On 1/9/23 15:52, Janosch Frank wrote:
On 1/9/23 15:31, Janosch Frank wrote:
On 1/9/23 14:53, Cédric Le Goater wrote:
On 1/9/23 14:45, Janosch Frank wrote:
On 1/9/23 14:30, Cédric Le Goater wrote:
On 1/9/23 10:49, Janosch Frank wrote:
On 1/9/23 10:27, Cédric Le Goater wrote:
On 1/9/23 10:04, Janosch Frank wrote:
On 1/6/23 08:53, Cédric Le Goater wrote:
From: Cédric Le Goater <c...@redhat.com>
If a secure kernel is started in a non-protected VM, the OS will hang
during boot without giving a proper error message to the user.
Most of the time you see nothing in the console because libvirt is too slow. If
you start the VM in paused mode, attach a console and then resume it, then
you'll see a nice error message.
If you wait long enough, the VM fails to mount / and falls into the dracut
initrams.
I have the feeling that we're not talking about the same thing here.>
> A PV VM always starts out as a non-PV VM and is put into PV mode via two
diag308 subcodes (8 & 10). ALL PV subcodes (8 - 10) are spec exceptions if the
host isn't enabled for PV.
The corner case this patch is trying to address is for a PV-enabled host,
a secure enabled OS and !PV-enabled QEMU.
Please run this command on a secure disk image :
qemu-system-s390x -M s390-ccw-virtio -accel kvm -drive
file=<file>,if=virtio,format=qcow2 -nographic -nodefaults -serial mon:stdio
and tell me what you get.
qemu-system-s390x -M s390-ccw-virtio -accel kvm -drive
file=u2204.qcow2,if=virtio,format=qcow2 -nographic -nodefaults -serial mon:stdio
LOADPARM=[ ]
Using virtio-blk.
Using SCSI scheme.
.............................................................................................................................
Secure unpack facility is not available
Yes. That's with a !PV-enabled host. Correct ?
Can you try with prot_virt=1 on the host please ?
With prot_virt=1 it boots until it doesn't find the file system (at
least if you give it a bit more memory than the standard 256MB):
qemu-system-s390x -M s390-ccw-virtio -accel kvm -drive
file=u2204.qcow2,if=virtio,format=qcow2 -nographic -nodefaults -serial
mon:stdio -m 4096
[Linux boot stuff]
ALERT! /dev/disk/by-path/ccw-0.0.0000-part1 does not exist. Dropping
to a shell!
I.e. it boots into secure mode just fine.
Now if you add iommu_platform=true to the device then it'll even boot from disk.
So we'd rather need an error message if you attach a device without the iommu
being set to true. The whole topic of PV iommu problems has a few windings
which I don't fully want to bring to electronic paper right now.
Either you start a secure guest that has devices with manual iommu entries or
you go the launch security route and let libvirt/qemu handle it for you.
aaahh. So "-machine confidential-guest-support=pv0 -object s390-pv-guest,id=pv0"
is equivalent to "-global virtio-device.iommu_platform=true". I should have
looked closer :/
Thanks for the clarification,
C.
