Xen PVH guests receive the address of the RSDP table from Xen. In order
to support booting a Xen PVH guest via Grub2 using the standard x86
boot entry we need a way for Grub2 to pass the RSDP address to the
kernel.
For this purpose expand the struct setup_header to hold the physical
address of the RSDP address. Being zero means it isn't specified and
has to be located the legacy way (searching through low memory or
EBDA).
While documenting the new setup_header layout and protocol version
2.14 add the missing documentation of protocol version 2.13.
There are Grub2 versions in several distros with a downstream patch
violating the boot protocol by writing past the end of setup_header.
This requires another update of the boot protocol to enable the kernel
to distinguish between a specified RSDP address and one filled with
garbage by such a broken Grub2.
From protocol 2.14 on Grub2 will write the version it is supporting
(but never a higher value than found to be supported by the kernel)
ored with 0x8000 to the version field of setup_header. This enables
the kernel to know up to which field Grub2 has written information
to. All fields after that are supposed to be clobbered.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: corbet@lwn.net
Cc: linux-doc@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181010061456.22238-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When a new resource group is created it is initialized with a default
allocation that considers which portions of cache are currently
available for sharing across all resource groups or which portions of
cache are currently unused.
If a CDP allocation forms part of a resource group that is in exclusive
mode then it should be ensured that no new allocation overlaps with any
resource that shares the underlying hardware. The current initial
allocation does not take this sharing of hardware into account and
a new allocation in a resource that shares the same
hardware would affect the exclusive resource group.
Fix this by considering the allocation of a peer RDT domain - a RDT
domain sharing the same hardware - as part of the test to determine
which portion of cache is in use and available for use.
Fixes: 95f0b77efa ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: jithu.joseph@intel.com
Cc: gavin.hindman@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/b1f7ec08b1695be067de416a4128466d49684317.1538603665.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The CBM overlap test is used to manage the allocations of RDT resources
where overlap is possible between resource groups. When a resource group
is in exclusive mode then there should be no overlap between resource
groups.
The current overlap test only considers overlap between the same
resources, for example, that usage of a RDT_RESOURCE_L2DATA resource
in one resource group does not overlap with usage of a RDT_RESOURCE_L2DATA
resource in another resource group. The problem with this is that it
allows overlap between a RDT_RESOURCE_L2DATA resource in one resource
group with a RDT_RESOURCE_L2CODE resource in another resource group -
even if both resource groups are in exclusive mode. This is a problem
because even though these appear to be different resources they end up
sharing the same underlying hardware and thus does not fulfill the
user's request for exclusive use of hardware resources.
Fix this by including the CDP peer (if there is one) in every CBM
overlap test. This does not impact the overlap between resources
within the same exclusive resource group that is allowed.
Fixes: 49f7b4efa1 ("x86/intel_rdt: Enable setting of exclusive mode")
Reported-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jithu Joseph <jithu.joseph@intel.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/e538b7f56f7ca15963dce2e00ac3be8edb8a68e1.1538603665.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce a utility that, when provided with a RDT resource and an
instance of this RDT resource (a RDT domain), would return pointers to
the RDT resource and RDT domain that share the same hardware. This is
specific to the CDP resources that share the same hardware.
For example, if a pointer to the RDT_RESOURCE_L2DATA resource (struct
rdt_resource) and a pointer to an instance of this resource (struct
rdt_domain) is provided, then it will return a pointer to the
RDT_RESOURCE_L2CODE resource as well as the specific instance that
shares the same hardware as the provided rdt_domain.
This utility is created in support of the "exclusive" resource group
mode where overlap of resource allocation between resource groups need
to be avoided. The overlap test need to consider not just the matching
resources, but also the resources that share the same hardware.
Temporarily mark it as unused in support of patch testing to avoid
compile warnings until it is used.
Fixes: 49f7b4efa1 ("x86/intel_rdt: Enable setting of exclusive mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jithu Joseph <jithu.joseph@intel.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/9b4bc4d59ba2e903b6a3eb17e16ef41a8e7b7c3e.1538603665.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While the DOC at the beginning of lib/bitmap.c explicitly states that
"The number of valid bits in a given bitmap does _not_ need to be an
exact multiple of BITS_PER_LONG.", some of the bitmap operations do
indeed access BITS_PER_LONG portions of the provided bitmap no matter
the size of the provided bitmap. For example, if bitmap_intersects()
is provided with an 8 bit bitmap the operation will access
BITS_PER_LONG bits from the provided bitmap. While the operation
ensures that these extra bits do not affect the result, the memory
is still accessed.
