From patchwork Fri Oct 1 08:25:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 12529883 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51190C433F5 for ; Fri, 1 Oct 2021 08:28:47 +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 026A961267 for ; Fri, 1 Oct 2021 08:28:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 026A961267 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:57652 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mWDuQ-0007I6-4S for qemu-devel@archiver.kernel.org; Fri, 01 Oct 2021 04:28:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50018) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mWDr8-0004WW-SB for qemu-devel@nongnu.org; Fri, 01 Oct 2021 04:25:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:39421) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mWDr2-0007Tt-Fj for qemu-devel@nongnu.org; Fri, 01 Oct 2021 04:25:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633076713; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=02VRuu+jbIJ5WWM36RzPFfnTYUvx0Hx5/oV8ujMoAjA=; b=QdU54voITG+Pcp3zbC/uznIZGID6MKy916os3VY8RKtt9ObL2cT57vNKfUfP79ZHLEFcbY iUHwv2Vu4bX+VqJs+iFcKKtH17npuDWcs5ekch3Be0Js729lwFkB8E+Qvy86vrDUeqLLeU Ob1XxFqKXr/uqk0xJJKm7HticVDyNcE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-420-e7G-pvVPMK-L-HOk7szwcw-1; Fri, 01 Oct 2021 04:25:09 -0400 X-MC-Unique: e7G-pvVPMK-L-HOk7szwcw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4FEACCC623; Fri, 1 Oct 2021 08:25:05 +0000 (UTC) Received: from thinkpad.redhat.com (unknown [10.39.192.246]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8403B102AE4B; Fri, 1 Oct 2021 08:25:03 +0000 (UTC) From: Laurent Vivier To: qemu-devel@nongnu.org Subject: [PATCH v3] failover: fix unplug pending detection Date: Fri, 1 Oct 2021 10:25:02 +0200 Message-Id: <20211001082502.1342878-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lvivier@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=lvivier@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: Ani Sinha , Igor Mammedov , Jens Freimann , Juan Quintela , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Failover needs to detect the end of the PCI unplug to start migration after the VFIO card has been unplugged. To do that, a flag is set in pcie_cap_slot_unplug_request_cb() and reset in pcie_unplug_device(). But since 17858a169508 ("hw/acpi/ich9: Set ACPI PCI hot-plug as default on Q35") we have switched to ACPI unplug and these functions are not called anymore and the flag not set. So failover migration is not able to detect if card is really unplugged and acts as it's done as soon as it's started. So it doesn't wait the end of the unplug to start the migration. We don't see any problem when we test that because ACPI unplug is faster than PCIe native hotplug and when the migration really starts the unplug operation is already done. See c000a9bd06ea ("pci: mark device having guest unplug request pending") a99c4da9fc2a ("pci: mark devices partially unplugged") Signed-off-by: Laurent Vivier Reviewed-by: Ani Sinha --- Notes: v3: add some inlined comments to explain partially_hotplugged and pending_deleted_event v2: move partially_hotplugged to acpi_pcihp_eject_slot() hw/acpi/pcihp.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c index f610a25d2ef9..30405b5113d7 100644 --- a/hw/acpi/pcihp.c +++ b/hw/acpi/pcihp.c @@ -222,9 +222,27 @@ static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slo PCIDevice *dev = PCI_DEVICE(qdev); if (PCI_SLOT(dev->devfn) == slot) { if (!acpi_pcihp_pc_no_hotplug(s, dev)) { - hotplug_ctrl = qdev_get_hotplug_handler(qdev); - hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort); - object_unparent(OBJECT(qdev)); + /* + * partially_hotplugged is used by virtio-net failover: + * failover has asked the guest OS to unplug the device + * but we need to keep some references to the device + * to be able to plug it back in case of failure so + * we don't execute hotplug_handler_unplug(). + */ + if (dev->partially_hotplugged) { + /* + * pending_deleted_event is set to true when + * virtio-net failover asks to unplug the device, + * and set to false here when the operation is done + * This is used by the migration loop to detect the + * end of the operation and really start the migration. + */ + qdev->pending_deleted_event = false; + } else { + hotplug_ctrl = qdev_get_hotplug_handler(qdev); + hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort); + object_unparent(OBJECT(qdev)); + } } } } @@ -396,6 +414,12 @@ void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev, return; } + /* + * pending_deleted_event is used by virtio-net failover to detect the + * end of the unplug operation, the flag is set to false in + * acpi_pcihp_eject_slot() when the operation is completed. + */ + pdev->qdev.pending_deleted_event = true; s->acpi_pcihp_pci_status[bsel].down |= (1U << slot); acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS); }