* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Skip cpus with apic-ids >= 255 in !x2apic_mode
x86, x2apic: Allow "nox2apic" to disable x2apic mode setup by BIOS
x86, x2apic: Fallback to xapic when BIOS doesn't setup interrupt-remapping
x86, acpi: Skip acpi x2apic entries if the x2apic feature is not present
x86, apic: Add probe() for apic_flat
x86: Simplify code by removing a !SMP #ifdefs from 'struct cpuinfo_x86'
x86: Convert per-cpu counter icr_read_retry_count into a member of irq_stat
x86: Add per-cpu stat counter for APIC ICR read tries
pci, x86/io-apic: Allow PCI_IOAPIC to be user configurable on x86
x86: Fix the !CONFIG_NUMA build of the new CPU ID fixup code support
x86: Add NumaChip support
x86: Add x86_init platform override to fix up NUMA core numbering
x86: Make flat_init_apic_ldr() available
This factors out the AMD native MMCONFIG discovery so we can use it
outside amd_bus.c.
amd_bus.c reads AMD MSRs so it can remove the MMCONFIG area from the
PCI resources. We may also need the MMCONFIG information to work
around BIOS defects in the ACPI MCFG table.
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: stable@kernel.org # 2.6.34+
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
x86 has two kinds of PCI root bus scanning:
(1) ACPI-based, using _CRS resources. This used pci_create_bus(), not
pci_scan_bus(), because ACPI hotplug needed to split the
pci_bus_add_devices() into a separate host bridge .start() method.
This patch parses the _CRS resources earlier, so we can build a list of
resources and pass it to pci_create_root_bus().
Note that as before, we parse the _CRS even if we aren't going to use
it so we can print it for debugging purposes.
(2) All other, which used either default resources (ioport_resource and
iomem_resource) or information read from the hardware via amd_bus.c or
similar. This used pci_scan_bus().
This patch converts x86_pci_root_bus_res_quirks() (previously called
from pcibios_fixup_bus()) to x86_pci_root_bus_resources(), which builds
a list of resources before we call pci_scan_root_bus().
We also use x86_pci_root_bus_resources() if we have ACPI but are
ignoring _CRS.
CC: Yinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This doesn't change any functionality, but it makes a subsequent patch
slightly simpler.
pci_scan_bus(NULL, ...) and pci_scan_bus_parented() are identical except
that pci_scan_bus() also calls pci_bus_add_devices():
pci_scan_bus_parented
pci_create_bus
pci_scan_child_bus
pci_scan_bus
pci_create_bus
pci_scan_child_bus
pci_bus_add_devices
All callers of pcibios_scan_root() call pci_bus_add_devices() explicitly,
and we don't pass a parent device, so we might as well use pci_scan_bus().
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We currently read the CNB20LE aperture information in a PCI quirk,
which happens after we've already created the root bus. This patch
changes it to read the apertures earlier so we can create the root
bus with the correct resources.
I believe the CNB20LE lives at "pci 0000:00:00" based on
https://lkml.org/lkml/2010/8/13/220
CC: Ira W. Snyder <iws@ovro.caltech.edu>
CC: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Commit 24d9b70b8c (x86: Use PCI method
for enabling AMD extended config space before MSR method) added a
message when IO access to PCI ECS was enabled via access to the NB_CFG
PCI register. This can lead to a bogus message like
[ 0.365177] Extended Config Space enabled on 0 nodes
which is misleading because IO ECS access is subsequently enabled for
AMD CPUs (that support this) by modifying the corresponding NB_CFG
MSR.
Furthermore it's not "Extended Config Space" that is enabled by this
register setting. It's the IO access that is enabled for extended
configruation space.
IMHO the ambiguous message needs to be cancelled.
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Robert Richter <robert.richter@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The 'latency timer' of PCI devices, both Type 0 and Type 1,
is setup in architecture-specific code [see: 'pcibios_set_master()'].
There are two approaches being taken by all the architectures - check
if the 'latency timer' is currently set between 16 and 255 and if not
bring it within bounds, or, do nothing (and then there is the
gratuitously different PA-RISC implementation).
There is nothing architecture-specific about PCI's 'latency timer' so
this patch pulls its setup functionality up into the PCI core by
creating a generic 'pcibios_set_master()' function using the '__weak'
attribute which can be used by all architectures as a default which,
if necessary, can then be over-ridden by architecture-specific code.
No functional change.
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This assures that a _CRS reserved host bridge window or window region is
not used if it is not addressable by the CPU. The new code either trims
the window to exclude the non-addressable portion or totally ignores the
window if the entire window is non-addressable.
The current code has been shown to be problematic with 32-bit non-PAE
kernels on systems where _CRS reserves resources above 4GB.
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Renninger <trenn@novell.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Enabling CRS by default breaks suspend on the Thinkpad SL510.
Details in https://bugzilla.redhat.com/show_bug.cgi?id=769657
Reported-by: Stefan Kirrmann <stefan.kirrmann@gmail.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The Dell Studio 1557 also doesn't suspend correctly when CRS is enabled.
Details at https://bugzilla.redhat.com/show_bug.cgi?id=769657
Reported-by: Gregory S. Hoerner <ghoerner@transcendingthought.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Some machines don't boot unless passed pci=nocrs.
(See https://bugzilla.redhat.com/show_bug.cgi?id=770308 for details of
one report. Waiting on dmidecode output for others).
Currently there is a DMI whitelist, even though the default is on.
v2: drop the 1536 blacklist entry, superceded by the PNP/MMCONFIG changes from
Bjorn
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file,
and it fixes the build error in the arch/x86/kernel/microcode_core.c
file, that the merge did not catch.
The microcode_core.c patch was provided by Stephen Rothwell
<sfr@canb.auug.org.au> who was invaluable in the merge issues involved
with the large sysdev removal process in the driver-core tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
sched/tracing: Add a new tracepoint for sleeptime
sched: Disable scheduler warnings during oopses
sched: Fix cgroup movement of waking process
sched: Fix cgroup movement of newly created process
sched: Fix cgroup movement of forking process
sched: Remove cfs bandwidth period check in tg_set_cfs_period()
sched: Fix load-balance lock-breaking
sched: Replace all_pinned with a generic flags field
sched: Only queue remote wakeups when crossing cache boundaries
sched: Add missing rcu_dereference() around ->real_parent usage
[S390] fix cputime overflow in uptime_proc_show
[S390] cputime: add sparse checking and cleanup
sched: Mark parent and real_parent as __rcu
sched, nohz: Fix missing RCU read lock
sched, nohz: Set the NOHZ_BALANCE_KICK flag for idle load balancer
sched, nohz: Fix the idle cpu check in nohz_idle_balance
sched: Use jump_labels for sched_feat
sched/accounting: Fix parameter passing in task_group_account_field
sched/accounting: Fix user/system tick double accounting
sched/accounting: Re-use scheduler statistics for the root cgroup
...
Fix up conflicts in
- arch/ia64/include/asm/cputime.h, include/asm-generic/cputime.h
usecs_to_cputime64() vs the sparse cleanups
- kernel/sched/fair.c, kernel/time/tick-sched.c
scheduler changes in multiple branches
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (106 commits)
perf kvm: Fix copy & paste error in description
perf script: Kill script_spec__delete
perf top: Fix a memory leak
perf stat: Introduce get_ratio_color() helper
perf session: Remove impossible condition check
perf tools: Fix feature-bits rework fallout, remove unused variable
perf script: Add generic perl handler to process events
perf tools: Use for_each_set_bit() to iterate over feature flags
perf tools: Unify handling of features when writing feature section
perf report: Accept fifos as input file
perf tools: Moving code in some files
perf tools: Fix out-of-bound access to struct perf_session
perf tools: Continue processing header on unknown features
perf tools: Improve macros for struct feature_ops
perf: builtin-record: Document and check that mmap_pages must be a power of two.
perf: builtin-record: Provide advice if mmap'ing fails with EPERM.
perf tools: Fix truncated annotation
perf script: look up thread using tid instead of pid
perf tools: Look up thread names for system wide profiling
perf tools: Fix comm for processes with named threads
...
