From patchwork Fri Sep 13 08:20:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11144057 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A9E1E1599 for ; Fri, 13 Sep 2019 08:22:10 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8204E207FC for ; Fri, 13 Sep 2019 08:22:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="iSNBXhtw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8204E207FC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:41156 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8gqG-0004qG-SV for patchwork-qemu-devel@patchwork.kernel.org; Fri, 13 Sep 2019 04:22:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43470) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8gp1-0003Qx-PR for qemu-devel@nongnu.org; Fri, 13 Sep 2019 04:20:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i8gp0-0001fO-4p for qemu-devel@nongnu.org; Fri, 13 Sep 2019 04:20:51 -0400 Received: from esa2.hc3370-68.iphmx.com ([216.71.145.153]:19379) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i8goz-0001eN-Tb for qemu-devel@nongnu.org; Fri, 13 Sep 2019 04:20:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1568362850; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6PlZ2lXpbh2CSB2DLWsfrhSBmytgBCKnemkIarlXGh4=; b=iSNBXhtwQ2JLyrounsamvY8ibLxOTf1Jo+lWsxG9UMwAMCFGWtxlutYJ +JlxRfynHqbyQ1unzjQLmpPh/SWNoKaoKwKusPgE/Z2aMix7a6RVrINv6 N0drEWfdfbnWNsnXJGtJUmHJBp1A2vlGxGa3MpH+44AzLD+zhml0pc3Ee E=; Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=paul.durrant@citrix.com; spf=Pass smtp.mailfrom=Paul.Durrant@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa2.hc3370-68.iphmx.com: no sender authenticity information available from domain of paul.durrant@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="Paul.Durrant@citrix.com"; x-sender="paul.durrant@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa2.hc3370-68.iphmx.com: domain of Paul.Durrant@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="Paul.Durrant@citrix.com"; x-sender="Paul.Durrant@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ~all" Received-SPF: None (esa2.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="Paul.Durrant@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: JvH9zJMIc1Jqc8eZ9wN7XhYgshMbSOEmpWZsCHHxfjz8n4DFk++dvzDDuIcC/GDJLwpGmEdKCb Bl1dBFB9z2rrwEB8mv8cbocpd6Pi7fZhAhL8vI2vljIfjkgVvifzHvngPWD66BrGKK6RZSocIp aEegCPSFY77SDeR+keLtK+RRR8VVoUjT+Iip8VklMzXjAqSXxV5Lq4oUVyjinrm3I8vggfbION hx17cxOVLA+q0UvIKrBO8m55CTADYXmfxc2VcTizXE0dm4oqe4m5/Yw+kfJFX7+XykuUr1TRNR trA= X-SBRS: 2.7 X-MesageID: 5522405 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.64,500,1559534400"; d="scan'208";a="5522405" From: Paul Durrant To: , Date: Fri, 13 Sep 2019 09:20:41 +0100 Message-ID: <20190913082043.31288-2-paul.durrant@citrix.com> X-Mailer: git-send-email 2.20.1.2.gb21ebb6 In-Reply-To: <20190913082043.31288-1-paul.durrant@citrix.com> References: <20190913082043.31288-1-paul.durrant@citrix.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x X-Received-From: 216.71.145.153 Subject: [Qemu-devel] [PATCH v3 1/3] xen / notify: introduce a new XenWatchList abstraction X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anthony Perard , Paul Durrant , Stefano Stabellini Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Xenstore watch call-backs are already abstracted away from XenBus using the XenWatch data structure but the associated NotifierList manipulation and file handle registration is still open coded in various xen_bus_...