Commit Graph

3153 Commits

Author SHA1 Message Date
Marcelo Tosatti f1e2b26003 KVM: Allow adjust_tsc_offset to be in host or guest cycles
Redefine the API to take a parameter indicating whether an
adjustment is in host or guest cycles.

Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:07 +02:00
Zachary Amsden 6f526ec538 KVM: Add last_host_tsc tracking back to KVM
The variable last_host_tsc was removed from upstream code.  I am adding
it back for two reasons.  First, it is unnecessary to use guest TSC
computation to conclude information about the host TSC.  The guest may
set the TSC backwards (this case handled by the previous patch), but
the computation of guest TSC (and fetching an MSR) is significanlty more
work and complexity than simply reading the hardware counter.  In addition,
we don't actually need the guest TSC for any part of the computation,
by always recomputing the offset, we can eliminate the need to deal with
the current offset and any scaling factors that may apply.

The second reason is that later on, we are going to be using the host
TSC value to restore TSC offsets after a host S4 suspend, so we need to
be reading the host values, not the guest values here.

Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:06 +02:00
Zachary Amsden 5d3cb0f6a8 KVM: Improve TSC offset matching
There are a few improvements that can be made to the TSC offset
matching code.  First, we don't need to call the 128-bit multiply
(especially on a constant number), the code works much nicer to
do computation in nanosecond units.

Second, the way everything is setup with software TSC rate scaling,
we currently have per-cpu rates.  Obviously this isn't too desirable
to use in practice, but if for some reason we do change the rate of
all VCPUs at runtime, then reset the TSCs, we will only want to
match offsets for VCPUs running at the same rate.

Finally, for the case where we have an unstable host TSC, but
rate scaling is being done in hardware, we should call the platform
code to compute the TSC offset, so the math is reorganized to recompute
the base instead, then transform the base into an offset using the
existing API.

[avi: fix 64-bit division on i386]

Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: Fix 64-bit division in kvm_write_tsc()

Breaks i386 build.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:03 +02:00
Zachary Amsden cc578287e3 KVM: Infrastructure for software and hardware based TSC rate scaling
This requires some restructuring; rather than use 'virtual_tsc_khz'
to indicate whether hardware rate scaling is in effect, we consider
each VCPU to always have a virtual TSC rate.  Instead, there is new
logic above the vendor-specific hardware scaling that decides whether
it is even necessary to use and updates all rate variables used by
common code.  This means we can simply query the virtual rate at
any point, which is needed for software rate scaling.

There is also now a threshold added to the TSC rate scaling; minor
differences and variations of measured TSC rate can accidentally
provoke rate scaling to be used when it is not needed.  Instead,
we have a tolerance variable called tsc_tolerance_ppm, which is
the maximum variation from user requested rate at which scaling
will be used.  The default is 250ppm, which is the half the
threshold for NTP adjustment, allowing for some hardware variation.

In the event that hardware rate scaling is not available, we can
kludge a bit by forcing TSC catchup to turn on when a faster than
hardware speed has been requested, but there is nothing available
yet for the reverse case; this requires a trap and emulate software
implementation for RDTSC, which is still forthcoming.

[avi: fix 64-bit division on i386]

Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:09:35 +02:00
Marcelo Tosatti a59cb29e4d KVM: x86: increase recommended max vcpus to 160
Increase recommended max vcpus from 64 to 160 (tested internally
at Red Hat).

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:57:34 +02:00
Igor Mammedov df156f90a0 x86: Introduce x86_cpuinit.early_percpu_clock_init hook
When kvm guest uses kvmclock, it may hang on vcpu hot-plug.
This is caused by an overflow in pvclock_get_nsec_offset,

    u64 delta = tsc - shadow->tsc_timestamp;

which in turn is caused by an undefined values from percpu
hv_clock that hasn't been initialized yet.
Uninitialized clock on being booted cpu is accessed from
   start_secondary
    -> smp_callin
      ->  smp_store_cpu_info
        -> identify_secondary_cpu
          -> mtrr_ap_init
            -> mtrr_restore
              -> stop_machine_from_inactive_cpu
                -> queue_stop_cpus_work
                  ...
                    -> sched_clock
                      -> kvm_clock_read
which is well before x86_cpuinit.setup_percpu_clockev call in
start_secondary, where percpu clock is initialized.

This patch introduces a hook that allows to setup/initialize
per_cpu clock early and avoid overflow due to reading
  - undefined values
  - old values if cpu was offlined and then onlined again

Another possible early user of this clock source is ftrace that
accesses it to get timestamps for ring buffer entries. So if
mtrr_ap_init is moved from identify_secondary_cpu to past
x86_cpuinit.setup_percpu_clockev in start_secondary, ftrace
may cause the same overflow/hang on cpu hot-plug anyway.

