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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 APIC updates from Thomas Gleixner:
"This update provides a major overhaul of the APIC initialization and
vector allocation code:
- Unification of the APIC and interrupt mode setup which was
scattered all over the place and was hard to follow. This also
distangles the timer setup from the APIC initialization which
brings a clear separation of functionality.
Great detective work from Dou Lyiang!
- Refactoring of the x86 vector allocation mechanism. The existing
code was based on nested loops and rather convoluted APIC callbacks
which had a horrible worst case behaviour and tried to serve all
different use cases in one go. This led to quite odd hacks when
supporting the new managed interupt facility for multiqueue devices
and made it more or less impossible to deal with the vector space
exhaustion which was a major roadblock for server hibernation.
Aside of that the code dealing with cpu hotplug and the system
vectors was disconnected from the actual vector management and
allocation code, which made it hard to follow and maintain.
Utilizing the new bitmap matrix allocator core mechanism, the new
allocator and management code consolidates the handling of system
vectors, legacy vectors, cpu hotplug mechanisms and the actual
allocation which needs to be aware of system and legacy vectors and
hotplug constraints into a single consistent entity.
This has one visible change: The support for multi CPU targets of
interrupts, which is only available on a certain subset of
CPUs/APIC variants has been removed in favour of single interrupt
targets. A proper analysis of the multi CPU target feature revealed
that there is no real advantage as the vast majority of interrupts
end up on the CPU with the lowest APIC id in the set of target CPUs
anyway. That change was agreed on by the relevant folks and allowed
to simplify the implementation significantly and to replace rather
fragile constructs like the vector cleanup IPI with straight
forward and solid code.
Furthermore this allowed to cleanly separate the allocation details
for legacy, normal and managed interrupts:
* Legacy interrupts are not longer wasting 16 vectors
unconditionally
* Managed interrupts have now a guaranteed vector reservation, but
the actual vector assignment happens when the interrupt is
requested. It's guaranteed not to fail.
* Normal interrupts no longer allocate vectors unconditionally
when the interrupt is set up (IO/APIC init or MSI(X) enable).
The mechanism has been switched to a best effort reservation
mode. The actual allocation happens when the interrupt is
requested. Contrary to managed interrupts the request can fail
due to vector space exhaustion, but drivers must handle a fail
of request_irq() anyway. When the interrupt is freed, the vector
is handed back as well.
This solves a long standing problem with large unconditional
vector allocations for a certain class of enterprise devices
which prevented server hibernation due to vector space
exhaustion when the unused allocated vectors had to be migrated
to CPU0 while unplugging all non boot CPUs.
The code has been equipped with trace points and detailed debugfs
information to aid analysis of the vector space"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
x86/vector/msi: Select CONFIG_GENERIC_IRQ_RESERVATION_MODE
PCI/MSI: Set MSI_FLAG_MUST_REACTIVATE in core code
genirq: Add config option for reservation mode
x86/vector: Use correct per cpu variable in free_moved_vector()
x86/apic/vector: Ignore set_affinity call for inactive interrupts
x86/apic: Fix spelling mistake: "symmectic" -> "symmetric"
x86/apic: Use dead_cpu instead of current CPU when cleaning up
ACPI/init: Invoke early ACPI initialization earlier
x86/vector: Respect affinity mask in irq descriptor
x86/irq: Simplify hotplug vector accounting
x86/vector: Switch IOAPIC to global reservation mode
x86/vector/msi: Switch to global reservation mode
x86/vector: Handle managed interrupts proper
x86/io_apic: Reevaluate vector configuration on activate()
iommu/amd: Reevaluate vector configuration on activate()
iommu/vt-d: Reevaluate vector configuration on activate()
x86/apic/msi: Force reactivation of interrupts at startup time
x86/vector: Untangle internal state from irq_cfg
x86/vector: Compile SMP only code conditionally
x86/apic: Remove unused callbacks
...
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Commit b70543a0b2b6("x86/idt: Move regular trap init to tables") moves
regular trap init for each trap vector into a table based
initialization. It introduced the initialization for vector X86_TRAP_BP
which was not in the code which it replaced. This breaks uprobe
functionality for x86_32; the probed program segfaults instead of handling
the probe proper.