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
cpu: Export cpu_up()
rcu: Apply ACCESS_ONCE() to rcu_boost() return value
Revert "rcu: Permit rt_mutex_unlock() with irqs disabled"
docs: Additional LWN links to RCU API
rcu: Augment rcu_batch_end tracing for idle and callback state
rcu: Add rcutorture tests for srcu_read_lock_raw()
rcu: Make rcutorture test for hotpluggability before offlining CPUs
driver-core/cpu: Expose hotpluggability to the rest of the kernel
rcu: Remove redundant rcu_cpu_stall_suppress declaration
rcu: Adaptive dyntick-idle preparation
rcu: Keep invoking callbacks if CPU otherwise idle
rcu: Irq nesting is always 0 on rcu_enter_idle_common
rcu: Don't check irq nesting from rcu idle entry/exit
rcu: Permit dyntick-idle with callbacks pending
rcu: Document same-context read-side constraints
rcu: Identify dyntick-idle CPUs on first force_quiescent_state() pass
rcu: Remove dynticks false positives and RCU failures
rcu: Reduce latency of rcu_prepare_for_idle()
rcu: Eliminate RCU_FAST_NO_HZ grace-period hang
rcu: Avoid needlessly IPIing CPUs at GP end
...
* 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
memblock: Reimplement memblock allocation using reverse free area iterator
memblock: Kill early_node_map[]
score: Use HAVE_MEMBLOCK_NODE_MAP
s390: Use HAVE_MEMBLOCK_NODE_MAP
mips: Use HAVE_MEMBLOCK_NODE_MAP
ia64: Use HAVE_MEMBLOCK_NODE_MAP
SuperH: Use HAVE_MEMBLOCK_NODE_MAP
sparc: Use HAVE_MEMBLOCK_NODE_MAP
powerpc: Use HAVE_MEMBLOCK_NODE_MAP
memblock: Implement memblock_add_node()
memblock: s/memblock_analyze()/memblock_allow_resize()/ and update users
memblock: Track total size of regions automatically
powerpc: Cleanup memblock usage
memblock: Reimplement memblock_enforce_memory_limit() using __memblock_remove()
memblock: Make memblock functions handle overflowing range @size
memblock: Reimplement __memblock_remove() using memblock_isolate_range()
memblock: Separate out memblock_isolate_range() from memblock_set_node()
memblock: Kill memblock_init()
memblock: Kill sentinel entries at the end of static region arrays
memblock: Add __memblock_dump_all()
...
It appears about all functions in arch/x86/lib/atomic64_cx8_32.S
are wrong in case cmpxchg8b must be restarted, because
LOCK_PREFIX macro defines a label "1" clashing with other local
labels :
1:
some_instructions
LOCK_PREFIX
cmpxchg8b (%ebp)
jne 1b / jumps to beginning of LOCK_PREFIX !
A possible fix is to use a magic label "672" in LOCK_PREFIX asm
definition, similar to the "671" one we defined in
LOCK_PREFIX_HERE.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1325608540.2320.103.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Just like the per-CPU ones they had several
problems/shortcomings:
Only the first memory operand was mentioned in the asm()
operands, and the 2x64-bit version didn't have a memory clobber
while the 2x32-bit one did. The former allowed the compiler to
not recognize the need to re-load the data in case it had it
cached in some register, while the latter was overly
destructive.
The types of the local copies of the old and new values were
incorrect (the types of the pointed-to variables should be used
here, to make sure the respective old/new variable types are
compatible).
The __dummy/__junk variables were pointless, given that local
copies of the inputs already existed (and can hence be used for
discarded outputs).
The 32-bit variant of cmpxchg_double_local() referenced
cmpxchg16b_local().
At once also:
- change the return value type to what it really is: 'bool'
- unify 32- and 64-bit variants
- abstract out the common part of the 'normal' and 'local' variants
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F01F12A020000780006A19B@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Seems Kconfig SELECT isn't selecting things hierarchically when
selected.
config APB_TIMER
def_bool y if X86_INTEL_MID
prompt "Intel MID APB Timer Support" if X86_INTEL_MID
select DW_APB_TIMER
depends on X86_INTEL_MID && SFI
when we select APB_TIMER doesn't select DW_APB_TIMER so do it by
hand.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-kpnaimplltk6d1lolusqj3ae@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
RDPMC is only privileged if CR4.PCE=0. check_rdpmc() already implements this,
so all we need to do is drop the Priv flag.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Intercept RDPMC and forward it to the PMU emulation code.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Intercept RDPMC and forward it to the PMU emulation code.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add a helper function that emulates the RDPMC instruction operation.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use perf_events to emulate an architectural PMU, version 2.
Based on PMU version 1 emulation by Avi Kivity.
[avi: adjust for cpuid.c]
[jan: fix anonymous field initialization for older gcc]
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Group 9: 0F C7
Rename em_grp9() to em_cmpxchg8b() and register it.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Drop bsp_vcpu pointer from kvm struct since its only use is incorrect
anyway.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Move the test for KVM_PIT_FLAGS_HPET_LEGACY into create_pit_timer
instead of replicating it on the caller site.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Works so far by change, but it is not guaranteed to stay like this.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
PMU virtualization needs to talk to Intel-specific bits of perf; these are
only available when CPU_SUP_INTEL=y.
Fixes
arch/x86/built-in.o: In function `atomic_switch_perf_msrs':
vmx.c:(.text+0x6b1d4): undefined reference to `perf_guest_get_msrs'
Reported-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Switch to using memdup_user when possible. This makes code more
smaller and compact, and prevents errors.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Switch to kmemdup() in two places to shorten the code and avoid possible bugs.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This was probably copy&pasted from the cr0 case, but it's unneeded here.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
freed_pages is never evaluated, so remove it as well as the return code
kvm_mmu_remove_some_alloc_mmu_pages so far delivered to its only user.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
percpu_xxx funcs are duplicated with this_cpu_xxx funcs, so replace them
for further code clean up.
And in preempt safe scenario, __this_cpu_xxx funcs has a bit better
performance since __this_cpu_xxx has no redundant preempt_disable()
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The unsync code should be stable now, maybe it is the time to remove this
parameter to cleanup the code a little bit
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Move the mmu code in kvm_arch_vcpu_init() to kvm_mmu_create()
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
KVM_EXIT_HYPERCALL is not used anymore, so remove the code
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The tracepoint is only used to audit mmu code, it should not be exposed to
user, let us replace it with jump-label.
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch cleans and simplifies kvm_dev_ioctl_get_supported_cpuid by using a table
instead of duplicating code as Avi suggested.
This patch also fixes a bug where kvm_dev_ioctl_get_supported_cpuid would return
-E2BIG when amount of entries passed was just right.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Intel latest cpu add 6 new features, refer http://software.intel.com/file/36945
The new feature cpuid listed as below:
1. FMA CPUID.EAX=01H:ECX.FMA[bit 12]
2. MOVBE CPUID.EAX=01H:ECX.MOVBE[bit 22]
3. BMI1 CPUID.EAX=07H,ECX=0H:EBX.BMI1[bit 3]
4. AVX2 CPUID.EAX=07H,ECX=0H:EBX.AVX2[bit 5]
5. BMI2 CPUID.EAX=07H,ECX=0H:EBX.BMI2[bit 8]
6. LZCNT CPUID.EAX=80000001H:ECX.LZCNT[bit 5]
This patch expose these features to guest.
Among them, FMA/MOVBE/LZCNT has already been defined, MOVBE/LZCNT has
already been exposed.
This patch defines BMI1/AVX2/BMI2, and exposes FMA/BMI1/AVX2/BMI2 to guest.