More complete description of the problem:
  https://lkml.org/lkml/2012/2/2/101

Credits to Marcelo Tosatti <mtosatti@redhat.com> for hook idea.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:57:32 +02:00
Takuya Yoshikawa 3ea8b75e47 KVM: MMU: Remove unused kvm_pte_chain
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:42 +02:00
Christian Borntraeger b9e5dc8d45 KVM: provide synchronous registers in kvm_run
On some cpus the overhead for virtualization instructions is in the same
range as a system call. Having to call multiple ioctls to get set registers
will make certain userspace handled exits more expensive than necessary.
Lets provide a section in kvm_run that works as a shared save area
for guest registers.
We also provide two 64bit flags fields (architecture specific), that will
specify
1. which parts of these fields are valid.
2. which registers were modified by userspace

Each bit for these flag fields will define a group of registers (like
general purpose) or a single register.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:22 +02:00
Boris Ostrovsky 2b036c6b86 KVM: SVM: Add support for AMD's OSVW feature in guests
In some cases guests should not provide workarounds for errata even when the
physical processor is affected. For example, because of erratum 400 on family
10h processors a Linux guest will read an MSR (resulting in VMEXIT) before
going to idle in order to avoid getting stuck in a non-C0 state. This is not
necessary: HLT and IO instructions are intercepted and therefore there is no
reason for erratum 400 workaround in the guest.

This patch allows us to present a guest with certain errata as fixed,
regardless of the state of actual hardware.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:21 +02:00
Linus Torvalds 7e16838d94 i387: support lazy restore of FPU state
This makes us recognize when we try to restore FPU state that matches
what we already have in the FPU on this CPU, and avoids the restore
entirely if so.

To do this, we add two new data fields:

 - a percpu 'fpu_owner_task' variable that gets written any time we
   update the "has_fpu" field, and thus acts as a kind of back-pointer
   to the task that owns the CPU.  The exception is when we save the FPU
   state as part of a context switch - if the save can keep the FPU
   state around, we leave the 'fpu_owner_task' variable pointing at the
   task whose FP state still remains on the CPU.

 - a per-thread 'last_cpu' field, that indicates which CPU that thread
   used its FPU on last.  We update this on every context switch
   (writing an invalid CPU number if the last context switch didn't
   leave the FPU in a lazily usable state), so we know that *that*
   thread has done nothing else with the FPU since.

These two fields together can be used when next switching back to the
task to see if the CPU still matches: if 'fpu_owner_task' matches the
task we are switching to, we know that no other task (or kernel FPU
usage) touched the FPU on this CPU in the meantime, and if the current
CPU number matches the 'last_cpu' field, we know that this thread did no
other FP work on any other CPU, so the FPU state on the CPU must match
what was saved on last context switch.

In that case, we can avoid the 'f[x]rstor' entirely, and just clear the
CR0.TS bit.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20 10:58:54 -08:00
Linus Torvalds 80ab6f1e8c i387: use 'restore_fpu_checking()' directly in task switching code
This inlines what is usually just a couple of instructions, but more
importantly it also fixes the theoretical error case (can that FPU
restore really ever fail? Maybe we should remove the checking).

We can't start sending signals from within the scheduler, we're much too
deep in the kernel and are holding the runqueue lock etc.  So don't
bother even trying.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20 10:58:28 -08:00
Linus Torvalds cea20ca3f3 i387: fix up some fpu_counter confusion
This makes sure we clear the FPU usage counter for newly created tasks,
just so that we start off in a known state (for example, don't try to
preload the FPU state on the first task switch etc).

It also fixes a thinko in when we increment the fpu_counter at task
switch time, introduced by commit 34ddc81a23 ("i387: re-introduce FPU
state preloading at context switch time").  We should increment the
*new* task fpu_counter, not the old task, and only if we decide to use
that state (whether lazily or preloaded).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20 10:24:09 -08:00
Linus Torvalds 34ddc81a23 i387: re-introduce FPU state preloading at context switch time
After all the FPU state cleanups and finally finding the problem that
caused all our FPU save/restore problems, this re-introduces the
preloading of FPU state that was removed in commit b3b0870ef3 ("i387:
do not preload FPU state at task switch time").

However, instead of simply reverting the removal, this reimplements
preloading with several fixes, most notably

 - properly abstracted as a true FPU state switch, rather than as
   open-coded save and restore with various hacks.

   In particular, implementing it as a proper FPU state switch allows us
   to optimize the CR0.TS flag accesses: there is no reason to set the
   TS bit only to then almost immediately clear it again.  CR0 accesses
   are quite slow and expensive, don't flip the bit back and forth for
   no good reason.

 - Make sure that the same model works for both x86-32 and x86-64, so
   that there are no gratuitous differences between the two due to the
   way they save and restore segment state differently due to
   architectural differences that really don't matter to the FPU state.

 - Avoid exposing the "preload" state to the context switch routines,
   and in particular allow the concept of lazy state restore: if nothing
   else has used the FPU in the meantime, and the process is still on
   the same CPU, we can avoid restoring state from memory entirely, just
   re-expose the state that is still in the FPU unit.

   That optimized lazy restore isn't actually implemented here, but the
   infrastructure is set up for it.  Of course, older CPU's that use
   'fnsave' to save the state cannot take advantage of this, since the
   state saving also trashes the state.

