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xen: add implementations of xen-block connect and disconnect functions... 

...and wire in the dataplane.

This patch adds the remaining code to make the xen-block XenDevice
functional. The parameters that a block frontend expects to find are
populated in the backend xenstore area, and the 'ring-ref' and
'event-channel' values specified in the frontend xenstore area are
mapped/bound and used to set up the dataplane.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This commit is contained in:
Paul Durrant 2019-01-08 14:48:59 +00:00 committed by Anthony PERARD
parent d4683cf952
commit b6af8926fb
5 changed files with 353 additions and 26 deletions
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166
hw/block/xen-block.c
View File

@ -10,7 +10,13 @@
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "hw/hw.h"
#include "hw/xen/xen_common.h"
#include "hw/block/xen_blkif.h"
#include "hw/xen/xen-block.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-backend.h"
#include "sysemu/iothread.h"
#include "dataplane/xen-block.h"
#include "trace.h"
static char *xen_block_get_name(XenDevice *xendev, Error **errp)
@ -28,6 +34,8 @@ static void xen_block_disconnect(XenDevice *xendev, Error **errp)
XenBlockVdev *vdev = &blockdev->props.vdev;
trace_xen_block_disconnect(type, vdev->disk, vdev->partition);
xen_block_dataplane_stop(blockdev->dataplane);
}
static void xen_block_connect(XenDevice *xendev, Error **errp)
@ -35,8 +43,72 @@ static void xen_block_connect(XenDevice *xendev, Error **errp)
XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
const char *type = object_get_typename(OBJECT(blockdev));
XenBlockVdev *vdev = &blockdev->props.vdev;
unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol;
char *str;
trace_xen_block_connect(type, vdev->disk, vdev->partition);
if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u",
&order) != 1) {
nr_ring_ref = 1;
ring_ref = g_new(unsigned int, nr_ring_ref);
if (xen_device_frontend_scanf(xendev, "ring-ref", "%u",
&ring_ref[0]) != 1) {
error_setg(errp, "failed to read ring-ref");
g_free(ring_ref);
return;
}
} else if (order <= blockdev->props.max_ring_page_order) {
unsigned int i;
nr_ring_ref = 1 << order;
ring_ref = g_new(unsigned int, nr_ring_ref);
for (i = 0; i < nr_ring_ref; i++) {
const char *key = g_strdup_printf("ring-ref%u", i);
if (xen_device_frontend_scanf(xendev, key, "%u",
&ring_ref[i]) != 1) {
error_setg(errp, "failed to read %s", key);
g_free((gpointer)key);
g_free(ring_ref);
return;
}
g_free((gpointer)key);
}
} else {
error_setg(errp, "invalid ring-page-order (%d)", order);
return;
}
if (xen_device_frontend_scanf(xendev, "event-channel", "%u",
&event_channel) != 1) {
error_setg(errp, "failed to read event-channel");
g_free(ring_ref);
return;
}
if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
&str) != 1) {
protocol = BLKIF_PROTOCOL_NATIVE;
} else {
if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
protocol = BLKIF_PROTOCOL_X86_32;
} else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) {
protocol = BLKIF_PROTOCOL_X86_64;
} else {
protocol = BLKIF_PROTOCOL_NATIVE;
}
free(str);
}
xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref,
event_channel, protocol, errp);
g_free(ring_ref);
}
static void xen_block_unrealize(XenDevice *xendev, Error **errp)
@ -56,6 +128,9 @@ static void xen_block_unrealize(XenDevice *xendev, Error **errp)
/* Disconnect from the frontend in case this has not already happened */
xen_block_disconnect(xendev, NULL);
xen_block_dataplane_destroy(blockdev->dataplane);
blockdev->dataplane = NULL;
if (blockdev_class->unrealize) {
blockdev_class->unrealize(blockdev, errp);
}
@ -68,6 +143,7 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
XEN_BLOCK_DEVICE_GET_CLASS(xendev);
const char *type = object_get_typename(OBJECT(blockdev));
XenBlockVdev *vdev = &blockdev->props.vdev;
BlockConf *conf = &blockdev->props.conf;
Error *local_err = NULL;
if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
@ -81,8 +157,62 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
blockdev_class->realize(blockdev, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
/*
* The blkif protocol does not deal with removable media, so it must
* always be present, even for CDRom devices.
*/
assert(conf->blk);
if (!blk_is_inserted(conf->blk)) {
error_setg(errp, "device needs media, but drive is empty");
return;
}
if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
false, errp)) {
return;
}
if (!(blockdev->info & VDISK_CDROM) &&
!blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) {
return;
}
blkconf_blocksizes(conf);
if (conf->logical_block_size > conf->physical_block_size) {
error_setg(
errp, "logical_block_size > physical_block_size not supported");
return;
}
blk_set_guest_block_size(conf->blk, conf->logical_block_size);
if (conf->discard_granularity > 0) {
xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
}
xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
blockdev->props.max_ring_page_order);
xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
xen_device_frontend_printf(xendev, "virtual-device", "%lu",
vdev->number);
xen_device_frontend_printf(xendev, "device-type", "%s",
blockdev->device_type);
xen_device_backend_printf(xendev, "sector-size", "%u",
conf->logical_block_size);
xen_device_backend_printf(xendev, "sectors", "%lu",
blk_getlength(conf->blk) /
conf->logical_block_size);
blockdev->dataplane =
xen_block_dataplane_create(xendev, conf, blockdev->props.iothread);
}
static void xen_block_frontend_changed(XenDevice *xendev,
@ -331,6 +461,11 @@ const PropertyInfo xen_block_prop_vdev = {
static Property xen_block_props[] = {
DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
xen_block_prop_vdev, XenBlockVdev),
DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
props.max_ring_page_order, 4),
DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
TYPE_IOTHREAD, IOThread *),
DEFINE_PROP_END_OF_LIST()
};
@ -339,6 +474,7 @@ static void xen_block_class_init(ObjectClass *class, void *data)
DeviceClass *dev_class = DEVICE_CLASS(class);
XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
xendev_class->device = "vbd";
xendev_class->get_name = xen_block_get_name;
xendev_class->realize = xen_block_realize;
xendev_class->frontend_changed = xen_block_frontend_changed;
@ -363,7 +499,18 @@ static void xen_disk_unrealize(XenBlockDevice *blockdev, Error **errp)
static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
{
BlockConf *conf = &blockdev->props.conf;
trace_xen_disk_realize();
blockdev->device_type = "disk";
if (!conf->blk) {
error_setg(errp, "drive property not set");
return;
}
blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
}
static void xen_disk_class_init(ObjectClass *class, void *data)
@ -391,7 +538,26 @@ static void xen_cdrom_unrealize(XenBlockDevice *blockdev, Error **errp)
static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
{
BlockConf *conf = &blockdev->props.conf;
trace_xen_cdrom_realize();
blockdev->device_type = "cdrom";
if (!conf->blk) {
int rc;
/* Set up an empty drive */
conf->blk = blk_new(0, BLK_PERM_ALL);
rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
if (!rc) {
error_setg_errno(errp, -rc, "failed to create drive");
return;
}
}
blockdev->info = VDISK_READONLY | VDISK_CDROM;
}
static void xen_cdrom_class_init(ObjectClass *class, void *data)

