On 31.03.20 04:43, PRAKHAR BANSAL wrote:
Hi Jan, Thanks for the confirmation to proceed on project proposal. Also, I tried installing Jailhouse on my VM after enabling VT-x/EPT and IOMMU for my VM(Guest OS- Ubuntu 18.04) on VMware fusion hypervisor with MacOS on the host side. However, Jailhouse hardware check was failed because of missing *Preemption timer and Virtualize APIC access*, could you please suggest, if this is hardware limitation? Is there any workaround here?
You will need a hypervisor that supports both when nesting, but I have no idea if there is one for the Mac. What is known to work is KVM on Linux hosts.
My laptop's processor is Intel quad-core i7. image.png Also, could you please suggest, if I can talk to you through an IRC or slack channel since it is a bit hard to communicate over email every time.
I'll be listening on #jailhouse, irc.freenode.net. Jan
Thanks, Prakhar On Mon, Mar 30, 2020 at 6:15 AM Jan Kiszka <jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx>> wrote: On 30.03.20 10:02, PRAKHAR BANSAL wrote: > Hi Jan, > > On Sat, Mar 28, 2020 at 4:12 AM Jan Kiszka <jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx> > <mailto:jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx>>> wrote: > > On 28.03.20 08:47, PRAKHAR BANSAL wrote: > > Hi Jan, > > > > Thanks for the reply! > > > > I was only considering the command-line tool "code" for reference > to the > > Jailhouse kernel API(ioctl calls) because I didn't find a > documentation > > of the Jailhouse kernel APIs. > > Right, the IOCTL API is not documented so far. It is currently only used > inside the Jailhouse project. This needs to be formalized when there > shall be external users like a libvirt driver. > > That might be a nice small contribution task: Create some > Documentation/driver-interfaces.md that describes the IOCTLs along with > their parameter structures and that also includes the current > sysfs-entries.txt as a section. Then send this as patch here. I'll help > out when details are not clear from reading the code. > > Sure. I will do that. > > > > > For the second part as you mentioned that Jailhouse can only create > > cells with the constraints defined in the root cell configuration. I > > have a few questions regarding that. > > > > 1. Is there a way to know if Jailhouse is enabled on the host and get > > the root cell configuration(s) from Jailhouse through an API? > This can > > be used while binding the libvirt to the Jailhouse hypervisor. > > Look at > https://github.com/siemens/jailhouse/blob/master/Documentation/sysfs-entries.txt > for what is reported as runtime information. Full configurations can't > be read back at this point. This might be reconsidered in the light of > [1], but I wouldn't plat for that yet. > > > Ok, sure. I am looking into it. > > > > > > 2. If Jailhouse is not enabled(again can we know this using some API) > > then, can libvirt enable/disable Jailhouse during the libvirt > binding of > > the Jailhouse driver with a given set of Jailhouse cell > configurations > > describing a complete partitioned system? > > With the API above and a given configuration set, yes. The config set > would have to be provided to the libvirt driver in some to-be-defined > way (e.g. /etc/libvirt/jailhouse.conf -> /etc/libvirt/jailhouse/*.cell). > > Cool, got it. Thanks! > > > > > 3. I was wondering, as you mentioned that libvirt driver should check > > for mismatch of the cell configuration with the root cell > configuration, > > the question is, isn't that done by Jailhouse itself? If yes, then > > libvirt can just pass on the cell creation requests to Jailhouse and > > return the response to the user as it is, rather than driver > doing any > > such mismatch check. > > With matching I'm referring to a libvirt user request like "create a > domain with 2 CPUs", while there are no cells left that have more than > one CPU. Or "give the domain 1G RAM", and you need to find an available > cell with that much memory. Those are simple examples. A request that > states "connect the domain to the host network A" implies that a cell > has a shared-memory link to, say, the root cell that can be configured > to bridge this. But let's keep that for later and start as simple as > possible. > > > Do I need to match the libvirt user-requested cell config with only root > cells or with all cells present at that time? With all non-root cells - the root cell will be occupied already (it runs libvirt e.g.). > > I wanted to request you for a favor for the proposal as the deadline is > approaching. Could I prepare a proposal for this project based on our > discussion here and improve it later based on feedback comments after > the deadline? I understand that I got late in starting on the project > search and selection. Sure, please go ahead. Jan > > Thanks, > Prakhar > > > Jan > > [1] > https://groups.google.com/d/msgid/jailhouse-dev/CADiTV-1QiRhSWZnw%2BkHhJMO-BoA4sAcOmTkQE7ZWbHkGh3Jexw%40mail.gmail.com > > > > > -Prakhar > > > > On Thu, Mar 26, 2020 at 1:49 AM Jan Kiszka <jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx> > <mailto:jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx>> > > <mailto:jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx> <mailto:jan.kiszka@xxxxxx <mailto:jan.kiszka@xxxxxx>>>> wrote: > > > > Hi Prakhar, > > > > On 25.03.20 05:36, PRAKHAR BANSAL wrote: > > > Hi Jan, > > > > > > Thanks for the reply. I looked deeper into the libvirt and > Jailhouse > > > source code and found following two things that seem > relevant to the > > > project I am interested in. > > > > > > - Libvirt driver interface at [libvirt.git] > > > <https://libvirt.org/git/?p=libvirt.git;a=tree;hb=HEAD> / src > > > > <https://libvirt.org/git/?p=libvirt.git;a=tree;f=src;hb=HEAD> / > > driver.h > > > > > > <https://libvirt.org/git/?p=libvirt.git;a=blob_plain;f=src/driver.h;hb=HEAD> > > > - Jailhouse tool, which is using the ioctl API of the > Jailhouse, > > > available at > > > > https://github.com/siemens/jailhouse/blob/master/tools/jailhouse.c. > > > > > > With the help of the above two, it looks like, a libvirt > driver > > for the > > > Jailhouse can be implemented. Let me know if I am moving > in the right > > > direction so far. > > > > From the Jailhouse perspective, it is important to not > consider the > > command line tool an interface anymore (like in the first > prototype) but > > build on top of the Linux driver API (ioctls, sysfs). There > is already a > > Python library which started to abstract this interface for > > Jailhouse-internal use cases. However, I strongly suspect > libvirt will > > rather want a native binding. > > > > > > > > I have been looking at the other libvirt driver > implementations for > > > hypervisors like HyperV and VMware to understand their > implementation > > > and learn from there. > > > > As Jailhouse is a static partitioning hypervisor without > abstraction of > > the underlying hardware, your starting point for the libvirt > binding > > should be a given set of Jailhouse cell configurations > describing a > > complete partitioned system. So rather than instantiating on > demand a > > domain (Jailhouse cell) with, say, a network adapter, the > driver should > > match a user request for a domain against the configuration > set and use > > what is there - or report the mismatch. What it could > organize, though, > > is interconnecting cells that have a (preconfigured) virtual > network > > link to the root cell. > > > > Due to this different concept, there will be no 1:1 mapping for > > commodity hypervisor drivers to the Jailhouse scenario. > Still, studying > > what they do is useful and needed in order to understand what > "normally" > > happens and find a reasonable translation. This is probably > the most > > challenging part of the project. > > > > Jan > > >