In other words, there is now an actual _design_ to the FPU state saving,
rather than just random historical baggage.  Hopefully it's easier to
follow as a result.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-18 14:03:48 -08:00
Linus Torvalds f94edacf99 i387: move TS_USEDFPU flag from thread_info to task_struct
This moves the bit that indicates whether a thread has ownership of the
FPU from the TS_USEDFPU bit in thread_info->status to a word of its own
(called 'has_fpu') in task_struct->thread.has_fpu.

This fixes two independent bugs at the same time:

 - changing 'thread_info->status' from the scheduler causes nasty
   problems for the other users of that variable, since it is defined to
   be thread-synchronous (that's what the "TS_" part of the naming was
   supposed to indicate).

   So perfectly valid code could (and did) do

	ti->status |= TS_RESTORE_SIGMASK;

   and the compiler was free to do that as separate load, or and store
   instructions.  Which can cause problems with preemption, since a task
   switch could happen in between, and change the TS_USEDFPU bit. The
   change to TS_USEDFPU would be overwritten by the final store.

   In practice, this seldom happened, though, because the 'status' field
   was seldom used more than once, so gcc would generally tend to
   generate code that used a read-modify-write instruction and thus
   happened to avoid this problem - RMW instructions are naturally low
   fat and preemption-safe.

 - On x86-32, the current_thread_info() pointer would, during interrupts
   and softirqs, point to a *copy* of the real thread_info, because
   x86-32 uses %esp to calculate the thread_info address, and thus the
   separate irq (and softirq) stacks would cause these kinds of odd
   thread_info copy aliases.

   This is normally not a problem, since interrupts aren't supposed to
   look at thread information anyway (what thread is running at
   interrupt time really isn't very well-defined), but it confused the
   heck out of irq_fpu_usable() and the code that tried to squirrel
   away the FPU state.

   (It also caused untold confusion for us poor kernel developers).

It also turns out that using 'task_struct' is actually much more natural
for most of the call sites that care about the FPU state, since they
tend to work with the task struct for other reasons anyway (ie
scheduling).  And the FPU data that we are going to save/restore is
found there too.

Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to
the %esp issue.

Cc: Arjan van de Ven <arjan@linux.intel.com>
Reported-and-tested-by: Raphael Prevost <raphael@buro.asia>
Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-18 10:19:41 -08:00
Linus Torvalds 4903062b54 i387: move AMD K7/K8 fpu fxsave/fxrstor workaround from save to restore
The AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is
pending.  In order to not leak FIP state from one process to another, we
need to do a floating point load after the fxsave of the old process,
and before the fxrstor of the new FPU state.  That resets the state to
the (uninteresting) kernel load, rather than some potentially sensitive
user information.

We used to do this directly after the FPU state save, but that is
actually very inconvenient, since it

 (a) corrupts what is potentially perfectly good FPU state that we might
     want to lazy avoid restoring later and

 (b) on x86-64 it resulted in a very annoying ordering constraint, where
     "__unlazy_fpu()" in the task switch needs to be delayed until after
     the DS segment has been reloaded just to get the new DS value.

Coupling it to the fxrstor instead of the fxsave automatically avoids
both of these issues, and also ensures that we only do it when actually
necessary (the FP state after a save may never actually get used).  It's
simply a much more natural place for the leaked state cleanup.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16 19:11:15 -08:00
Linus Torvalds b3b0870ef3 i387: do not preload FPU state at task switch time
Yes, taking the trap to re-load the FPU/MMX state is expensive, but so
is spending several days looking for a bug in the state save/restore
code.  And the preload code has some rather subtle interactions with
both paravirtualization support and segment state restore, so it's not
nearly as simple as it should be.

Also, now that we no longer necessarily depend on a single bit (ie
TS_USEDFPU) for keeping track of the state of the FPU, we migth be able
to do better.  If we are really switching between two processes that
keep touching the FP state, save/restore is inevitable, but in the case
of having one process that does most of the FPU usage, we may actually
be able to do much better than the preloading.

In particular, we may be able to keep track of which CPU the process ran
on last, and also per CPU keep track of which process' FP state that CPU
has.  For modern CPU's that don't destroy the FPU contents on save time,
that would allow us to do a lazy restore by just re-enabling the
existing FPU state - with no restore cost at all!

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16 15:45:23 -08:00
Linus Torvalds 6d59d7a9f5 i387: don't ever touch TS_USEDFPU directly, use helper functions
This creates three helper functions that do the TS_USEDFPU accesses, and
makes everybody that used to do it by hand use those helpers instead.

In addition, there's a couple of helper functions for the "change both
CR0.TS and TS_USEDFPU at the same time" case, and the places that do
that together have been changed to use those.  That means that we have
fewer random places that open-code this situation.

The intent is partly to clarify the code without actually changing any
semantics yet (since we clearly still have some hard to reproduce bug in
this area), but also to make it much easier to use another approach
entirely to caching the CR0.TS bit for software accesses.