The capacity bitmasks (CBMs) are typically stored in u32 since they
can never exceed 32 bits. A few instances exist where a bitmap_*
operation is performed on a CBM by simply pointing the bitmap operation
to the stored u32 value.
The consequence of this pattern is that some bitmap_* operations will
access out-of-bounds memory when interacting with the provided CBM. This
is confirmed with a KASAN test that reports:
BUG: KASAN: stack-out-of-bounds in __bitmap_intersects+0xa2/0x100
and
BUG: KASAN: stack-out-of-bounds in __bitmap_weight+0x58/0x90
Fix this by moving any CBM provided to a bitmap operation needing
BITS_PER_LONG to an 'unsigned long' variable.
[ tglx: Changed related function arguments to unsigned long and got rid
of the _cbm extra step ]
Fixes: 72d5050566 ("x86/intel_rdt: Add utilities to test pseudo-locked region possibility")
Fixes: 49f7b4efa1 ("x86/intel_rdt: Enable setting of exclusive mode")
Fixes: d9b48c86eb ("x86/intel_rdt: Display resource groups' allocations' size in bytes")
Fixes: 95f0b77efa ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/69a428613a53f10e80594679ac726246020ff94f.1538686926.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce FS/GS base access functionality via <asm/fsgsbase.h>,
not yet used by anything directly.
Factor out task_seg_base() from x86/ptrace.c and rename it to
x86_fsgsbase_read_task() to make it part of the new helpers.
This will allow us to enhance FSGSBASE support and eventually enable
the FSBASE/GSBASE instructions.
An "inactive" GS base refers to a base saved at kernel entry
and being part of an inactive, non-running/stopped user-task.
(The typical ptrace model.)
Here are the new functions:
x86_fsbase_read_task()
x86_gsbase_read_task()
x86_fsbase_write_task()
x86_gsbase_write_task()
x86_fsbase_read_cpu()
x86_fsbase_write_cpu()
x86_gsbase_read_cpu_inactive()
x86_gsbase_write_cpu_inactive()
As an advantage of the unified namespace we can now see all FS/GSBASE
API use in the kernel via the following 'git grep' pattern:
$ git grep x86_.*sbase
[ mingo: Wrote new changelog. ]
Based-on-code-from: Andy Lutomirski <luto@kernel.org>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537312139-5580-3-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As described in:
77b0bf55bc: ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")
GCC's inlining heuristics are broken with common asm() patterns used in
kernel code, resulting in the effective disabling of inlining.
The workaround is to set an assembly macro and call it from the inline
assembly block. As a result GCC considers the inline assembly block as
a single instruction. (Which it isn't, but that's the best we can get.)
In this patch we wrap the paravirt call section tricks in a macro,
to hide it from GCC.
The effect of the patch is a more aggressive inlining, which also
causes a size increase of kernel.
text data bss dec hex filename
18147336 10226688 2957312 31331336 1de1408 ./vmlinux before
18162555 10226288 2957312 31346155 1de4deb ./vmlinux after (+14819)
The number of static text symbols (non-inlined functions) goes down:
Before: 40053
After: 39942 (-111)
[ mingo: Rewrote the changelog. ]
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alok Kataria <akataria@vmware.com>
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: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20181003213100.189959-8-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As described in:
77b0bf55bc: ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")
GCC's inlining heuristics are broken with common asm() patterns used in
kernel code, resulting in the effective disabling of inlining.
The workaround is to set an assembly macro and call it from the inline
assembly block. As a result GCC considers the inline assembly block as
a single instruction. (Which it isn't, but that's the best we can get.)
This patch increases the kernel size:
text data bss dec hex filename
18146889 10225380 2957312 31329581 1de0d2d ./vmlinux before
18147336 10226688 2957312 31331336 1de1408 ./vmlinux after (+1755)
But enables more aggressive inlining (and probably better branch decisions).
The number of static text symbols in vmlinux is much lower:
Before: 40218
After: 40053 (-165)
The assembly code gets harder to read due to the extra macro layer.
[ mingo: Rewrote the changelog. ]
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@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/20181003213100.189959-7-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As described in:
77b0bf55bc: ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")
GCC's inlining heuristics are broken with common asm() patterns used in
kernel code, resulting in the effective disabling of inlining.
The workaround is to set an assembly macro and call it from the inline
assembly block - i.e. to macrify the affected block.
As a result GCC considers the inline assembly block as a single instruction.
This patch handles the LOCK prefix, allowing more aggresive inlining:
text data bss dec hex filename
18140140 10225284 2957312 31322736 1ddf270 ./vmlinux before
18146889 10225380 2957312 31329581 1de0d2d ./vmlinux after (+6845)
This is the reduction in non-inlined functions:
Before: 40286
After: 40218 (-68)
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@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/20181003213100.189959-6-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As described in:
77b0bf55bc: ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")
GCC's inlining heuristics are broken with common asm() patterns used in
kernel code, resulting in the effective disabling of inlining.
