From patchwork Fri May 4 21:15:11 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Whitcroft X-Patchwork-Id: 156993 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 54847B6F62 for ; Sat, 5 May 2012 07:16:12 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932267Ab2EDVPT (ORCPT ); Fri, 4 May 2012 17:15:19 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:33149 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932237Ab2EDVPR (ORCPT ); Fri, 4 May 2012 17:15:17 -0400 Received: from 79-78-211-128.dynamic.dsl.as9105.com ([79.78.211.128] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1SQPqN-00076I-S1; Fri, 04 May 2012 21:15:16 +0000 From: Andy Whitcroft To: Jeff Garzik , linux-ide@vger.kernel.org Cc: Andy Whitcroft , linux-kernel@vger.kernel.org, "K. Y. Srinivasan" , Mike Sterling , Alan Cox Subject: [PATCH 2/2] ata_piix: defer disks to the Hyper-V drivers by default Date: Fri, 4 May 2012 22:15:11 +0100 Message-Id: <1336166111-20483-3-git-send-email-apw@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1336166111-20483-1-git-send-email-apw@canonical.com> References: <4F903529.40800@mvista.com> <1336166111-20483-1-git-send-email-apw@canonical.com> Sender: linux-ide-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org When we are hosted on a Microsoft Hyper-V hypervisor the guest disks are exposed both via the Hyper-V paravirtualised drivers and via an emulated SATA disk drive. In this case we want to use the paravirtualised drivers if we can as they are much more efficient. Note that the Hyper-V paravirtualised drivers only expose the virtual hard disk devices, the CDROM/DVD devices must still be enumerated. Mark the host controller ATA_HOST_IGNORE_ATA to prevent enumeration of disk devices. BugLink: http://bugs.launchpad.net/bugs/929545 BugLink: http://bugs.launchpad.net/bugs/942316 Signed-off-by: Andy Whitcroft --- drivers/ata/ata_piix.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c index 68013f9..8fea06b 100644 --- a/drivers/ata/ata_piix.c +++ b/drivers/ata/ata_piix.c @@ -1552,6 +1552,39 @@ static bool piix_broken_system_poweroff(struct pci_dev *pdev) return false; } +static int prefer_ms_hyperv = 1; +module_param(prefer_ms_hyperv, int, 0); + +static void piix_ignore_devices_quirk(struct ata_host *host) +{ +#if IS_ENABLED(CONFIG_HYPERV_STORAGE) + static const struct dmi_system_id ignore_hyperv[] = { + { + /* On Hyper-V hypervisors the disks are exposed on + * both the emulated SATA controller and on the + * paravirtualised drivers. The CD/DVD devices + * are only exposed on the emulated controller. + * Request we ignore ATA devices on this host. + */ + .ident = "Hyper-V Virtual Machine", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, + "Microsoft Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "Virtual Machine"), + }, + }, + { } /* terminate list */ + }; + const struct dmi_system_id *dmi = dmi_first_match(ignore_hyperv); + + if (dmi && prefer_ms_hyperv) { + host->flags |= ATA_HOST_IGNORE_ATA; + dev_info(host->dev, "%s detected, ATA device ignore set\n", + dmi->ident); + } +#endif +} + /** * piix_init_one - Register PIIX ATA PCI device with kernel services * @pdev: PCI device to register @@ -1667,6 +1700,9 @@ static int __devinit piix_init_one(struct pci_dev *pdev, } host->flags |= ATA_HOST_PARALLEL_SCAN; + /* Allow hosts to specify device types to ignore when scanning. */ + piix_ignore_devices_quirk(host); + pci_set_master(pdev); return ata_pci_sff_activate_host(host, ata_bmdma_interrupt, sht); }