File 0061-xen_platform-unplug-also-SCSI-disks.patch of Package qemu

From cec4bfa7796221b6a02b8f74490be71d4415dd8e Mon Sep 17 00:00:00 2001
From: Olaf Hering <olaf@aepfle.de>
Date: Thu, 1 Sep 2016 09:38:29 +0200
Subject: [PATCH] xen_platform: unplug also SCSI disks

References: bnc#953518 - disks added via SCSI controller are visible twice on HVM XEN guest systems

Using 'vdev=sd[a-o]' will create an emulated LSI controller, which can
be used by the emulated BIOS to boot from disk. If the HVM domU has also
PV driver the disk may appear twice in the guest. To avoid this an
unplug of the emulated hardware is needed, similar to what is done for
IDE and NIC drivers already.

Since the SCSI controller provides only disks the entire controller can
be unplugged at once.

Impact of the change for classic and pvops based guest kernels:

 vdev=sda:disk0
before: pvops:   disk0=pv xvda + emulated sda
        classic: disk0=pv sda  + emulated sdq
after:  pvops:   disk0=pv xvda
        classic: disk0=pv sda

 vdev=hda:disk0, vdev=sda:disk1
before: pvops:   disk0=pv xvda
                 disk1=emulated sda
        classic: disk0=pv hda
                 disk1=pv sda  + emulated sdq
after:  pvops:   disk0=pv xvda
                 disk1=not accessible by blkfront, index hda==index sda
        classic: disk0=pv hda
                 disk1=pv sda

 vdev=hda:disk0, vdev=sda:disk1, vdev=sdb:disk2
before: pvops:   disk0=pv xvda
                 disk1=emulated sda
                 disk2=pv xvdb + emulated sdb
        classic: disk0=pv hda
                 disk1=pv sda  + emulated sdq
                 disk2=pv sdb  + emulated sdr
after:  pvops:   disk0=pv xvda
                 disk1=not accessible by blkfront, index hda==index sda
                 disk2=pv xvdb
        classic: disk0=pv hda
                 disk1=pv sda
                 disk2=pv sda

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 hw/i386/xen/xen_platform.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index 48800c1..d15ef67 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -115,6 +115,11 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
             && strcmp(d->name, "xen-pci-passthrough") != 0) {
         pci_piix3_xen_ide_unplug(DEVICE(d));
     }
+    else if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
+            PCI_CLASS_STORAGE_SCSI
+            && strcmp(d->name, "xen-pci-passthrough") != 0) {
+        object_unparent(OBJECT(d));
+    }
 }
 
 static void pci_unplug_disks(PCIBus *bus)