History log of /linux-master/arch/x86/boot/mkcpustr.c
Revision Date Author Comments
# 14442a15 20-Dec-2019 Sean Christopherson <seanjc@google.com>

x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*

Add support for generating VMX feature names in capflags.c and use the
resulting x86_vmx_flags to print the VMX flags in /proc/cpuinfo. Don't
print VMX flags if no bits are set in word 0, which holds Pin Controls.
Pin Control's INTR and NMI exiting are fundamental pillars of VMX, if
they are not supported then the CPU is broken, it does not actually
support VMX, or the kernel wasn't built with support for the target CPU.

Print the features in a dedicated "vmx flags" line to avoid polluting
the common "flags" and to avoid having to prefix all flags with "vmx_",
which results in horrendously long names.

Keep synthetic VMX flags in cpufeatures to preserve /proc/cpuinfo's ABI
for those flags. This means that "flags" and "vmx flags" will have
duplicate entries for tpr_shadow (virtual_tpr), vnmi, ept, flexpriority,
vpid and ept_ad, but caps the pollution of "flags" at those six VMX
features. The vendor-specific code that populates the synthetic flags
will be consolidated in a future patch to further minimize the lasting
damage.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-12-sean.j.christopherson@intel.com


# d6910058 22-May-2019 Thomas Gleixner <tglx@linutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 83

Based on 1 normalized pattern(s):

this file is part of the linux kernel and is made available under
the terms of the gnu general public license version 2 or at your
option any later version incorporated herein by reference

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 18 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520075211.321157221@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# cd4d09ec 26-Jan-2016 Borislav Petkov <bp@suse.de>

x86/cpufeature: Carve out X86_FEATURE_*

Move them to a separate header and have the following
dependency:

x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h

This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>


# 381aa07a 11-Sep-2014 Dave Hansen <dave.hansen@linux.intel.com>

x86: Introduce disabled-features

I believe the REQUIRED_MASK aproach was taken so that it was
easier to consult in assembly (arch/x86/kernel/verify_cpu.S).
DISABLED_MASK does not have the same restriction, but I
implemented it the same way for consistency.

We have a REQUIRED_MASK... which does two things:
1. Keeps a list of cpuid bits to check in very early boot and
refuse to boot if those are not present.
2. Consulted during cpu_has() checks, which allows us to
optimize out things at compile-time. In other words, if we
*KNOW* we will not boot with the feature off, then we can
safely assume that it will be present forever.

But, we don't have a similar mechanism for CPU features which
may be present but that we know we will not use. We simply
use our existing mechanisms to repeatedly check the status of
the bit at runtime (well, the alternatives patching helps here
but it does not provide compile-time optimization).

Adding a feature to disabled-features.h allows the bit to be
checked via a new macro: cpu_feature_enabled(). Note that
for features in DISABLED_MASK, checks with this macro have
all of the benefits of an #ifdef. Before, we would have done
this in a header:

#ifdef CONFIG_X86_INTEL_MPX
#define cpu_has_mpx cpu_has(X86_FEATURE_MPX)
#else
#define cpu_has_mpx 0
#endif

and this in the code:

if (cpu_has_mpx)
do_some_mpx_thing();

Now, just add your feature to DISABLED_MASK and you can do this
everywhere, and get the same benefits you would have from
#ifdefs:

if (cpu_feature_enabled(X86_FEATURE_MPX))
do_some_mpx_thing();

We need a new function and *not* a modification to cpu_has()
because there are cases where we actually need to check the CPU
itself, despite what features the kernel supports. The best
example of this is a hypervisor which has no control over what
features its guests are using and where the guest does not depend
on the host for support.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140911211513.9E35E931@viggo.jf.intel.com
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>


# abbf1590 02-Oct-2012 David Howells <dhowells@redhat.com>

UAPI: Partition the header include path sets and add uapi/ header directories

Partition the header include path flags into two sets, one for kernelspace
builds and one for userspace builds.

Add the following directories to build after the ordinary include directories
so that #include will pick up the UAPI header directly if the kernel header
has been moved there.

The userspace set (represented by the USERINCLUDE make variable) contains:

-I $(srctree)/arch/$(hdr-arch)/include/uapi
-I arch/$(hdr-arch)/include/generated/uapi
-I $(srctree)/include/uapi
-I include/generated/uapi
-include $(srctree)/include/linux/kconfig.h

and the kernelspace set (represented by the LINUXINCLUDE make variable)
contains:

-I $(srctree)/arch/$(hdr-arch)/include
-I arch/$(hdr-arch)/include/generated
-I $(srctree)/include
-I include --- if not building in the source tree

plus everything in the USERINCLUDE set.

Then use USERINCLUDE in building the x86 boot code.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>


# 3235dc3f 06-Feb-2010 Frans Pop <elendil@planet.nl>

x86: Remove trailing spaces in messages

Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Avi Kivity <avi@redhat.com>
Cc: x86@kernel.org
LKML-Reference: <1265478443-31072-10-git-send-email-elendil@planet.nl>
[ Left out the KVM bits. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>


# 97fc0555 16-Sep-2008 H. Peter Anvin <hpa@zytor.com>

x86 setup: handle more than 8 CPU flag words

Checkin e38e05a85828dac23540cd007df5f20985388afc added a 9th CPU flag
word, but didn't adjust the boot code to match. This patch adds the
necessary boot code support.

Note: due to a typo in an #if statement, it didn't trigger the #error
this was supposed to do.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# 7414aa41 27-Aug-2008 H. Peter Anvin <hpa@zytor.com>

x86: generate names for /proc/cpuinfo from <asm/cpufeature.h>

We have had a number of cases where <asm/cpufeature.h> (and its
predecessors) have diverged substantially from the names list in
/proc/cpuinfo. This patch generates the latter from the former.

It retains the option for explicitly overriding the strings, but by
making that require a separate action it should at least be less
likely to happen.

It would be good to do a future pass and rename strings that are
gratuituously different in the kernel (/proc/cpuinfo is a userspace
interface and must remain constant.)

Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# f0be6c6a 04-Feb-2008 H. Peter Anvin <hpa@zytor.com>

x86 setup: print missing CPU features in cleartext

Instead of obscure numbers, print the list of missing CPU features in
cleartext. To conserve space, use a host program (mkcpustr.c) to
produce a compact list of mandatory features only.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>