29ecd660 ("KVM: x86: avoid uninitialized variable warning",
2015-09-06) introduced a not-so-subtle problem, which probably
escaped review because it was not part of the patch context.

Before the patch, leaf was always equal to iterator.level.  After,
it is equal to iterator.level - 1 in the call to is_shadow_zero_bits_set,
and when is_shadow_zero_bits_set does another "-1" the check on
reserved bits becomes incorrect.  Using "iterator.level" in the call
fixes this call trace:

WARNING: CPU: 2 PID: 17000 at arch/x86/kvm/mmu.c:3385 handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]()
Modules linked in: tun sha256_ssse3 sha256_generic drbg binfmt_misc ipv6 vfat fat fuse dm_crypt dm_mod kvm_amd kvm crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd fam15h_power amd64_edac_mod k10temp edac_core amdkfd amd_iommu_v2 radeon acpi_cpufreq
[...]
Call Trace:
  dump_stack+0x4e/0x84
  warn_slowpath_common+0x95/0xe0
  warn_slowpath_null+0x1a/0x20
  handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]
  tdp_page_fault+0x231/0x290 [kvm]
  ? emulator_pio_in_out+0x6e/0xf0 [kvm]
  kvm_mmu_page_fault+0x36/0x240 [kvm]
  ? svm_set_cr0+0x95/0xc0 [kvm_amd]
  pf_interception+0xde/0x1d0 [kvm_amd]
  handle_exit+0x181/0xa70 [kvm_amd]
  ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm]
  kvm_arch_vcpu_ioctl_run+0x6f6/0x1730 [kvm]
  ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm]
  ? preempt_count_sub+0x9b/0xf0
  ? mutex_lock_killable_nested+0x26f/0x490
  ? preempt_count_sub+0x9b/0xf0
  kvm_vcpu_ioctl+0x358/0x710 [kvm]
  ? __fget+0x5/0x210
  ? __fget+0x101/0x210
  do_vfs_ioctl+0x2f4/0x560
  ? __fget_light+0x29/0x90
  SyS_ioctl+0x4c/0x90
  entry_SYSCALL_64_fastpath+0x16/0x73
---[ end trace 37901c8686d84de6 ]---
Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Intel CPUID on AMD host or vice versa is a weird case, but it can
happen.  Handle it by checking the host CPU vendor instead of the
guest's in reset_tdp_shadow_zero_bits_mask.  For speed, the
check uses the fact that Intel EPT has an X (executable) bit while
AMD NPT has NX.
Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

kvm_set_cr0 may want to call kvm_zap_gfn_range and thus access the
memslots array (SRCU protected).  Using a mini SRCU critical section
is ugly, and adding it to kvm_arch_vcpu_create doesn't work because
the VMX vcpu_create callback calls synchronize_srcu.

Fixes this lockdep splat:

===============================
[ INFO: suspicious RCU usage. ]
4.3.0-rc1+ #1 Not tainted
-------------------------------
include/linux/kvm_host.h:488 suspicious rcu_dereference_check() usage!

other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
1 lock held by qemu-system-i38/17000:
 #0:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: kvm_zap_gfn_range+0x24/0x1a0 [kvm]

[...]
Call Trace:
 dump_stack+0x4e/0x84
 lockdep_rcu_suspicious+0xfd/0x130
 kvm_zap_gfn_range+0x188/0x1a0 [kvm]
 kvm_set_cr0+0xde/0x1e0 [kvm]
 init_vmcb+0x760/0xad0 [kvm_amd]
 svm_create_vcpu+0x197/0x250 [kvm_amd]
 kvm_arch_vcpu_create+0x47/0x70 [kvm]
 kvm_vm_ioctl+0x302/0x7e0 [kvm]
 ? __lock_is_held+0x51/0x70
 ? __fget+0x101/0x210
 do_vfs_ioctl+0x2f4/0x560
 ? __fget_light+0x29/0x90
 SyS_ioctl+0x4c/0x90
 entry_SYSCALL_64_fastpath+0x16/0x73
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

