[PATCH v5 00/43] arm64: Support for Arm CCA in KVM

[Jean-Philippe Brucker]

On Mon, Dec 02, 2024 at 08:54:11AM +0000, Steven Price wrote:
> Hi Itaru,
> 
> On 02/12/2024 05:10, Itaru Kitayama wrote:
> > On Fri, Oct 04, 2024 at 04:27:21PM +0100, Steven Price wrote:
> >> This series adds support for running protected VMs using KVM under the
> >> Arm Confidential Compute Architecture (CCA).
> ...
> > 
> > On FVP, the v5+v7 kernel is unable to execute virt-manager:
> > 
> > Starting install...
> > Allocating 'test9.qcow2'                                    |    0 B  00:00 ...
> > Removing disk 'test9.qcow2'                                 |    0 B  00:00
> > ERROR    internal error: process exited while connecting to monitor: 2024-12-04T18:56:11.646168Z qemu-system-aarch64: -accel kvm: ioctl(KVM_CREATE_VM) failed: Invalid argument
> > 2024-12-04T18:56:11.646520Z qemu-system-aarch64: -accel kvm: failed to initialize kvm: Invalid argument
> > Domain installation does not appear to have been successful.
> 
> Can you check that the kernel has detected the RMM being available, you
> should have a message like below when the host kernel is booting:
> 
> kvm [1]: RMI ABI version 1.0
> 
> My guess is that you've got mismatched versions of the RMM and TF-A. The
> interface between those two components isn't stable and there were
> breaking changes fairly recently. And obviously if the RMM hasn't
> initialised successfully then confidential VMs won't be available.
> 
> > Below is my virt-manager options:
> > 
> > virt-install --machine=virt --arch=aarch64 --name=test9 --memory=2048 --vcpu=1 --nographic --check all=off --features acpi=off --virt-type kvm --boot kernel=Image-cca,initrd=rootfs.cpio,kernel_args='earlycon console=ttyAMA0 rdinit=/sbin/init rw root=/dev/vda acpi=off' --qemu-commandline='-M virt,confidential-guest-support=rme0,gic-version=3 -cpu host -object rme-guest,id=rme0 -nodefaults' --disk size=4 --import --osinfo detect=on,require=off
> > 
> > Userland is Ubuntu 24.10, the VMM is Linaro's cca/2024-11-20:
> > 
> > https://git.codelinaro.org/linaro/dcap/qemu/-/tree/cca/2024-11-20?ref_type=heads

Indeed, QEMU branch 2024-11-20 has to be used with an older version of the
KVM patch and older RMM. For KVM v5+v7 you need the most recent QEMU
branch, confusingly called cca/v3 (because it's the third patch series).

Thanks,
Jean

> 
> I don't think this is the latest QEMU tree, Jean-Philippe posted an
> update last week:
> 
> https://lore.kernel.org/qemu-devel/20241125195626.856992-2-jean-philippe@linaro.org/
> 
> I'm not sure if there were any important updates there, but there are
> detailed instructions that might help.
> 
> Regards,
> Steve
>