[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v9 04/18] xen: create xenstore areas for XenDevice-s
This patch adds a new source module, xen-bus-helper.c, which builds on basic libxenstore primitives to provide functions to create (setting permissions appropriately) and destroy xenstore areas, and functions to 'printf' and 'scanf' nodes therein. The main xen-bus code then uses these primitives [1] to initialize and destroy the frontend and backend areas for a XenDevice during realize and unrealize respectively. The 'xen-block' implementation is extended with a 'get_name' method that returns the VBD number. This number is required to 'name' the xenstore areas. NOTE: An exit handler is also added to make sure the xenstore areas are cleaned up if QEMU terminates without devices being unrealized. [1] The 'scanf' functions are actually not yet needed, but they will be needed by code delivered in subsequent patches. Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx> Reviewed-by: Anthony Perard <anthony.perard@xxxxxxxxxx> --- Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> Cc: Kevin Wolf <kwolf@xxxxxxxxxx> Cc: Max Reitz <mreitz@xxxxxxxxxx> v5: - Re-base v3: - Add transaction id parameters to xen-bus-helper functions - Not added Anthony's R-b because of change v2: - Fix boilerplate - Add error pointers to all xs_node... helpers - Add GCC_FMT_ATTR to declarations of printf-like helpers --- hw/block/xen-block.c | 9 + hw/xen/Makefile.objs | 2 +- hw/xen/trace-events | 12 +- hw/xen/xen-bus-helper.c | 150 +++++++++++++++ hw/xen/xen-bus.c | 321 +++++++++++++++++++++++++++++++- include/hw/xen/xen-bus-helper.h | 39 ++++ include/hw/xen/xen-bus.h | 12 ++ 7 files changed, 540 insertions(+), 5 deletions(-) create mode 100644 hw/xen/xen-bus-helper.c create mode 100644 include/hw/xen/xen-bus-helper.h diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index 8e78b6a034..d27a2865bc 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -13,6 +13,14 @@ #include "hw/xen/xen-block.h" #include "trace.h" +static char *xen_block_get_name(XenDevice *xendev, Error **errp) +{ + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + XenBlockVdev *vdev = &blockdev->props.vdev; + + return g_strdup_printf("%lu", vdev->number); +} + static void xen_block_unrealize(XenDevice *xendev, Error **errp) { XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); @@ -262,6 +270,7 @@ 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->get_name = xen_block_get_name; xendev_class->realize = xen_block_realize; xendev_class->unrealize = xen_block_unrealize; diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs index d9d6d7b4f9..77c0868190 100644 --- a/hw/xen/Makefile.objs +++ b/hw/xen/Makefile.objs @@ -1,5 +1,5 @@ # xen backend driver support -common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-common.o xen-bus.o +common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-common.o xen-bus.o xen-bus-helper.o obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_graphics.o xen_pt_msi.o diff --git a/hw/xen/trace-events b/hw/xen/trace-events index 0172cd4e26..75dc226d75 100644 --- a/hw/xen/trace-events +++ b/hw/xen/trace-events @@ -16,5 +16,13 @@ xen_domid_restrict(int err) "err: %u" # include/hw/xen/xen-bus.c xen_bus_realize(void) "" xen_bus_unrealize(void) "" -xen_device_realize(const char *type) "type: %s" -xen_device_unrealize(const char *type) "type: %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_frontend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s" + +# include/hw/xen/xen-bus-helper.c +xs_node_create(const char *node) "%s" +xs_node_destroy(const char *node) "%s" +xs_node_vprintf(char *path, char *value) "%s %s" +xs_node_vscanf(char *path, char *value) "%s %s" diff --git a/hw/xen/xen-bus-helper.c b/hw/xen/xen-bus-helper.c new file mode 100644 index 0000000000..15b3ad8d78 --- /dev/null +++ b/hw/xen/xen-bus-helper.c @@ -0,0 +1,150 @@ +/* + * Copyright (c) 2018 Citrix Systems Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "hw/hw.h" +#include "hw/sysbus.h" +#include "hw/xen/xen.h" +#include "hw/xen/xen-bus.h" +#include "hw/xen/xen-bus-helper.h" +#include "qapi/error.h" + +#include <glib/gprintf.h> + +struct xs_state { + enum xenbus_state statenum; + const char *statestr; +}; +#define XS_STATE(state) { state, #state } + +static struct xs_state xs_state[] = { + XS_STATE(XenbusStateUnknown), + XS_STATE(XenbusStateInitialising), + XS_STATE(XenbusStateInitWait), + XS_STATE(XenbusStateInitialised), + XS_STATE(XenbusStateConnected), + XS_STATE(XenbusStateClosing), + XS_STATE(XenbusStateClosed), + XS_STATE(XenbusStateReconfiguring), + XS_STATE(XenbusStateReconfigured), +}; + +#undef XS_STATE + +const char *xs_strstate(enum xenbus_state state) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(xs_state); i++) { + if (xs_state[i].statenum == state) { + return xs_state[i].statestr; + } + } + + return "INVALID"; +} + +void xs_node_create(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, struct xs_permissions perms[], + unsigned int nr_perms, Error **errp) +{ + trace_xs_node_create(node); + + if (!xs_write(xsh, tid, node, "", 0)) { + error_setg_errno(errp, errno, "failed to create node '%s'", node); + return; + } + + if (!xs_set_permissions(xsh, tid, node, perms, nr_perms)) { + error_setg_errno(errp, errno, "failed to set node '%s' permissions", + node); + } +} + +void xs_node_destroy(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, Error **errp) +{ + trace_xs_node_destroy(node); + + if (!xs_rm(xsh, tid, node)) { + error_setg_errno(errp, errno, "failed to destroy node '%s'", node); + } +} + +void xs_node_vprintf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, va_list ap) +{ + char *path, *value; + int len; + + path = (strlen(node) != 0) ? g_strdup_printf("%s/%s", node, key) : + g_strdup(key); + len = g_vasprintf(&value, fmt, ap); + + trace_xs_node_vprintf(path, value); + + if (!xs_write(xsh, tid, path, value, len)) { + error_setg_errno(errp, errno, "failed to write '%s' to '%s'", + value, path); + } + + g_free(value); + g_free(path); +} + +void xs_node_printf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + xs_node_vprintf(xsh, tid, node, key, errp, fmt, ap); + va_end(ap); +} + +int xs_node_vscanf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, va_list ap) +{ + char *path, *value; + int rc; + + path = (strlen(node) != 0) ? g_strdup_printf("%s/%s", node, key) : + g_strdup(key); + value = xs_read(xsh, tid, path, NULL); + + trace_xs_node_vscanf(path, value); + + if (value) { + rc = vsscanf(value, fmt, ap); + } else { + error_setg_errno(errp, errno, "failed to read from '%s'", + path); + rc = EOF; + } + + free(value); + g_free(path); + + return rc; +} + +int xs_node_scanf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, ...) +{ + va_list ap; + int rc; + + va_start(ap, fmt); + rc = xs_node_vscanf(xsh, tid, node, key, errp, fmt, ap); + va_end(ap); + + return rc; +} diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index bc04da748b..843fda26a9 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -8,24 +8,102 @@ #include "qemu/osdep.h" #include "hw/hw.h" #include "hw/sysbus.h" +#include "hw/xen/xen.h" #include "hw/xen/xen-bus.h" +#include "hw/xen/xen-bus-helper.h" +#include "monitor/monitor.h" #include "qapi/error.h" +#include "sysemu/sysemu.h" #include "trace.h" +static char *xen_device_get_backend_path(XenDevice *xendev) +{ + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); + XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev); + const char *type = object_get_typename(OBJECT(xendev)); + const char *backend = xendev_class->backend; + + if (!backend) { + backend = type; + } + + return g_strdup_printf("/local/domain/%u/backend/%s/%u/%s", + xenbus->backend_id, backend, xendev->frontend_id, + xendev->name); +} + +static char *xen_device_get_frontend_path(XenDevice *xendev) +{ + XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev); + const char *type = object_get_typename(OBJECT(xendev)); + const char *device = xendev_class->device; + + if (!device) { + device = type; + } + + return g_strdup_printf("/local/domain/%u/device/%s/%s", + xendev->frontend_id, device, xendev->name); +} + +static void xen_bus_print_dev(Monitor *mon, DeviceState *dev, int indent) +{ + XenDevice *xendev = XEN_DEVICE(dev); + + monitor_printf(mon, "%*sname = '%s' frontend_id = %u\n", + indent, "", xendev->name, xendev->frontend_id); +} + +static char *xen_bus_get_dev_path(DeviceState *dev) +{ + return xen_device_get_backend_path(XEN_DEVICE(dev)); +} + static void xen_bus_unrealize(BusState *bus, Error **errp) { + XenBus *xenbus = XEN_BUS(bus); + trace_xen_bus_unrealize(); + + if (!xenbus->xsh) { + return; + } + + xs_close(xenbus->xsh); } static void xen_bus_realize(BusState *bus, Error **errp) { + XenBus *xenbus = XEN_BUS(bus); + unsigned int domid; + trace_xen_bus_realize(); + + xenbus->xsh = xs_open(0); + if (!xenbus->xsh) { + error_setg_errno(errp, errno, "failed xs_open"); + goto fail; + } + + if (xs_node_scanf(xenbus->xsh, XBT_NULL, "", /* domain root node */ + "domid", NULL, "%u", &domid) == 1) { + xenbus->backend_id = domid; + } else { + xenbus->backend_id = 0; /* Assume lack of node means dom0 */ + } + + return; + +fail: + xen_bus_unrealize(bus, &error_abort); } static void xen_bus_class_init(ObjectClass *class, void *data) { BusClass *bus_class = BUS_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; } @@ -42,27 +120,241 @@ static const TypeInfo xen_bus_type_info = { }, }; +static 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; + va_list ap; + + g_assert(xenbus->xsh); + + va_start(ap, fmt); + xs_node_vprintf(xenbus->xsh, XBT_NULL, xendev->backend_path, key, + &local_err, fmt, ap); + va_end(ap); + + if (local_err) { + error_report_err(local_err); + } +} + +static void xen_device_backend_set_state(XenDevice *xendev, + enum xenbus_state state) +{ + const char *type = object_get_typename(OBJECT(xendev)); + + if (xendev->backend_state == state) { + return; + } + + trace_xen_device_backend_state(type, xendev->name, + xs_strstate(state)); + + xendev->backend_state = state; + xen_device_backend_printf(xendev, "state", "%u", state); +} + +static void xen_device_backend_create(XenDevice *xendev, Error **errp) +{ + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); + struct xs_permissions perms[2]; + Error *local_err = NULL; + + xendev->backend_path = xen_device_get_backend_path(xendev); + + perms[0].id = xenbus->backend_id; + perms[0].perms = XS_PERM_NONE; + perms[1].id = xendev->frontend_id; + perms[1].perms = XS_PERM_READ; + + g_assert(xenbus->xsh); + + xs_node_create(xenbus->xsh, XBT_NULL, xendev->backend_path, perms, + ARRAY_SIZE(perms), &local_err); + if (local_err) { + error_propagate_prepend(errp, local_err, + "failed to create backend: "); + } +} + +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_path) { + return; + } + + g_assert(xenbus->xsh); + + xs_node_destroy(xenbus->xsh, XBT_NULL, xendev->backend_path, + &local_err); + g_free(xendev->backend_path); + xendev->backend_path = NULL; + + if (local_err) { + error_report_err(local_err); + } +} + +static 