The CET spec has been published and guest kernels are starting to get support.
Introduce the CPUID and MSRs, and fully block the MSRs from guest use.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
master commit: 4803a67114
master date: 2020-04-21 16:52:03 +0100
I was (mistakenly, as - looking at the code - it's clearly not intended
to work) passing the tool "Raw" and "Host" as command line arguments.
Avoid printing just "Raw " with not even a newline at the end in
such a case. Instead report what wasn't understood by the parsing logic.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
AMD Pre-Fam17h CPUs "optimise" {F,}X{SAVE,RSTOR} by not saving/restoring
FOP/FIP/FDP if an x87 exception isn't pending. This causes an information
leak, CVE-2006-1056, and worked around by several OSes, including Xen. AMD
Fam17h CPUs no longer have this leak, and advertise so in a CPUID bit.
Introduce the RSTR_FP_ERR_PTRS feature, as specified by AMD, and expose to all
guests by default. While adjusting libxl's cpuid table, add CLZERO which
looks to have been omitted previously.
Also introduce an X86_BUG bit to trigger the (F)XRSTOR workaround, and set it
on AMD hardware where RSTR_FP_ERR_PTRS is not advertised. Optimise the
conditions for the workaround paths.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Rev 037 of Intel's ISA extensions document does not state intercept
behavior for the insn (I've been unofficially told that the distinction
is going to be by exit qualification, as I would have assumed
considering that this way it's sufficiently transparent to unaware
software, as using WBINVD in place of WBNOINVD is always correct, just
less efficient). Similarly AMD's PM volume 2 version 3.31 only states
that both use the same VMEXIT, but not how to distinugish them (other
than by decoding the insn). Therefore in the HVM case for now it'll be
backed by the same ->wbinvd_intercept() handlers.
Use this occasion and also add the two missing table entries for
CLDEMOTE, which doesn't require any further changes to make work.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Make handling in do_pm_op() more homogeneous: Before interpreting
op->cpuid as such, handle all operations not acting on a particular
CPU. Also expose the setting via xenpm.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
While the MWAIT idle driver already takes it to mean an actual C state,
the ACPI idle driver so far used it as a list index. The list index,
however, is an implementation detail of Xen and affected by firmware
settings (i.e. not necessarily uniform for a particular system).
While touching this code also avoid invoking menu_get_trace_data()
when tracing is not active. For consistency do this also for the
MWAIT driver.
Note that I'm intentionally not adding any sorting logic to set_cx():
Before and after this patch we assume entries to arrive in order, so
this would be an orthogonal change.
Take the opportunity and add minimal documentation for the command line
option.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The AVX512_BF16 feature flag resides in this so far blank sub-leaf.
Expand infrastructure accordingly.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The MD_CLEAR feature can be automatically offered to guests. No
infrastructure is needed in Xen to support the guest making use of it.
This is part of XSA-297, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Remove all tmem related code in libxc.
Leave some stubs in libxl in case anyone has linked to those functions
before the removal.
Remove all tmem related commands in xl, all tmem related code in other
utilities we ship.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
The majority of the static tables is never written to. Add const where
possible.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Currently, a user can in principle combine the output of `xl info -n`, the
APCI tables, and some manual CPUID data to figure out which CPU numbers to
feed into `xen-hptool cpu-offline` to effectively disable SMT at runtime.
A more convenient option is to teach Xen how to perform this action.
Extend XEN_SYSCTL_cpu_hotplug with two new operations. Introduce a new
smt_up_down_helper() which wraps the cpu_{up,down}_helper() helpers with logic
which understands siblings based on their APIC_ID.
Add libxc stubs, and extend xen-hptool with smt-{enable,disable} options.
These are intended to be shorthands for a loop over cpu-{online,offline}.
To simplify the implemention, they will strictly enable/disable secondary
siblings (those with a non-zero thread id). This functionality is intended
for use in production scenarios where debugging options such as `maxcpus=` or
other manual plug/unplug configuration has not been used.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Bring libxl's in line with the public header, and update xen-cpuid's to
the latest information available in Intel's documentation (SDM ver 068
and ISA extensions ver 035), with (as before) the exception on MAWAU.
Some pre-existing strings get changed to match SDM naming. This should
be benign in xen-cpuid, and I hope it's also acceptable in libxl, where
people actually using the slightly wrong names would have to update
their guest config files.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The CPUID bit and MSR are deliberately not exposed to guests, because they
won't exist on newer processors. As vPMU isn't security supported, the
misbehaviour of PCR3 isn't expected to impact production deployments.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
This utility can't possibly work with modern Xen setup: none of the
sysfs path used (under /sys/devices/xen-backend) is documented as
stable ABI in upstream Linux kernel.