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
INSB : 6C
INSW/INSD : 6D
OUTSB : 6E
OUTSW/OUTSD: 6F
The I/O port address is read from the DX register when we decode the
operand because we see the SrcDX/DstDX flag is set.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce id_to_memslot to get memslot by slot id
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce kvm_for_each_memslot to walk all valid memslot
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce update_memslots to update slot which will be update to
kvm->memslots
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
vmx_load_host_state() does not handle msrs switching (except
MSR_KERNEL_GS_BASE) since commit 26bb0981b3. Remove call to it
where it is no longer make sense.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, write protecting a slot needs to walk all the shadow pages
and checks ones which have a pte mapping a page in it.
The walk is overly heavy when dirty pages in that slot are not so many
and checking the shadow pages would result in unwanted cache pollution.
To mitigate this problem, we use rmap_write_protect() and check only
the sptes which can be reached from gfns marked in the dirty bitmap
when the number of dirty pages are less than that of shadow pages.
This criterion is reasonable in its meaning and worked well in our test:
write protection became some times faster than before when the ratio of
dirty pages are low and was not worse even when the ratio was near the
criterion.
Note that the locking for this write protection becomes fine grained.
The reason why this is safe is descripted in the comments.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Needed for the next patch which uses this number to decide how to write
protect a slot.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
rmap_write_protect() calls gfn_to_rmap() for each level with gfn fixed.
This results in calling gfn_to_memslot() repeatedly with that gfn.
This patch introduces __gfn_to_rmap() which takes the slot as an
argument to avoid this.
This is also needed for the following dirty logging optimization.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Remove redundant checks and use is_large_pte() macro.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
The host side pv mmu support has been marked for feature removal in
January 2011. It's not in use, is slower than shadow or hardware
assisted paging, and a maintenance burden. It's November 2011, time to
remove it.
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This has not been used for some years now. It's time to remove it.
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The vcpu reference of a kvm_timer can't become NULL while the timer is
valid, so drop this redundant test. This also makes it pointless to
carry a separate __kvm_timer_fn, fold it into kvm_timer_fn.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Detecting write-flooding does not work well, when we handle page written, if
the last speculative spte is not accessed, we treat the page is
write-flooding, however, we can speculative spte on many path, such as pte
prefetch, page synced, that means the last speculative spte may be not point
to the written page and the written page can be accessed via other sptes, so
depends on the Accessed bit of the last speculative spte is not enough
Instead of detected page accessed, we can detect whether the spte is accessed
after it is written, if the spte is not accessed but it is written frequently,
we treat is not a page table or it not used for a long time
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Sometimes, we only modify the last one byte of a pte to update status bit,
for example, clear_bit is used to clear r/w bit in linux kernel and 'andb'
instruction is used in this function, in this case, kvm_mmu_pte_write will
treat it as misaligned access, and the shadow page table is zapped
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm_mmu_pte_write is too long, we split it for better readable
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In kvm_mmu_pte_write, we do not need to alloc shadow page, so calling
kvm_mmu_free_some_pages is really unnecessary
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Fast prefetch spte for the unsync shadow page on invlpg path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Directly Use mmu_page_zap_pte to zap spte in FNAME(invlpg), also remove the
same code between FNAME(invlpg) and FNAME(sync_page)
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In current code, the accessed bit is always set when page fault occurred,
do not need to set it on pte write path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Remove the same code between emulator_pio_in_emulated and
emulator_pio_out_emulated
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the emulation is caused by #PF and it is non-page_table writing instruction,
it means the VM-EXIT is caused by shadow page protected, we can zap the shadow
page and retry this instruction directly
The idea is from Avi
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The idea is from Avi:
| tag instructions that are typically used to modify the page tables, and
| drop shadow if any other instruction is used.
| The list would include, I'd guess, and, or, bts, btc, mov, xchg, cmpxchg,
| and cmpxchg8b.
This patch is used to tag the instructions and in the later path, shadow page
is dropped if it is written by other instructions
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm_mmu_pte_write is unsafe since we need to alloc pte_list_desc in the
function when spte is prefetched, unfortunately, we can not know how many
spte need to be prefetched on this path, that means we can use out of the
free pte_list_desc object in the cache, and BUG_ON() is triggered, also some
path does not fill the cache, such as INS instruction emulated that does not
trigger page fault
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When L0 wishes to inject an interrupt while L2 is running, it emulates an exit
to L1 with EXIT_REASON_EXTERNAL_INTERRUPT. This was explained in the original
nVMX patch 23, titled "Correct handling of interrupt injection".
Unfortunately, it is possible (though rare) that at this point there is valid
idt_vectoring_info in vmcs02. For example, L1 injected some interrupt to L2,
and when L2 tried to run this interrupt's handler, it got a page fault - so
it returns the original interrupt vector in idt_vectoring_info. The problem
is that if this is the case, we cannot exit to L1 with EXTERNAL_INTERRUPT
like we wished to, because the VMX spec guarantees that idt_vectoring_info
and exit_reason_external_interrupt can never happen together. This is not
just specified in the spec - a KVM L1 actually prints a kernel warning
"unexpected, valid vectoring info" if we violate this guarantee, and some
users noticed these warnings in L1's logs.
In order to better emulate a processor, which would never return the external
interrupt and the idt-vectoring-info together, we need to separate the two
injection steps: First, complete L1's injection into L2 (i.e., enter L2,
injecting to it the idt-vectoring-info); Second, after entry into L2 succeeds
and it exits back to L0, exit to L1 with the EXIT_REASON_EXTERNAL_INTERRUPT.
Most of this is already in the code - the only change we need is to remain
in L2 (and not exit to L1) in this case.
Note that the previous patch ensures (by using KVM_REQ_IMMEDIATE_EXIT) that
although we do enter L2 first, it will exit immediately after processing its
injection, allowing us to promptly inject to L1.
Note how we test vmcs12->idt_vectoring_info_field; This isn't really the
vmcs12 value (we haven't exited to L1 yet, so vmcs12 hasn't been updated),
but rather the place we save, at the end of vmx_vcpu_run, the vmcs02 value
of this field. This was explained in patch 25 ("Correct handling of idt
vectoring info") of the original nVMX patch series.
Thanks to Dave Allan and to Federico Simoncelli for reporting this bug,
to Abel Gordon for helping me figure out the solution, and to Avi Kivity
for helping to improve it.
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a new vcpu->requests bit, KVM_REQ_IMMEDIATE_EXIT.
This bit requests that when next entering the guest, we should run it only
for as little as possible, and exit again.
We use this new option in nested VMX: When L1 launches L2, but L0 wishes L1
to continue running so it can inject an event to it, we unfortunately cannot
just pretend to have run L2 for a little while - We must really launch L2,
otherwise certain one-off vmcs12 parameters (namely, L1 injection into L2)
will be lost. So the existing code runs L2 in this case.
But L2 could potentially run for a long time until it exits, and the
injection into L1 will be delayed. The new KVM_REQ_IMMEDIATE_EXIT allows us
to request that L2 will be entered, as necessary, but will exit as soon as
possible after entry.
Our implementation of this request uses smp_send_reschedule() to send a
self-IPI, with interrupts disabled. The interrupts remain disabled until the
guest is entered, and then, after the entry is complete (often including
processing an injection and jumping to the relevant handler), the physical
interrupt is noticed and causes an exit.
On recent Intel processors, we could have achieved the same goal by using
MTF instead of a self-IPI. Another technique worth considering in the future
is to use VM_EXIT_ACK_INTR_ON_EXIT and a highest-priority vector IPI - to
slightly improve performance by avoiding the useless interrupt handler
which ends up being called when smp_send_reschedule() is used.
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Unlike all of the other cpuid bits, the TSC deadline timer bit is set
unconditionally, regardless of what userspace wants.
This is broken in several ways:
- if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC
deadline timer feature, a guest that uses the feature will break
- live migration to older host kernels that don't support the TSC deadline
timer will cause the feature to be pulled from under the guest's feet;
breaking it
- guests that are broken wrt the feature will fail.
