For machinetypes with a pci-root bus (all legacy PCI), libvirt will
make a "fake" reservation for one extra slot prior to assigning
addresses to unaddressed PCI endpoint devices in the domain. This will
trigger auto-adding of a pci-bridge for the final device to be
assigned an address *if that device would have otherwise instead been
the last device on the last available pci-bridge*; thus it assures
that there will always be at least one slot left open in the domain's
bus topology for expansion (which is important both for hotplug (since
a new pci-bridge can't be added while the guest is running) as well as
for offline additions to the config (since adding a new device might
otherwise in some cases require re-addressing existing devices, which
we want to avoid)).
It's important to note that for the above case (legacy PCI), we must
check for the special case of all slots on all buses being occupied
*prior to assigning any addresses*, and avoid attempting to reserve
the extra address in that case, because there is no free address in
the existing topology, so no place to auto-add a pci-bridge for
expansion (i.e. it would always fail anyway). Since that condition can
only be reached by manual intervention, this is acceptable.
For machinetypes with pcie-root (Q35, aarch64 virt), libvirt's
methodology for automatically expanding the bus topology is different
- pcie-root-ports are plugged into slots (soon to be functions) of
pcie-root as needed, and the new endpoint devices are assigned to the
single slot in each pcie-root-port. This is done so that the devices
are, by default, hotpluggable (the slots of pcie-root don't support
hotplug, but the single slot of the pcie-root-port does). Since
pcie-root-ports can only be plugged into pcie-root, and we don't
auto-assign endpoint devices to the pcie-root slots, this means
topology expansion doesn't compete with endpoint devices for slots, so
we don't need to worry about checking for all "useful" slots being
free *prior* to assigning addresses to new endpoint devices - as a
matter of fact, if we attempt to reserve the open slots before the
used slots, it can lead to errors.
Instead this patch just reserves one slot for a "future potential"
PCIe device after doing the assignment for actual devices, but only
if the only PCI controller defined prior to starting address
assignment was pcie-root, and only if we auto-added at least one PCI
controller during address assignment. This assures two things:
1) that reserving the open slots will only be done when the domain is
initially defined, never at any time after, and
2) that if the user understands enough about PCI controllers that they
are adding them manually, that we don't mess up their plan by
adding extras - if they know enough to add one pcie-root-port, or
to manually assign addresses such that no pcie-root-ports are
needed, they know enough to add extra pcie-root-ports if they want
them (this could be called the "libguestfs clause", since
libguestfs needs to be able to create domains with as few
devices/controllers as possible).
This is set to reserve a single free port for now, but could be
increased in the future if public sentiment goes in that direction
(it's easy to increase later, but essentially impossible to decrease)
Real Q35 hardware has an ICH9 chip that includes several integrated
devices at particular addresses (see the file docs/q35-chipset.cfg in
the qemu source). libvirt already attempts to put the first two sets
of ich9 USB2 controllers it finds at 00:1D.* and 00:1A.* to match the
real hardware. This patch does the same for the ich9 "HD audio"
device.
The main inspiration for this patch is that currently the *only*
device in a reasonable "workstation" type virtual machine config that
requires a legacy PCI slot is the audio device, Without this patch,
the standard Q35 machine created by virt-manager will have a
dmi-to-pci-bridge and a pci-bridge just for the sound device; with the
patch (and if you change the sound device model from the default
"ich6" to "ich9"), the machine definition constructed by virt-manager
has absolutely no legacy PCI controllers - any legacy PCI devices
(e.g. video and sound) are on pcie-root as integrated devices.
Previously we added a set of EHCI+UHCI controllers to Q35 machines to
mimic real hardware as closely as possible, but recent discussions
have pointed out that the nec-usb-xhci (USB3) controller is much more
virtualization-friendly (uses less CPU), so this patch switches the
default for Q35 machinetypes to add an XHCI instead (if it's
supported, which it of course *will* be).
