This is a note to let you know that I've just added the patch titled
ata_piix: defer disks to the Hyper-V drivers by default
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ata_piix-defer-disks-to-the-hyper-v-drivers-by-default.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From cd006086fa5d91414d8ff9ff2b78fbb593878e3c Mon Sep 17 00:00:00 2001
From: Andy Whitcroft <[email protected]>
Date: Fri, 4 May 2012 22:15:11 +0100
Subject: ata_piix: defer disks to the Hyper-V drivers by default
From: Andy Whitcroft <[email protected]>
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 <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
Cc: Victor Miasnikov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/ata/ata_piix.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1554,6 +1554,39 @@ static bool piix_broken_system_poweroff(
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(struc
}
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);
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.4/libata-add-a-host-flag-to-ignore-detected-ata-devices.patch
queue-3.4/ata_piix-defer-disks-to-the-hyper-v-drivers-by-default.patch
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