Previous patch handled the runtime case where a non-x86 host is
fetching /proc/cpuinfo data for a microcode info that we know
it doesn't exist. This change alone speeded everything by a
bit for non-x86, but there is at least one major culprit left.
qemuxml2argvtest does several arch-specific tests, and a good
chunk of them are x86 exclusive. This means that 'hostArch'
will be seen as x86 for these tests, even when running in
non-x86 hosts. In a Power 9 server with 128 CPUs, qemuxml2argvtest
takes 298 seconds to complete in average, and 'perf record'
indicates that 95% of the time is spent in
virHostCPUGetMicrocodeVersion().
This patch mocks virHostCPUGetMicrocodeVersion() to always return
0 in the tests, avoiding /proc/cpuinfo reads. This will make all
tests behave arch-agnostic, and the microcode value being 0 has no
impact on any existing test.
This is a CI speed across the board for all archs, including x86,
given that we're not reading /proc/cpuinfo in the tests. For
a Thinkpad T480 laptop with 8 Intel i7 CPUs, qemuxml2argvtest
went from 15.50 sec to 12.50 seconds. The performance gain is even
more noticeable for huge servers with lots of CPUs. For the
Power 9 server mentioned above, this patch speeds qemuxml2argvtest
to 9 seconds, down from 298 sec.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Non-x86 archs does not have a 'microcode' version like x86. This is
covered already inside the function - just return 0 if no microcode
is found. Regardless of that, a read of /proc/cpuinfo is always made.
Each read will invoke the kernel to fill in the CPU details every time.
Now let's consider a non-x86 host, like a Power 9 server with 128 CPUs.
Each /proc/cpuinfo read will need to fetch data for each CPU and it
won't even matter because we know beforehand that PowerPC chips don't
have microcode information.
We can do better for non-x86 hosts by skipping this process entirely.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The idea is to have a function that calls virHostCPUGetOnlineBitmap()
but, instead of returning NULL if the host does not have CPU
offlining capabilities, fall back to a bitmap containing all
present CPUs.
Next patch will use this helper in two other places.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The purpose of this function is to give a short description that would
be change when a host CPU is replaced with a different model. This is
currently implemented by reading /proc/cpuinfo.
It should be implemented for all architectures for which the QEMU driver
stores host CPU data in the capabilities cache. In other words for archs
that support host-model CPUs.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Update the host CPU code to report the die_id in the NUMA topology
capabilities. On systems with multiple dies, this fixes the bug
where CPU cores can't be distinguished:
<cpus num='12'>
<cpu id='0' socket_id='0' core_id='0' siblings='0'/>
<cpu id='1' socket_id='0' core_id='1' siblings='1'/>
<cpu id='2' socket_id='0' core_id='0' siblings='2'/>
<cpu id='3' socket_id='0' core_id='1' siblings='3'/>
</cpus>
Notice how core_id is repeated within the scope of the same socket_id.
It now reports
<cpus num='12'>
<cpu id='0' socket_id='0' die_id='0' core_id='0' siblings='0'/>
<cpu id='1' socket_id='0' die_id='0' core_id='1' siblings='1'/>
<cpu id='2' socket_id='0' die_id='1' core_id='0' siblings='2'/>
<cpu id='3' socket_id='0' die_id='1' core_id='1' siblings='3'/>
</cpus>
So core_id is now unique within a (socket_id, die_id) pair.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
On a KVM x86_64 host which supports invariant TSC this function can be
used to detect the TSC frequency and the availability of TSC scaling.
The magic MSR numbers required to check if VMX scaling is supported on
the host are documented in Volume 3 of the Intel® 64 and IA-32
Architectures Software Developer’s Manual.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The new virHostCPUGetMSR internal API will try to read the MSR from
/dev/cpu/0/msr and if it is not possible (the device does not exist or
libvirt is running unprivileged), it will fallback to asking KVM for the
MSR using KVM_GET_MSRS ioctl.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Require that all headers are guarded by a symbol named
LIBVIRT_$FILENAME
where $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.
Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This introduces a syntax-check script that validates header files use a
common layout:
/*
...copyright header...
*/
<one blank line>
#ifndef SYMBOL
# define SYMBOL
....content....
#endif /* SYMBOL */
For any file ending priv.h, before the #ifndef, we will require a
guard to prevent bogus imports:
#ifndef SYMBOL_ALLOW
# error ....
#endif /* SYMBOL_ALLOW */
<one blank line>
The many mistakes this script identifies are then fixed.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.
In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.
With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to find the
author of a particular bit of code.
This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.
The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This new API reads host's CPU microcode version from /proc/cpuinfo.
Unfortunately, there is no other way of reading microcode version which
would be usable from both system and session daemon.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This reverts commit e4b980c853.
When a binary links against a .a archive (as opposed to a shared library),
any symbols which are marked as 'weak' get silently dropped. As a result
when the binary later runs, those 'weak' functions have an address of
0x0 and thus crash when run.
This happened with virtlogd and virtlockd because they don't link to
libvirt.so, but instead just libvirt_util.a and libvirt_rpc.a. The
virRandomBits symbols was weak and so left out of the virtlogd &
virtlockd binaries, despite being required by virHashTable functions.
Various other binaries like libvirt_lxc, libvirt_iohelper, etc also
link directly to .a files instead of libvirt.so, so are potentially
at risk of dropping symbols leading to a later runtime crash.
This is normal linker behaviour because a weak symbol is not treated
as undefined, so nothing forces it to be pulled in from the .a You
have to force the linker to pull in weak symbols using -u$SYMNAME
which is not a practical approach.
This risk is silent bad linkage that affects runtime behaviour is
not acceptable for a fix that was merely trying to fix the test
suite. So stop using __weak__ again.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently all mockable functions are annotated with the 'noinline'
attribute. This is insufficient to guarantee that a function can
be reliably mocked with an LD_PRELOAD. The C language spec allows
the compiler to assume there is only a single implementation of
each function. It can thus do things like propagating constant
return values into the caller at compile time, or creating
multiple specialized copies of the function body each optimized
for a different caller. To prevent these optimizations we must
also set the 'noclone' and 'weak' attributes.
This fixes the test suite when libvirt.so is built with CLang
with optimization enabled.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
CLang's optimizer is more aggressive at inlining functions than
gcc and so will often inline functions that our tests want to
mock-override. This causes the test to fail in bizarre ways.
We don't want to disable inlining completely, but we must at
least prevent inlining of mocked functions. Fortunately there
is a 'noinline' attribute that lets us control this per function.
A syntax check rule is added that parses tests/*mock.c to extract
the list of functions that are mocked (restricted to names starting
with 'vir' prefix). It then checks that src/*.h header file to
ensure it has a 'ATTRIBUTE_NOINLINE' annotation. This should prevent
use from bit-rotting in future.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
While on that, drop support for kernels from RHEL-5 era (missing
cpu/present file). Also add some useful functions and export them.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
The functions to retrieve online and present host CPU information
are only supported on Linux for the time being.
This leads to runtime errors if these function are used on other
platforms. To avoid that, code in higher levels using the functions
must replicate the conditional compilation in higher level which
is error prone (and is plainly spoken ugly).
Adding a function virHostCPUHasBitmap that can be used to check
for host CPU bitmap support.
NB: There are other functions including the host CPU count that
are lacking support on all platforms, but they are too essential
in order to be bypassed.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
We will need this function shortly when implementing
nodeGetCPUStats in the test driver.
Signed-off-by: Tomáš Ryšavý <tom.rysavy.0@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This kvmGetMaxVCPUs() needs to be used at two different places
so move it to utils with appropriate name and mark it as private
global now.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
Move all APIs with a virHostCPU name prefix out into new
util/virhostcpu.h & util/virhostcpu.c files
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