3
hw/xen/trace-events
View File

@ -22,8 +22,11 @@ xen_bus_watch(const char *token) "token: %s"
xen_device_realize(const char *type, char *name) "type: %s name: %s"
xen_device_unrealize(const char *type, char *name) "type: %s name: %s"
xen_device_backend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s"
xen_device_backend_online(const char *type, char *name, bool online) "type: %s name: %s -> %u"
xen_device_backend_changed(const char *type, char *name) "type: %s name: %s"
xen_device_frontend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s"
xen_device_frontend_changed(const char *type, char *name) "type: %s name: %s"
xen_device_unplug(const char *type, char *name) "type: %s name: %s"
# include/hw/xen/xen-bus-helper.c
xs_node_create(const char *node) "%s"

187
hw/xen/xen-bus.c
View File

@ -48,6 +48,54 @@ static char *xen_device_get_frontend_path(XenDevice *xendev)
xendev->frontend_id, device, xendev->name);
}
static void xen_device_unplug(XenDevice *xendev, Error **errp)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
const char *type = object_get_typename(OBJECT(xendev));
Error *local_err = NULL;
xs_transaction_t tid;
trace_xen_device_unplug(type, xendev->name);
/* Mimic the way the Xen toolstack does an unplug */
again:
tid = xs_transaction_start(xenbus->xsh);
if (tid == XBT_NULL) {
error_setg_errno(errp, errno, "failed xs_transaction_start");
return;
}
xs_node_printf(xenbus->xsh, tid, xendev->backend_path, "online",
&local_err, "%u", 0);
if (local_err) {
goto abort;
}
xs_node_printf(xenbus->xsh, tid, xendev->backend_path, "state",
&local_err, "%u", XenbusStateClosing);
if (local_err) {
goto abort;
}
if (!xs_transaction_end(xenbus->xsh, tid, false)) {
if (errno == EAGAIN) {
goto again;
}
error_setg_errno(errp, errno, "failed xs_transaction_end");
}
return;
abort:
/*
* We only abort if there is already a failure so ignore any error
* from ending the transaction.
*/
xs_transaction_end(xenbus->xsh, tid, true);
error_propagate(errp, local_err);
}
static void xen_bus_print_dev(Monitor *mon, DeviceState *dev, int indent)
{
XenDevice *xendev = XEN_DEVICE(dev);
@ -208,14 +256,26 @@ fail:
xen_bus_unrealize(bus, &error_abort);
}
static void xen_bus_unplug_request(HotplugHandler *hotplug,
DeviceState *dev,
Error **errp)
{
XenDevice *xendev = XEN_DEVICE(dev);
xen_device_unplug(xendev, errp);
}
static void xen_bus_class_init(ObjectClass *class, void *data)
{
BusClass *bus_class = BUS_CLASS(class);
HotplugHandlerClass *hotplug_class = HOTPLUG_HANDLER_CLASS(class);
bus_class->print_dev = xen_bus_print_dev;
bus_class->get_dev_path = xen_bus_get_dev_path;
bus_class->realize = xen_bus_realize;
bus_class->unrealize = xen_bus_unrealize;
hotplug_class->unplug_request = xen_bus_unplug_request;
}
static const TypeInfo xen_bus_type_info = {
@ -230,8 +290,8 @@ static const TypeInfo xen_bus_type_info = {
},
};
static void xen_device_backend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
void xen_device_backend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
Error *local_err = NULL;
@ -287,6 +347,70 @@ enum xenbus_state xen_device_backend_get_state(XenDevice *xendev)
return xendev->backend_state;
}
static void xen_device_backend_set_online(XenDevice *xendev, bool online)
{
const char *type = object_get_typename(OBJECT(xendev));
if (xendev->backend_online == online) {
return;
}
trace_xen_device_backend_online(type, xendev->name, online);
xendev->backend_online = online;
xen_device_backend_printf(xendev, "online", "%u", online);
}
static void xen_device_backend_changed(void *opaque)
{
XenDevice *xendev = opaque;
const char *type = object_get_typename(OBJECT(xendev));
enum xenbus_state state;
unsigned int online;
trace_xen_device_backend_changed(type, xendev->name);
if (xen_device_backend_scanf(xendev, "state", "%u", &state) != 1) {
state = XenbusStateUnknown;
}
xen_device_backend_set_state(xendev, state);
if (xen_device_backend_scanf(xendev, "online", "%u", &online) != 1) {
online = 0;
}
xen_device_backend_set_online(xendev, !!online);
/*