The workaround is to set an assembly macro and call it from the inline
assembly block. As a result GCC considers the inline assembly block as
a single instruction. (Which it isn't, but that's the best we can get.)
This patch allows GCC to inline simple functions such as __get_seccomp_filter().
To no-one's surprise the result is that GCC performs more aggressive (read: correct)
inlining decisions in these senarios, which reduces the kernel size and presumably
also speeds it up:
text data bss dec hex filename
18140970 10225412 2957312 31323694 1ddf62e ./vmlinux before
18140140 10225284 2957312 31322736 1ddf270 ./vmlinux after (-958)
16 fewer static text symbols:
Before: 40302
After: 40286 (-16)
these got inlined instead.
Functions such as kref_get(), free_user(), fuse_file_get() now get inlined. Hurray!
[ mingo: Rewrote the changelog. ]
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Josh Poimboeuf <jpoimboe@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/20181003213100.189959-5-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As described in:
77b0bf55bc: ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")
GCC's inlining heuristics are broken with common asm() patterns used in
kernel code, resulting in the effective disabling of inlining.
In the case of objtool the resulting borkage can be significant, since all the
annotations of objtool are discarded during linkage and never inlined,
yet GCC bogusly considers most functions affected by objtool annotations
as 'too large'.
The workaround is to set an assembly macro and call it from the inline
assembly block. As a result GCC considers the inline assembly block as
a single instruction. (Which it isn't, but that's the best we can get.)
This increases the kernel size slightly:
text data bss dec hex filename
18140829 10224724 2957312 31322865 1ddf2f1 ./vmlinux before
18140970 10225412 2957312 31323694 1ddf62e ./vmlinux after (+829)
The number of static text symbols (i.e. non-inlined functions) is reduced:
Before: 40321
After: 40302 (-19)
[ mingo: Rewrote the changelog. ]
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-sparse@vger.kernel.org
Link: http://lkml.kernel.org/r/20181003213100.189959-4-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Using macros in inline assembly allows us to work around bugs
in GCC's inlining decisions.
Compile macros.S and use it to assemble all C files.
Currently only x86 will use it.
Background:
The inlining pass of GCC doesn't include an assembler, so it's not aware
of basic properties of the generated code, such as its size in bytes,
or that there are such things as discontiuous blocks of code and data
due to the newfangled linker feature called 'sections' ...
Instead GCC uses a lazy and fragile heuristic: it does a linear count of
certain syntactic and whitespace elements in inlined assembly block source
code, such as a count of new-lines and semicolons (!), as a poor substitute
for "code size and complexity".
Unsurprisingly this heuristic falls over and breaks its neck whith certain
common types of kernel code that use inline assembly, such as the frequent
practice of putting useful information into alternative sections.
As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions
are effectively disabled for inlined functions that make use of such asm()
blocks, because GCC thinks those sections of code are "large" - when in
reality they are often result in just a very low number of machine
instructions.
This absolute lack of inlining provess when GCC comes across such asm()
blocks both increases generated kernel code size and causes performance
overhead, which is particularly noticeable on paravirt kernels, which make
frequent use of these inlining facilities in attempt to stay out of the
way when running on baremetal hardware.
Instead of fixing the compiler we use a workaround: we set an assembly macro
and call it from the inlined assembly block. As a result GCC considers the
inline assembly block as a single instruction. (Which it often isn't but I digress.)
This uglifies and bloats the source code - for example just the refcount
related changes have this impact:
Makefile | 9 +++++++--
arch/x86/Makefile | 7 +++++++
arch/x86/kernel/macros.S | 7 +++++++
scripts/Kbuild.include | 4 +++-
scripts/mod/Makefile | 2 ++
5 files changed, 26 insertions(+), 3 deletions(-)
Yay readability and maintainability, it's not like assembly code is hard to read
and maintain ...
We also hope that GCC will eventually get fixed, but we are not holding
our breath for that. Yet we are optimistic, it might still happen, any decade now.
[ mingo: Wrote new changelog describing the background. ]
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In resctrl filesystem, mount options exist to enable L3/L2 CDP and MBA
Software Controller features if the platform supports them:
mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps]] /sys/fs/resctrl
But currently only "cdp" option is displayed in /proc/mounts. "cdpl2" and
"mba_MBps" options are not shown even when they are active.