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; + va_list ap; + + g_assert(xenbus->xsh); + + va_start(ap, fmt); + xs_node_vprintf(xenbus->xsh, XBT_NULL, xendev->frontend_path, key, + &local_err, fmt, ap); + va_end(ap); + + if (local_err) { + error_report_err(local_err); + } +} + +static void xen_device_frontend_set_state(XenDevice *xendev, + enum xenbus_state state) +{ + const char *type = object_get_typename(OBJECT(xendev)); + + if (xendev->frontend_state == state) { + return; + } + + trace_xen_device_frontend_state(type, xendev->name, + xs_strstate(state)); + + xendev->frontend_state = state; + xen_device_frontend_printf(xendev, "state", "%u", state); +} + +static void xen_device_frontend_create(XenDevice *xendev, Error **errp) +{ + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); + struct xs_permissions perms[2]; + Error *local_err = NULL; + + xendev->frontend_path = xen_device_get_frontend_path(xendev); + + perms[0].id = xendev->frontend_id; + perms[0].perms = XS_PERM_NONE; + perms[1].id = xenbus->backend_id; + perms[1].perms = XS_PERM_READ | XS_PERM_WRITE; + + g_assert(xenbus->xsh); + + xs_node_create(xenbus->xsh, XBT_NULL, xendev->frontend_path, perms, + ARRAY_SIZE(perms), &local_err); + if (local_err) { + error_propagate_prepend(errp, local_err, + "failed to create frontend: "); + } +} + +static void xen_device_frontend_destroy(XenDevice *xendev) +{ + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); + Error *local_err = NULL; + + if (!xendev->frontend_path) { + return; + } + + g_assert(xenbus->xsh); + + xs_node_destroy(xenbus->xsh, XBT_NULL, xendev->frontend_path, + &local_err); + g_free(xendev->frontend_path); + xendev->frontend_path = NULL; + + if (local_err) { + error_report_err(local_err); + } +} + static void xen_device_unrealize(DeviceState *dev, Error **errp) { XenDevice *xendev = XEN_DEVICE(dev); XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev); const char *type = object_get_typename(OBJECT(xendev)); - trace_xen_device_unrealize(type); + if (!xendev->name) { + return; + } + + trace_xen_device_unrealize(type, xendev->name); + + if (xendev->exit.notify) { + qemu_remove_exit_notifier(&xendev->exit); + xendev->exit.notify = NULL; + } if (xendev_class->unrealize) { xendev_class->unrealize(xendev, errp); } + + xen_device_frontend_destroy(xendev); + xen_device_backend_destroy(xendev); + + g_free(xendev->name); + xendev->name = NULL; +} + +static void xen_device_exit(Notifier *n, void *data) +{ + XenDevice *xendev = container_of(n, XenDevice, exit); + + xen_device_unrealize(DEVICE(xendev), &error_abort); } static void xen_device_realize(DeviceState *dev, Error **errp) { XenDevice *xendev = XEN_DEVICE(dev); XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev); + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); const char *type = object_get_typename(OBJECT(xendev)); Error *local_err = NULL; - trace_xen_device_realize(type); + if (xendev->frontend_id == DOMID_INVALID) { + xendev->frontend_id = xen_domid; + } + + if (xendev->frontend_id >= DOMID_FIRST_RESERVED) { + error_setg(errp, "invalid frontend-id"); + goto unrealize; + } + + if (!xendev_class->get_name) { + error_setg(errp, "get_name method not implemented"); + goto unrealize; + } + + xendev->name = xendev_class->get_name(xendev, &local_err); + if (local_err) { + error_propagate_prepend(errp, local_err, + "failed to get device name: "); + goto unrealize; + } + + trace_xen_device_realize(type, xendev->name); + + xen_device_backend_create(xendev, &local_err); + if (local_err) { + error_propagate(errp, local_err); + goto unrealize; + } + + xen_device_frontend_create(xendev, &local_err); + if (local_err) { + error_propagate(errp, local_err); + goto unrealize; + } if (xendev_class->realize) { xendev_class->realize(xendev, &local_err); @@ -72,18 +364,43 @@ static void xen_device_realize(DeviceState *dev, Error **errp) } } + xen_device_backend_printf(xendev, "frontend", "%s", + 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_state(xendev, XenbusStateInitWait); + + xen_device_frontend_printf(xendev, "backend", "%s", + xendev->backend_path); + xen_device_frontend_printf(xendev, "backend-id", "%u", + xenbus->backend_id); + + xen_device_frontend_set_state(xendev, XenbusStateInitialising); + + xendev->exit.notify = xen_device_exit; + qemu_add_exit_notifier(&xendev->exit); return; unrealize: xen_device_unrealize(dev, &error_abort); } +static Property xen_device_props[] = { + DEFINE_PROP_UINT16("frontend-id", XenDevice, frontend_id, + DOMID_INVALID), + DEFINE_PROP_END_OF_LIST() +}; + static void xen_device_class_init(ObjectClass *class, void *data) { DeviceClass *dev_class = DEVICE_CLASS(class); dev_class->realize = xen_device_realize; dev_class->unrealize = xen_device_unrealize; + dev_class->props = xen_device_props; dev_class->bus_type = TYPE_XEN_BUS; } diff --git a/include/hw/xen/xen-bus-helper.h b/include/hw/xen/xen-bus-helper.h new file mode 100644 index 0000000000..5cd9c3d759 --- /dev/null +++ b/include/hw/xen/xen-bus-helper.h @@ -0,0 +1,39 @@ +/* + * Copyright (c) 2018 Citrix Systems Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef HW_XEN_BUS_HELPER_H +#define HW_XEN_BUS_HELPER_H + +#include "hw/xen/xen_common.h" + +const char *xs_strstate(enum xenbus_state state); + +void xs_node_create(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, struct xs_permissions perms[], + unsigned int nr_perms, Error **errp); +void xs_node_destroy(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, Error **errp); + +/* Write to node/key unless node is empty, in which case write to key */ +void xs_node_vprintf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, va_list ap) + GCC_FMT_ATTR(6, 0); +void xs_node_printf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, ...) + GCC_FMT_ATTR(6, 7); + +/* Read from node/key unless node is empty, in which case read from key */ +int xs_node_vscanf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, va_list ap); +int xs_node_scanf(struct xs_handle *xsh, xs_transaction_t tid, + const char *node, const char *key, Error **errp, + const char *fmt, ...); + +#endif /* HW_XEN_BUS_HELPER_H */ diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h index 0cb12464ce..85a75d8dec 100644 --- a/include/hw/xen/xen-bus.h +++ b/include/hw/xen/xen-bus.h @@ -8,12 +8,19 @@ #ifndef HW_XEN_BUS_H #define HW_XEN_BUS_H +#include "hw/xen/xen_common.h" #include "hw/sysbus.h" typedef struct XenDevice { DeviceState qdev; + domid_t frontend_id; + char *name; + char *backend_path, *frontend_path; + enum xenbus_state backend_state, frontend_state; + Notifier exit; } XenDevice; +typedef char *(*XenDeviceGetName)(XenDevice *xendev, Error **errp); typedef void (*XenDeviceRealize)(XenDevice *xendev, Error **errp); typedef void (*XenDeviceUnrealize)(XenDevice *xendev, Error **errp); @@ -21,6 +28,9 @@ typedef struct XenDeviceClass { /*< private >*/ DeviceClass parent_class; /*< public >*/ + const char *backend; + const char *device; + XenDeviceGetName get_name; XenDeviceRealize realize; XenDeviceUnrealize unrealize; } XenDeviceClass; @@ -35,6 +45,8 @@ typedef struct XenDeviceClass { typedef struct XenBus { BusState qbus; + domid_t backend_id; + struct xs_handle *xsh; } XenBus; typedef struct XenBusClass { -- 2.20.1.2.gb21ebb6 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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