Right now we use a bit in the thread-info 'status' variable (this patch
does not change that), but we might want to make it a full field of its
own or even make it a per-cpu variable.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16 13:33:12 -08:00
Linus Torvalds b6c66418dc i387: move TS_USEDFPU clearing out of __save_init_fpu and into callers
Touching TS_USEDFPU without touching CR0.TS is confusing, so don't do
it.  By moving it into the callers, we always do the TS_USEDFPU next to
the CR0.TS accesses in the source code, and it's much easier to see how
the two go hand in hand.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16 12:22:48 -08:00
Linus Torvalds 15d8791cae i387: fix x86-64 preemption-unsafe user stack save/restore
Commit 5b1cbac377 ("i387: make irq_fpu_usable() tests more robust")
added a sanity check to the #NM handler to verify that we never cause
the "Device Not Available" exception in kernel mode.

However, that check actually pinpointed a (fundamental) race where we do
cause that exception as part of the signal stack FPU state save/restore
code.

Because we use the floating point instructions themselves to save and
restore state directly from user mode, we cannot do that atomically with
testing the TS_USEDFPU bit: the user mode access itself may cause a page
fault, which causes a task switch, which saves and restores the FP/MMX
state from the kernel buffers.

This kind of "recursive" FP state save is fine per se, but it means that
when the signal stack save/restore gets restarted, it will now take the
'#NM' exception we originally tried to avoid.  With preemption this can
happen even without the page fault - but because of the user access, we
cannot just disable preemption around the save/restore instruction.

There are various ways to solve this, including using the
"enable/disable_page_fault()" helpers to not allow page faults at all
during the sequence, and fall back to copying things by hand without the
use of the native FP state save/restore instructions.

However, the simplest thing to do is to just allow the #NM from kernel
space, but fix the race in setting and clearing CR0.TS that this all
exposed: the TS bit changes and the TS_USEDFPU bit absolutely have to be
atomic wrt scheduling, so while the actual state save/restore can be
interrupted and restarted, the act of actually clearing/setting CR0.TS
and the TS_USEDFPU bit together must not.

Instead of just adding random "preempt_disable/enable()" calls to what
is already excessively ugly code, this introduces some helper functions
that mostly mirror the "kernel_fpu_begin/end()" functionality, just for
the user state instead.

Those helper functions should probably eventually replace the other
ad-hoc CR0.TS and TS_USEDFPU tests too, but I'll need to think about it
some more: the task switching functionality in particular needs to
expose the difference between the 'prev' and 'next' threads, while the
new helper functions intentionally were written to only work with
'current'.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16 09:15:04 -08:00
Linus Torvalds c38e234562 i387: fix sense of sanity check
The check for save_init_fpu() (introduced in commit 5b1cbac37798: "i387:
make irq_fpu_usable() tests more robust") was the wrong way around, but
I hadn't noticed, because my "tests" were bogus: the FPU exceptions are
disabled by default, so even doing a divide by zero never actually
triggers this code at all unless you do extra work to enable them.

So if anybody did enable them, they'd get one spurious warning.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-15 08:05:18 -08:00
Linus Torvalds 5b1cbac377 i387: make irq_fpu_usable() tests more robust
Some code - especially the crypto layer - wants to use the x86
FP/MMX/AVX register set in what may be interrupt (typically softirq)
context.

That *can* be ok, but the tests for when it was ok were somewhat
suspect.  We cannot touch the thread-specific status bits either, so
we'd better check that we're not going to try to save FP state or
anything like that.

Now, it may be that the TS bit is always cleared *before* we set the
USEDFPU bit (and only set when we had already cleared the USEDFP
before), so the TS bit test may actually have been sufficient, but it
certainly was not obviously so.

So this explicitly verifies that we will not touch the TS_USEDFPU bit,
and adds a few related sanity-checks.  Because it seems that somehow
AES-NI is corrupting user FP state.  The cause is not clear, and this
patch doesn't fix it, but while debugging it I really wanted the code to
be more obviously correct and robust.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-13 13:56:14 -08:00
Linus Torvalds be98c2cdb1 i387: math_state_restore() isn't called from asm
It was marked asmlinkage for some really old and stale legacy reasons.
Fix that and the equally stale comment.

Noticed when debugging the irq_fpu_usable() bugs.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-13 13:47:25 -08:00
Linus Torvalds 14fdbf7eb4 Merge branch 'kvm-updates/3.3' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Fixing a regression with the PMU MSRs when PMU virtualization is
disabled, a guest-internal DoS with the SYSCALL instruction, and a dirty
memory logging race that may cause live migration to fail.

