From patchwork Mon Jun 24 15:32:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony PERARD X-Patchwork-Id: 11013689 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ABD936C5 for ; Mon, 24 Jun 2019 15:35:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9ADBC28BB8 for ; Mon, 24 Jun 2019 15:35:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8F1F928BC4; Mon, 24 Jun 2019 15:35:23 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E6AEE28BB3 for ; Mon, 24 Jun 2019 15:35:21 +0000 (UTC) Received: from localhost ([::1]:52392 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfR05-0005Rg-99 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 24 Jun 2019 11:35:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44889) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfQy2-0003XC-FL for qemu-devel@nongnu.org; Mon, 24 Jun 2019 11:33:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hfQy0-0000NZ-JM for qemu-devel@nongnu.org; Mon, 24 Jun 2019 11:33:14 -0400 Received: from esa3.hc3370-68.iphmx.com ([216.71.145.155]:11953) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hfQy0-0000JY-5X for qemu-devel@nongnu.org; Mon, 24 Jun 2019 11:33:12 -0400 Authentication-Results: esa3.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=anthony.perard@citrix.com; spf=Pass smtp.mailfrom=anthony.perard@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa3.hc3370-68.iphmx.com: no sender authenticity information available from domain of anthony.perard@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa3.hc3370-68.iphmx.com; envelope-from="anthony.perard@citrix.com"; x-sender="anthony.perard@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa3.hc3370-68.iphmx.com: domain of anthony.perard@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa3.hc3370-68.iphmx.com; envelope-from="anthony.perard@citrix.com"; x-sender="anthony.perard@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 (esa3.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=esa3.hc3370-68.iphmx.com; envelope-from="anthony.perard@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: 6XlC+kfUtMxsI8oTe0+5atL7DmyD1sz2vK1kvMokSAcBeJ9YpKBeTXj7eWQaYqeRNdbo2oVFc6 g/IKHty2USXEUYbu+b/4rSFnAM02FMZXjtotfE+heHswqbdgtcVhggVxETPd/V60KyvuwSkoAY YfijP97pVCWU4VfN0dtQF/9kSI70yqls3WQbdt6ax7d8MkhMDT4oBMrgEDEoRgtX+sd2EOFTic TKdSOjLQteeW8/G6N9mv2I+6AsMdOb5P7am9sHO7rL0RFoyKcjLcOtLjVSnTnFlmwgDH6tt/TS Snk= X-SBRS: 2.7 X-MesageID: 2148099 X-Ironport-Server: esa3.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.63,412,1557201600"; d="scan'208";a="2148099" From: Anthony PERARD To: Date: Mon, 24 Jun 2019 16:32:53 +0100 Message-ID: <20190624153257.20163-5-anthony.perard@citrix.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190624153257.20163-1-anthony.perard@citrix.com> References: <20190624153257.20163-1-anthony.perard@citrix.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x X-Received-From: 216.71.145.155 Subject: [Qemu-devel] [PULL 4/8] xen-bus / xen-block: add support for event channel polling 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 , xen-devel@lists.xenproject.org, Peter Maydell Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Paul Durrant This patch introduces a poll callback for event channel fd-s and uses this to invoke the channel callback function. To properly support polling, it is necessary for the event channel callback function to return a boolean saying whether it has done any useful work or not. Thus xen_block_dataplane_event() is modified to directly invoke xen_block_handle_requests() and the latter only returns true if it actually processes any requests. This also means that the call to qemu_bh_schedule() is moved into xen_block_complete_aio(), which is more intuitive since the only