Re: [Qemu-devel] Cannot boot my VM image after switching to ahci.

[John Baboval]

I assume Windows 7 or newer?

In order to speed boot time, Windows will remove the AHCI driver from 
the critical driver database when you boot with no AHCI controller on 
the bus. If you later want to switch to AHCI mode, you have to boot with 
IDE again, and re-add the AHCI driver, reboot, and then reboot again 
with QEMU AHCI enabled.

To do this on Windows 7, set 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci\Start to 0
To do this on Windows 8, delete the entire StartOverride key under 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\storahci

Good luck.

On 04/23/2014 04:33 PM, Alex Davis wrote:
> I currently run my QEMU VM using the following command:
> /spare/qemu-1.7.1/bin/qemu-system-x86_64 -soundhw ac97 -sdl -vga std -net 
> nic,macaddr=de:ad:be:ef:89:32 -net user -m 2048 -enable-kvm -drive 
> file="$1",media=disk,if=ide,index=0 -drive 
> file=/dev/sr0,media=cdrom,if=ide,index=1 -boot c -smp 2
>
> I'm trying to run the VM using the following command:
> /spare/qemu-1.7.1/bin/qemu-system-x86_64 \
> -machine type=q35,accel=kvm \
> -acpitable file=/spare/qemu-1.7.1/share/qemu/q35-acpi-dsdt.aml \
> -soundhw ac97 \
> -sdl -vga std \
> -net nic,macaddr=de:ad:be:ef:89:32 \
> -net user \
> -m 2G -enable-kvm \
> -device ahci,id=ahci0 \
> -drive file=win7.img,if=none,id=drive-sata0-0-0,index=0,media=disk \
> -drive file=/dev/sr0,if=none,id=drive-sata0-0-1,index=1,media=cdrom \
> -device ide-drive,bus=ahci0.0,unit=0,drive=drive-sata0-0-0,id=drive-sata0-0-0 \
> -device ide-cd,bus=ahci0.1,unit=0,drive=drive-sata0-0-1,id=drive-sata0-0-1 \
> -boot menu=on -smp 2 -monitor stdio
>
> I get 0x00000007B unable to find boot device. I can boot into rescue mode and 
> start a command prompt: the 'disk' and 'cdrom'
> are seen as d: and e:, instead of c: and d:. Any suggestions?
>
> I code, therefore I am