Fix by not enabling the feature automatically; instead report it to userspace.
Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee
will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not
KVM_GET_SUPPORTED_CPUID.
Fixes the Illumos guest kernel, which uses the TSC deadline timer feature.
[avi: add the KVM_CAP + documentation]
Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* pm-sleep: (51 commits)
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
PM / Sleep: Recommend [un]lock_system_sleep() over using pm_mutex directly
PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()
PM / Sleep: Make [un]lock_system_sleep() generic
PM / Sleep: Use the freezer_count() functions in [un]lock_system_sleep() APIs
PM / Freezer: Remove the "userspace only" constraint from freezer[_do_not]_count()
PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c with 'else'
Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer
PM / Sleep: Unify diagnostic messages from device suspend/resume
ACPI / PM: Do not save/restore NVS on Asus K54C/K54HR
PM / Hibernate: Remove deprecated hibernation test modes
PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path
...
Conflicts:
kernel/kmod.c
User space may create the PIT and forgets about setting up the irqchips.
In that case, firing PIT IRQs will crash the host:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000128
IP: [<ffffffffa10f6280>] kvm_set_irq+0x30/0x170 [kvm]
...
Call Trace:
[<ffffffffa11228c1>] pit_do_work+0x51/0xd0 [kvm]
[<ffffffff81071431>] process_one_work+0x111/0x4d0
[<ffffffff81071bb2>] worker_thread+0x152/0x340
[<ffffffff81075c8e>] kthread+0x7e/0x90
[<ffffffff815a4474>] kernel_thread_helper+0x4/0x10
Prevent this by checking the irqchip mode before starting a timer. We
can't deny creating the PIT if the irqchips aren't set up yet as
current user land expects this order to work.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If the x2apic mode is disabled for reasons like interrupt-remapping
not available etc, then we need to skip the logical cpu bringup of
apic-id's >= 255. Otherwise as the platform is in xapic mode, init/startup
IPI's will consider only the low 8-bits and there is a possibility of
re-sending init/startup IPI's to the logical cpu that is already online.
This will avoid potential reboots/unpredictable behavior etc.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/20111222014632.702932458@sbsiddha-desk.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Currently "nox2apic" boot parameter was not enabling x2apic mode if the cpu,
kernel are all capable of enabling x2apic mode and the OS handover
happened in xapic mode.
However If the bios enabled x2apic prior to OS handover, using "nox2apic"
boot parameter had no effect.
If the boot cpu's apicid is < 255, enable "nox2apic" boot parameter to
disable the x2apic mode setup by the bios. This will enable the kernel to
fallback to xapic mode and bringup only the cpu's which has apic-id < 255.
-v2: fix patch error and two compiling warning
make disable_x2apic to be __init
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/CAE9FiQUeB-3uxJAMiHsz=uPWoFv5Hg1pVepz7aU6YtqOxMC-=Q@mail.gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
On some of the recent Intel SNB platforms, by default bios is pre-enabling
x2apic mode in the cpu with out setting up interrupt-remapping.
This case was resulting in the kernel to panic as the cpu is already in
x2apic mode but the OS was not able to enable interrupt-remapping (which
is a pre-req for using x2apic capability).
On these platforms all the apic-ids are < 255 and the kernel can fallback to
xapic mode if the bios has not enabled interrupt-remapping (which is
mostly the case if the bios has not exported interrupt-remapping tables to the
OS).
Reported-by: Berck E. Nash <flyboy@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20111222014632.600418637@sbsiddha-desk.sc.intel.com
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If the x2apic feature is not present (either the cpu is not capable of it
or the user has disabled the feature using boot-parameter etc), ignore the
x2apic MADT and SRAT entries provided by the ACPI tables.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20111222014632.540896503@sbsiddha-desk.sc.intel.com
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Currently we start with the default apic_flat mode and switch to some other
apic model depending on the apic drivers acpi_madt_oem_check() routines and
later followed by the apic drivers probe() routines.
Once we selected non flat mode there was no case where we fall back to
flat mode again.
Upcoming changes allow bios-enabled x2apic mode to be disabled by the OS
if interrupt-remapping etc is not setup properly by the bios.
We now has a case for the apic to fall back to legacy flat mode during
apic driver probe() seqeuence. Add a simple flat_probe() which allows
the apic_flat mode to be the last fallback option.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20111222014632.484984298@sbsiddha-desk.sc.intel.com
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Use raw_spin_unlock_irqrestore() as equivalent to
raw_spin_lock_irqsave().
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1324646665-13334-1-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We simply say that regular this_cpu use must be safe regardless of
preemption and interrupt state. That has no material change for x86
and s390 implementations of this_cpu operations. However, arches that
do not provide their own implementation for this_cpu operations will
now get code generated that disables interrupts instead of preemption.
-tj: This is part of on-going percpu API cleanup. For detailed
discussion of the subject, please refer to the following thread.
http://thread.gmane.org/gmane.linux.kernel/1222078
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <alpine.DEB.2.00.1112221154380.11787@router.home>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
net: Add a flow_cache_flush_deferred function
ipv4: reintroduce route cache garbage collector
net: have ipconfig not wait if no dev is available
sctp: Do not account for sizeof(struct sk_buff) in estimated rwnd
asix: new device id
davinci-cpdma: fix locking issue in cpdma_chan_stop
sctp: fix incorrect overflow check on autoclose
r8169: fix Config2 MSIEnable bit setting.
llc: llc_cmsg_rcv was getting called after sk_eat_skb.
net: bpf_jit: fix an off-one bug in x86_64 cond jump target
iwlwifi: update SCD BC table for all SCD queues
Revert "Bluetooth: Revert: Fix L2CAP connection establishment"
Bluetooth: Clear RFCOMM session timer when disconnecting last channel
Bluetooth: Prevent uninitialized data access in L2CAP configuration
iwlwifi: allow to switch to HT40 if not associated
iwlwifi: tx_sync only on PAN context
mwifiex: avoid double list_del in command cancel path
ath9k: fix max phy rate at rate control init
nfc: signedness bug in __nci_request()
iwlwifi: do not set the sequence control bit is not needed
The sysdev.h file should not be needed by any in-kernel code, so remove
the .h file from these random files that seem to still want to include
it.
The sysdev code will be going away soon, so this include needs to be
removed no matter what.
Cc: Jiandong Zheng <jdzheng@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "Venkatesh Pallipadi
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.
After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.
Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* master: (848 commits)
SELinux: Fix RCU deref check warning in sel_netport_insert()
binary_sysctl(): fix memory leak
mm/vmalloc.c: remove static declaration of va from __get_vm_area_node
ipmi_watchdog: restore settings when BMC reset
oom: fix integer overflow of points in oom_badness
memcg: keep root group unchanged if creation fails
nilfs2: potential integer overflow in nilfs_ioctl_clean_segments()
nilfs2: unbreak compat ioctl
cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemask
evm: prevent racing during tfm allocation
evm: key must be set once during initialization
mmc: vub300: fix type of firmware_rom_wait_states module parameter
Revert "mmc: enable runtime PM by default"
mmc: sdhci: remove "state" argument from sdhci_suspend_host
x86, dumpstack: Fix code bytes breakage due to missing KERN_CONT
IB/qib: Correct sense on freectxts increment and decrement
RDMA/cma: Verify private data length
cgroups: fix a css_set not found bug in cgroup_attach_proc
oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
Revert "xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel"
...
Conflicts:
kernel/cgroup_freezer.c
Mathieu Desnoyers pointed out a case that can cause issues with
NMIs running on the debug stack:
int3 -> interrupt -> NMI -> int3
Because the interrupt changes the stack, the NMI will not see that
it preempted the debug stack. Looking deeper at this case,
interrupts only happen when the int3 is from userspace or in
an a location in the exception table (fixup).
userspace -> int3 -> interurpt -> NMI -> int3
All other int3s that happen in the kernel should be processed
without ever enabling interrupts, as the do_trap() call will
panic the kernel if it is called to process any other location
within the kernel.