reason for doing a deferred poll of the shared ring should be because there were previously insufficient resources to fully complete a previous poll. Signed-off-by: Paul Durrant Reviewed-by: Anthony PERARD Message-Id: <20190408151617.13025-4-paul.durrant@citrix.com> Signed-off-by: Anthony PERARD --- hw/block/dataplane/xen-block.c | 17 +++++++++-------- hw/xen/xen-bus.c | 11 +++++++++-- include/hw/xen/xen-bus.h | 2 +- 3 files changed, 19 insertions(+), 11 deletions(-) diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c index aadca75644..0f200c5fb0 100644 --- a/hw/block/dataplane/xen-block.c +++ b/hw/block/dataplane/xen-block.c @@ -318,7 +318,9 @@ static void xen_block_complete_aio(void *opaque, int ret) } xen_block_release_request(request); - qemu_bh_schedule(dataplane->bh); + if (dataplane->more_work) { + qemu_bh_schedule(dataplane->bh); + } done: aio_context_release(dataplane->ctx); @@ -515,12 +517,13 @@ static int xen_block_get_request(XenBlockDataPlane *dataplane, */ #define IO_PLUG_THRESHOLD 1 -static void xen_block_handle_requests(XenBlockDataPlane *dataplane) +static bool xen_block_handle_requests(XenBlockDataPlane *dataplane) { RING_IDX rc, rp; XenBlockRequest *request; int inflight_atstart = dataplane->requests_inflight; int batched = 0; + bool done_something = false; dataplane->more_work = 0; @@ -552,6 +555,7 @@ static void xen_block_handle_requests(XenBlockDataPlane *dataplane) } xen_block_get_request(dataplane, request, rc); dataplane->rings.common.req_cons = ++rc; + done_something = true; /* parse them */ if (xen_block_parse_request(request) != 0) { @@ -603,10 +607,7 @@ static void xen_block_handle_requests(XenBlockDataPlane *dataplane) blk_io_unplug(dataplane->blk); } - if (dataplane->more_work && - dataplane->requests_inflight < dataplane->max_requests) { - qemu_bh_schedule(dataplane->bh); - } + return done_something; } static void xen_block_dataplane_bh(void *opaque) @@ -618,11 +619,11 @@ static void xen_block_dataplane_bh(void *opaque) aio_context_release(dataplane->ctx); } -static void xen_block_dataplane_event(void *opaque) +static bool xen_block_dataplane_event(void *opaque) { XenBlockDataPlane *dataplane = opaque; - qemu_bh_schedule(dataplane->bh); + return xen_block_handle_requests(dataplane); } XenBlockDataPlane *xen_block_dataplane_create(XenDevice *xendev, diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 2210526490..7503eea9e9 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -932,13 +932,20 @@ struct XenEventChannel { void *opaque; }; +static bool xen_device_poll(void *opaque) +{ + XenEventChannel *channel = opaque; + + return channel->handler(channel->opaque); +} + static void xen_device_event(void *opaque) { XenEventChannel *channel = opaque; unsigned long port = xenevtchn_pending(channel->xeh); if (port == channel->local_port) { - channel->handler(channel->opaque); + xen_device_poll(channel); xenevtchn_unmask(channel->xeh, port); } @@ -973,7 +980,7 @@ XenEventChannel *xen_device_bind_event_channel(XenDevice *xendev, channel->ctx = ctx; aio_set_fd_handler(channel->ctx, xenevtchn_fd(channel->xeh), true, - xen_device_event, NULL, NULL, channel); + xen_device_event, NULL, xen_device_poll, channel); QLIST_INSERT_HEAD(&xendev->event_channels, channel, list); diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h index 8183b98c7d..1c2d9dfdb8 100644 --- a/include/hw/xen/xen-bus.h +++ b/include/hw/xen/xen-bus.h @@ -119,7 +119,7 @@ void xen_device_copy_grant_refs(XenDevice *xendev, bool to_domain, XenDeviceGrantCopySegment segs[], unsigned int nr_segs, Error **errp); -typedef void (*XenEventHandler)(void *opaque); +typedef bool (*XenEventHandler)(void *opaque); XenEventChannel *xen_device_bind_event_channel(XenDevice *xendev, AioContext *ctx,