* 'kvm-updates/3.3' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: do not #GP on perf MSR writes when vPMU is disabled
  KVM: x86: fix missing checks in syscall emulation
  KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid"
  KVM: Fix __set_bit() race in mark_page_dirty() during dirty logging
2012-02-06 16:26:58 -08:00
Stephan Bärwolf c2226fc9e8 KVM: x86: fix missing checks in syscall emulation
On hosts without this patch, 32bit guests will crash (and 64bit guests
may behave in a wrong way) for example by simply executing following
nasm-demo-application:

    [bits 32]
    global _start
    SECTION .text
    _start: syscall

(I tested it with winxp and linux - both always crashed)

    Disassembly of section .text:

    00000000 <_start>:
       0:   0f 05                   syscall

The reason seems a missing "invalid opcode"-trap (int6) for the
syscall opcode "0f05", which is not available on Intel CPUs
within non-longmodes, as also on some AMD CPUs within legacy-mode.
(depending on CPU vendor, MSR_EFER and cpuid)

Because previous mentioned OSs may not engage corresponding
syscall target-registers (STAR, LSTAR, CSTAR), they remain
NULL and (non trapping) syscalls are leading to multiple
faults and finally crashs.

Depending on the architecture (AMD or Intel) pretended by
guests, various checks according to vendor's documentation
are implemented to overcome the current issue and behave
like the CPUs physical counterparts.

[mtosatti: cleanup/beautify code]

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-02-01 11:43:40 +02:00
Stephan Bärwolf bdb42f5afe KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid"
In order to be able to proceed checks on CPU-specific properties
within the emulator, function "get_cpuid" is introduced.
With "get_cpuid" it is possible to virtually call the guests
"cpuid"-opcode without changing the VM's context.

[mtosatti: cleanup/beautify code]

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-02-01 11:43:33 +02:00
Jan Beulich fc395b9291 x86: Properly parenthesize cmpxchg() macro arguments
Quite oddly, all of the arguments passed through from the top
level macros to the second level which didn't need parentheses
had them, while the only expression (involving a parameter)
needing them didn't.

Very recently I got bitten by the lack thereof when using
something like "array + index" for the first operand, with
"array" being an array more narrow than int.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F2183A9020000780006F3E6@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26 21:18:29 +01:00
Andreas Herrmann 652847aa44 x86/amd: Add missing feature flag for fam15h models 10h-1fh processors
That is the last one missing for those CPUs.

Others were recently added with commits

 fb215366b3
 (KVM: expose latest Intel cpu new features (BMI1/BMI2/FMA/AVX2) to guest)

and

 commit 969df4b829
 (x86: Report cpb and eff_freq_ro flags correctly)

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Link: http://lkml.kernel.org/r/20120120163823.GC24508@alberich.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26 12:06:38 +01:00
Russ Anderson 5a51467b14 x86/uv: Fix uv_gpa_to_soc_phys_ram() shift
uv_gpa_to_soc_phys_ram() was inadvertently ignoring the
shift values.  This fix takes the shift into account.

Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/20120119020753.GA7228@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26 10:58:27 +01:00
H. Peter Anvin 4f2f81a562 x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits
In checkin

  303395ac3b x86: Generate system call tables and unistd_*.h from tables

the feature macros in <asm/unistd.h> were unified between 32 and 64
bits.  Unfortunately 32 bits requires __ARCH_WANT_SYS_IPC and this was
inadvertently dropped.

Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/CALLzPKbeXN5gdngo8uYYU8mAow=XhrwBFBhKfG811f37BubQOg@mail.gmail.com
2012-01-19 12:57:09 -08:00
H. Peter Anvin 282f445a77 Merge remote-tracking branch 'linus/master' into x86/urgent 2012-01-19 12:56:50 -08:00
Cliff Wickman b54bd9be35 x86/UV2: Add accounting for BAU strong nacks
This patch adds separate accounting of UV2 message "strong
nack's" in the BAU statistics.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212238.GF5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-17 09:09:59 +01:00
Cliff Wickman c5d35d399e x86/UV2: Work around BAU bug
This patch implements a workaround for a UV2 hardware bug.
The bug is a non-atomic update of a memory-mapped register. When
hardware message delivery and software message acknowledge occur
simultaneously the pending message acknowledge for the arriving
message may be lost.  This causes the sender's message status to
stay busy.

Part of the workaround is to not acknowledge a completed message
until it is verified that no other message is actually using the
resource that is mistakenly recorded in the completed message.

Part of the workaround is to test for long elapsed time in such
a busy condition, then handle it by using a spare sending
descriptor. The stay-busy condition is eventually timed out by
hardware, and then the original sending descriptor can be
re-used. Most of that logic change is in keeping track of the
current descriptor and the state of the spares.

The occurrences of the workaround are added to the BAU
statistics.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211947.GC5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-17 09:09:54 +01:00
Cliff Wickman da87c937e5 x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode
Update the use of the Broadcast Assist Unit on SGI Altix UV2 to
the use of native UV2 mode on new hardware (not the legacy mode).