These have roughly the same purpose as the SMRR, which we do not need
to implement in KVM.  However, Linux accesses MSR_K8_TSEG_ADDR at
boot, which causes problems when running a Xen dom0 under KVM.
Just return 0, meaning that processor protection of SMRAM is not
in effect.
Reported-by: M A Young <m.a.young@durham.ac.uk>
Cc: stable@vger.kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Access to the kvm->buses (like with the kvm_io_bus_read() and -write()
functions) has to be protected via the kvm->srcu lock.
The kvmppc_h_logical_ci_load() and -store() functions are missing
this lock so far, so let's add it there, too.
This fixes the problem that the kernel reports "suspicious RCU usage"
when lock debugging is enabled.

Cc: stable@vger.kernel.org # v4.1+
Fixes: 99342cf8Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

In guest_exit_cont we call kvmhv_commence_exit which expects the trap
number as the argument. However r3 doesn't contain the trap number at
this point and as a result we would be calling the function with a
spurious trap number.

Fix this by copying r12 into r3 before calling kvmhv_commence_exit as
r12 contains the trap number.

Cc: stable@vger.kernel.org # v4.1+
Fixes: eddb60fbSigned-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This fixes a bug which results in stale vcore pointers being left in
the per-cpu preempted vcore lists when a VM is destroyed.  The result
of the stale vcore pointers is usually either a crash or a lockup
inside collect_piggybacks() when another VM is run.  A typical
lockup message looks like:

[  472.161074] NMI watchdog: BUG: soft lockup - CPU#24 stuck for 22s! [qemu-system-ppc:7039]
[  472.161204] Modules linked in: kvm_hv kvm_pr kvm xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ses enclosure shpchp rtc_opal i2c_opal powernv_rng binfmt_misc dm_service_time scsi_dh_alua radeon i2c_algo_bit drm_kms_helper ttm drm tg3 ptp pps_core cxgb3 ipr i2c_core mdio dm_multipath [last unloaded: kvm_hv]
[  472.162111] CPU: 24 PID: 7039 Comm: qemu-system-ppc Not tainted 4.2.0-kvm+ #49
[  472.162187] task: c000001e38512750 ti: c000001e41bfc000 task.ti: c000001e41bfc000
[  472.162262] NIP: c00000000096b094 LR: c00000000096b08c CTR: c000000000111130
[  472.162337] REGS: c000001e41bff520 TRAP: 0901   Not tainted  (4.2.0-kvm+)
[  472.162399] MSR: 9000000100009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24848844  XER: 00000000
[  472.162588] CFAR: c00000000096b0ac SOFTE: 1
GPR00: c000000000111170 c000001e41bff7a0 c00000000127df00 0000000000000001
GPR04: 0000000000000003 0000000000000001 0000000000000000 0000000000874821
GPR08: c000001e41bff8e0 0000000000000001 0000000000000000 d00000000efde740
GPR12: c000000000111130 c00000000fdae400
[  472.163053] NIP [c00000000096b094] _raw_spin_lock_irqsave+0xa4/0x130
[  472.163117] LR [c00000000096b08c] _raw_spin_lock_irqsave+0x9c/0x130
[  472.163179] Call Trace:
[  472.163206] [c000001e41bff7a0] [c000001e41bff7f0] 0xc000001e41bff7f0 (unreliable)
[  472.163295] [c000001e41bff7e0] [c000000000111170] __wake_up+0x40/0x90
[  472.163375] [c000001e41bff830] [d00000000efd6fc0] kvmppc_run_core+0x1240/0x1950 [kvm_hv]
[  472.163465] [c000001e41bffa30] [d00000000efd8510] kvmppc_vcpu_run_hv+0x5a0/0xd90 [kvm_hv]
[  472.163559] [c000001e41bffb70] [d00000000e9318a4] kvmppc_vcpu_run+0x44/0x60 [kvm]
[  472.163653] [c000001e41bffba0] [d00000000e92e674] kvm_arch_vcpu_ioctl_run+0x64/0x170 [kvm]
[  472.163745] [c000001e41bffbe0] [d00000000e9263a8] kvm_vcpu_ioctl+0x538/0x7b0 [kvm]
[  472.163834] [c000001e41bffd40] [c0000000002d0f50] do_vfs_ioctl+0x480/0x7c0
[  472.163910] [c000001e41bffde0] [c0000000002d1364] SyS_ioctl+0xd4/0xf0
[  472.163986] [c000001e41bffe30] [c000000000009260] system_call+0x38/0xd0
[  472.164060] Instruction dump:
[  472.164098] ebc1fff0 ebe1fff8 7c0803a6 4e800020 60000000 60000000 60420000 8bad02e2
[  472.164224] 7fc3f378 4b6a57c1 60000000 7c210b78 <e92d0000> 89290009 792affe3 40820070