Adding a counter around the sections that enable interrupts while
using the debug stack allows the NMI to also check that case.
If the NMI sees that it either interrupted a task using the debug
stack or the debug counter is non-zero, then it will have to
change the IDT table to make the int3 not change stacks (which will
corrupt the stack if it does).
Note, I had to move the debug_usage functions out of processor.h
and into debugreg.h because of the static inlined functions to
inc and dec the debug_usage counter. __get_cpu_var() requires
smp.h which includes processor.h, and would fail to build.
Link: http://lkml.kernel.org/r/1323976535.23971.112.camel@gandalf.stny.rr.com
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
With i386, NMIs and breakpoints use the current stack and they
do not reset the stack pointer to a fix point that might corrupt
a previous NMI or breakpoint (as it does in x86_64). But NMIs are
still not made to be re-entrant, and need to prevent the case that
an NMI hitting a breakpoint (which does an iret), doesn't allow
another NMI to run.
The fix is to let the NMI be in 3 different states:
1) not running
2) executing
3) latched
When no NMI is executing on a given CPU, the state is "not running".
When the first NMI comes in, the state is switched to "executing".
On exit of that NMI, a cmpxchg is performed to switch the state
back to "not running" and if that fails, the NMI is restarted.
If a breakpoint is hit and does an iret, which re-enables NMIs,
and another NMI comes in before the first NMI finished, it will
detect that the state is not in the "not running" state and the
current NMI is nested. In this case, the state is switched to "latched"
to let the interrupted NMI know to restart the NMI handler, and
the nested NMI exits without doing anything.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
We want to allow NMI handlers to have breakpoints to be able to
remove stop_machine from ftrace, kprobes and jump_labels. But if
an NMI interrupts a current breakpoint, and then it triggers a
breakpoint itself, it will switch to the breakpoint stack and
corrupt the data on it for the breakpoint processing that it
interrupted.
Instead, have the NMI check if it interrupted breakpoint processing
by checking if the stack that is currently used is a breakpoint
stack. If it is, then load a special IDT that changes the IST
for the debug exception to keep the same stack in kernel context.
When the NMI is done, it puts it back.
This way, if the NMI does trigger a breakpoint, it will keep
using the same stack and not stomp on the breakpoint data for
the breakpoint it interrupted.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In x86, when an NMI goes off, the CPU goes into an NMI context that
prevents other NMIs to trigger on that CPU. If an NMI is suppose to
trigger, it has to wait till the previous NMI leaves NMI context.
At that time, the next NMI can trigger (note, only one more NMI will
trigger, as only one can be latched at a time).
The way x86 gets out of NMI context is by calling iret. The problem
with this is that this causes problems if the NMI handle either
triggers an exception, or a breakpoint. Both the exception and the
breakpoint handlers will finish with an iret. If this happens while
in NMI context, the CPU will leave NMI context and a new NMI may come
in. As NMI handlers are not made to be re-entrant, this can cause
havoc with the system, not to mention, the nested NMI will write
all over the previous NMI's stack.
Linus Torvalds proposed the following workaround to this problem:
https://lkml.org/lkml/2010/7/14/264
"In fact, I wonder if we couldn't just do a software NMI disable
instead? Hav ea per-cpu variable (in the _core_ percpu areas that get
allocated statically) that points to the NMI stack frame, and just
make the NMI code itself do something like
NMI entry:
- load percpu NMI stack frame pointer
- if non-zero we know we're nested, and should ignore this NMI:
- we're returning to kernel mode, so return immediately by using
"popf/ret", which also keeps NMI's disabled in the hardware until the
"real" NMI iret happens.
- before the popf/iret, use the NMI stack pointer to make the NMI
return stack be invalid and cause a fault
- set the NMI stack pointer to the current stack pointer
NMI exit (not the above "immediate exit because we nested"):
clear the percpu NMI stack pointer
Just do the iret.
Now, the thing is, now the "iret" is atomic. If we had a nested NMI,
we'll take a fault, and that re-does our "delayed" NMI - and NMI's
will stay masked.
And if we didn't have a nested NMI, that iret will now unmask NMI's,
and everything is happy."
I first tried to follow this advice but as I started implementing this
code, a few gotchas showed up.
One, is accessing per-cpu variables in the NMI handler.
The problem is that per-cpu variables use the %gs register to get the
variable for the given CPU. But as the NMI may happen in userspace,
we must first perform a SWAPGS to get to it. The NMI handler already
does this later in the code, but its too late as we have saved off
all the registers and we don't want to do that for a disabled NMI.
Peter Zijlstra suggested to keep all variables on the stack. This
simplifies things greatly and it has the added benefit of cache locality.
Two, faulting on the iret.
I really wanted to make this work, but it was becoming very hacky, and
I never got it to be stable. The iret already had a fault handler for
userspace faulting with bad segment registers, and getting NMI to trigger
a fault and detect it was very tricky. But for strange reasons, the system
would usually take a double fault and crash. I never figured out why
and decided to go with a simple "jmp" approach. The new approach I took
also simplified things.
Finally, the last problem with Linus's approach was to have the nested
NMI handler do a ret instead of an iret to give the first NMI NMI-context
again.
The problem is that ret is much more limited than an iret. I couldn't figure
out how to get the stack back where it belonged. I could have copied the
current stack, pushed the return onto it, but my fear here is that there
may be some place that writes data below the stack pointer. I know that
is not something code should depend on, but I don't want to chance it.
I may add this feature later, but for now, an NMI handler that loses NMI
context will not get it back.
Here's what is done:
When an NMI comes in, the HW pushes the interrupt stack frame onto the
per cpu NMI stack that is selected by the IST.
A special location on the NMI stack holds a variable that is set when
the first NMI handler runs. If this variable is set then we know that
this is a nested NMI and we process the nested NMI code.
There is still a race when this variable is cleared and an NMI comes
in just before the first NMI does the return. For this case, if the
variable is cleared, we also check if the interrupted stack is the
NMI stack. If it is, then we process the nested NMI code.
Why the two tests and not just test the interrupted stack?
If the first NMI hits a breakpoint and loses NMI context, and then it
hits another breakpoint and while processing that breakpoint we get a
nested NMI. When processing a breakpoint, the stack changes to the
breakpoint stack. If another NMI comes in here we can't rely on the
interrupted stack to be the NMI stack.
If the variable is not set and the interrupted task's stack is not the
NMI stack, then we know this is the first NMI and we can process things
normally. But in order to do so, we need to do a few things first.
1) Set the stack variable that tells us that we are in an NMI handler
2) Make two copies of the interrupt stack frame.
One copy is used to return on iret
The other is used to restore the first one if we have a nested NMI.
This is what the stack will look like:
+-------------------------+
| original SS |
| original Return RSP |
| original RFLAGS |
| original CS |
| original RIP |
+-------------------------+
| temp storage for rdx |
+-------------------------+
| NMI executing variable |
+-------------------------+
| Saved SS |
| Saved Return RSP |
| Saved RFLAGS |
| Saved CS |
| Saved RIP |
+-------------------------+
| copied SS |
| copied Return RSP |
| copied RFLAGS |
| copied CS |
| copied RIP |
+-------------------------+
| pt_regs |
+-------------------------+
The original stack frame contains what the HW put in when we entered
the NMI.
We store %rdx as a temp variable to use. Both the original HW stack
frame and this %rdx storage will be clobbered by nested NMIs so we
can not rely on them later in the first NMI handler.
The next item is the special stack variable that is set when we execute
the rest of the NMI handler.
Then we have two copies of the interrupt stack. The second copy is
modified by any nested NMIs to let the first NMI know that we triggered
a second NMI (latched) and that we should repeat the NMI handler.