Since none of the existing test cases left out USB controllers in the
input XML, a new Q35 test case was added which has *no* devices, so
ends up with only the defaults always put in by qemu, plus those added
by libvirt.
Previously libvirt would only add pci-bridge devices automatically
when an address was requested for a device that required a legacy PCI
slot and none was available. This patch expands that support to
dmi-to-pci-bridge (which is needed in order to add a pci-bridge on a
machine with a pcie-root), and pcie-root-port (which is needed to add
a hotpluggable PCIe device). It does *not* automatically add
pcie-switch-upstream-ports or pcie-switch-downstream-ports (and
currently there are no plans for that).
Given the existing code to auto-add pci-bridge devices, automatically
adding pcie-root-ports is fairly straightforward. The
dmi-to-pci-bridge support is a bit tricky though, for a few reasons:
1) Although the only reason to add a dmi-to-pci-bridge is so that
there is a reasonable place to plug in a pci-bridge controller,
most of the time it's not the presence of a pci-bridge *in the
config* that triggers the requirement to add a dmi-to-pci-bridge.
Rather, it is the presence of a legacy-PCI device in the config,
which triggers auto-add of a pci-bridge, which triggers auto-add of
a dmi-to-pci-bridge (this is handled in
virDomainPCIAddressSetGrow() - if there's a request to add a
pci-bridge we'll check if there is a suitable bus to plug it into;
if not, we first add a dmi-to-pci-bridge).
2) Once there is already a single dmi-to-pci-bridge on the system,
there won't be a need for any more, even if it's full, as long as
there is a pci-bridge with an open slot - you can also plug
pci-bridges into existing pci-bridges. So we have to make sure we
don't add a dmi-to-pci-bridge unless there aren't any
dmi-to-pci-bridges *or* any pci-bridges.
3) Although it is strongly discouraged, it is legal for a pci-bridge
to be directly plugged into pcie-root, and we don't want to
auto-add a dmi-to-pci-bridge if there is already a pci-bridge
that's been forced directly into pcie-root.
Although libvirt will now automatically create a dmi-to-pci-bridge
when it's needed, the code still remains for now that forces a
dmi-to-pci-bridge on all domains with pcie-root (in
qemuDomainDefAddDefaultDevices()). That will be removed in a future
patch.
For now, the pcie-root-ports are added one to a slot, which is a bit
wasteful and means it will fail after 31 total PCIe devices (30 if
there are also some PCI devices), but helps keep the changeset down
for this patch. A future patch will have 8 pcie-root-ports sharing the
functions on a single slot.
The nec-usb-xhci device (which is a USB3 controller) has always
presented itself as a PCI device when plugged into a legacy PCI slot,
and a PCIe device when plugged into a PCIe slot, but libvirt has
always auto-assigned it to a legacy PCI slot.
This patch changes that behavior to auto-assign to a PCIe slot on
systems that have pcie-root (e.g. Q35 and aarch64/virt).
Since we don't yet auto-create pcie-*-port controllers on demand, this
means a config with an nec-xhci USB controller that has no PCI address
assigned will also need to have an otherwise-unused pcie-*-port
controller specified:
<controller type='pci' model='pcie-root-port'/>
<controller type='usb' model='nec-xhci'/>
(this assumes there is an otherwise-unused slot on pcie-root to accept
the pcie-root-port)
libvirt previously assigned nearly all devices to a "hotpluggable"
legacy PCI slot even on machines with a PCIe root bus (and even though
most such machines don't even support hotplug on legacy PCI slots!)
Forcing all devices onto legacy PCI slots means that the domain will
need a dmi-to-pci-bridge (to convert from PCIe to legacy PCI) and a
pci-bridge (to provide hotpluggable legacy PCI slots which, again,
usually aren't hotpluggable anyway).
