[Fedora-xen] virt-manager and Xen not presenting SATA AHCI disks to guests

Hello,

I have a Linux 3.2 VM panicking when trying to boot (HVM) on Xen.

I think this is related to the virtual storage controller that is presented to the VM.

The qcow2 image runs fine on KVM, but on Xen panics during boot with "VFS: Cannot open root device "(null)" or unknown-block(0,0)".

Both the KVM and Xen hosts are running stock Fedora 23, and virt-manager was used to configure both VMs.

To troubleshoot, I cycled the guest image through every permutation of disk type (IDE, SCSI, SATA) using virt-manager on both KVM and Xen.  Please see below for a difference between Xen and KVM.

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On Xen, the guest's boot menu reports the following for each disk type:

SATA disk: 

lsi 00:02.0 1:0 Drive QEMU QEMU HARDDISK 2.5+

Guest panics

SCSI disk: 

lsi 00:02.0 1:0 Drive QEMU QEMU HARDDISK 2.5+

Guest panics

IDE disk: 

ata0-0: QEMU HARDDISK ATA-7 Hard-Disk

Guest panics

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On KVM, the guest's boot menu reports the following for each disk type:

SATA disk: 

ACHI/0: QEMU HARDDISK ATA-7 Hard-Disk

***Guest works!

SCSI disk: 

lsi 00:02.0 1:0 Drive QEMU QEMU HARDDISK 2.5+

Guest panics

IDE disk: 

ata0-0: QEMU HARDDISK ATA-7 Hard-Disk

Guest panics

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Please note the difference in the SATA disk between Xen and KVM.  As far as I know, both are using the same version of QEMU.  Does anyone know how to get the SATA disk to show up as an ACHI disk (instead of lsi) using virt-manager/libvirt on Xen?

Thanks in advance!

~Micah