* If the toolstack (or unplug request callback) has set the backend
* state to Closing, but there is no active frontend (i.e. the
* state is not Connected) then set the backend state to Closed.
*/
if (xendev->backend_state == XenbusStateClosing &&
xendev->frontend_state != XenbusStateConnected) {
xen_device_backend_set_state(xendev, XenbusStateClosed);
}
/*
* If a backend is still 'online' then its state should be cycled
* back round to InitWait in order for a new frontend instance to
* connect. This may happen when, for example, a frontend driver is
* re-installed or updated.
* If a backend is not 'online' then the device should be destroyed.
*/
if (xendev->backend_online &&
xendev->backend_state == XenbusStateClosed) {
xen_device_backend_set_state(xendev, XenbusStateInitWait);
} else if (!xendev->backend_online &&
(xendev->backend_state == XenbusStateClosed ||
xendev->backend_state == XenbusStateInitialising ||
xendev->backend_state == XenbusStateInitWait ||
xendev->backend_state == XenbusStateUnknown)) {
object_unparent(OBJECT(xendev));
}
}
static void xen_device_backend_create(XenDevice *xendev, Error **errp)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
@ -307,6 +431,27 @@ static void xen_device_backend_create(XenDevice *xendev, Error **errp)
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to create backend: ");
return;
}
xendev->backend_state_watch =
xen_bus_add_watch(xenbus, xendev->backend_path,
"state", xen_device_backend_changed,
xendev, &local_err);
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to watch backend state: ");
return;
}
xendev->backend_online_watch =
xen_bus_add_watch(xenbus, xendev->backend_path,
"online", xen_device_backend_changed,
xendev, &local_err);
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to watch backend online: ");
return;
}
}
@ -315,6 +460,16 @@ static void xen_device_backend_destroy(XenDevice *xendev)
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
Error *local_err = NULL;
if (xendev->backend_online_watch) {
xen_bus_remove_watch(xenbus, xendev->backend_online_watch, NULL);
xendev->backend_online_watch = NULL;
}
if (xendev->backend_state_watch) {
xen_bus_remove_watch(xenbus, xendev->backend_state_watch, NULL);
xendev->backend_state_watch = NULL;
}
if (!xendev->backend_path) {
return;
}
@ -331,8 +486,8 @@ static void xen_device_backend_destroy(XenDevice *xendev)
}
}
static void xen_device_frontend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
void xen_device_frontend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
Error *local_err = NULL;
@ -350,8 +505,8 @@ static void xen_device_frontend_printf(XenDevice *xendev, const char *key,
}
}
static int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
const char *fmt, ...)
int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
const char *fmt, ...)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
va_list ap;
@ -407,24 +562,6 @@ static void xen_device_frontend_changed(void *opaque)
error_reportf_err(local_err, "frontend change error: ");
}
}
/*
* If a backend is still 'online' then its state should be cycled
* back round to InitWait in order for a new frontend instance to
* connect. This may happen when, for example, a frontend driver is
* re-installed or updated.
*/
if (xendev->backend_state == XenbusStateClosed) {
unsigned int online;
if (xen_device_backend_scanf(xendev, "online", "%u", &online) != 1) {
online = 0;
}
if (online) {
xen_device_backend_set_state(xendev, XenbusStateInitWait);
}
}
}
static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
@ -824,9 +961,9 @@ static void xen_device_realize(DeviceState *dev, Error **errp)
xendev->frontend_path);
xen_device_backend_printf(xendev, "frontend-id", "%u",
xendev->frontend_id);
xen_device_backend_printf(xendev, "online", "%u", 1);
xen_device_backend_printf(xendev, "hotplug-status", "connected");
xen_device_backend_set_online(xendev, true);
xen_device_backend_set_state(xendev, XenbusStateInitWait);
xen_device_frontend_printf(xendev, "backend", "%s",