The bug is that kvmppc_run_vcpu does not correctly handle the case
where a vcpu task receives a signal while its guest vcpu is executing
in the guest as a result of being piggy-backed onto the execution of
another vcore.  In that case we need to wait for the vcpu to finish
executing inside the guest, and then remove this vcore from the
preempted vcores list.  That way, we avoid leaving this vcpu's vcore
on the preempted vcores list when the vcpu gets interrupted.

Fixes: ec257165Reported-by: Thomas Huth <thuth@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

When INIT/SIPI sequence is sent to VCPU which before that
was in use by OS, VMRUN might fail with:

 KVM: entry failed, hardware error 0xffffffff
 EAX=00000000 EBX=00000000 ECX=00000000 EDX=000006d3
 ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
 EIP=00000000 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
 ES =0000 00000000 0000ffff 00009300
 CS =9a00 0009a000 0000ffff 00009a00
 [...]
 CR0=60000010 CR2=b6f3e000 CR3=01942000 CR4=000007e0
 [...]
 EFER=0000000000000000

with corresponding SVM error:
 KVM: FAILED VMRUN WITH VMCB:
 [...]
 cpl:            0                efer:         0000000000001000
 cr0:            0000000080010010 cr2:          00007fd7fe85bf90
 cr3:            0000000187d0c000 cr4:          0000000000000020
 [...]

What happens is that VCPU state right after offlinig:
CR0: 0x80050033  EFER: 0xd01  CR4: 0x7e0
  -> long mode with CR3 pointing to longmode page tables

and when VCPU gets INIT/SIPI following transition happens
CR0: 0 -> 0x60000010 EFER: 0x0  CR4: 0x7e0
  -> paging disabled with stale CR3

However SVM under the hood puts VCPU in Paged Real Mode*
which effectively translates CR0 0x60000010 -> 80010010 after

   svm_vcpu_reset()
       -> init_vmcb()
           -> kvm_set_cr0()
               -> svm_set_cr0()

but from  kvm_set_cr0() perspective CR0: 0 -> 0x60000010
only caching bits are changed and
commit d81135a5
 ("KVM: x86: do not reset mmu if CR0.CD and CR0.NW are changed")'
regressed svm_vcpu_reset() which relied on MMU being reset.

As result VMRUN after svm_vcpu_reset() tries to run
VCPU in Paged Real Mode with stale MMU context (longmode page tables),
which causes some AMD CPUs** to bail out with VMEXIT_INVALID.

Fix issue by unconditionally resetting MMU context
at init_vmcb() time.

	* AMD64 Architecture Programmer’s Manual,
	    Volume 2: System Programming, rev: 3.25
	      15.19 Paged Real Mode
	** Opteron 1216
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Fixes: d81135a5
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Commit 2ee507c4 ("sched: Add function single_task_running to let a task
check if it is the only task running on a cpu") referenced the current
runqueue with the smp_processor_id.  When CONFIG_DEBUG_PREEMPT is enabled,
that is only allowed if preemption is disabled or the currrent task is
bound to the local cpu (e.g. kernel worker).

With commit f7819512 ("kvm: add halt_poll_ns module parameter") KVM
calls single_task_running. If CONFIG_DEBUG_PREEMPT is enabled that
generates a lot of kernel messages.

To avoid adding preemption in that cases, as it would limit the usefulness,
we change single_task_running to access directly the cpu local runqueue.