The reason for this is that TRAP_BP is set up as system interrupt gate
(DPL3) in the early IDT and then replaced by a regular interrupt gate
(DPL0) in idt_setup_traps(). The DPL0 restriction causes the int3 trap
to fail with a #GP resulting in a SIGSEGV of the probed program.
On 64bit this does not cause a problem because the IDT entry is replaced
with a system interrupt gate (DPL3) with interrupt stack afterwards.
Remove X86_TRAP_BP from the def_idts table which is used in
idt_setup_traps(). Remove a redundant entry for X86_TRAP_NMI in def_idts
while at it. Tested on both x86_64 and x86_32.
[ tglx: Amended changelog with a description of the root cause ]
Fixes: b70543a0b2b6("x86/idt: Move regular trap init to tables")
Reported-and-tested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: a.p.zijlstra@chello.nl
Cc: ast@fb.com
Cc: oleg@redhat.com
Cc: luto@kernel.org
Cc: kernel-team@fb.com
Link: https://lkml.kernel.org/r/20171108192845.552709-1-yhs@fb.com
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used_vectors is a nisnomer as it only has the system vectors which are
excluded from the regular vector allocation marked. It's not what the name
suggests storage for the actually used vectors.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213154.150209009@linutronix.de
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Andrei Vagin reported a CRIU regression and bisected it back to:
90f6225fba0c ("x86/idt: Move IST stack based traps to table init")
This table init conversion loses the system-gate property of X86_TRAP_BP
and erroneously moves it from DPL3 to DPL0.
Fix it.
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: dvlasenk@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: peterz@infradead.org
Cc: brgerst@gmail.com
Cc: rostedt@goodmis.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: jpoimboe@redhat.com
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: torvalds@linux-foundation.org
Cc: tip-bot for Jacob Shin <tipbot@zytor.com>
Link: http://lkml.kernel.org/r/20170901082630.xvyi5bwk6etmppqc@gmail.com
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set_intr_gate() is an internal function of the IDT code. The only user left
is the KVM code which replaces the pagefault handler eventually.
Provide an explicit update_intr_gate() function and make set_intr_gate()
static. While at it replace the magic number 14 in the KVM code with the
proper trap define.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.663008004@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The only users of alloc_intr_gate() are hypervisors, which both check the
used_vectors bitmap whether they have allocated the gate already. Move that
check into alloc_intr_gate() and simplify the users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.580830286@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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None of this is performance sensitive in any way - so debloat the kernel.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.502052875@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Move the gate intialization from interrupt init to the IDT code so all IDT
related operations are at a single place.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.340209198@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Replace the APIC/SMP vector gate initialization with the table based
mechanism.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.260177013@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Initialize the regular traps with a table.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.182128165@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Initialize the IST based traps via a table.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.091328949@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Add the debug_idt init table and make use of it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.006502252@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Add the initialization table for the early trap setup and replace the early
trap init code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.929139008@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The IDT setup code is handled in several places. All of them use variants
of set_intr_gate() inlines. This can be done with a table based
initialization, which allows to reduce the inline zoo and puts all IDT
related code and information into a single place.
Add the infrastructure.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.849877032@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The early IDT setup can be done in C code like it's done on 64-bit kernels.
Reuse the 64-bit version.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.757980775@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The early IDT handler setup is done in C entry code on 64-bit kernels and in
ASM entry code on 32-bit kernels.
Move the 64-bit variant to the IDT code so it can be shared with 32-bit
in the next step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.679561404@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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kexec and reboot have both code to invalidate IDT. Create a common function
and use it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.600953282@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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32-bit kernels have the idt_descr defined in the low level assembly entry code,
but there is no good reason for that.
Move it into the C file and use the 64-bit version of it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.445862201@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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IDT related code lives scattered around in various places. Create a new
source file in arch/x86/kernel/idt.c to hold it.
Move the idt_tables and descriptors to it for a start. Follow up patches
will gradually move more code over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.367081121@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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