If the first NMI hits an exception or breakpoint that takes it out of
NMI context, if a second NMI comes in before the first one finishes,
it will update the copied interrupt stack to point to a fix up location
to trigger another NMI.
When the first NMI calls iret, it will instead jump to the fix up
location. This fix up location will copy the saved interrupt stack back
to the copy and execute the nmi handler again.
Note, the nested NMI knows enough to check if it preempted a previous
NMI handler while it is in the fixup location. If it has, it will not
modify the copied interrupt stack and will just leave as if nothing
happened. As the NMI handle is about to execute again, there's no reason
to latch now.
To test all this, I forced the NMI handler to call iret and take itself
out of NMI context. I also added assemble code to write to the serial to
make sure that it hits the nested path as well as the fix up path.
Everything seems to be working fine.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Linus cleaned up the NMI handler but it still needs some comments to
explain why it uses save_paranoid but not paranoid_exit. Just to keep
others from adding that in the future, document why it's not used.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The NMI handler uses the paranoid_exit routine that checks the
NEED_RESCHED flag, and if it is set and the return is for userspace,
then interrupts are enabled, the stack is swapped to the thread's stack,
and schedule is called. The problem with this is that we are still in an
NMI context until an iret is executed. This means that any new NMIs are
now starved until an interrupt or exception occurs and does the iret.
As NMIs can not be masked and can interrupt any location, they are
treated as a special case. NEED_RESCHED should not be set in an NMI
handler. The interruption by the NMI should not disturb the work flow
for scheduling. Any IPI sent to a processor after sending the
NEED_RESCHED would have to wait for the NMI anyway, and after the IPI
finishes the schedule would be called as required.
There is no reason to do anything special leaving an NMI. Remove the
call to paranoid_exit and do a simple return. This not only fixes the
bug of starved NMIs, but it also cleans up the code.
Link: http://lkml.kernel.org/r/CA+55aFzgM55hXTs4griX5e9=v_O+=ue+7Rj0PTD=M7hFYpyULQ@mail.gmail.com
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add event maps for Intel x86 processors (with architected PMU v2 or later).
On AMD, there is frequency scaling but no Turbo. There is no core
cycle event not subject to frequency scaling, therefore we do not
provide a mapping.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-4-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds the encoding and definitions necessary for the
unhalted_reference_cycles event avaialble since Intel Core 2 processors.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Several fields in struct cpuinfo_x86 were not defined for the
!SMP case, likely to save space. However, those fields still
have some meaning for UP, and keeping them allows some #ifdef
removal from other files. The additional size of the UP kernel
from this change is not significant enough to worry about
keeping up the distinction:
text data bss dec hex filename
4737168 506459 972040 6215667 5ed7f3 vmlinux.o.before
4737444 506459 972040 6215943 5ed907 vmlinux.o.after
for a difference of 276 bytes for an example UP config.
If someone wants those 276 bytes back badly then it should
be implemented in a cleaner way.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Cc: Steffen Persvold <sp@numascale.com>
Link: http://lkml.kernel.org/r/1324428742-12498-1-git-send-email-kjwinchester@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* commit 'v3.2-rc3': (412 commits)
Linux 3.2-rc3
virtio-pci: make reset operation safer
virtio-mmio: Correct the name of the guest features selector
virtio: add HAS_IOMEM dependency to MMIO platform bus driver
eCryptfs: Extend array bounds for all filename chars
eCryptfs: Flush file in vma close
eCryptfs: Prevent file create race condition
regulator: TPS65910: Fix VDD1/2 voltage selector count
i2c: Make i2cdev_notifier_call static
i2c: Delete ANY_I2C_BUS
i2c: Fix device name for 10-bit slave address
i2c-algo-bit: Generate correct i2c address sequence for 10-bit target
drm: integer overflow in drm_mode_dirtyfb_ioctl()
Revert "of/irq: of_irq_find_parent: check for parent equal to child"
drivers/gpu/vga/vgaarb.c: add missing kfree
drm/radeon/kms/atom: unify i2c gpio table handling
drm/radeon/kms: fix up gpio i2c mask bits for r4xx for real
ttm: Don't return the bo reserved on error path
mount_subtree() pointless use-after-free
iio: fix a leak due to improper use of anon_inode_getfd()
...
Since LRW & XTS are selected by serpent-sse2, we don't need these #ifdefs
anymore.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since LRW & XTS are selected by twofish-x86_64-3way, we don't need these
#ifdefs anymore.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When printing the code bytes in show_registers(), the markers around the
byte at the fault address could make the printk() format string look
like a valid log level and facility code. This would prevent this byte
from being printed and result in a spurious newline:
[ 7555.765589] Code: 8b 32 e9 94 00 00 00 81 7d 00 ff 00 00 00 0f 87 96 00 00 00 48 8b 83 c0 00 00 00 44 89 e2 44 89 e6 48 89 df 48 8b 80 d8 02 00 00
[ 7555.765683] 8b 48 28 48 89 d0 81 e2 ff 0f 00 00 48 c1 e8 0c 48 c1 e0 04
Add KERN_CONT where needed, and elsewhere in show_registers() for
consistency.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Link: http://lkml.kernel.org/r/4EEFA7AE.9020407@ladisch.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86 jump instruction size is 2 or 5 bytes (near/long jump), not 2 or 6
bytes.
In case a conditional jump is followed by a long jump, conditional jump
target is one byte past the start of target instruction.
Signed-off-by: Markus Kötter <nepenthesdev@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
LAPIC related statistics are grouped inside the per-cpu
structure irq_stat, so there is no need for icr_read_retry_count
to be a standalone per-cpu variable.
This patch moves icr_read_retry_count to where it belongs.
Suggested-y: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: Jörn Engel <joern@logfs.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Added additional debug output that we always seem to add
during power ons to validate firmware operation.
Signed-off-by: Michael Demeter <michael.demeter@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20111215223116.10166.50803.stgit@bob.linux.org.uk
[ fixed line breaks, formatting and commit title. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
gcc noticed (when using -Wempty-body) that our use of
lock_cmos() and unlock_cmos() in
arch/x86/include/asm/mach_traps.h is potentially problematic :
arch/x86/include/asm/mach_traps.h:32:15: warning: suggest braces around empty body in an ¡else¢ statement [-Wempty-body]
arch/x86/include/asm/mach_traps.h:40:16: warning: suggest braces around empty body in an ¡else¢ statement [-Wempty-body]
Let's just use the standard 'do {} while (0)' solution. That
shuts up gcc and also prevents future problems if the macros
should end up being used in a similar situation elsewhere.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1112180103130.21784@swampdragon.chaosbits.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If one builds the kernel with -Wempty-body one gets this
warning:
mm/memory.c:3432:46: warning: suggest braces around empty body in an ¡if¢ statement [-Wempty-body]
due to the fact that 'flush_tlb_fix_spurious_fault' is a macro
that can sometimes be defined to nothing.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: linux-mm@kvack.org
Cc: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1112180128070.21784@swampdragon.chaosbits.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
mce-inject provides a mechanism to simulate errors so that test
scripts can check for correct operation of the kernel without
requiring any specialized hardware to create rare events.
The existing code can simulate events in normal process context
and also in NMI context - but not in IRQ context. This patch
fills that gap.
Link: https://lkml.org/lkml/2011/12/7/537
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The efi boot stub tries to read the entire initrd in 1 go, however
some efi implementations hang if too much if asked to read too much
data at the same time. After some experimentation I found out that my
asrock p67 board will hang if asked to read chunks of 4MiB, so use a
safe value.
elilo reads in chunks of 16KiB, but since that requires many read
calls I use a value of 1 MiB. hpa suggested adding individual
blacklists for when systems are found where this value causes a crash.
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Link: http://lkml.kernel.org/r/4EEB3A02.3090201@gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Doh.. pass the brown paper bags - preferably filled with mince
pies..