UV2 native mode has a different format for a broadcast message.
We also need quick differentiaton between UV1 and UV2.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211750.GA5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-17 09:09:51 +01:00
Linus Torvalds 5674124f9f Merge branch 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move <asm/asm-offsets.h> from trace_syscalls.c to asm/syscall.h
  x86, um: Fix typo in 32-bit system call modifications
  um: Use $(srctree) not $(KBUILD_SRC)
  x86, um: Mark system call tables readonly
  x86, um: Use the same style generated syscall tables as native
  um: Generate headers before generating user-offsets.s
  um: Run host archheaders, allow use of host generated headers
  kbuild, headers.sh: Don't make archheaders explicitly
  x86, syscall: Allow syscall offset to be symbolic
  x86, syscall: Re-fix typo in comment
  x86: Simplify syscallhdr.sh
  x86: Generate system call tables and unistd_*.h from tables
  checksyscalls: Use arch/x86/syscalls/syscall_32.tbl as source
  x86: Machine-readable syscall tables and scripts to process them
  trace: Include <asm/asm-offsets.h> in trace_syscalls.c
  x86-64, ia32: Move compat_ni_syscall into C and its own file
  x86-64, syscall: Adjust comment spacing and remove typo
  kbuild: Add support for an "archheaders" target
  kbuild: Add support for installing generated asm headers
2012-01-16 18:19:19 -08:00
Greg Kroah-Hartman e032d80774 mce: fix warning messages about static struct mce_device
When suspending, there was a large list of warnings going something like:

	Device 'machinecheck1' does not have a release() function, it is broken and must be fixed

This patch turns the static mce_devices into dynamically allocated, and
properly frees them when they are removed from the system.  It solves
the warning messages on my laptop here.

Reported-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Djalal Harouni <tixxdz@opendz.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@amd64.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-16 17:08:42 -08:00
Anton Vorontsov f10448689d x86: Get rid of dubious one-bit signed bitfield
This very noisy sparse warning appears on almost every file in
the kernel:

  CHECK   init/main.c
  arch/x86/include/asm/thread_info.h:43:55: error: dubious one-bit
  signed bitfield arch/x86/include/asm/thread_info.h:44:46: error:
  dubious one-bit signed bitfield

Sparse is right and this patch changes sig_on_uaccess_error and
uaccess_err flags to unsigned type and thus fixes the warning.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Andy Lutomirski <luto@mit.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Dan Carpenter <error27@gmail.com>
Link: http://lkml.kernel.org/r/20120111011146.GA30428@oksana.dev.rtsoft.ru
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-16 09:39:54 +01:00
Linus Torvalds 83c2f912b4 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
  perf tools: Fix compile error on x86_64 Ubuntu
  perf report: Fix --stdio output alignment when --showcpuutilization used
  perf annotate: Get rid of field_sep check
  perf annotate: Fix usage string
  perf kmem: Fix a memory leak
  perf kmem: Add missing closedir() calls
  perf top: Add error message for EMFILE
  perf test: Change type of '-v' option to INCR
  perf script: Add missing closedir() calls
  tracing: Fix compile error when static ftrace is enabled
  recordmcount: Fix handling of elf64 big-endian objects.
  perf tools: Add const.h to MANIFEST to make perf-tar-src-pkg work again
  perf tools: Add support for guest/host-only profiling
  perf kvm: Do guest-only counting by default
  perf top: Don't update total_period on process_sample
  perf hists: Stop using 'self' for struct hist_entry
  perf hists: Rename total_session to total_period
  x86: Add counter when debug stack is used with interrupts enabled
  x86: Allow NMIs to hit breakpoints in i386
  x86: Keep current stack in NMI breakpoints
  ...
2012-01-15 11:26:35 -08:00
Linus Torvalds f0ed5b9a28 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, atomic: atomic64_read() take a const pointer
  x86, UV: Update Boot messages for SGI UV2 platform
2012-01-15 11:26:09 -08:00
Anton Vorontsov bccd17294a x86: Get rid of 'dubious one-bit signed bitfield' sprase warning
This very noisy sparse warning appears on almost every file in the
kernel:

  CHECK   init/main.c
  arch/x86/include/asm/thread_info.h:43:55: error: dubious one-bit signed bitfield
  arch/x86/include/asm/thread_info.h:44:46: error: dubious one-bit signed bitfield

