We're trying to nest virtualisation using 64bit Xen
inside a Hyper-V virtual machine.
When we enable CONFIG_HYPERV_STORAGE and boot with the
Xen hypervisor
we can't see /dev/sda. If we boot the Linux kernel
without Xen it works fine.
The full dmesg for booting with and without Xen is
attached.
Without Xen, first the disk is deliberately ignored:
[ 3.728055] ata_piix 0000:00:07.1: Hyper-V Virtual
Machine detected, ATA device ignore set
And later picked up by hv_storevsc:
[ 8.432089] scsi host0: storvsc_host_t
[ 8.432946] scsi 0:0:0:0: Direct-Access Msft
Virtual Disk 1.0 PQ: 0 ANSI: 4
[ 8.434538] scsi host1: storvsc_host_t
[ 8.435324] sd 0:0:0:0: Attached scsi generic sg0 type
0
Any ideas why sda is never attached under Xen or how I
can further diagnose this?