Before:
# mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl
# grep resctrl /proc/mounts
/sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp 0 0
After:
# mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl
# grep resctrl /proc/mounts
/sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp,mba_MBps 0 0
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1536796118-60135-1-git-send-email-fenghua.yu@intel.com
Going primarily by:
https://en.wikipedia.org/wiki/List_of_Intel_Atom_microprocessors
with additional information gleaned from other related pages; notably:
- Bonnell shrink was called Saltwell
- Moorefield is the Merriefield refresh which makes it Airmont
The general naming scheme is: FAM6_ATOM_UARCH_SOCTYPE
for i in `git grep -l FAM6_ATOM` ; do
sed -i -e 's/ATOM_PINEVIEW/ATOM_BONNELL/g' \
-e 's/ATOM_LINCROFT/ATOM_BONNELL_MID/' \
-e 's/ATOM_PENWELL/ATOM_SALTWELL_MID/g' \
-e 's/ATOM_CLOVERVIEW/ATOM_SALTWELL_TABLET/g' \
-e 's/ATOM_CEDARVIEW/ATOM_SALTWELL/g' \
-e 's/ATOM_SILVERMONT1/ATOM_SILVERMONT/g' \
-e 's/ATOM_SILVERMONT2/ATOM_SILVERMONT_X/g' \
-e 's/ATOM_MERRIFIELD/ATOM_SILVERMONT_MID/g' \
-e 's/ATOM_MOOREFIELD/ATOM_AIRMONT_MID/g' \
-e 's/ATOM_DENVERTON/ATOM_GOLDMONT_X/g' \
-e 's/ATOM_GEMINI_LAKE/ATOM_GOLDMONT_PLUS/g' ${i}
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: dave.hansen@linux.intel.com
Cc: len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The success of a cache pseudo-locked region is measured using
performance monitoring events that are programmed directly at the time
the user requests a measurement.
Modifying the performance event registers directly is not appropriate
since it circumvents the in-kernel perf infrastructure that exists to
manage these resources and provide resource arbitration to the
performance monitoring hardware.
The cache pseudo-locking measurements are modified to use the in-kernel
perf infrastructure. Performance events are created and validated with
the appropriate perf API. The performance counters are still read as
directly as possible to avoid the additional cache hits. This is
done safely by first ensuring with the perf API that the counters have
been programmed correctly and only accessing the counters in an
interrupt disabled section where they are not able to be moved.
As part of the transition to the in-kernel perf infrastructure the L2
and L3 measurements are split into two separate measurements that can
be triggered independently. This separation prevents additional cache
misses incurred during the extra testing code used to decide if a
L2 and/or L3 measurement should be made.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: peterz@infradead.org
Cc: acme@kernel.org
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/fc24e728b446404f42c78573c506e98cd0599873.1537468643.git.reinette.chatre@intel.com
A perf event has many attributes that are maintained in a separate
structure that should be provided when a new perf_event is created.
In preparation for the transition to perf_events the required attribute
structures are created for all the events that may be used in the
measurements. Most attributes for all the events are identical. The
actual configuration, what specifies what needs to be measured, is what
will be different between the events used. This configuration needs to
be done with X86_CONFIG that cannot be used as part of the designated
initializers used here, this will be introduced later.
Although they do look identical at this time the attribute structures
needs to be maintained separately since a perf_event will maintain a
pointer to its unique attributes.
In support of patch testing the new structs are given the unused attribute
until their use in later patches.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: acme@kernel.org
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/1822f6164e221a497648d108913d056ab675d5d0.1537377064.git.reinette.chatre@intel.com
Local register variables were used in an effort to improve the
accuracy of the measurement of cache residency of a pseudo-locked
region. This was done to ensure that only the cache residency of
the memory is measured and not the cache residency of the variables
used to perform the measurement.
While local register variables do accomplish the goal they do require
significant care since different architectures have different registers
available. Local register variables also cannot be used with valuable
developer tools like KASAN.
Significant testing has shown that similar accuracy in measurement
results can be obtained by replacing local register variables with
regular local variables.
Make use of local variables in the critical code but do so with
READ_ONCE() to prevent the compiler from merging or refetching reads.
Ensure these variables are initialized before the measurement starts,
and ensure it is only the local variables that are accessed during
the measurement.
With the removal of the local register variables and using READ_ONCE()
there is no longer a motivation for using a direct wrmsr call (that
avoids the additional tracing code that may clobber the local register
variables).
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: acme@kernel.org
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/f430f57347414e0691765d92b144758ab93d8407.1537377064.git.reinette.chatre@intel.com
Use the for_each_of_cpu_node iterator to iterate over cpu nodes. This
has the side effect of defaulting to iterating using "cpu" node names in
preference to the deprecated (for FDT) device_type == "cpu".
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