This patch changes sig_on_uaccess_error and uaccess_err flags to unsigned
type and thus fixes the warning.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Andy Lutomirski <luto@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 09:32:21 -08:00
Linus Torvalds 9fc5c3e323 Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel config: Fix the APB_TIMER selection
  x86/mrst: Add additional debug prints for pb_keys
  x86/intel config: Revamp configuration to allow for Moorestown and Medfield
  x86/intel/scu/ipc: Match the changes in the x86 configuration
  x86/apb: Fix configuration constraints
  x86: Fix INTEL_MID silly
  x86/Kconfig: Cyclone-timer depends on x86-summit
  x86: Reduce clock calibration time during slave cpu startup
  x86/config: Revamp configuration for MID devices
  x86/sfi: Kill the IRQ as id hack
2012-01-11 19:13:40 -08:00
Linus Torvalds 541048a1d3 Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, reboot: Fix typo in nmi reboot path
  x86, NMI: Add to_cpumask() to silence compile warning
  x86, NMI: NMI selftest depends on the local apic
  x86: Add stack top margin for stack overflow checking
  x86, NMI: NMI-selftest should handle the UP case properly
  x86: Fix the 32-bit stackoverflow-debug build
  x86, NMI: Add knob to disable using NMI IPIs to stop cpus
  x86, NMI: Add NMI IPI selftest
  x86, reboot: Use NMI instead of REBOOT_VECTOR to stop cpus
  x86: Clean up the range of stack overflow checking
  x86: Panic on detection of stack overflow
  x86: Check stack overflow in detail
2012-01-11 19:13:04 -08:00
Linus Torvalds bcede2f64a Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: Break up large initrd reads
  x86, efi: EFI boot stub support
  efi: Add EFI file I/O data types
  efi.h: Add boottime->locate_handle search types
  efi.h: Add graphics protocol guids
  efi.h: Add allocation types for boottime->allocate_pages()
  efi.h: Add efi_image_loaded_t
  efi.h: Add struct definition for boot time services
  x86: Don't use magic strings for EFI loader signature
  x86: Add missing bzImage fields to struct setup_header
2012-01-11 19:12:33 -08:00
Linus Torvalds d0b9706c20 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/numa: Add constraints check for nid parameters
  mm, x86: Remove debug_pagealloc_enabled
  x86/mm: Initialize high mem before free_all_bootmem()
  arch/x86/kernel/e820.c: quiet sparse noise about plain integer as NULL pointer
  arch/x86/kernel/e820.c: Eliminate bubble sort from sanitize_e820_map()
  x86: Fix mmap random address range
  x86, mm: Unify zone_sizes_init()
  x86, mm: Prepare zone_sizes_init() for unification
  x86, mm: Use max_low_pfn for ZONE_NORMAL on 64-bit
  x86, mm: Wrap ZONE_DMA32 with CONFIG_ZONE_DMA32
  x86, mm: Use max_pfn instead of highend_pfn
  x86, mm: Move zone init from paging_init() on 64-bit
  x86, mm: Use MAX_DMA_PFN for ZONE_DMA on 32-bit
2012-01-11 19:12:10 -08:00
Linus Torvalds 7b67e75147 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (80 commits)
  x86/PCI: Expand the x86_msi_ops to have a restore MSIs.
  PCI: Increase resource array mask bit size in pcim_iomap_regions()
  PCI: DEVICE_COUNT_RESOURCE should be equal to PCI_NUM_RESOURCES
  PCI: pci_ids: add device ids for STA2X11 device (aka ConneXT)
  PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB
  x86/PCI: amd: factor out MMCONFIG discovery
  PCI: Enable ATS at the device state restore
  PCI: msi: fix imbalanced refcount of msi irq sysfs objects
  PCI: kconfig: English typo in pci/pcie/Kconfig
  PCI/PM/Runtime: make PCI traces quieter
  PCI: remove pci_create_bus()
  xtensa/PCI: convert to pci_scan_root_bus() for correct root bus resources
  x86/PCI: convert to pci_create_root_bus() and pci_scan_root_bus()
  x86/PCI: use pci_scan_bus() instead of pci_scan_bus_parented()
  x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan
  sparc32, leon/PCI: convert to pci_scan_root_bus() for correct root bus resources
  sparc/PCI: convert to pci_create_root_bus()
  sh/PCI: convert to pci_scan_root_bus() for correct root bus resources
  powerpc/PCI: convert to pci_create_root_bus()
  powerpc/PCI: split PHB part out of pcibios_map_io_space()
  ...

