From patchwork Tue Dec 11 15:57:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 1011173 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=citrix.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43DlJ92w0mz9s3l for ; Wed, 12 Dec 2018 03:09:29 +1100 (AEDT) Received: from localhost ([::1]:39607 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gWkb8-0004ai-U4 for incoming@patchwork.ozlabs.org; Tue, 11 Dec 2018 11:09:26 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gWkQv-0005Hh-RC for qemu-devel@nongnu.org; Tue, 11 Dec 2018 10:58:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gWkQs-0004R0-Ce for qemu-devel@nongnu.org; Tue, 11 Dec 2018 10:58:53 -0500 Received: from smtp03.citrix.com ([162.221.156.55]:60104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gWkQs-0004QM-0K; Tue, 11 Dec 2018 10:58:50 -0500 X-IronPort-AV: E=Sophos;i="5.56,342,1539648000"; d="scan'208";a="73004769" From: Paul Durrant To: , , Date: Tue, 11 Dec 2018 15:57:38 +0000 Message-ID: <1544543862-9997-15-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1544543862-9997-1-git-send-email-paul.durrant@citrix.com> References: <1544543862-9997-1-git-send-email-paul.durrant@citrix.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 162.221.156.55 Subject: [Qemu-devel] [PATCH v4 14/18] xen: add implementations of xen-block connect and disconnect functions... X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anthony Perard , Kevin Wolf , Paul Durrant , Stefano Stabellini , Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" ...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 Reviewed-by: Anthony PERARD --- Cc: Stefano Stabellini Cc: Anthony Perard Cc: Kevin Wolf Cc: Max Reitz v3: - Add missing return statement to xen_block_realize() - Set device name to 'vbd' now the backend is functional - Add an unplug handler - Move backend watch code from subsequent patch since it's now needed to handle unplug v2: - Tidy up header inclusions - Stop leaking ring_ref on error - Auto-create drive for CDRom devices --- hw/block/xen-block.c | 166 ++++++++++++++++++++++++++++++++++++++++ hw/xen/trace-events | 3 + hw/xen/xen-bus.c | 187 +++++++++++++++++++++++++++++++++++++++------ include/hw/xen/xen-block.h | 9 +++ include/hw/xen/xen-bus.h | 14 +++- 5 files changed, 353 insertions(+), 26 deletions(-) diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index 5932672..f3d21c6 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -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->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->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->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); } @@ -69,6 +144,7 @@ static void xen_block_realize(XenDevice *xendev, Error **errp) const char *type = object_get_typename(OBJECT(blockdev)); XenBlockVdev *vdev = &blockdev->vdev; Error *local_err = NULL; + BlockConf *conf = &blockdev->conf; if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { error_setg(errp, "vdev property not set"); @@ -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->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->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, vdev, xen_block_prop_vdev, XenBlockVdev), + DEFINE_BLOCK_PROPERTIES(XenBlockDevice, conf), + DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice, + max_ring_page_order, 4), + DEFINE_PROP_LINK("iothread", XenBlockDevice, 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->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->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) diff --git a/hw/xen/trace-events b/hw/xen/trace-events index 22055b5..d4651bd 100644 --- a/hw/xen/trace-events +++ b/hw/xen/trace-events @@ -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" diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 9443f27..a22aa49 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -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) @@ -822,9 +959,9 @@ 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", diff --git a/include/hw/xen/xen-block.h b/include/hw/xen/xen-block.h index 067932a..37ed8a6 100644 --- a/include/hw/xen/xen-block.h +++ b/include/hw/xen/xen-block.h @@ -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, @@ -29,6 +32,12 @@ typedef struct XenBlockVdev { typedef struct XenBlockDevice { XenDevice xendev; XenBlockVdev vdev; + BlockConf conf; + const char *device_type; + unsigned int info; + unsigned int max_ring_page_order; + IOThread *iothread; + XenBlockDataPlane *dataplane; } XenBlockDevice; typedef void (*XenBlockDeviceRealize)(XenBlockDevice *blockdev, Error **errp); diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h index f83a95c..0834cb3 100644 --- a/include/hw/xen/xen-bus.h +++ b/include/hw/xen/xen-bus.h @@ -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; @@ -84,6 +86,16 @@ 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,