On Tue, 4 Feb 2020 09:13:06 +0100 Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote: > On 03.02.20 17:13, Cornelia Huck wrote: > > On Mon, 3 Feb 2020 08:19:49 -0500 > > Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote: > > > >> From: Janosch Frank <frankja@xxxxxxxxxxxxx> > >> > >> Description of changes that are necessary to move a KVM VM into > >> Protected Virtualization mode. > > > > Maybe move this up to the top of the series, so that new reviewers can > > get a quick idea about the architecture as a whole? It might also make > Will do. > > sense to make the two documents link to each other... > I added both files to the kvm index file and changed the title > to contain s390. I also added a link to the base doc. Sounds good. > > > > >> > >> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> > >> --- > >> Documentation/virt/kvm/s390-pv-boot.rst | 64 +++++++++++++++++++++++++ > >> 1 file changed, 64 insertions(+) > >> create mode 100644 Documentation/virt/kvm/s390-pv-boot.rst > >> > >> diff --git a/Documentation/virt/kvm/s390-pv-boot.rst b/Documentation/virt/kvm/s390-pv-boot.rst > >> new file mode 100644 > >> index 000000000000..431cd5d7f686 > >> --- /dev/null > >> +++ b/Documentation/virt/kvm/s390-pv-boot.rst > >> @@ -0,0 +1,64 @@ > >> +.. SPDX-License-Identifier: GPL-2.0 > >> +========================= > >> +Boot/IPL of Protected VMs > >> +========================= > > > > ...especially as the reader will have no idea what a "Protected VM" is, > > unless they have read the other document before. > > > > > > >> + > >> +Summary > >> +------- > >> +Protected VMs are encrypted while not running. On IPL a small > >> +plaintext bootloader is started which provides information about the > >> +encrypted components and necessary metadata to KVM to decrypt it. > > > > s/it/the PVM/ ? > > ack > > This section looks now: > > --- > Protected Virtual Machines (PVM) are not accessible by I/O or the > hypervisor. When the hypervisor wants to access the memory of PVMs > the memory needs to be made accessible. When doing so, the memory will > be encrypted. See :doc:`s390-pv` for details. > > On IPL a.... ok > --- > > > > >> + > >> +Based on this data, KVM will make the PV known to the Ultravisor and > > > > I think the other document uses 'PVM'... probably better to keep that > > consistent. > > The feature name might change to secure execution (SE). I will need to > go over this again. But I think we can continue to name the virtual > machines protected virtual machines as this is more a description than > a brand name. I would stick with "protected virtual machines" as well; especially as the kernel parameter is called "prot_virt", and people might wonder why you're talking about SELinux :) (...) > >> +Subcodes 4 and 7 will result in specification exceptions. > > > > "Subcodes 4 and 7, which would not clear the guest memory, ..." ? > > Subcodes 4 and 7 will result in specification exceptions as they would > not clear out the guest memory. ok > > > > >> +When removing a secure VM, the UV will clear all memory, so we can't > >> +have non-clearing IPL subcodes. > >> + > >> +Subcodes 8, 9, 10 will result in specification exceptions. > >> +Re-IPL into a protected mode is only possible via a detour into non > >> +protected mode. > > > > In general, this looks like a good overview about how the guest can > > move into protected virt mode. > > > > Some information I'm missing in this doc: Where do the keys come from? > > I assume from the machine... is there one key per CEC? Can keys be > > transferred? Can an image be introspected to find out if it is possible > > to run it on a given system? > > > > (Not sure if there is a better resting place for that kind of > > information.) > > There will be tooling as part of the s390-tools. I will add > > --- > Keys > ---- > Every CEC will have a unique public key to enable tooling to build > encrypted images. > See `s390-tools <https://github.com/ibm-s390-tools/s390-tools/>`_ > for the tooling. Sounds good. > --- > > The s390 tools part is not yet upstream but it will be soon. I'll look forward to the s390 tools part for details on key handling, then :)
