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  1. 02 4月, 2013 5 次提交
  3. 08 3月, 2013 7 次提交
  5. 06 3月, 2013 1 次提交
  7. 05 3月, 2013 3 次提交
  9. 14 2月, 2013 2 次提交
    • M
      s390/mm: implement software dirty bits · abf09bed
      由 Martin Schwidefsky 提交于 
      The s390 architecture is unique in respect to dirty page detection,
it uses the change bit in the per-page storage key to track page
modifications. All other architectures track dirty bits by means
of page table entries. This property of s390 has caused numerous
problems in the past, e.g. see git commit ef5d437f
"mm: fix XFS oops due to dirty pages without buffers on s390".

To avoid future issues in regard to per-page dirty bits convert
s390 to a fault based software dirty bit detection mechanism. All
user page table entries which are marked as clean will be hardware
read-only, even if the pte is supposed to be writable. A write by
the user process will trigger a protection fault which will cause
the user pte to be marked as dirty and the hardware read-only bit
is removed.

With this change the dirty bit in the storage key is irrelevant
for Linux as a host, but the storage key is still required for
KVM guests. The effect is that page_test_and_clear_dirty and the
related code can be removed. The referenced bit in the storage
key is still used by the page_test_and_clear_young primitive to
provide page age information.

For page cache pages of mappings with mapping_cap_account_dirty
there will not be any change in behavior as the dirty bit tracking
already uses read-only ptes to control the amount of dirty pages.
Only for swap cache pages and pages of mappings without
mapping_cap_account_dirty there can be additional protection faults.
To avoid an excessive number of additional faults the mk_pte
primitive checks for PageDirty if the pgprot value allows for writes
and pre-dirties the pte. That avoids all additional faults for
tmpfs and shmem pages until these pages are added to the swap cache.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      abf09bed
    • H
      s390/time: rename tod clock access functions · 1aae0560
      由 Heiko Carstens 提交于 
      Fix name clash with some common code device drivers and add "tod"
to all tod clock access function names.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      1aae0560
  11. 11 2月, 2013 1 次提交
  13. 30 1月, 2013 2 次提交
    • C
      s390/kvm: Fix instruction decoding · 0c29b229
      由 Christian Borntraeger 提交于 
      Instructions with long displacement have a signed displacement.
Currently the sign bit is interpreted as 2^20: Lets fix it by doing the
sign extension from 20bit to 32bit and then use it as a signed variable
in the addition (see kvm_s390_get_base_disp_rsy).

Furthermore, there are lots of "int" in that code. This is problematic,
because shifting on a signed integer is undefined/implementation defined
if the bit value happens to be negative.
Fortunately the promotion rules will make the right hand side unsigned
anyway, so there is no real problem right now.
Let's convert them anyway to unsigned where appropriate to avoid
problems if the code is changed or copy/pasted later on.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
      0c29b229
    • C
      s390/kvm: Fix store status for ACRS/FPRS · 15bc8d84
      由 Christian Borntraeger 提交于 
      On store status we need to copy the current state of registers
into a save area. Currently we might save stale versions:
The sie state descriptor doesnt have fields for guest ACRS,FPRS,
those registers are simply stored in the host registers. The host
program must copy these away if needed. We do that in vcpu_put/load.

If we now do a store status in KVM code between vcpu_put/load, the
saved values are not up-to-date. Lets collect the ACRS/FPRS before
saving them.

This also fixes some strange problems with hotplug and virtio-ccw,
since the low level machine check handler (on hotplug a machine check
will happen) will revalidate all registers with the content of the
save area.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Signed-off-by: NGleb Natapov <gleb@redhat.com>
      15bc8d84
  15. 17 1月, 2013 1 次提交
  17. 16 1月, 2013 1 次提交
    • H
      s390/time: fix sched_clock() overflow · ed4f2094
      由 Heiko Carstens 提交于 
      Converting a 64 Bit TOD format value to nanoseconds means that the value
must be divided by 4.096. In order to achieve that we multiply with 125
and divide by 512.
When used within sched_clock() this triggers an overflow after appr.
417 days. Resulting in a sched_clock() return value that is much smaller
than previously and therefore may cause all sort of weird things in
subsystems that rely on a monotonic sched_clock() behaviour.

