From patchwork Fri Jun 17 06:36:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 636813 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rW9vX154lz9t21 for ; Fri, 17 Jun 2016 16:53:44 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b=UbUEJt5s; dkim-atps=neutral Received: from localhost ([::1]:54303 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDnew-0007gG-3H for incoming@patchwork.ozlabs.org; Fri, 17 Jun 2016 02:53:42 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50433) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDnN4-0005bd-EY for qemu-devel@nongnu.org; Fri, 17 Jun 2016 02:35:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bDnMy-0008FC-JV for qemu-devel@nongnu.org; Fri, 17 Jun 2016 02:35:13 -0400 Received: from ozlabs.org ([103.22.144.67]:45507) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDnMy-0008CU-8n; Fri, 17 Jun 2016 02:35:08 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 3rW9Tt6CF1z9t2H; Fri, 17 Jun 2016 16:34:58 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1466145298; bh=USV22Pxn4Fihpk5oLhE48hRYIX66YWPDca++8O81H7A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UbUEJt5sOIhOdu9IABPeffp0KKM45PB2nr/z+YYprdaGDzPJ4LlcrtzbHwCLRSiNk UJnyxXwVeLsAgGldiib7pBquYOXVoIRdaMhikViI0AY0MbEW3En8rlOqzqS2GnvR5t ifdJXmt/ww8ymfFMGmX0+lGRzfacZFUJSU9Thg90= From: David Gibson To: peter.maydell@linaro.org Date: Fri, 17 Jun 2016 16:36:30 +1000 Message-Id: <1466145399-32209-10-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1466145399-32209-1-git-send-email-david@gibson.dropbear.id.au> References: <1466145399-32209-1-git-send-email-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 103.22.144.67 Subject: [Qemu-devel] [PULL 09/18] 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: qemu-devel@nongnu.org, aik@ozlabs.ru, mdroth@linux.vnet.ibm.com, agraf@suse.de, qemu-ppc@nongnu.org, bharata@linux.vnet.ibm.com, imammedo@redhat.com, David Gibson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Bharata B Rao 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] Signed-off-by: David Gibson --- 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 94c875d..d276db3a 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; @@ -373,6 +375,10 @@ 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), @@ -421,6 +427,12 @@ 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;