Cc: Tim Chen <tim.c.chen@linux.intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Fixes: 2ee507c4Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'kvm-arm-for-4.3-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

Second set of KVM/ARM changes for 4.3-rc2

- Workaround for a Cortex-A57 erratum
- Bug fix for the debugging infrastructure
- Fix for 32bit guests with more than 4GB of address space
  on a 32bit host
- A number of fixes for the (unusual) case when we don't use
  the in-kernel GIC emulation
- Removal of ThumbEE handling on arm64, since these have been
  dropped from the architecture before anyone actually ever
  built a CPU
- Remove the KVM_ARM_MAX_VCPUS limitation which has become
  fairly pointless

This patch removes config option of KVM_ARM_MAX_VCPUS,
and like other ARCHs, just choose the maximum allowed
value from hardware, and follows the reasons:

1) from distribution view, the option has to be
defined as the max allowed value because it need to
meet all kinds of virtulization applications and
need to support most of SoCs;

2) using a bigger value doesn't introduce extra memory
consumption, and the help text in Kconfig isn't accurate
because kvm_vpu structure isn't allocated until request
of creating VCPU is sent from QEMU;

3) the main effect is that the field of vcpus[] in 'struct kvm'
becomes a bit bigger(sizeof(void *) per vcpu) and need more cache
lines to hold the structure, but 'struct kvm' is one generic struct,
and it has worked well on other ARCHs already in this way. Also,
the world switch frequecy is often low, for example, it is ~2000
when running kernel building load in VM from APM xgene KVM host,
so the effect is very small, and the difference can't be observed
in my test at all.

Cc: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Although the ThumbEE registers and traps were present in earlier
versions of the v8 architecture, it was retrospectively removed and so
we can do the same.

Whilst this breaks migrating a guest started on a previous version of
the kernel, it is much better to kill these (non existent) registers
as soon as possible.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[maz: added commend about migration]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

When running a guest with the architected timer disabled (with QEMU and
the kernel_irqchip=off option, for example), it is important to make
sure the timer gets turned off. Otherwise, the guest may try to
enable it anyway, leading to a screaming HW interrupt.

The fix is to unconditionally turn off the virtual timer on guest
exit.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

When running a guest with the architected timer disabled (with QEMU and
the kernel_irqchip=off option, for example), it is important to make
sure the timer gets turned off. Otherwise, the guest may try to
enable it anyway, leading to a screaming HW interrupt.

The fix is to unconditionally turn off the virtual timer on guest
exit.

Cc: stable@vger.kernel.org
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Until b26e5fda ("arm/arm64: KVM: introduce per-VM ops"),
kvm_vgic_map_resources() used to include a check on irqchip_in_kernel(),
and vgic_v2_map_resources() still has it.

But now vm_ops are not initialized until we call kvm_vgic_create().
Therefore kvm_vgic_map_resources() can being called without a VGIC,
and we die because vm_ops.map_resources is NULL.

Fixing this restores QEMU's kernel-irqchip=off option to a working state,
allowing to use GIC emulation in userspace.

Fixes: b26e5fda ("arm/arm64: KVM: introduce per-VM ops")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
[maz: reworked commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

The offending commit accidentally replaces an atomic_clear with an
atomic_or instead of an atomic_andnot in kvm_s390_vcpu_request_handled.
The symptom is that kvm guests on s390 hang on startup.
This patch simply replaces the incorrect atomic_or with atomic_andnot

Fixes: 805de8f4 (atomic: Replace atomic_{set,clear}_mask() usage)
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

A critical bug has been found in device memory stage1 translation for
VMs with more then 4GB of address space. Once vm_pgoff size is smaller
then pa (which is true for LPAE case, u32 and u64 respectively) some
more significant bits of pa may be lost as a shift operation is performed
on u32 and later cast onto u64.

Example: vm_pgoff(u32)=0x00210030, PAGE_SHIFT=12
        expected pa(u64):   0x0000002010030000
        produced pa(u64):   0x0000000010030000

The fix is to change the order of operations (casting first onto phys_addr_t
and then shifting).
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
[maz: fixed changelog and patch formatting]
Cc: stable@vger.kernel.org
Signed-off-by: Marek Majtyka <marek.majtyka@tieto.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

When setting the debug register from userspace, make sure that
copy_from_user() is called with its parameters in the expected
order. It otherwise doesn't do what you think.

