Add CPUID/MSR enumeration details for Processor Trace. For now, we will only
support its use inside VMX operation. Fill in the vmtrace_available boolean
to activate the newly introduced common infrastructure for allocating trace
buffers.
For now, Processor Trace is going to be operated in Single Output mode behind
the guests back. Add the MSRs to struct vcpu_msrs, and set up the buffer
limit in vmx_init_ipt() as it is fixed for the lifetime of the domain.
Context switch the most of the MSRs in and out of vCPU context, but the main
control register needs to reside in the MSR load/save lists. Explicitly pull
the msrs pointer out into a local variable, because the optimiser cannot keep
it live across the memory clobbers in the MSR accesses.
Signed-off-by: Michał Leszczyński <michal.leszczynski@cert.pl>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
memshrtool is a tool for a human to use, rather than a test. Move it into
misc/ as a more appropriate location to live. Also rename it to
xen-memshare
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-access is a tool for a human to use, rather than a test. Move it
into misc/ as a more appropriate location to live.
Move the -DXC_WANT_COMPAT_DEVICEMODEL_API from CFLAGS into xen-access.c itself
to avoid adding Makefile complexity.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
These are VEX-encoded equivalents of the EVEX-encoded AVX512-VNNI ISA
extension.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Relying on presence / absence of hypervisor leaves in raw / escaped
CPUID output cannot be used to tell apart PV and HVM on CPUID faulting
capable hardware. Utilize a PV-only feature flag to avoid false positive
HVM detection.
While at it also short circuit the main detection loop: For PV, only
the base group of leaves can possibly hold hypervisor information.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Switch all usages of xs_daemon_open*() and xs_domain_open() to use
xs_open() instead. While at it switch xs_daemon_close() users to
xs_close().
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The last libxc internal used by xen-mfndump.c is the ERROR() macro.
Add a simple definition for that macro to xen-mfndump.c and replace
the libxc private header includes by official ones.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The definition of PAGE_SIZE comes from xc_private.h, which shouldn't be
used by xen-mfndump.c. Replace PAGE_SIZE by XC_PAGE_SIZE, as
xc_private.h contains:
#define PAGE_SIZE XC_PAGE_SIZE
For the same reason PAGE_SHIFT_X86 needs to replaced with
XC_PAGE_SHIFT.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
xen-mfndump.c is including the libxc private header xg_save_restore.h.
Avoid that by moving the definition of is_mapped() to xen-mfndump.c
(it is used there only) and by duplicating the definition of
M2P_SIZE() in xen-mfndump.c.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
xen-hptool is including private headers from tools/libxc without any
need. Switch it to use official headers only.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
There are quite some places in Makefiles assuming libxenguest and
libxenctrl being built in the same directory via a single Makefile.
Drop this assumption by specifying the dependencies and path variables
for both libraries correctly.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Also prevent warning: directory /boot: remove failed
Before:
[root@TestCloud1 xen]# rpm -hiv dist/xen*rpm
Preparing... ################################# [100%]
file /boot from install of xen-4.15-unstable.x86_64 conflicts with file from package filesystem-3.2-25.el7.x86_64
file /usr/bin from install of xen-4.15-unstable.x86_64 conflicts with file from package filesystem-3.2-25.el7.x86_64
file /usr/lib from install of xen-4.15-unstable.x86_64 conflicts with file from package filesystem-3.2-25.el7.x86_64
file /usr/lib64 from install of xen-4.15-unstable.x86_64 conflicts with file from package filesystem-3.2-25.el7.x86_64
file /usr/sbin from install of xen-4.15-unstable.x86_64 conflicts with file from package filesystem-3.2-25.el7.x86_64
[root@TestCloud1 xen]# rpm -e xen
warning: directory /boot: remove failed: Device or resource busy
After:
[root@TestCloud1 xen]# rpm -hiv dist/xen*rpm
Preparing... ################################# [100%]
Updating / installing...