9
include/hw/xen/xen-block.h
View File

@ -9,6 +9,9 @@
#define HW_XEN_BLOCK_H
#include "hw/xen/xen-bus.h"
#include "hw/block/block.h"
#include "hw/block/dataplane/xen-block.h"
#include "sysemu/iothread.h"
typedef enum XenBlockVdevType {
XEN_BLOCK_VDEV_TYPE_INVALID,
@ -28,11 +31,17 @@ typedef struct XenBlockVdev {
typedef struct XenBlockProperties {
XenBlockVdev vdev;
BlockConf conf;
unsigned int max_ring_page_order;
IOThread *iothread;
} XenBlockProperties;
typedef struct XenBlockDevice {
XenDevice xendev;
XenBlockProperties props;
const char *device_type;
unsigned int info;
XenBlockDataPlane *dataplane;
} XenBlockDevice;
typedef void (*XenBlockDeviceRealize)(XenBlockDevice *blockdev, Error **errp);

14
include/hw/xen/xen-bus.h
View File

@ -23,7 +23,9 @@ typedef struct XenDevice {
char *backend_path, *frontend_path;
enum xenbus_state backend_state, frontend_state;
Notifier exit;
XenWatch *frontend_state_watch;
XenWatch *backend_state_watch, *frontend_state_watch;
bool backend_online;
XenWatch *backend_online_watch;
xengnttab_handle *xgth;
bool feature_grant_copy;
xenevtchn_handle *xeh;
@ -83,6 +85,16 @@ void xen_device_backend_set_state(XenDevice *xendev,
enum xenbus_state state);
enum xenbus_state xen_device_backend_get_state(XenDevice *xendev);
void xen_device_backend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
GCC_FMT_ATTR(3, 4);
void xen_device_frontend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
GCC_FMT_ATTR(3, 4);
int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
const char *fmt, ...);
void xen_device_set_max_grant_refs(XenDevice *xendev, unsigned int nr_refs,
Error **errp);
void *xen_device_map_grant_refs(XenDevice *xendev, uint32_t *refs,