To help reduce the need for these legacy controllers, this patch tries
to assign virtio-1.0-capable devices to PCIe slots whenever possible,
by setting appropriate connectFlags in
virDomainCalculateDevicePCIConnectFlags(). Happily, when that function
was written (just a few commits ago) it was created with a
"virtioFlags" argument, set by both of its callers, which is the
proper connectFlags to set for any virtio-*-pci device - depending on
the arch/machinetype of the domain, and whether or not the qemu binary
supports virtio-1.0, that flag will have either been set to PCI or
PCIe. This patch merely enables the functionality by setting the flags
for the device to whatever is in virtioFlags if the device is a
virtio-*-pci device.
NB: the first virtio video device will be placed directly on bus 0
slot 1 rather than on a pcie-root-port due to the override for primary
video devices in qemuDomainValidateDevicePCISlotsQ35(). Whether or not
to change that is a topic of discussion, but this patch doesn't change
that particular behavior.
NB2: since the slot must be hotpluggable, and pcie-root (the PCIe root
complex) does *not* support hotplug, this means that suitable
controllers must also be in the config (i.e. either pcie-root-port, or
pcie-downstream-port). For now, libvirt doesn't add those
automatically, so if you put virtio devices in a config for a qemu
that has PCIe-capable virtio devices, you'll need to add extra
pcie-root-ports yourself. That requirement will be eliminated in a
future patch, but for now, it's simple to do this:
<controller type='pci' model='pcie-root-port'/>
<controller type='pci' model='pcie-root-port'/>
<controller type='pci' model='pcie-root-port'/>
...
Partially Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1330024
Simplify handling of the 'dimm' address element by allowing to specify
the slot number only. This will allow libvirt to allocate slot numbers
before starting qemu.
Propagate the selected or default level to qemu if it's supported.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1376009
Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
QEMU added support for ivshmem-plain and ivshmem-doorbell. Those are
reworked varians of legacy ivshmem that are compatible from the guest
POV, but not from host's POV and have sane specification and handling.
Details about the newer device type can be found in qemu's commit
5400c02b90bb:
http://git.qemu.org/?p=qemu.git;a=commit;h=5400c02b90bb
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Support for virtio disks was added in commit id 'fceeeda', but not for
SCSI drives. Add the secret for the server when hotplugging a SCSI drive.
No need to make any adjustments for unplug since that's handled during
the qemuDomainDetachDiskDevice call to qemuDomainRemoveDiskDevice in
the qemuDomainDetachDeviceDiskLive switch.
Added a test to/for the command line processing to show the command line
options when adding a SCSI drive for the guest.
Add the secret object so the 'passwordid=' can be added if the command line
if there's a secret defined in/on the host for TCP chardev TLS objects.
Preparation for the secret involves adding the secinfo to the char source
device prior to command line processing. There are multiple possibilities
for TCP chardev source backend usage.
Add test for at least a serial chardev as an example.
Add in the block I/O throttling length/duration parameter to the command
line if supported. If not supported, fail command creation.
Add the xml2argvtest for testing.
Add an optional "tls='yes|no'" attribute for a TCP chardev.
For QEMU, this will allow for disabling the host config setting of the
'chardev_tls' for a domain chardev channel by setting the value to "no" or
to attempt to use a host TLS environment when setting the value to "yes"
when the host config 'chardev_tls' setting is disabled, but a TLS environment
is configured via either the host config 'chardev_tls_x509_cert_dir' or
'default_tls_x509_cert_dir'
Signed-off-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The code is entirely correct, but it still managed to trip me
up when I first ran into it because I did not realize right away
that VIR_PCI_CONNECT_TYPES_ENDPOINT was not a single flag, but
rather a mask including both VIR_PCI_CONNECT_TYPE_PCI_DEVICE and
VIR_PCI_CONNECT_TYPE_PCIE_DEVICE.
In order to save the next distracted traveler in PCI Address Land
some time, document this fact with a comment. Add a test case for
the behavior as well.