1:xen-4.15-unstable ################################# [100%]
[root@TestCloud1 xen]# rpm -e xen
[root@TestCloud1 xen]#
Signed-off-by: Don Slutz <Don.Slutz@Gmail.com>
Acked-by: Wei Liu <wl@xen.org>
We've grown to a mix of dashes and underscores - switch to consistent
naming in the hope that future additions will play by this.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The standard memory access pattern once again should allow us to go
without a test harness addition beyond the EVEX Disp8-scaling one.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Otherwise it's difficult to know if operation failed inside the automation.
While at it, also switch to returning 1 and 2 instead of errno to avoid
incompatibilies between errno and special exit code numbers.
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Release-acked-by: Paul Durrant <paul@xen.org>
Reviewed-by: Igor Druzhinin <igor.druzhinin@citrix.com>
As compilers are free to choose the width of an enum they should be
avoided in stable interfaces when declaring a variable. So the
struct xenhypfs_dirent definition should be modified to have explicitly
sized members for type and encoding and the related enums should be
defined separately.
Additionally it is better to have a larger flags member in that struct
with the "writable" indicator occupying only a single bit. This will
make future additions easier.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Release-acked-by: Paul Durrant <paul@xen.org>
asprintf() can fail, so check its return value. Additionally fix a
memory leak in xenhypfs.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Release-acked-by: Paul Durrant <paul@xen.org>
Whenever python scripts are install, have the shebang be modified to use
whatever PYTHON_PATH is. This is useful for system where python isn't available, or
where the package build tools prevent unversioned shebang.
INSTALL_PYTHON_PROG only looks for "#!/usr/bin/env python".
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
There's nothing to be done by the emulator, as we unconditionally abort
any XBEGIN.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
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>
For now, write the same content for both. Update the users of the
initialisers to use the new name, and extend xen-cpuid to dump both default
and max featuresets.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Just as with c/s 96dc77b4b1 for XEN_SYSCTL_get_cpu_policy,
XEN_SYSCTL_get_cpu_featureset wants to become conditional.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Policy objects aren't tiny, and the derivation logic isn't trivial. We are
about to increase the number of policy objects, so will have the opportunity
to drop logic and storage space based on CONFIG_{PV,HVM}.
Start by causing XEN_SYSCTL_get_cpu_policy to fail with -EOPNOTSUPP when
requesting data for a compiled-out subsystem. Update xen-cpuid to cope and
continue to further system policies, seeing as the indicies are interleaved.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
A splitlock is an atomic operation which crosses a cache line boundary. It
serialises operations in the cache coherency fabric and comes with a
multi-thousand cycle stall.
Intel Tremont CPUs introduce MSR_CORE_CAPS to enumerate various core-specific
features, and MSR_TEST_CTRL to adjust the behaviour in the case of a
splitlock.
Virtualising this for guests is distinctly tricky owing to the fact that
MSR_TEST_CTRL has core rather than thread scope. In the meantime however,
prevent the MSR values leaking into guests.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wl@xen.org>
Quoting the respective Linux commit:
Intel Xeons from Ivy Bridge onwards support a processor identification
number set in the factory. To the user this is a handy unique number to
identify a particular CPU. Intel can decode this to the fab/production
run to track errors. On systems that have it, include it in the machine
check record. I'm told that this would be helpful for users that run
large data centers with multi-socket servers to keep track of which CPUs
are seeing errors.
Newer AMD CPUs support this too, at different MSR numbers.
Take the opportunity and hide __MC_NMSRS from the public interface going
forward.
[Linux commit 3f5a7896a5096fd50030a04d4c3f28a7441e30a5]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Extend the livepatch list operation to fetch also payloads' metadata.
This is achieved by extending the sysctl list interface with 2 extra
guest handles:
* metadata - an array of arbitrary size strings
* metadata_len - an array of metadata strings' lengths (uin32_t each)
Payloads' metadata is a string of arbitrary size and does not have an
upper bound limit. It may also vary in size between payloads.
In order to let the userland allocate enough space for the incoming
data add a metadata total size field to the list sysctl operation and
fill it with total size of all payloads' metadata.
Extend the libxc to handle the metadata back-to-back data transfers
as well as metadata length array data transfers.