Fixes: 84e690bf ("KVM: arm64: introduce vcpu->arch.debug_ptr")
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Cc: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Reference SDM 28.1:

The current VPID is 0000H in the following situations:
- Outside VMX operation. (This includes operation in system-management
  mode under the default treatment of SMIs and SMM with VMX operation;
  see Section 34.14.)
- In VMX root operation.
- In VMX non-root operation when the “enable VPID” VM-execution control
  is 0.

The VPID should never be 0000H in non-root operation when "enable VPID"
VM-execution control is 1. However, commit 34a1cd60 ("kvm: x86: vmx:
move some vmx setting from vmx_init() to hardware_setup()") remove the
codes which reserve 0000H for VMX root operation.

This patch fix it by again reserving 0000H for VMX root operation.

Cc: stable@vger.kernel.org # 3.19+
Fixes: 34a1cd60Reported-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This new statistic can help diagnosing VCPUs that, for any reason,
trigger bad behavior of halt_poll_ns autotuning.

For example, say halt_poll_ns = 480000, and wakeups are spaced exactly
like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes
10+20+40+80+160+320+480 = 1110 microseconds out of every
479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then
is consuming about 30% more CPU than it would use without
polling.  This would show as an abnormally high number of
attempted polling compared to the successful polls.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com<
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Currently, if we had a zero length mmio eventfd assigned on
KVM_MMIO_BUS. It will never be found by kvm_io_bus_cmp() since it
always compares the kvm_io_range() with the length that guest
wrote. This will cause e.g for vhost, kick will be trapped by qemu
userspace instead of vhost. Fixing this by using zero length if an
iodevice is zero length.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

We register wildcard mmio eventfd on two buses, once for KVM_MMIO_BUS
and once on KVM_FAST_MMIO_BUS but with a single iodev
instance. This will lead to an issue: kvm_io_bus_destroy() knows
nothing about the devices on two buses pointing to a single dev. Which
will lead to double free[1] during exit. Fix this by allocating two
instances of iodevs then registering one on KVM_MMIO_BUS and another
on KVM_FAST_MMIO_BUS.

CPU: 1 PID: 2894 Comm: qemu-system-x86 Not tainted 3.19.0-26-generic #28-Ubuntu
Hardware name: LENOVO 2356BG6/2356BG6, BIOS G7ET96WW (2.56 ) 09/12/2013
task: ffff88009ae0c4b0 ti: ffff88020e7f0000 task.ti: ffff88020e7f0000
RIP: 0010:[<ffffffffc07e25d8>]  [<ffffffffc07e25d8>] ioeventfd_release+0x28/0x60 [kvm]
RSP: 0018:ffff88020e7f3bc8  EFLAGS: 00010292
RAX: dead000000200200 RBX: ffff8801ec19c900 RCX: 000000018200016d
RDX: ffff8801ec19cf80 RSI: ffffea0008bf1d40 RDI: ffff8801ec19c900
RBP: ffff88020e7f3bd8 R08: 000000002fc75a01 R09: 000000018200016d
R10: ffffffffc07df6ae R11: ffff88022fc75a98 R12: ffff88021e7cc000
R13: ffff88021e7cca48 R14: ffff88021e7cca50 R15: ffff8801ec19c880
FS:  00007fc1ee3e6700(0000) GS:ffff88023e240000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f389d8000 CR3: 000000023dc13000 CR4: 00000000001427e0
Stack:
ffff88021e7cc000 0000000000000000 ffff88020e7f3be8 ffffffffc07e2622
ffff88020e7f3c38 ffffffffc07df69a ffff880232524160 ffff88020e792d80
 0000000000000000 ffff880219b78c00 0000000000000008 ffff8802321686a8
Call Trace:
[<ffffffffc07e2622>] ioeventfd_destructor+0x12/0x20 [kvm]
[<ffffffffc07df69a>] kvm_put_kvm+0xca/0x210 [kvm]
[<ffffffffc07df818>] kvm_vcpu_release+0x18/0x20 [kvm]
[<ffffffff811f69f7>] __fput+0xe7/0x250
[<ffffffff811f6bae>] ____fput+0xe/0x10
[<ffffffff81093f04>] task_work_run+0xd4/0xf0
[<ffffffff81079358>] do_exit+0x368/0xa50
[<ffffffff81082c8f>] ? recalc_sigpending+0x1f/0x60
[<ffffffff81079ad5>] do_group_exit+0x45/0xb0
[<ffffffff81085c71>] get_signal+0x291/0x750
[<ffffffff810144d8>] do_signal+0x28/0xab0
[<ffffffff810f3a3b>] ? do_futex+0xdb/0x5d0
[<ffffffff810b7028>] ? __wake_up_locked_key+0x18/0x20
[<ffffffff810f3fa6>] ? SyS_futex+0x76/0x170
[<ffffffff81014fc9>] do_notify_resume+0x69/0xb0
[<ffffffff817cb9af>] int_signal+0x12/0x17
Code: 5d c3 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 8b 7f 20 e8 06 d6 a5 c0 48 8b 43 08 48 8b 13 48 89 df 48 89 42 08 <48> 89 10 48 b8 00 01 10 00 00
 RIP  [<ffffffffc07e25d8>] ioeventfd_release+0x28/0x60 [kvm]
 RSP <ffff88020e7f3bc8>