Fix up conflicts in drivers/pci/msi.c and include/linux/pci_regs.h due
to the same patches being applied in other branches.
2012-01-11 18:50:26 -08:00
Linus Torvalds 4f58cb90bc Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (54 commits)
  crypto: gf128mul - remove leftover "(EXPERIMENTAL)" in Kconfig
  crypto: serpent-sse2 - remove unneeded LRW/XTS #ifdefs
  crypto: serpent-sse2 - select LRW and XTS
  crypto: twofish-x86_64-3way - remove unneeded LRW/XTS #ifdefs
  crypto: twofish-x86_64-3way - select LRW and XTS
  crypto: xts - remove dependency on EXPERIMENTAL
  crypto: lrw - remove dependency on EXPERIMENTAL
  crypto: picoxcell - fix boolean and / or confusion
  crypto: caam - remove DECO access initialization code
  crypto: caam - fix polarity of "propagate error" logic
  crypto: caam - more desc.h cleanups
  crypto: caam - desc.h - convert spaces to tabs
  crypto: talitos - convert talitos_error to struct device
  crypto: talitos - remove NO_IRQ references
  crypto: talitos - fix bad kfree
  crypto: convert drivers/crypto/* to use module_platform_driver()
  char: hw_random: convert drivers/char/hw_random/* to use module_platform_driver()
  crypto: serpent-sse2 - should select CRYPTO_CRYPTD
  crypto: serpent - rename serpent.c to serpent_generic.c
  crypto: serpent - cleanup checkpatch errors and warnings
  ...
2012-01-10 22:01:27 -08:00
Linus Torvalds 1c8106528a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (53 commits)
  iommu/amd: Set IOTLB invalidation timeout
  iommu/amd: Init stats for iommu=pt
  iommu/amd: Remove unnecessary cache flushes in amd_iommu_resume
  iommu/amd: Add invalidate-context call-back
  iommu/amd: Add amd_iommu_device_info() function
  iommu/amd: Adapt IOMMU driver to PCI register name changes
  iommu/amd: Add invalid_ppr callback
  iommu/amd: Implement notifiers for IOMMUv2
  iommu/amd: Implement IO page-fault handler
  iommu/amd: Add routines to bind/unbind a pasid
  iommu/amd: Implement device aquisition code for IOMMUv2
  iommu/amd: Add driver stub for AMD IOMMUv2 support
  iommu/amd: Add stat counter for IOMMUv2 events
  iommu/amd: Add device errata handling
  iommu/amd: Add function to get IOMMUv2 domain for pdev
  iommu/amd: Implement function to send PPR completions
  iommu/amd: Implement functions to manage GCR3 table
  iommu/amd: Implement IOMMUv2 TLB flushing routines
  iommu/amd: Add support for IOMMUv2 domain mode
  iommu/amd: Add amd_iommu_domain_direct_map function
  ...
2012-01-10 11:08:21 -08:00
Linus Torvalds 3dcf6c1b6b Merge branch 'kvm-updates/3.3' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/3.3' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (74 commits)
  KVM: PPC: Whitespace fix for kvm.h
  KVM: Fix whitespace in kvm_para.h
  KVM: PPC: annotate kvm_rma_init as __init
  KVM: x86 emulator: implement RDPMC (0F 33)
  KVM: x86 emulator: fix RDPMC privilege check
  KVM: Expose the architectural performance monitoring CPUID leaf
  KVM: VMX: Intercept RDPMC
  KVM: SVM: Intercept RDPMC
  KVM: Add generic RDPMC support
  KVM: Expose a version 2 architectural PMU to a guests
  KVM: Expose kvm_lapic_local_deliver()
  KVM: x86 emulator: Use opcode::execute for Group 9 instruction
  KVM: x86 emulator: Use opcode::execute for Group 4/5 instructions
  KVM: x86 emulator: Use opcode::execute for Group 1A instruction
  KVM: ensure that debugfs entries have been created
  KVM: drop bsp_vcpu pointer from kvm struct
  KVM: x86: Consolidate PIT legacy test
  KVM: x86: Do not rely on implicit inclusions
  KVM: Make KVM_INTEL depend on CPU_SUP_INTEL
  KVM: Use memdup_user instead of kmalloc/copy_from_user
  ...
2012-01-10 09:57:11 -08:00
H. Peter Anvin 8030c36d13 x86, atomic: atomic64_read() take a const pointer
atomic64_read() doesn't actually write anything (as far as the C
environment is concerned... the CPU does actually write but that's an
implementation quirk), so it should take a const pointer.

This does NOT mean that it is safe to use atomic64_read() on an object
in readonly storage (it will trap!)

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/20120109165859.1879abda.akpm@linux-foundation.org
2012-01-09 19:33:24 -08:00
Linus Torvalds 6b3da11b3c Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Remove irqsafe_cpu_xxx variants

Fix up conflict in arch/x86/include/asm/percpu.h due to clash with
cebef5beed ("x86: Fix and improve percpu_cmpxchg{8,16}b_double()")
which edited the (now removed) irqsafe_cpu_cmpxchg*_double code.
2012-01-09 13:08:28 -08:00
Linus Torvalds 5983faf942 Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (65 commits)
  tty: serial: imx: move del_timer_sync() to avoid potential deadlock
  imx: add polled io uart methods
  imx: Add save/restore functions for UART control regs
  serial/imx: let probing fail for the dt case without a valid alias
  serial/imx: propagate error from of_alias_get_id instead of using -ENODEV
  tty: serial: imx: Allow UART to be a source for wakeup
  serial: driver for m32 arch should not have DEC alpha errata
  serial/documentation: fix documented name of DCD cpp symbol
  atmel_serial: fix spinlock lockup in RS485 code
  tty: Fix memory leak in virtual console when enable unicode translation
  serial: use DIV_ROUND_CLOSEST instead of open coding it
  serial: add support for 400 and 800 v3 series Titan cards
  serial: bfin-uart: Remove ASYNC_CTS_FLOW flag for hardware automatic CTS.
  serial: bfin-uart: Enable hardware automatic CTS only when CTS pin is available.
  serial: make FSL errata depend on 8250_CONSOLE, not just 8250
  serial: add irq handler for Freescale 16550 errata.
  serial: manually inline serial8250_handle_port
  serial: make 8250 timeout use the specified IRQ handler
  serial: export the key functions for an 8250 IRQ handler
  serial: clean up parameter passing for 8250 Rx IRQ handling
  ...
2012-01-09 12:09:24 -08:00