From patchwork Thu Jun 22 19:14:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 9805179 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id F044C600C5 for ; Thu, 22 Jun 2017 19:16:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DF1E226E3A for ; Thu, 22 Jun 2017 19:16:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D00232522B; Thu, 22 Jun 2017 19:16:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 604B22522B for ; Thu, 22 Jun 2017 19:16:41 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dO7Yo-0007wd-OH; Thu, 22 Jun 2017 19:14:34 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dO7Yn-0007v2-Ql for xen-devel@lists.xen.org; Thu, 22 Jun 2017 19:14:33 +0000 Received: from [193.109.254.147] by server-4.bemta-6.messagelabs.com id BA/2E-02956-9171C495; Thu, 22 Jun 2017 19:14:33 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrJLMWRWlGSWpSXmKPExsVybKJssq6EuE+ kwdknyhZLPi5mcWD0OLr7N1MAYxRrZl5SfkUCa8bjh0YFP1Qqnsw4xdzA+Equi5GLQ0igjUni aftf5i5GTg4WAQeJC49vsHYxcnAwCsRIPPhhDRJmFAiTmHx5CSuIzSZgKPH3ySY2EFtEQFri2 ufLjCBzmAUmM0q8fvcLbI6wgI3EyduT2EHmsAioSrTv9AAJ8wq4SSz9cZIRxJYQkJM4eWwy2E xOAXeJpuZzbBD3tDNK9H5+yT6BkXcBI8MqRo3i1KKy1CJdQ2O9pKLM9IyS3MTMHF1DAzO93NT i4sT01JzEpGK95PzcTYzAYGAAgh2MX5YFHGKU5GBSEuXdXOwdKcSXlJ9SmZFYnBFfVJqTWnyI UYaDQ0mC96OoT6SQYFFqempFWmYOMCxh0hIcPEoivF/4gNK8xQWJucWZ6RCpU4y6HBtWr//CJ MSSl5+XKiXOextkhgBIUUZpHtwIWIxcYpSVEuZlBDpKiKcgtSg3swRV/hWjOAejkjCvkRjQFJ 7MvBK4Ta+AjmACOuLFEQ+QI0oSEVJSDYyKk3cfeLkn9m+8/QLuDPdggd2LdS7KFzDI5srP4Zm 27sTx+R+qz93br/ZijZyo83or/YPsi1tuil3Wzd82f7N2pMOL9KAUj9T/YR9ObGpTynllVHyD rWCK33uZpVpc10or5x9IfRoj8PzApAnzxQM/PsrmEyqU7oquDGfe9l/irMaS5oSAl5uUWIozE g21mIuKEwG4VqCPjAIAAA== X-Env-Sender: sstabellini@kernel.org X-Msg-Ref: server-9.tower-27.messagelabs.com!1498158871!109152036!1 X-Originating-IP: [198.145.29.99] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.4.19; banners=-,-,- X-VirusChecked: Checked Received: (qmail 65065 invoked from network); 22 Jun 2017 19:14:32 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.99) by server-9.tower-27.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 22 Jun 2017 19:14:32 -0000 Received: from localhost.localdomain (unknown [99.165.194.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A8CFD22B68; Thu, 22 Jun 2017 19:14:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8CFD22B68 From: Stefano Stabellini To: xen-devel@lists.xen.org Date: Thu, 22 Jun 2017 12:14:13 -0700 Message-Id: <1498158867-25426-4-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1498158867-25426-1-git-send-email-sstabellini@kernel.org> References: <1498158867-25426-1-git-send-email-sstabellini@kernel.org> Cc: jgross@suse.com, Stefano Stabellini , boris.ostrovsky@oracle.com, sstabellini@kernel.org, linux-kernel@vger.kernel.org Subject: [Xen-devel] [PATCH v5 04/18] xen/pvcalls: xenbus state handling X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Introduce the code to handle xenbus state changes. Implement the probe function for the pvcalls backend. Write the supported versions, max-page-order and function-calls nodes to xenstore, as required by the protocol. Introduce stub functions for disconnecting/connecting to a frontend. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-back.c | 152 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index 9044cf2..7bce750 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -25,20 +25,172 @@ #include #include +#define PVCALLS_VERSIONS "1" +#define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER + struct pvcalls_back_global { struct list_head frontends; struct semaphore frontends_lock; } pvcalls_back_global; +static int backend_connect(struct xenbus_device *dev) +{ + return 0; +} + +static int backend_disconnect(struct xenbus_device *dev) +{ + return 0; +} + static int pvcalls_back_probe(struct xenbus_device *dev, const struct xenbus_device_id *id) { + int err, abort; + struct xenbus_transaction xbt; + +again: + abort = 1; + + err = xenbus_transaction_start(&xbt); + if (err) { + pr_warn("%s cannot create xenstore transaction\n", __func__); + return err; + } + + err = xenbus_printf(xbt, dev->nodename, "versions", "%s", + PVCALLS_VERSIONS); + if (err) { + pr_warn("%s write out 'version' failed\n", __func__); + goto abort; + } + + err = xenbus_printf(xbt, dev->nodename, "max-page-order", "%u", + MAX_RING_ORDER); + if (err) { + pr_warn("%s write out 'max-page-order' failed\n", __func__); + goto abort; + } + + err = xenbus_printf(xbt, dev->nodename, "function-calls", + XENBUS_FUNCTIONS_CALLS); + if (err) { + pr_warn("%s write out 'function-calls' failed\n", __func__); + goto abort; + } + + abort = 0; +abort: + err = xenbus_transaction_end(xbt, abort); + if (err) { + if (err == -EAGAIN && !abort) + goto again; + pr_warn("%s cannot complete xenstore transaction\n", __func__); + return err; + } + + xenbus_switch_state(dev, XenbusStateInitWait); + return 0; } +static void set_backend_state(struct xenbus_device *dev, + enum xenbus_state state) +{ + while (dev->state != state) { + switch (dev->state) { + case XenbusStateClosed: + switch (state) { + case XenbusStateInitWait: + case XenbusStateConnected: + xenbus_switch_state(dev, XenbusStateInitWait); + break; + case XenbusStateClosing: + xenbus_switch_state(dev, XenbusStateClosing); + break; + default: + __WARN(); + } + break; + case XenbusStateInitWait: + case XenbusStateInitialised: + switch (state) { + case XenbusStateConnected: + backend_connect(dev); + xenbus_switch_state(dev, XenbusStateConnected); + break; + case XenbusStateClosing: + case XenbusStateClosed: + xenbus_switch_state(dev, XenbusStateClosing); + break; + default: + __WARN(); + } + break; + case XenbusStateConnected: + switch (state) { + case XenbusStateInitWait: + case XenbusStateClosing: + case XenbusStateClosed: + down(&pvcalls_back_global.frontends_lock); + backend_disconnect(dev); + up(&pvcalls_back_global.frontends_lock); + xenbus_switch_state(dev, XenbusStateClosing); + break; + default: + __WARN(); + } + break; + case XenbusStateClosing: + switch (state) { + case XenbusStateInitWait: + case XenbusStateConnected: + case XenbusStateClosed: + xenbus_switch_state(dev, XenbusStateClosed); + break; + default: + __WARN(); + } + break; + default: + __WARN(); + } + } +} + static void pvcalls_back_changed(struct xenbus_device *dev, enum xenbus_state frontend_state) { + switch (frontend_state) { + case XenbusStateInitialising: + set_backend_state(dev, XenbusStateInitWait); + break; + + case XenbusStateInitialised: + case XenbusStateConnected: + set_backend_state(dev, XenbusStateConnected); + break; + + case XenbusStateClosing: + set_backend_state(dev, XenbusStateClosing); + break; + + case XenbusStateClosed: + set_backend_state(dev, XenbusStateClosed); + if (xenbus_dev_is_online(dev)) + break; + device_unregister(&dev->dev); + break; + case XenbusStateUnknown: + set_backend_state(dev, XenbusStateClosed); + device_unregister(&dev->dev); + break; + + default: + xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", + frontend_state); + break; + } } static int pvcalls_back_remove(struct xenbus_device *dev)