The idea is to have function that does some checking of the
arguments at its beginning and then have one big switch for all
the interface types it supports. Each one of them generating the
corresponding part of the command line.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The idea is to have function that does some checking of the
arguments at its beginning and then have one big switch for all
the interface types it supports. Each one of them generating the
corresponding part of the command line.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This improves commit 706b5b6277 in a way that we check qemu capabilities
instead of what architecture we are running on to detect whether we can
use *virtio-vga* model or not. This is not a case only for arm/aarch64.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Before this patch we've checked qemu capabilities for video devices
only while constructing qemu command line using "-device" option.
Since we support qemu only if "-device" option is present we can use
the same capabilities to check also video devices while using "-vga"
option to construct qemu command line.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
We generally uses QEMU_CAPS_DEVICE_$NAME to probe for existence of some
device and QEMU_CAPS_$NAME_$PROP to probe for existence of some property
of that device.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
If QEMU in question supports QMP, this capability is set if
QEMU_CAPS_DEVICE_QXL was set based on existence of "-device qxl". If
libvirt needs to parse *help*, because there is no QMP support, it
checks for existence of "-vga qxl", but it also parses output of
"-device ?" and sets QEMU_CAPS_DEVICE_QXL too.
Now that libvirt supports only QEMU that has "-device" implemented it's
safe to drop this capability and stop using it.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
This patch simplifies QEMU capabilities for QXL video device. QEMU
exposes this device as *qxl-vga* and *qxl* and they are both the same
device with the same set of parameters, the only difference is that
*qxl-vga* includes VGA compatibility.
Based on QEMU code they are tied together so it's safe to check only for
presence of only one of them.
This patch also removes an invalid test case "video-qxl-sec-nodevice"
where there is only *qxl-vga* device and *qxl* device is not present.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
If one of QEMU_CAPS_DEVICE_QXL_VGA or QEMU_CAPS_DEVICE_QXL is set the
other one will always be set as well because both devices are tied
together in QEMU.
The change of args files is caused by the presence of capability
QEMU_CAPS_DEVICE_VIDEO_PRIMARY which means it's safe to use
"-device qxl-vga" instead of "-vga qxl", see commit (e3f2686b) and
by the fact that if QEMU_CAPS_VGA_QXL is set QEMU_CAPS_DEVICE_QXL_VGA
and QEMU_CAPS_DEVICE_QXL would be set too (since we support only qemu
with "-device" option).
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The intel-iommu device has existed since QEMU 2.2.0, but
it was only possible to create it with -device since
QEMU 2.7.0, thanks to:
commit 621d983a1f9051f4cfc3f402569b46b77d8449fc
Author: Marcel Apfelbaum <marcel@redhat.com>
Date: Mon Jun 27 18:38:34 2016 +0300
hw/iommu: enable iommu with -device
Use the standard '-device intel-iommu' to create the IOMMU device.
The legacy '-machine,iommu=on' can still be used.
The libvirt capability check & command line formatting code
is thus broken for all QEMU versions 2.2.0 -> 2.6.0 inclusive.
This fixes it to use iommu=on instead.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The qemucapsprobe helper calls virQEMUCapsNewForBinaryInternal with
caps == NULL, causing the following crash:
Program received signal SIGSEGV, Segmentation fault.
#0 0x00007ffff788775f in virQEMUCapsInitHostCPUModel
(qemuCaps=qemuCaps@entry=0x649680, host=host@entry=0x10) at
src/qemu/qemu_capabilities.c:2969
#1 0x00007ffff7889dbf in virQEMUCapsNewForBinaryInternal
(caps=caps@entry=0x0, binary=<optimized out>,
libDir=libDir@entry=0x4033f6 "/tmp", cacheDir=cacheDir@entry=0x0,
runUid=runUid@entry=4294967295, runGid=runGid@entry=4294967295,
qmpOnly=true) at src/qemu/qemu_capabilities.c:4039
#2 0x0000000000401702 in main (argc=2, argv=0x7fffffffd968) at
tests/qemucapsprobe.c:73
Caused by v2.2.0-182-g68c7011.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
We want to pass the proper opaque pointer instead of NULL to
virDomainDefParse and subsequently virDomainDefParseNode too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Host capabilities provide libvirt's view of the host CPU, but for a
useful support for host-model CPUs we really need a hypervisor's view of
the CPU. And since the view can be differ with emulator, qemu
capabilities is the best place to store the host CPU model.