This fixes occasional build failures.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-r0oc1knlvzuqr69artaeq8s8@git.kernel.org
[ extended the changelog a bit ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fls(N), ffs(N) and fls64(N) can be optimised on x86_64. Currently they use a
CMOV instruction after the BSR/BSF to set the destination register to -1 if the
value to be scanned was 0 (in which case BSR/BSF set the Z flag).
Instead, according to the AMD64 specification, we can make use of the fact that
BSR/BSF doesn't modify its output register if its input is 0. By preloading
the output with -1 and incrementing the result, we achieve the desired result
without the need for a conditional check.
The Intel x86_64 specification, however, says that the result of BSR/BSF in
such a case is undefined. That said, when queried, one of the Intel CPU
architects said that the behaviour on all Intel CPUs is that:
(1) with BSRQ/BSFQ, the 64-bit destination register is written with its
original value if the source is 0, thus, in essence, giving the effect we
want. And,
(2) with BSRL/BSFL, the lower half of the 64-bit destination register is
written with its original value if the source is 0, and the upper half is
cleared, thus giving us the effect we want (we return a 4-byte int).
Further, it was indicated that they (Intel) are unlikely to get away with
changing the behaviour.
It might be possible to optimise the 32-bit versions of these functions, but
there's a lot more variation, and so the effective non-destructive property of
BSRL/BSRF cannot be relied on.
[ hpa: specifically, some 486 chips are known to NOT have this property. ]
I have benchmarked these functions on my Core2 Duo test machine using the
following program:
#include <stdlib.h>
#include <stdio.h>
#ifndef __x86_64__
#error
#endif
#define PAGE_SHIFT 12
typedef unsigned long long __u64, u64;
typedef unsigned int __u32, u32;
#define noinline __attribute__((noinline))
static __always_inline int fls64(__u64 x)
{
long bitpos = -1;
asm("bsrq %1,%0"
: "+r" (bitpos)
: "rm" (x));
return bitpos + 1;
}
static inline unsigned long __fls(unsigned long word)
{
asm("bsr %1,%0"
: "=r" (word)
: "rm" (word));
return word;
}
static __always_inline int old_fls64(__u64 x)
{
if (x == 0)
return 0;
return __fls(x) + 1;
}
static noinline // __attribute__((const))
int old_get_order(unsigned long size)
{
int order;
size = (size - 1) >> (PAGE_SHIFT - 1);
order = -1;
do {
size >>= 1;
order++;
} while (size);
return order;
}
static inline __attribute__((const))
int get_order_old_fls64(unsigned long size)
{
int order;
size--;
size >>= PAGE_SHIFT;
order = old_fls64(size);
return order;
}
static inline __attribute__((const))
int get_order(unsigned long size)
{
int order;
size--;
size >>= PAGE_SHIFT;
order = fls64(size);
return order;
}
unsigned long prevent_optimise_out;
static noinline unsigned long test_old_get_order(void)
{
unsigned long n, total = 0;
long rep, loop;
for (rep = 1000000; rep > 0; rep--) {
for (loop = 0; loop <= 16384; loop += 4) {
n = 1UL << loop;
total += old_get_order(n);
}
}
return total;
}
static noinline unsigned long test_get_order_old_fls64(void)
{
unsigned long n, total = 0;
long rep, loop;
for (rep = 1000000; rep > 0; rep--) {
for (loop = 0; loop <= 16384; loop += 4) {
n = 1UL << loop;
total += get_order_old_fls64(n);
}
}
return total;
}
static noinline unsigned long test_get_order(void)
{
unsigned long n, total = 0;
long rep, loop;
for (rep = 1000000; rep > 0; rep--) {
for (loop = 0; loop <= 16384; loop += 4) {
n = 1UL << loop;
total += get_order(n);
}
}
return total;
}
int main(int argc, char **argv)
{
unsigned long total;
switch (argc) {
case 1: total = test_old_get_order(); break;
case 2: total = test_get_order_old_fls64(); break;
default: total = test_get_order(); break;
}
prevent_optimise_out = total;
return 0;
}
This allows me to test the use of the old fls64() implementation and the new
fls64() implementation and also to contrast these to the out-of-line loop-based
implementation of get_order(). The results were:
warthog>time ./get_order
real 1m37.191s
user 1m36.313s
sys 0m0.861s
warthog>time ./get_order x
real 0m16.892s
user 0m16.586s
sys 0m0.287s
warthog>time ./get_order x x
real 0m7.731s
user 0m7.727s
sys 0m0.002s
Using the current upstream fls64() as a basis for an inlined get_order() [the
second result above] is much faster than using the current out-of-line
loop-based get_order() [the first result above].
Using my optimised inline fls64()-based get_order() [the third result above]
is even faster still.
[ hpa: changed the selection of 32 vs 64 bits to use CONFIG_X86_64
instead of comparing BITS_PER_LONG, updated comments, rebased manually
on top of 83d99df7c4 x86, bitops: Move fls64.h inside __KERNEL__ ]
Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20111213145654.14362.39868.stgit@warthog.procyon.org.uk
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We would include <asm-generic/bitops/fls64.h> even without __KERNEL__,
but that doesn't make sense, as:
1. That file provides fls64(), but the corresponding function fls() is
not exported to user space.
2. The implementation of fls64.h uses kernel-only symbols.
3. fls64.h is not exported to user space.
This appears to have been a bug introduced in checkin:
d57594c203 bitops: use __fls for fls64 on 64-bit archs
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Alexander van Heukelum <heukelum@mailshack.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/4EEA77E1.6050009@zytor.com
* 'stable/for-linus-fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/swiotlb: Use page alignment for early buffer allocation.
xen: only limit memory map to maximum reservation for domain 0.
d312ae878b "xen: use maximum reservation to limit amount of usable RAM"
clamped the total amount of RAM to the current maximum reservation. This is
correct for dom0 but is not correct for guest domains. In order to boot a guest
"pre-ballooned" (e.g. with memory=1G but maxmem=2G) in order to allow for
future memory expansion the guest must derive max_pfn from the e820 provided by
the toolstack and not the current maximum reservation (which can reflect only
the current maximum, not the guest lifetime max). The existing algorithm
already behaves this correctly if we do not artificially limit the maximum
number of pages for the guest case.
For a guest booted with maxmem=512, memory=128 this results in:
[ 0.000000] BIOS-provided physical RAM map:
[ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable)
[ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)
-[ 0.000000] Xen: 0000000000100000 - 0000000008100000 (usable)
-[ 0.000000] Xen: 0000000008100000 - 0000000020800000 (unusable)
+[ 0.000000] Xen: 0000000000100000 - 0000000020800000 (usable)
...
[ 0.000000] NX (Execute Disable) protection: active
[ 0.000000] DMI not present or invalid.
[ 0.000000] e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved)
[ 0.000000] e820 remove range: 00000000000a0000 - 0000000000100000 (usable)
-[ 0.000000] last_pfn = 0x8100 max_arch_pfn = 0x1000000
+[ 0.000000] last_pfn = 0x20800 max_arch_pfn = 0x1000000
[ 0.000000] initial memory mapped : 0 - 027ff000
[ 0.000000] Base memory trampoline at [c009f000] 9f000 size 4096
-[ 0.000000] init_memory_mapping: 0000000000000000-0000000008100000
-[ 0.000000] 0000000000 - 0008100000 page 4k
-[ 0.000000] kernel direct mapping tables up to 8100000 @ 27bb000-27ff000
+[ 0.000000] init_memory_mapping: 0000000000000000-0000000020800000
+[ 0.000000] 0000000000 - 0020800000 page 4k
+[ 0.000000] kernel direct mapping tables up to 20800000 @ 26f8000-27ff000
[ 0.000000] xen: setting RW the range 27e8000 - 27ff000
[ 0.000000] 0MB HIGHMEM available.
-[ 0.000000] 129MB LOWMEM available.
-[ 0.000000] mapped low ram: 0 - 08100000
-[ 0.000000] low ram: 0 - 08100000
+[ 0.000000] 520MB LOWMEM available.