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This patch factors out core eventfd assign/deassign logic and leaves
the argument checking and bus index selection to callers.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

We only want zero length mmio eventfd to be registered on
KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to
make sure this.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

After 'commit 0b8ba4a2 ("KVM: fix checkpatch.pl errors in
kvm/coalesced_mmio.h")', the declaration of the two function will exceed 80
characters.

This patch reduces the TAPs to make each line in 80 characters.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When restoring the system register state for an AArch32 guest at EL2,
writes to DACR32_EL2 may not be correctly synchronised by Cortex-A57,
which can lead to the guest effectively running with junk in the DACR
and running into unexpected domain faults.

This patch works around the issue by re-ordering our restoration of the
AArch32 register aliases so that they happen before the AArch64 system
registers. Ensuring that the registers are restored in this order
guarantees that they will be correctly synchronised by the core.

Cc: <stable@vger.kernel.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Merge tag 'kvm-arm-for-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/ARM changes for 4.3-rc2

- Fix timer interrupt injection after the rework
  that went in during the merge window
- Reset the timer to zero on reboot
- Make sure the TCR_EL2 RES1 bits are really set to 1
- Fix a PSCI affinity bug for non-existing vcpus

If there is already some polling ongoing, it's impossible to disable the
polling, since as soon as somebody sets halt_poll_ns to 0, polling will
never stop, as grow and shrink are only handled if halt_poll_ns is != 0.

This patch fix it by reset vcpu->halt_poll_ns in order to stop polling
when polling is disabled.
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull CRIS updates from Jesper Nilsson:
 "Mostly removal of old cruft of which we can use a generic version, or
  fixes for code not commonly run in the cris port, but also additions
  to enable some good debug"

* tag 'cris-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris: (25 commits)
  CRISv10: delete unused lib/dmacopy.c
  CRISv10: delete unused lib/old_checksum.c
  CRIS: fix switch_mm() lockdep splat
  CRISv32: enable LOCKDEP_SUPPORT
  CRIS: add STACKTRACE_SUPPORT
  CRISv32: annotate irq enable in idle loop
  CRISv32: add support for irqflags tracing
  CRIS: UAPI: use generic types.h
  CRIS: UAPI: use generic shmbuf.h
  CRIS: UAPI: use generic msgbuf.h
  CRIS: UAPI: use generic socket.h
  CRIS: UAPI: use generic sembuf.h
  CRIS: UAPI: use generic sockios.h
  CRIS: UAPI: use generic auxvec.h
  CRIS: UAPI: use generic headers via Kbuild
  CRIS: UAPI: fix elf.h export
  CRIS: don't make asm/elf.h depend on asm/user.h
  CRIS: UAPI: fix ptrace.h
  CRISv32: Squash compile warnings for axisflashmap
  CRISv32: Add GPIO driver to the default configs
  ...

rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not
a boolean value.

