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 <o...@aepfle.de>
---
hw/i386/xen/xen_platform.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index aa78393..53be3c7 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -114,6 +114,10 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
PCI_CLASS_STORAGE_IDE
&& 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));
}
}
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
