There are still few uses of direct xenstore access, most of them are
xen-specific (so doesn't need to be portable). For now simply don't
connect to xenstore when no 'xen.lowlevel.xs' module present. It will
break such xen-specific accesses - it must be somehow reworked - either
by adding appropriate conditionals, or moving such code somewhere else
(custom methods of libvirt driver?).
There is still use of it: QubesHost.get_free_xen_memory and
QubesHost.measure_cpu_usage. Will migrate them to libvirt later (for now
some things will be broken - namely qubes-manager).
Currently <vm-dir>/<vm-name>.conf file is used only for debugging
purposes - the real one is passed directly to libvirt, without storing
on disk for it.
In some cases (e.g. qvm-clone) QubesVM.create_config_file() can be
called before VM directory exists and in this case it would fail.
Because it isn't critical fail in any means (the config file will be
recreated on next occasion) just ignore this error.
Final version most likely will have this part of code removed
completely.
Mostly done. Things still using xenstore/not working at all:
- DispVM
- qubesutils.py (especially qvm-block and qvm-usb code)
- external IP change notification for ProxyVM (should be done via RPC
service)
libvirt_domain object needs to be recreated, so force it. Also fix
config path setting (missing extension) - create_config_file
uses it as custom config indicator (if such detected, VM settings -
especially name, would not be updated).
1. Fake dom0 object doesn't need proper maxmem nor vcpus - set
statically to 0 instead of getting from physical host.
2. QubesHVM doesn't preserve maxmem setting, so set it to self.memory
earlier (to suppress default total_memory/2 calculation).
This makes easier to import right objects in submodules (only one
object). This also implement lazy connection - at first access, not at
module import, which speeds up tools, which doesn't need runtime
information (like qvm-prefs or qvm-service). In the future this will
ease migration from xenstore to QubesDB.
Also implement "offline mode" - operate on qubes.xml without connecting
to VMM - raise exception at such try.
This is needed to run tools during installation, where only minimal
set of services are started, especially no libvirt.
Do not recreate them at each startup. This will save some time and also
solve some problems from invalidated libvirt handles after domain
shutdown (e.g. causes qubes-manager crashes).
This requires storing uuid in qubes.xml.
Move DispVM creation to qfile-daemon-dvm/QubesDisposableVm from
qubes-restore. As actual restore is handled by libvirt, we don't get
much from separate qubes-restore process.
This code still needs some improvements, especially on performance.
Forking daemon after initializing hypervisor connection can cause
problems (and actually does in case of libvirt).
To notify systemd when daemon is ready use notify socket (previously it
was termination of parent process).
EOF transmission actually doesn't work in some cases in R2. It is rather
hard to change without introducing big changes (which we don't want to
do in R2). It should be fixed in R3.
BTW The said changes are in my qrexec-sockets branch in core-agent-linux
and linux-utils (then application should use shutdown(2) instead of
close). Alternatively qrexec-agent can use PAM directly (instead of
calling "su"). This is also implemented (pam branch in
core-agent-linux), but IMO it isn't the way to go (reimplementing "su"
in qrexec-agent code).