() functions. This patch creates a new XenWatchList data structure to allow these interactions to be abstracted away from XenBus as well. This is in preparation for a subsequent patch which will introduce separate watch lists for XenBus and XenDevice objects. NOTE: This patch also introduces a new notifier_list_empty() helper function for the purposes of adding an assertion that a XenWatchList is not freed whilst its associated NotifierList is still occupied. Signed-off-by: Paul Durrant Reviewed-by: Anthony Perard --- Cc: Stefano Stabellini --- hw/xen/trace-events | 5 +- hw/xen/xen-bus.c | 117 +++++++++++++++++++++++++-------------- include/hw/xen/xen-bus.h | 3 +- include/qemu/notify.h | 2 + util/notify.c | 5 ++ 5 files changed, 87 insertions(+), 45 deletions(-) diff --git a/hw/xen/trace-events b/hw/xen/trace-events index bc82ecb1a5..ac8d9c20d2 100644 --- a/hw/xen/trace-events +++ b/hw/xen/trace-events @@ -19,9 +19,8 @@ xen_bus_unrealize(void) "" xen_bus_enumerate(void) "" xen_bus_type_enumerate(const char *type) "type: %s" xen_bus_backend_create(const char *type, const char *path) "type: %s path: %s" -xen_bus_add_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s" -xen_bus_remove_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s" -xen_bus_watch(const char *token) "token: %s" +xen_bus_add_watch(const char *node, const char *key) "node: %s key: %s" +xen_bus_remove_watch(const char *node, const char *key) "node: %s key: %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" diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 025df5e59f..28efaccff2 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -157,18 +157,60 @@ static void free_watch(XenWatch *watch) g_free(watch); } -static XenWatch *xen_bus_add_watch(XenBus *xenbus, const char *node, - const char *key, XenWatchHandler handler, - void *opaque, Error **errp) +struct XenWatchList { + struct xs_handle *xsh; + NotifierList notifiers; +}; + +static void watch_list_event(void *opaque) +{ + XenWatchList *watch_list = opaque; + char **v; + const char *token; + + v = xs_check_watch(watch_list->xsh); + if (!v) { + return; + } + + token = v[XS_WATCH_TOKEN]; + + notifier_list_notify(&watch_list->notifiers, (void *)token); + + free(v); +} + +static XenWatchList *watch_list_create(struct xs_handle *xsh) +{ + XenWatchList *watch_list = g_new0(XenWatchList, 1); + + g_assert(xsh); + + watch_list->xsh = xsh; + notifier_list_init(&watch_list->notifiers); + qemu_set_fd_handler(xs_fileno(watch_list->xsh), watch_list_event, NULL, + watch_list); + + return watch_list; +} + +static void watch_list_destroy(XenWatchList *watch_list) +{ + g_assert(notifier_list_empty(&watch_list->notifiers)); + qemu_set_fd_handler(xs_fileno(watch_list->xsh), NULL, NULL, NULL); + g_free(watch_list); +} + +static XenWatch *watch_list_add(XenWatchList *watch_list, const char *node, + const char *key, XenWatchHandler handler, + void *opaque, Error **errp) { XenWatch *watch = new_watch(node, key, handler, opaque); Error *local_err = NULL; - trace_xen_bus_add_watch(watch->node, watch->key, watch->token); + notifier_list_add(&watch_list->notifiers, &watch->notifier); - notifier_list_add(&xenbus->watch_notifiers, &watch->notifier); - - xs_node_watch(xenbus->xsh, node, key, watch->token, &local_err); + xs_node_watch(watch_list->xsh, node, key, watch->token, &local_err); if (local_err) { error_propagate(errp, local_err); @@ -181,18 +223,34 @@ static XenWatch *xen_bus_add_watch(XenBus *xenbus, const char *node, return watch; } -static void xen_bus_remove_watch(XenBus *xenbus, XenWatch *watch, - Error **errp) +static void watch_list_remove(XenWatchList *watch_list, XenWatch *watch, + Error **errp) { - trace_xen_bus_remove_watch(watch->node, watch->key, watch->token); - - xs_node_unwatch(xenbus->xsh, watch->node, watch->key, watch->token, + xs_node_unwatch(watch_list->xsh, watch->node, watch->key, watch->token, errp); notifier_remove(&watch->notifier); free_watch(watch); } +static XenWatch *xen_bus_add_watch(XenBus *xenbus, const char *node, + const char *key, XenWatchHandler handler, + void *opaque, Error **errp) +{ + trace_xen_bus_add_watch(node, key); + + return watch_list_add(xenbus->watch_list, node, key, handler, opaque, + errp); +} + +static void xen_bus_remove_watch(XenBus *xenbus, XenWatch *watch, + Error **errp) +{ + trace_xen_bus_remove_watch(watch->node, watch->key); + + watch_list_remove(xenbus->watch_list, watch, errp); +} + static void xen_bus_backend_create(XenBus *xenbus, const char *type, const char *name, char *path, Error **errp) @@ -338,35 +396,14 @@ static void xen_bus_unrealize(BusState *bus, Error **errp) xenbus->backend_watch = NULL; } - if (!xenbus->xsh) { - return; + if (xenbus->watch_list) { + watch_list_destroy(xenbus->watch_list); + xenbus->watch_list = NULL; } - qemu_set_fd_handler(xs_fileno(xenbus->xsh), NULL, NULL, NULL); - - xs_close(xenbus->xsh); -} - -static void xen_bus_watch(void *opaque) -{ - XenBus *xenbus = opaque; - char **v; - const char *token; - - g_assert(xenbus->xsh); - - v = xs_check_watch(xenbus->xsh); - if (!v) { - return; + if (xenbus->xsh) { + xs_close(xenbus->xsh); } - - token = v[XS_WATCH_TOKEN]; - - trace_xen_bus_watch(token); - - notifier_list_notify(&xenbus->watch_notifiers, (void *)token); - - free(v); } static void xen_bus_realize(BusState *bus, Error **errp) @@ -390,9 +427,7 @@ static void xen_bus_realize(BusState *bus, Error **errp) xenbus->backend_id = 0; /* Assume lack of node means dom0 */ } - notifier_list_init(&xenbus->watch_notifiers); - qemu_set_fd_handler(xs_fileno(xenbus->xsh), xen_bus_watch, NULL, - xenbus); + xenbus->watch_list = watch_list_create(xenbus->xsh); module_call_init(MODULE_INIT_XEN_BACKEND); diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h index 1c2d9dfdb8..88b84e29bb 100644 --- a/include/hw/xen/xen-bus.h +++ b/include/hw/xen/xen-bus.h @@ -14,6 +14,7 @@ typedef void (*XenWatchHandler)(void *opaque); +typedef struct XenWatchList XenWatchList; typedef struct XenWatch XenWatch; typedef struct XenEventChannel XenEventChannel; @@ -63,7 +64,7 @@ typedef struct XenBus { BusState qbus; domid_t backend_id; struct xs_handle *xsh; - NotifierList watch_notifiers; + XenWatchList *watch_list; XenWatch *backend_watch; } XenBus; diff --git a/include/qemu/notify.h b/include/qemu/notify.h index a3d73e4bc7..bcfa70fb2e 100644 --- a/include/qemu/notify.h +++ b/include/qemu/notify.h @@ -40,6 +40,8 @@ void notifier_remove(Notifier *notifier); void notifier_list_notify(NotifierList *list, void *data); +bool notifier_list_empty(NotifierList *list); + /* Same as Notifier but allows .notify() to return errors */ typedef struct NotifierWithReturn NotifierWithReturn; diff --git a/util/notify.c b/util/notify.c index aee8d93cb0..76bab212ae 100644 --- a/util/notify.c +++ b/util/notify.c @@ -40,6 +40,11 @@ void notifier_list_notify(NotifierList *list, void *data) } } +bool notifier_list_empty(NotifierList *list) +{ + return QLIST_EMPTY(&list->notifiers); +} + void notifier_with_return_list_init(NotifierWithReturnList *list) { QLIST_INIT(&list->notifiers);