Now, admittedly the "!= 0" doesn't really change the value (0 stays as
zero, 1 stays as one), but it's not only redundant, it confuses gcc, and
causes gcc to warn about the construct

    switch (rq_data_dir(req)) {
        case READ:
            ...
        case WRITE:
            ...

that we have in a few drivers.

Now, the gcc warning is silly and stupid (it seems to warn not about the
switch value having a different type from the case statements, but about
_any_ boolean switch value), but in this case the code itself is silly
and stupid too, so let's just change it, and get rid of warnings like
this:

  drivers/block/hd.c: In function ‘hd_request’:
  drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool]
     switch (rq_data_dir(req)) {

The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in
commit 5953316d ("block: make rq->cmd_flags be 64-bit") and is
presumably because the old code (that just did a logical 'and' with 1)
would then end up making the type of rq_data_dir() be u64 too.

But if we want to retain the old regular integer type, let's just cast
the result to 'int' rather than use that rather odd '!= 0'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix up the writeback plugging introduced in commit d353d758
("writeback: plug writeback at a high level") that then caused problems
due to the unplug happening with a spinlock held.

* writeback-plugging:
  writeback: plug writeback in wb_writeback() and writeback_inodes_wb()
  Revert "writeback: plug writeback at a high level"

We had to revert the pluggin in writeback_sb_inodes() because the
wb->list_lock is held, but we could easily plug at a higher level before
taking that lock, and unplug after releasing it.  This does that.

Chris will run performance numbers, just to verify that this approach is
comparable to the alternative (we could just drop and re-take the lock
around the blk_finish_plug() rather than these two commits.

I'd have preferred waiting for actual performance numbers before picking
one approach over the other, but I don't want to release rc1 with the
known "sleeping function called from invalid context" issue, so I'll
pick this cleanup version for now.  But if the numbers show that we
really want to plug just at the writeback_sb_inodes() level, and we
should just play ugly games with the spinlock, we'll switch to that.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I didn't notice this when merging the thermal code from Zhang, but his
merge (commit 5a924a07: "Merge branches 'thermal-core' and
'thermal-intel' of .git into next") of the thermal-core and
thermal-intel branches was wrong.

In thermal-core, commit 17e8351a ("thermal: consistently use int for
temperatures") converted the thermal layer to use "int" for
temperatures.

But in parallel, in the thermal-intel branch commit d0a12625
("thermal: Add Intel PCH thermal driver") added support for the intel
PCH thermal sensor using the old interfaces that used "unsigned long"
pointers.

This resulted in warnings like this:

  drivers/thermal/intel_pch_thermal.c:184:14: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
    .get_temp = pch_thermal_get_temp,
                ^
  drivers/thermal/intel_pch_thermal.c:184:14: note: (near initialization for ‘tzd_ops.get_temp’)
  drivers/thermal/intel_pch_thermal.c:186:19: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
    .get_trip_temp = pch_get_trip_temp,
                     ^
  drivers/thermal/intel_pch_thermal.c:186:19: note: (near initialization for ‘tzd_ops.get_trip_temp’)

This fixes it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge fourth patch-bomb from Andrew Morton:

 - sys_membarier syscall

 - seq_file interface changes

 - a few misc fixups

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each"
  mm/early_ioremap: add explicit #include of asm/early_ioremap.h
  fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void
  selftests: enhance membarrier syscall test
  selftests: add membarrier syscall test
  sys_membarrier(): system-wide memory barrier (generic, x86)
  MODSIGN: fix a compilation warning in extract-cert

Newer bitfiles needs the reduced clk even for SMP builds

Cc: <stable@vger.kernel.org>  #4.2
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull NTB fixes from Jon Mason:
 "NTB bug and documentation fixes, new device IDs, performance
  improvements, and adding a mailing list to MAINTAINERS for NTB"