+[ 0.000000] mapped low ram: 0 - 20800000
+[ 0.000000] low ram: 0 - 20800000
With this change "xl mem-set <domain> 512M" will successfully increase the
guest RAM (by reducing the balloon).
There is no change for dom0.
Reported-and-Tested-by: George Shuklin <george.shuklin@gmail.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: stable@kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
My box with following cpuinfo needs the cx8 enabling still:
vendor_id : CentaurHauls
cpu family : 6
model : 13
model name : VIA Eden Processor 1200MHz
stepping : 0
cpu MHz : 1199.940
cache size : 128 KB
This fixes valgrind to work on my box (it requires and checks
cx8 from cpuinfo).
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Link: http://lkml.kernel.org/r/1323961888-10223-1-git-send-email-timo.teras@iki.fi
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
They had several problems/shortcomings:
Only the first memory operand was mentioned in the 2x32bit asm()
operands, and 2x64-bit version had a memory clobber. The first
allowed the compiler to not recognize the need to re-load the
data in case it had it cached in some register, and the second
was overly destructive.
The memory operand in the 2x32-bit asm() was declared to only be
an output.
The types of the local copies of the old and new values were
incorrect (as in other per-CPU ops, the types of the per-CPU
variables accessed should be used here, to make sure the
respective types are compatible).
The __dummy variable was pointless (and needlessly initialized
in the 2x32-bit case), given that local copies of the inputs
already exist.
The 2x64-bit variant forced the address of the first object into
%rsi, even though this is needed only for the call to the
emulation function. The real cmpxchg16b can operate on an
memory.
At once also change the return value type to what it really is -
'bool'.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4EE86D6502000078000679FE@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the flags to get rid of the [9] and [10] feature names
in cpuinfo's 'power management' fields and replace them with
meaningful names.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1323875574-17881-1-git-send-email-joerg.roedel@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Thermal throttle and power limit events are not defined as MCE errors in x86
architecture and should not generate MCE errors in mcelog.
Current kernel generates fake software defined MCE errors for these events.
This may confuse users because they may think the machine has real MCE errors
while actually only thermal throttle or power limit events happen.
To make it worse, buggy firmware on some platforms may falsely generate
the events. Therefore, kernel reports MCE errors which users think as real
hardware errors. Although the firmware bugs should be fixed, on the other hand,
kernel should not report MCE errors either.
So mcelog is not a good mechanism to report these events. To report the events, we count them in respective counters (core_power_limit_count,
package_power_limit_count, core_throttle_count, and package_throttle_count) in
/sys/devices/system/cpu/cpu#/thermal_throttle/. Users can check the counters
for each event on each CPU. Please note that all CPU's on one package report
duplicate counters. It's user application's responsibity to retrieve a package
level counter for one package.
This patch doesn't report package level power limit, core level power limit, and
package level thermal throttle events in mcelog. When the events happen, only
report them in respective counters in sysfs.
Since core level thermal throttle has been legacy code in kernel for a while and
users accepted it as MCE error in mcelog, core level thermal throttle is still
reported in mcelog. In the mean time, the event is counted in a counter in sysfs
as well.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Borislav Petkov <bp@amd64.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20111215001945.GA21009@linux-os.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Add a function which drains whatever MCEs were logged in already during
boot and before the decoder chains were registered.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
No functionality change, this is done so that in a follow-on patch all
queued-up MCEs can be decoded after registering on the chain.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Once we've found and validated the ucode patch for the current CPU,
there's no need to iterate over the remaining patches in the binary
image. Exit then and save us a bunch of cycles.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Basically, what we did until now is take out a chunk of the firmware
image, vmalloc space for it and inspect it before application. And
repeat.
This patch changes all that so that we look at each ucode patch from
the firmware image, check it for sanity and copy it to local buffer for
application only once and if it passes all checks. Thus, vmalloc-ing for
each piece is gone, we can do proper size checking only of the patch
which is destined for the CPU of the current machine instead of each
single patch, which is clearly wrong.
Oh yeah, simplify and cleanup the code while at it, along with adding
comments as to what actually happens.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add a simple 4K page which gets allocated on driver init and freed on
driver exit instead of vmalloc'ing small buffers for each ucode patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
In the IPI delivery slow path (NMI delivery) we retry the ICR
read to check for delivery completion a limited number of times.
[ The reason for the limited retries is that some of the places
where it is used (cpu boot, kdump, etc) IPI delivery might not
succeed (due to a firmware bug or system crash, for example)
and in such a case it is better to give up and resume
execution of other code. ]
This patch adds a new entry to /proc/interrupts, RTR, which
tells user space the number of times we retried the ICR read in
the IPI delivery slow path.
This should give some insight into how well the APIC
message delivery hardware is working - if the counts are way
too large then we are hitting a (very-) slow path way too
often.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: Jörn Engel <joern@logfs.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/n/tip-vzsp20lo2xdzh5f70g0eis2s@git.kernel.org
[ extended the changelog ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There is currently a large divide between kernel development and the
development of EFI boot loaders. The idea behind this patch is to give
the kernel developers full control over the EFI boot process. As
H. Peter Anvin put it,
"The 'kernel carries its own stub' approach been very successful in
dealing with BIOS, and would make a lot of sense to me for EFI as
well."
This patch introduces an EFI boot stub that allows an x86 bzImage to
be loaded and executed by EFI firmware. The bzImage appears to the
firmware as an EFI application. Luckily there are enough free bits
within the bzImage header so that it can masquerade as an EFI
application, thereby coercing the EFI firmware into loading it and
jumping to its entry point. The beauty of this masquerading approach
is that both BIOS and EFI boot loaders can still load and run the same
bzImage, thereby allowing a single kernel image to work in any boot
environment.
The EFI boot stub supports multiple initrds, but they must exist on
the same partition as the bzImage. Command-line arguments for the
kernel can be appended after the bzImage name when run from the EFI
shell, e.g.
Shell> bzImage console=ttyS0 root=/dev/sdb initrd=initrd.img
v7:
- Fix checkpatch warnings.
v6:
- Try to allocate initrd memory just below hdr->inird_addr_max.
v5:
- load_options_size is UTF-16, which needs dividing by 2 to convert
to the corresponding ASCII size.
v4:
- Don't read more than image->load_options_size
v3:
- Fix following warnings when compiling CONFIG_EFI_STUB=n
arch/x86/boot/tools/build.c: In function ‘main’:
arch/x86/boot/tools/build.c:138:24: warning: unused variable ‘pe_header’
arch/x86/boot/tools/build.c:138:15: warning: unused variable ‘file_sz’
- As reported by Matthew Garrett, some Apple machines have GOPs that
don't have hardware attached. We need to weed these out by
searching for ones that handle the PCIIO protocol.
- Don't allocate memory if no initrds are on cmdline
- Don't trust image->load_options_size
Maarten Lankhorst noted:
- Don't strip first argument when booted from efibootmgr
- Don't allocate too much memory for cmdline
- Don't update cmdline_size, the kernel considers it read-only
- Don't accept '\n' for initrd names
v2:
- File alignment was too large, was 8192 should be 512. Reported by
Maarten Lankhorst on LKML.
- Added UGA support for graphics
- Use VIDEO_TYPE_EFI instead of hard-coded number.
- Move linelength assignment until after we've assigned depth
- Dynamically fill out AddressOfEntryPoint in tools/build.c
- Don't use magic number for GDT/TSS stuff. Requested by Andi Kleen
- The bzImage may need to be relocated as it may have been loaded at
a high address address by the firmware. This was required to get my
macbook booting because the firmware loaded it at 0x7cxxxxxx, which
triggers this error in decompress_kernel(),
if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
error("Destination address too large");
Cc: Mike Waychison <mikew@google.com>
Cc: Matthew Garrett <mjg@redhat.com>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1321383097.2657.9.camel@mfleming-mobl1.ger.corp.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