To fix this implement a tod_to_ns() helper function which converts TOD
values without overflow and call this function from both places that
open coded the conversion: sched_clock() and kvm_s390_handle_wait().

Cc: stable@kernel.org
Reviewed-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      ed4f2094
  19. 12 1月, 2013 1 次提交
    • K
      arch/s390/kvm: remove depends on CONFIG_EXPERIMENTAL · b186ba6e
      由 Kees Cook 提交于 
      The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Avi Kivity <avi@redhat.com>
CC: Marcelo Tosatti <mtosatti@redhat.com>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Cornelia Huck <cornelia.huck@de.ibm.com>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
      b186ba6e
  21. 11 1月, 2013 1 次提交
  23. 08 1月, 2013 7 次提交
  25. 14 12月, 2012 1 次提交
  27. 28 11月, 2012 1 次提交
  29. 30 10月, 2012 1 次提交
    • F
      kvm: Directly account vtime to system on guest switch · b080935c
      由 Frederic Weisbecker 提交于 
      Switching to or from guest context is done on ioctl context.
So by the time we call kvm_guest_enter() or kvm_guest_exit()
we know we are not running the idle task.

As a result, we can directly account the cputime using
vtime_account_system().

There are two good reasons to do this:

* We avoid some useless checks on guest switch. It optimizes
a bit this fast path.

* In the case of CONFIG_IRQ_TIME_ACCOUNTING, calling vtime_account()
checks for irq time to account. This is pointless since we know
we are not in an irq on guest switch. This is wasting cpu cycles
for no good reason. vtime_account_system() OTOH is a no-op in
this config option.

* We can remove the irq disable/enable around kvm guest switch in s390.

A further optimization may consist in introducing a vtime_account_guest()
that directly calls account_guest_time().
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Xiantao Zhang <xiantao.zhang@intel.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      b080935c
  31. 11 10月, 2012 2 次提交
    • C
      s390/kvm: dont announce RRBM support · 87cac8f8
      由 Christian Borntraeger 提交于 
      Newer kernels (linux-next with the transparent huge page patches)
use rrbm if the feature is announced via feature bit 66.
RRBM will cause intercepts, so KVM does not handle it right now,
causing an illegal instruction in the guest.
The  easy solution is to disable the feature bit for the guest.

This fixes bugs like:
Kernel BUG at 0000000000124c2a [verbose debug info unavailable]
illegal operation: 0001 [#1] SMP
Modules linked in: virtio_balloon virtio_net ipv6 autofs4
CPU: 0 Not tainted 3.5.4 #1
Process fmempig (pid: 659, task: 000000007b712fd0, ksp: 000000007bed3670)
Krnl PSW : 0704d00180000000 0000000000124c2a (pmdp_clear_flush_young+0x5e/0x80)
     R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3
     00000000003cc000 0000000000000004 0000000000000000 0000000079800000
     0000000000040000 0000000000000000 000000007bed3918 000000007cf40000
     0000000000000001 000003fff7f00000 000003d281a94000 000000007bed383c
     000000007bed3918 00000000005ecbf8 00000000002314a6 000000007bed36e0
 Krnl Code:>0000000000124c2a: b9810025          ogr     %r2,%r5
           0000000000124c2e: 41343000           la      %r3,0(%r4,%r3)
           0000000000124c32: a716fffa           brct    %r1,124c26
           0000000000124c36: b9010022           lngr    %r2,%r2
           0000000000124c3a: e3d0f0800004       lg      %r13,128(%r15)
           0000000000124c40: eb22003f000c       srlg    %r2,%r2,63
[ 2150.713198] Call Trace:
[ 2150.713223] ([<00000000002312c4>] page_referenced_one+0x6c/0x27c)
[ 2150.713749]  [<0000000000233812>] page_referenced+0x32a/0x410
[...]

CC: stable@vger.kernel.org
CC: Alex Graf <agraf@suse.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      87cac8f8
    • J
      s390/kvm: Interrupt injection bugfix · 82a12737
      由 Jason J. Herne 提交于 
      EXTERNAL_CALL and EMERGENCY type interrupts need to preserve their interrupt
code parameter when being injected from user space.
Signed-off-by: NJason J. Herne <jjherne@us.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      82a12737
  33. 28 9月, 2012 1 次提交
  35. 26 9月, 2012 2 次提交