Archaeology shows that the path used could have been part of the
xenolinux fork which never got upstreamed.
Its utility is zero nowadays. Drop it.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-bugtool relies on code that has been removed in commit 9e8672f1c3
"tools: remove xend and associated python modules", more than 5 years
ago. Remove it, since it confuses users.
-$ /usr/sbin/xen-bugtool
Traceback (most recent call last):
File "/usr/sbin/xen-bugtool", line 9, in <module>
from xen.util import bugtool
ImportError: No module named xen.util
Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=866380
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
In almost all cases, Xen and libxc will agree on the featureset length,
because they are built from the same source.
However, there are circumstances (e.g. security hotfixes) where the featureset
gets longer and dom0 will, after installing updates, be running with an old
Xen but new libxc. Despite writing the code with this scenario in mind, there
were some bugs.
First, xen-cpuid's get_featureset() erroneously allocates a buffer based on
Xen's featureset length, but records libxc's length, which may be longer.
In this situation, the hypercall bounce buffer code reads/writes the recorded
length, which is beyond the end of the allocated object, and a later free()
encounters corrupt heap metadata. Fix this by recording the same length that
we allocate.
Secondly, get_cpuid_domain_info() has a related bug when the passed-in
featureset is a different length to libxc's.
A large amount of the libxc cpuid functionality depends on info->featureset
being as long as expected, and it is allocated appropriately. However, in the
case that a shorter external featureset is passed in, the logic to check for
trailing nonzero bits may read off the end of it. Rework the logic to use the
correct upper bound.
In addition, leave a comment next to the fields in struct cpuid_domain_info
explaining the relationship between the various lengths, and how to cope with
different lengths.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The 'vp_assist' page is currently an example of a guest page which needs to
be kept mapped throughout the life-time of a guest, but there are other
such examples in the specifiction [1]. This patch therefore introduces a
generic 'viridian_page' type and converts the current vp_assist/apic_assist
related code to use it. Subsequent patches implementing other enlightments
can then also make use of it.
This patch also renames the 'vp_assist_pending' field in struct
hvm_viridian_vcpu_context to 'apic_assist_pending' to more accurately
reflect its meaning. The term 'vp_assist' applies to the whole page rather
than just the EOI-avoidance enlightenment. New versons of the specification
have defined data structures for other enlightenments within the same page.
No functional change.
[1] https://github.com/MicrosoftDocs/Virtualization-Documentation/raw/live/tlfs/Hypervisor%20Top%20Level%20Functional%20Specification%20v5.0C.pdf
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Roger Pau Monne <roger.pau@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Also add emacs boilerplate to avoid future problems.
Purely cosmetic. No functional change.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Clang reports:
xen-cpuid.c:307:29: error: format specifies type 'unsigned long' but the
argument has type 'uint64_t' (aka 'unsigned long long') [-Werror,-Wformat]
msrs[l].idx, msrs[l].val);
^~~~~~~~~~~
Use PRIx64 instead.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
This finally (after literally years of work!) marks the point where the
toolstack can ask the hypervisor for the current CPUID configuration of a
specific domain.
Introduce a new flask access vector and update the default policies.
Also extend xen-cpuid's --policy mode to be able to take a domid and dump a
specific domains CPUID and MSR policy.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Provide a SYSCTL for the toolstack to obtain complete system CPUID and MSR
policy information.
For the flask side of things, this subop is closely related to
{phys,cputopo,numa}info, so shares the physinfo access vector.
