk_softc *sc)
{
@@ -862,7 +1034,7 @@ vtblk_get_ident(struct vtblk_softc *sc)
dp = sc->vtblk_disk;
len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE);
- if (vtblk_no_ident != 0)
+ if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0)
return;
req = vtblk_dequeue_request(sc);
@@ -912,8 +1084,10 @@ vtblk_prepare_dump(struct vtblk_softc *s
*/
vtblk_drain_vq(sc, 1);
- if (virtio_reinit(dev, sc->vtblk_features) != 0)
- panic("cannot reinit VirtIO block device during dump");
+ if (virtio_reinit(dev, sc->vtblk_features) != 0) {
+ panic("%s: cannot reinit VirtIO block device during dump",
+ device_get_nameunit(dev));
+ }
virtqueue_disable_intr(vq);
virtio_reinit_complete(dev);
@@ -966,7 +1140,6 @@ static int
vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req)
{
struct virtqueue *vq;
- struct vtblk_request *r;
int error;
vq = sc->vtblk_vq;
@@ -979,14 +1152,12 @@ vtblk_poll_request(struct vtblk_softc *s
return (error);
virtqueue_notify(vq);
-
- r = virtqueue_poll(vq, NULL);
- KASSERT(r == req, ("unexpected request response: %p/%p", r, req));
+ virtqueue_poll(vq, NULL);
error = vtblk_request_error(req);
if (error && bootverbose) {
device_printf(sc->vtblk_dev,
- "%s: IO error: %d\n", __FUNCTION__, error);
+ "%s: IO error: %d\n", __func__, error);
}
return (error);
@@ -1117,7 +1288,7 @@ vtblk_free_requests(struct vtblk_softc *
struct vtblk_request *req;
KASSERT(TAILQ_EMPTY(&sc->vtblk_req_ready),
- ("ready requests left on queue"));
+ ("%s: ready requests left on queue", __func__));
while ((req = vtblk_dequeue_request(sc)) != NULL) {
sc->vtblk_request_count--;
@@ -1125,7 +1296,7 @@ vtblk_free_requests(struct vtblk_softc *
}
KASSERT(sc->vtblk_request_count == 0,
- ("leaked requests: %d", sc->vtblk_request_count));
+ ("%s: leaked %d requests", __func__, sc->vtblk_request_count));
}
static struct vtblk_request *
@@ -1199,3 +1370,33 @@ vtblk_finish_bio(struct bio *bp, int err
biodone(bp);
}
+
+static void
+vtblk_setup_sysctl(struct vtblk_softc *sc)
+{
+ device_t dev;
+ struct sysctl_ctx_list *ctx;
+ struct sysctl_oid *tree;
+ struct sysctl_oid_list *child;
+
+ dev = sc->vtblk_dev;
+ ctx = device_get_sysctl_ctx(dev);
+ tree = device_get_sysctl_tree(dev);
+ child = SYSCTL_CHILDREN(tree);
+
+ SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode",
+ CTLTYPE_INT | CTLFLAG_RW, sc, 0, vtblk_write_cache_sysctl,
+ "I", "Write cache mode (writethrough (0) or writeback (1))");
+}
+
+static int
+vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def)
+{
+ char path[64];
+
+ snprintf(path, sizeof(path),
+ "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob);
+ TUNABLE_INT_FETCH(path, &def);
+
+ return (def);
+}
Modified: head/sys/dev/virtio/block/virtio_blk.h
==============================================================================
--- head/sys/dev/virtio/block/virtio_blk.h Thu Jul 4 17:50:11 2013
(r252702)
+++ head/sys/dev/virtio/block/virtio_blk.h Thu Jul 4 17:53:02 2013
(r252703)
@@ -39,8 +39,9 @@
#define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */
#define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/
#define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */
-#define VIRTIO_BLK_F_FLUSH 0x0200 /* Cache flush command support */
+#define VIRTIO_BLK_F_WCE 0x0200 /* Writeback mode enabled after reset */
#define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */
+#define VIRTIO_BLK_F_CONFIG_WCE 0x0800 /* Writeback mode available in config */
#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */
@@ -51,15 +52,27 @@ struct virtio_blk_config {
uint32_t size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
uint32_t seg_max;
- /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
+ /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
struct virtio_blk_geometry {
uint16_t cylinders;
uint8_t heads;
uint8_t sectors;
} geometry;
- /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
+ /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
uint32_t blk_size;
+
+ /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */
+ struct virtio_blk_topology {
+ uint8_t physical_block_exp;
+ uint8_t alignment_offset;
+ uint16_t min_io_size;
+ uint16_t opt_io_size;
+ } topology;
+
+ /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
+ uint8_t writeback;
+
} __packed;
/*
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