Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAndy Whitcroft <apw@canonical.com>2012-05-04 22:15:11 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-17 11:21:29 -0700
commit0d48d35de9b7dbe7e68d2a741c2f8d6a9e2eed3f (patch)
tree9ff276a43a413e6732d01222a35b5dbcfb60fa51
parent54a40b2cf40d655dbbdcc017288be75b1ae1b701 (diff)
ata_piix: defer disks to the Hyper-V drivers by default
commit cd006086fa5d91414d8ff9ff2b78fbb593878e3c upstream. 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 <apw@canonical.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Cc: Victor Miasnikov <vvm@tut.by> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/ata/ata_piix.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index 7857e8fd0a3e..3c809bfbccf5 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1554,6 +1554,39 @@ 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
@@ -1669,6 +1702,9 @@ 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);
}