Extend the xen-cpuid utility to be able to dump the system policies. An
example output is:
Xen reports there are maximum 113 leaves and 3 MSRs
Raw policy: 93 leaves, 3 MSRs
CPUID:
leaf subleaf -> eax ebx ecx edx
00000000:ffffffff -> 0000000d:756e6547:6c65746e:49656e69
00000001:ffffffff -> 000306c3:00100800:7ffafbff:bfebfbff
00000002:ffffffff -> 76036301:00f0b5ff:00000000:00c10000
00000004:00000000 -> 1c004121:01c0003f:0000003f:00000000
00000004:00000001 -> 1c004122:01c0003f:0000003f:00000000
00000004:00000002 -> 1c004143:01c0003f:000001ff:00000000
00000004:00000003 -> 1c03c163:03c0003f:00001fff:00000006
00000005:ffffffff -> 00000040:00000040:00000003:00042120
00000006:ffffffff -> 00000077:00000002:00000009:00000000
00000007:00000000 -> 00000000:000027ab:00000000:9c000000
0000000a:ffffffff -> 07300403:00000000:00000000:00000603
0000000b:00000000 -> 00000001:00000002:00000100:00000000
0000000b:00000001 -> 00000004:00000008:00000201:00000000
0000000d:00000000 -> 00000007:00000340:00000340:00000000
0000000d:00000001 -> 00000001:00000000:00000000:00000000
0000000d:00000002 -> 00000100:00000240:00000000:00000000
80000000:ffffffff -> 80000008:00000000:00000000:00000000
80000001:ffffffff -> 00000000:00000000:00000021:2c100800
80000002:ffffffff -> 65746e49:2952286c:6f655820:2952286e
80000003:ffffffff -> 55504320:2d334520:30343231:20337620
80000004:ffffffff -> 2e332040:48473034:0000007a:00000000
80000006:ffffffff -> 00000000:00000000:01006040:00000000
80000007:ffffffff -> 00000000:00000000:00000000:00000100
80000008:ffffffff -> 00003027:00000000:00000000:00000000
MSRs:
index -> value
000000ce -> 0000000080000000
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Use physinfo.max_cpu_id instead of physinfo.nr_cpus to get max CPU id.
This fixes for example 'xenpm get-cpufreq-para' with smt=off, which
otherwise would miss half of the cores.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Also specify field widths of the multiple similar lines printed in the
course of the loop, to help readability.
Make the iteration variable unsigned.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The casts weren't even to the right type - all LAPIC registers are
32-bit (pairs/groups of registers may be combined to form larger logical
ones, but this is not visible in the given data representation).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Also avoid printing the MSR flags (they're always zero as of commit
2f1add6e1c "x86/vmx: Don't leak host syscall MSR state into HVM
guests"), and print FPU registers only when the respective flag
indicates the space holds valid data.
Adjust format specifiers a little at the same time, in particular to
avoid at least some leading zeros to be printed when the positions
can't ever be non-zero. This helps readability in my opinion.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
This requires calling dpkg-deb directly and pass it -z0.
It reduces the time to run the mkdeb script from 14 seconds to 3
seconds on my workstation with SSD, from 87s to 15s on a machine
with HDD. The deb file grows from 49M to 58M.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
rpmbuild -bb spents alot of time in compressing the binaries. Reduce the
turnaround time of 'make rpmball' by using gzip as compression tool.
This reduces the buildtime from 'w9.xzdio'/138 seconds to 'w1.gzdio'/88
seconds in my environment.
The downside is an increased filesize of xen.rpm, 19MB vs. 37MB.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Wei Liu <wei.liu2@citrix.com>
xen-tools/libs.h currently contains a shared BUILD_BUG_ON() implementation and
is used by some tools. Extend this to include ARRAY_SIZE and clean up all the
opencoding.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
To combat GPZ SP4 "Speculative Store Bypass", Intel have extended their
speculative sidechannel mitigations specification as follows:
* A feature bit to indicate that Speculative Store Bypass Disable is
supported.
* A new bit in MSR_SPEC_CTRL which, when set, disables memory disambiguation
in the pipeline.
* A new bit in MSR_ARCH_CAPABILITIES, which will be set in future hardware,
indicating that the hardware is not susceptible to Speculative Store Bypass
sidechannels.
For contemporary processors, this interface will be implemented via a
microcode update.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
qemu upstream uses git submodules. git archive does not work with git
submodules (and could not work properly with them, because this is one
of the many things it is inherently impossible to do correctly with
git submodules).
qemu upstream have worked around this by providing a rather scary
shell script which attempts to do roughly the right thing. It's close
enough that we can use it with only minor precautions.
Unfortunately this does mean that `mktarball' now executes the qemu
source code it was using, rather than merely shuffling it about, as it
did previously. I think this is a less bad ill than copying (and,
effectively, forking) the scary script.
CC: Wei Liu <wei.liu2@citrix.com>
CC: George Dunlap <george.dunlap@eu.citrix.com>
CC: Juergen Gross <jgross@suse.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
gcc-8 complains:
xen-lowmemd.c: In function 'handle_low_mem':
xen-lowmemd.c:80:55: error: '%s' directive output may be truncated writing up to 511 bytes into a region of size 489 [-Werror=format-truncation=]
snprintf(error, BUFSZ,"Failed to write target %s to xenstore", data);
^~ ~~~~
xen-lowmemd.c:80:9: note: 'snprintf' output between 36 and 547 bytes into a destination of size 512
snprintf(error, BUFSZ,"Failed to write target %s to xenstore", data);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In practice it wouldn't happen, because 'data' contains string
representation of 64-bit unsigned number (20 characters at most).