The xen-livepatch userland tool is extended to always display the
metadata for each received module. The metadata is received with the
following format: key=value\0key=value\0...key=value\0. The format is
modified to the following one: key=value;key=value;...key=value.
The new format allows to easily parse the metadata for a given module
by a machine.
Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
Reviewed-by: Martin Pohlack <mpohlack@amazon.de>
Reviewed-by: Norbert Manthey <nmanthey@amazon.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
The payloads' name strings can be of arbitrary size (typically small
with an upper bound of XEN_LIVEPATCH_NAME_SIZE).
Current implementation of the list operation interface allows to copy
names in the XEN_LIVEPATCH_NAME_SIZE chunks regardless of its actual
size and enforces space allocation requirements on userland tools.
To unify and simplify the interface, handle the name strings of
arbitrary size by copying them in adhering chunks to the userland.
In order to let the userland allocate enough space for the incoming
data add an auxiliary interface xc_livepatch_list_get_sizes() that
provides the current number of payload entries and the total size of
all name strings. This is achieved by extending the sysctl list
interface with an extra fields: name_total_size.
The xc_livepatch_list_get_sizes() issues the livepatch sysctl list
operation with the nr field set to 0. In this mode the operation
returns the number of payload entries and calculates the total sizes
for all payloads' names.
When the sysctl operation is issued with a non-zero nr field (for
instance with a value obtained earlier with the prior call to the
xc_livepatch_list_get_sizes()) the new field name_total_size provides
the total size of actually copied data.
Extend the libxc to handle the name back-to-back data transfers.
The xen-livepatch tool is modified to start the list operation with a
call to the xc_livepatch_list_get_sizes() to obtain the actual number
of payloads as well as the necessary space for names.
The tool now always requests the actual number of entries and leaves
the preemption handling to the libxc routine. The libxc still returns
'done' and 'left' parameters with the same semantic allowing the tool
to detect anomalies and react to them. At the moment it is expected
that the tool receives the exact number of entries as requested.
The xen-livepatch tool has been also modified to handle the name
back-to-back transfers correctly.
Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
Reviewed-by: Bjoern Doebel <doebel@amazon.de>
Reviewed-by: Martin Pohlack <mpohlack@amazon.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
By default Livepatch enforces the following buildid-based dependency
chain between livepatch modules:
1) first module depends on given hypervisor buildid
2) every consecutive module depends on previous module's buildid
This way proper livepatch stack order is maintained and enforced.
While it is important for production livepatches it limits agility and
blocks usage of testing or debug livepatches. These kinds of livepatch
modules are typically expected to be loaded at any time irrespective
of current state of the modules stack.
To enable testing and debug livepatches allow user dynamically ignore
the inter-modules dependency. In this case only hypervisor buildid
match is verified and enforced.
To allow userland pass additional paremeters for livepatch actions
add support for action flags.
Each of the apply, revert, unload and revert action gets additional
32-bit parameter 'flags' where extra flags can be applied in a mask
form.
Initially only one flag '--nodeps' is added for the apply action.
This flag modifies the default buildid dependency check as described
above.
The global sysctl interface input flag parameter is defined with a
single corresponding flag macro:
LIVEPATCH_ACTION_APPLY_NODEPS (1 << 0)
The userland xen-livepatch tool is modified to support the '--nodeps'
flag for apply and load commands. A general mechanism for specifying
more flags in the future for apply and other action is however added.
Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
Reviewed-by: Eslam Elnikety <elnikety@amazon.de>
Reviewed-by: Petre Eftime <epetre@amazon.com>
Reviewed-by: Leonard Foerster <foersleo@amazon.de>
Reviewed-by: Martin Pohlack <mpohlack@amazon.de>
Reviewed-by: Norbert Manthey <nmanthey@amazon.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
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>
Michał Leszczyński
Andrew Cooper
Jan Beulich
Juergen Gross
Don Slutz
Olaf Hering
Igor Druzhinin
Anthony PERARD
Konrad Rzeszutek Wilk
Pawel Wieczorkiewicz
Chao Gao
Ross Lagerwall
Wei Liu
Hans van Kranenburg