From patchwork Thu May 12 03:48:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharata B Rao X-Patchwork-Id: 9076601 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 685299F1C3 for ; Thu, 12 May 2016 03:53:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C4ABB201C7 for ; Thu, 12 May 2016 03:53:42 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 07824201D3 for ; Thu, 12 May 2016 03:53:42 +0000 (UTC) Received: from localhost ([::1]:55275 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0hgz-0006AU-7t for patchwork-qemu-devel@patchwork.kernel.org; Wed, 11 May 2016 23:53:41 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45957) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0hcS-00057C-OW for qemu-devel@nongnu.org; Wed, 11 May 2016 23:49:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b0hcO-0002Qu-D5 for qemu-devel@nongnu.org; Wed, 11 May 2016 23:48:59 -0400 Received: from e28smtp05.in.ibm.com ([125.16.236.5]:52261) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0hcN-0002QJ-MI for qemu-devel@nongnu.org; Wed, 11 May 2016 23:48:56 -0400 Received: from localhost by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 12 May 2016 09:18:52 +0530 X-IBM-Helo: d28dlp03.in.ibm.com X-IBM-MailFrom: bharata@linux.vnet.ibm.com X-IBM-RcptTo: qemu-devel@nongnu.org;qemu-ppc@nongnu.org Received: from d28relay06.in.ibm.com (d28relay06.in.ibm.com [9.184.220.150]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 17911125805E; Thu, 12 May 2016 09:20:59 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay06.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4C3moiL31785112; Thu, 12 May 2016 09:18:50 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4C3mjpF014384; Thu, 12 May 2016 09:18:49 +0530 Received: from bharata.in.ibm.com ([9.124.35.211]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u4C3mVWX013715; Thu, 12 May 2016 09:18:44 +0530 From: Bharata B Rao To: qemu-devel@nongnu.org Date: Thu, 12 May 2016 09:18:21 +0530 Message-Id: <1463024905-28401-12-git-send-email-bharata@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1463024905-28401-1-git-send-email-bharata@linux.vnet.ibm.com> References: <1463024905-28401-1-git-send-email-bharata@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16051203-0017-0000-0000-00001EC11B74 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 125.16.236.5 Subject: [Qemu-devel] [for-2.7 PATCH v3 11/15] spapr_drc: Prevent detach racing against attach for CPU DR 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: mjrosato@linux.vnet.ibm.com, thuth@redhat.com, pkrempa@redhat.com, ehabkost@redhat.com, aik@ozlabs.ru, Bharata B Rao , armbru@redhat.com, agraf@suse.de, borntraeger@de.ibm.com, qemu-ppc@nongnu.org, pbonzini@redhat.com, imammedo@redhat.com, mdroth@linux.vnet.ibm.com, afaerber@suse.de, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If a CPU is hot removed while hotplug of the same is still in progress, the guest crashes. Prevent this by ensuring that detach is done only after attach has completed. The existing code already prevents such race for PCI hotplug. However given that CPU is a logical DR unlike PCI and starts with ISOLATED state, we need a logic that works for CPU too. Signed-off-by: Bharata B Rao Reviewed-by: Michael Roth Signed-off-by: Michael Roth [Don't set awaiting_attach for PCI devices] --- hw/ppc/spapr_drc.c | 12 ++++++++++++ include/hw/ppc/spapr_drc.h | 1 + 2 files changed, 13 insertions(+) diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c index 1f5f1d7..e146267 100644 --- a/hw/ppc/spapr_drc.c +++ b/hw/ppc/spapr_drc.c @@ -140,6 +140,8 @@ static uint32_t set_allocation_state(sPAPRDRConnector *drc, DPRINTFN("finalizing device removal"); drck->detach(drc, DEVICE(drc->dev), drc->detach_cb, drc->detach_cb_opaque, NULL); + } else if (drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_USABLE) { + drc->awaiting_allocation = false; } } return RTAS_OUT_SUCCESS; @@ -376,6 +378,10 @@ static void attach(sPAPRDRConnector *drc, DeviceState *d, void *fdt, drc->signalled = (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI) ? true : coldplug; + if (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI) { + drc->awaiting_allocation = true; + } + object_property_add_link(OBJECT(drc), "device", object_get_typename(OBJECT(drc->dev)), (Object **)(&drc->dev), @@ -424,6 +430,12 @@ static void detach(sPAPRDRConnector *drc, DeviceState *d, return; } + if (drc->awaiting_allocation) { + drc->awaiting_release = true; + DPRINTFN("awaiting allocation to complete before removal"); + return; + } + drc->indicator_state = SPAPR_DR_INDICATOR_STATE_INACTIVE; if (drc->detach_cb) { diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h index fa21ba0..08e8411 100644 --- a/include/hw/ppc/spapr_drc.h +++ b/include/hw/ppc/spapr_drc.h @@ -152,6 +152,7 @@ typedef struct sPAPRDRConnector { bool awaiting_release; bool signalled; + bool awaiting_allocation; /* device pointer, via link property */ DeviceState *dev;