* tag 'ntb-4.3' of git://github.com/jonmason/ntb:
  NTB: Fix range check on memory window index
  NTB: Improve index handling in B2B MW workaround
  NTB: Fix documentation for ntb_peer_db_clear.
  NTB: Fix documentation for ntb_link_is_up
  NTB: Use unique DMA channels for TX and RX
  NTB: Remove dma_sync_wait from ntb_async_rx
  NTB: Clean up QP stats info
  NTB: Make the transport list in order of discovery
  NTB: Add PCI Device IDs for Broadwell Xeon
  NTB: Add flow control to the ntb_netdev
  NTB: Add list to MAINTAINERS

Pull more input updates from Dmitry Torokhov:
 "Second round of updates for the input subsystem.

  This introduces two brand new touchscreen drivers (Colibri and
  imx6ul_tsc), some small driver fixes, and we are no longer report
  errors from evdev_flush() as users do not really have a way of
  handling errors, error codes that we were returning were not on the
  list of errors supposed to be returned by close(), and errors were
  causing issues with one of older versions of systemd"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: imx_keypad - remove obsolete comment
  Input: touchscreen - add imx6ul_tsc driver support
  Input: Add touchscreen support for Colibri VF50
  Input: i8042 - lower log level for "no controller" message
  Input: evdev - do not report errors form flush()
  Input: elants_i2c - extend the calibration timeout to 12 seconds
  Input: sparcspkr - fix module autoload for OF platform drivers
  Input: regulator-haptic - fix module autoload for OF platform driver
  Input: pwm-beeper - fix module autoload for OF platform driver
  Input: ab8500-ponkey - Fix module autoload for OF platform driver
  Input: cyttsp - remove unnecessary MODULE_ALIAS()
  Input: elan_i2c - add ACPI ID "ELAN1000"

Pull more power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups on top of the previous PM+ACPI
  pull request (cpufreq core and drivers, cpuidle, generic power domains
  framework).  Some of them didn't make to that pull request and some
  fix issues introduced by it.

  The only really new thing is the support for suspend frequency in the
  cpufreq-dt driver, but it is needed to fix an issue with Exynos
  platforms.

  Specifics:

   - build fix for the new Mediatek MT8173 cpufreq driver (Guenter
     Roeck).

   - generic power domains framework fixes (power on error code path,
     subdomain removal) and cleanup of a deprecated API user (Geert
     Uytterhoeven, Jon Hunter, Ulf Hansson).

   - cpufreq-dt driver fixes including two fixes for bugs related to the
     new Operating Performance Points Device Tree bindings introduced
     recently (Viresh Kumar).

   - suspend frequency support for the cpufreq-dt driver (Bartlomiej
     Zolnierkiewicz, Viresh Kumar).

   - cpufreq core cleanups (Viresh Kumar).

   - intel_pstate driver fixes (Chen Yu, Kristen Carlson Accardi).

   - additional sanity check in the cpuidle core (Xunlei Pang).

   - fix for a comment related to CPU power management (Lina Iyer)"

* tag 'pm+acpi-4.3-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  intel_pstate: fix PCT_TO_HWP macro
  intel_pstate: Fix user input of min/max to legal policy region
  PM / OPP: Return suspend_opp only if it is enabled
  cpufreq-dt: add suspend frequency support
  cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency
  PM / OPP: add dev_pm_opp_get_suspend_opp() helper
  staging: board: Migrate away from __pm_genpd_name_add_device()
  cpufreq: Use __func__ to print function's name
  cpufreq: staticize cpufreq_cpu_get_raw()
  PM / Domains: Ensure subdomain is not in use before removing
  cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL
  cpuidle/coupled: Add sanity check for safe_state_index
  PM / Domains: Try power off masters in error path of __pm_genpd_poweron()
  cpufreq: dt: Tolerance applies on both sides of target voltage
  cpufreq: dt: Print error on failing to mark OPPs as shared
  cpufreq: dt: Check OPP count before marking them shared
  kernel/cpu_pm: fix cpu_cluster_pm_exit comment