This patch just copies the CPU model from host capabilities, but this
will change in the future.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Testing PPC64/AArch64 KVM domains on x86_64 host only works because we
have a lot of bugs in our code. Since this series is going to fix them,
we need to make sure the host architecture matches guest for KVM
domains.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Adding x86 CPU models into a list of supported CPUs for non-x86
architectures is not a very good idea. Each architecture we test needs
to maintain its own list of supported CPU models.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
qemu_command.c should deal with translating our domain definition into a
QEMU command line and nothing else.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Some parts of qemuCaps depend on guest architecture, machine type, and
possibly other things that we know only once the domain XML has been
parsed. Let's move all these updates into a dedicated function.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
testCompareXMLToArgv will soon need to call a few function which are
defined further in the code. Let's move them up a bit.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The list of supported CPU models in domain capabilities is stored in
virDomainCapsCPUModels. Let's use the same object for storing CPU models
in QEMU capabilities.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Most of QEMU's PCI display device models, such as:
libvirt video/model/@type QEMU -device
------------------------- ------------
cirrus cirrus-vga
vga VGA
qxl qxl-vga
virtio virtio-vga
come with a linear framebuffer (sometimes called "VGA compatibility
framebuffer"). This linear framebuffer lives in one of the PCI device's
MMIO BARs, and allows guest code (primarily: firmware drivers, and
non-accelerated OS drivers) to display graphics with direct memory access.
Due to architectural reasons on aarch64/KVM hosts, this kind of
framebuffer doesn't / can't work in
qemu-system-(arm|aarch64) -M virt
machines. Cache coherency issues guarantee a corrupted / unusable display.
The problem has been researched by several people, including kvm-arm
maintainers, and it's been decided that the best way (practically the only
way) to have boot time graphics for such guests is to consolidate on
QEMU's "virtio-gpu-pci" device.
>From <https://bugzilla.redhat.com/show_bug.cgi?id=1195176>, libvirt
supports
<devices>
<video>
<model type='virtio'/>
</video>
</devices>
but libvirt unconditionally maps @type='virtio' to QEMU's "virtio-vga"
device model. (See the qemuBuildDeviceVideoStr() function and the
"qemuDeviceVideo" enum impl.)
According to the above, this is not right for the "virt" machine type; the
qemu-system-(arm|aarch64) binaries don't even recognize the "virtio-vga"
device model (justifiedly). Whereas "virtio-gpu-pci", which is a pure
virtio device without a compatibility framebuffer, is available, and works
fine.
(The ArmVirtQemu ("AAVMF") platform of edk2 -- that is, the UEFI firmware
for "virt" -- supports "virtio-gpu-pci", as of upstream commit
3ef3209d3028. See
<https://tianocore.acgmultimedia.com/show_bug.cgi?id=66>.)
Override the default mapping of "virtio", from "virtio-vga" to
"virtio-gpu-pci", if qemuDomainMachineIsVirt() evaluates to true.
Cc: Andrea Bolognani <abologna@redhat.com>
Cc: Drew Jones <drjones@redhat.com>
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Martin Kletzander <mkletzan@redhat.com>
Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1372901
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Martin Kletzander <mkletzan@redhat.com>
The test qemuxml2argv-serial-tcp-tlsx509-chardev.args
will fail if libvirt is built with a --sysconfdir
arg that is not /etc. Fix this by setting a hardcoded
path in the test code.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When building a chardev device string for tcp, add the necessary pieces to
access provide the TLS X.509 path to qemu. This includes generating the
'tls-creds-x509' object and then adding the 'tls-creds' parameter to the
VIR_DOMAIN_CHR_TYPE_TCP command line.