But place a limit to mute gcc warning.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-Acked-by: Juergen Gross <jgross@suse.com>
Now that it is possible to get and set the migration
delay via the SCHEDOP sysctl, use that in xenpm, instead
of the special purpose libxc interface (which will be
removed in a following commit).
The sysctl, however, requires a cpupool-id argument,
for knowing on which scheduler it is operating on. In
this case, since we don't want to alter xenpm's command
line interface, we always use '0', which means xenpm
will always act on the default cpupool ('Pool-0').
>From this commit on, `xenpm {set,get}-vcpu-migration-delay'
commands work again. But that is only for the sake of
backward compatibility, and their use is deprecated, in
favour of 'xl sched-credit -s [-c <poolid>] -m <delay>'.
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The recent commit 66bf4ef0 "x86/hvm: re-work viridian APIC assist code"
modified one of the field names in struct hvm_viridian_vcpu_context but
did not accordingly modify xen-hvmctx, leading to a failure to build tools.
This patch makes the necessary change to fix the build.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Contemporary processors are gaining Indirect Branch Controls via microcode
updates. Intel are introducing one bit to indicate IBRS and IBPB support, and
a second bit for STIBP. AMD are introducing IBPB only, so enumerate it with a
separate bit.
Furthermore, depending on compiler and microcode availability, we may want to
run Xen with IBRS set, or clear.
To use these facilities, we synthesise separate IBRS and IBPB bits for
internal use. A lot of infrastructure is required before these features are
safe to offer to guests.
This is part of XSA-254.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
It makes more sense to put a tool to be used by other subsystems
to be in 'tools/misc' along 'mkrpm','mkdeb', etc.
The patch titled "xen/livepatch/x86/arm32: Force .livepatch.depends
section to be uint32_t aligned" uses mkhex.
Acked-by: Wei Liu <wei.liu2@citrix.com>
Suggested-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
DEPS_INCLUDE is currently the same as DEPS, so no functional change.
This patch is the result of this perl rune:
git-grep -l 'include.*DEPS' | xargs perl -i -pe 'next unless m/^-?include/; s/\bDEPS\b/DEPS_INCLUDE/'
I have verified that I haven't missed anything, with this rune:
git-grep '\bDEPS\b'
Reported-by: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
DEPS_RM is currently the same as DEPS, so no functional change.
This patch is the result of two perl runes:
git-grep -l 'rm.*DEPS' | xargs perl -i~ -pe 'next unless m/^\t+rm\b/; s/\bDEPS\b/DEPS_RM/;'
git-grep -l 'RM.*DEPS' | xargs perl -i~ -pe 'next unless m/^\t+\$\(RM\)/; s/\bDEPS\b/DEPS_RM/;'
And editing tools/xenstat/libxenstat/Makefile by hand.
I verified that I didn't miss anything with this rune:
git-grep '\bDEPS\b' | grep -v include |less
Reported-by: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Running "make uninstall" does not remove all installed files, a
situation which might cause link related issues if xen is re-installed
in a different location.
In order to make uninstall correctly remove the files it is best
the process should be done recursively by mirroring each "install"
target with an "uninstall" who removes the installed files.
An exception to this rule is uninstalling the files produced by
"qemu-xen-dir-remote" and "qemu-xen-traditional-dir", which are external
to the project. These projects do not implement an "uninstall" target so
the files have to be removed manually.
Signed-off-by: Petre Pircalabu <ppircalabu@bitdefender.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
As both xen-netfront and xen-blkfront support multi-queue, they would
consume a lot of grant table references when there are many paravirtual
devices and vcpus assigned to guest. Guest domU might panic or hang due to
grant allocation failure when nr_grant_frames in guest has reached its max
value.
This utility would help the administrators to diagnose xen issue. There is
only one command gnttab_query_size so far to monitor the guest grant table
frame usage on dom0 side so that it is not required to debug on guest
kernel side for crash/hang analysis anymore.
It is extensible for adding new commands for more diagnostic functions and
the framework of xen-diag.c is from xen-livepatch.c.
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Instead of relying on cpuid instruction behaviour to tell which domain
type we are just try asking the kernel via the appropriate sysfs node
(added in Linux kernel 4.13).
Keep the old detection logic as a fallback for older kernels.
Signed-off-by: Juergen Gross <jgross@suse.com>