Finally add the tests for the qemu command line. This test will make use
of the "new(ish)" /etc/pki/qemu setting for a TLS certificate environment
by *not* "resetting" the chardevTLSx509certdir prior to running the test.
Also use the default "verify" option (which is "no").
Signed-off-by: John Ferlan <jferlan@redhat.com>
We already have the ability to turn off dumping of guest
RAM via the domain XML. This is not particularly useful
though, as it is under control of the management application.
What is needed is a way for the sysadmin to turn off guest
RAM defaults globally, regardless of whether the mgmt app
provides its own way to set this in the domain XML.
So this adds a 'dump_guest_core' option in /etc/libvirt/qemu.conf
which defaults to false. ie guest RAM will never be included in
the QEMU core dumps by default. This default is different from
historical practice, but is considered to be more suitable as
a default because
a) guest RAM can be huge and so inflicts a DOS on the host
I/O subsystem when dumping core for QEMU crashes
b) guest RAM can contain alot of sensitive data belonging
to the VM owner. This should not generally be copied
around inside QEMU core dumps submitted to vendors for
debugging
c) guest RAM contents are rarely useful in diagnosing
QEMU crashes
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add support for using the new approach to hotplug vcpus using device_add
during startup of qemu to allow sparse vcpu topologies.
There are a few limitations imposed by qemu on the supported
configuration:
- vcpu0 needs to be always present and not hotpluggable
- non-hotpluggable cpus need to be ordered at the beginning
- order of the vcpus needs to be unique for every single hotpluggable
entity
Qemu also doesn't really allow to query the information necessary to
start a VM with the vcpus directly on the commandline. Fortunately they
can be hotplugged during startup.
The new hotplug code uses the following approach:
- non-hotpluggable vcpus are counted and put to the -smp option
- qemu is started
- qemu is queried for the necessary information
- the configuration is checked
- the hotpluggable vcpus are hotplugged
- vcpus are started
This patch adds a lot of checking code and enables the support to
specify the individual vcpu element with qemu.
If any of the devices referenced a USB hub that does not exist,
defining the domain would either fail with:
error: An error occurred, but the cause is unknown
(if only the last hub in the path is missing)
or crash.
Return a proper error instead of crashing.
https://bugzilla.redhat.com/show_bug.cgi?id=1367130
More misunderstanding/mistaken assumptions on my part - I had thought
that a pci-expander-bus could be plugged into any legacy PCI slot, and
that pcie-expander-bus could be plugged into any PCIe slot. This isn't
correct - they can both be plugged ontly into their respective root
buses. This patch adds that restriction.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1358712
libvirt had allowed a dmi-to-pci-bridge to be plugged in anywhere a
normal PCIe endpoint can be connected, but this is wrong - it will
only work if it's plugged into pcie-root (the PCIe root complex) or a
pcie-expander-bus (the qemu device pxb-pcie). This patch adjusts the
connection flags accordingly.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1363648
The generated command line wouldn't work since QEMU doesn't know what
'cmt' is. The following patch will fix this issue.
https://bugzilla.redhat.com/show_bug.cgi?id=1355857
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
In qemu, enabling this feature boils down to adding the following
onto the command line:
-global driver=cfi.pflash01,property=secure,value=on
However, there are some constraints resulting from the
implementation. For instance, System Management Mode (SMM) is
required to be enabled, the machine type must be q35-2.4 or
later, and the guest should be x86_64. While technically it is
possible to have 32 bit guests with secure boot, some non-trivial
CPU flags tuning is required (for instance lm and nx flags must
be prohibited). Given complexity of our CPU driver, this is not
trivial. Therefore I've chosen to forbid 32 bit guests for now.
If there's ever need, we can refine the check later.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
