linux/arch
Wanpeng Li e70b57a6ce KVM: X86: Fix softlockup when get the current kvmclock
watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [qemu-system-x86:10185]
 CPU: 6 PID: 10185 Comm: qemu-system-x86 Tainted: G           OE   4.14.0-rc4+ #4
 RIP: 0010:kvm_get_time_scale+0x4e/0xa0 [kvm]
 Call Trace:
  get_time_ref_counter+0x5a/0x80 [kvm]
  kvm_hv_process_stimers+0x120/0x5f0 [kvm]
  kvm_arch_vcpu_ioctl_run+0x4b4/0x1690 [kvm]
  kvm_vcpu_ioctl+0x33a/0x620 [kvm]
  do_vfs_ioctl+0xa1/0x5d0
  SyS_ioctl+0x79/0x90
  entry_SYSCALL_64_fastpath+0x1e/0xa9

This can be reproduced when running kvm-unit-tests/hyperv_stimer.flat and
cpu-hotplug stress simultaneously. __this_cpu_read(cpu_tsc_khz) returns 0
(set in kvmclock_cpu_down_prep()) when the pCPU is unhotplug which results
in kvm_get_time_scale() gets into an infinite loop.

This patch fixes it by treating the unhotplug pCPU as not using master clock.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:32:53 +01:00
..
alpha pci-v4.15-changes 2017-11-15 15:01:28 -08:00
arc Merge branch 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2017-11-15 10:14:11 -08:00
arm GICv4 Support for KVM/ARM for v4.15 2017-11-17 13:20:01 +01:00
arm64 GICv4 Support for KVM/ARM for v4.15 2017-11-17 13:20:01 +01:00
blackfin This is the bulk of pin control changes for the v4.15 2017-11-16 10:57:11 -08:00
c6x DeviceTree for 4.15: 2017-11-14 18:25:40 -08:00
cris pci-v4.15-changes 2017-11-15 15:01:28 -08:00
frv Merge branch 'akpm' (patches from Andrew) 2017-11-15 19:42:40 -08:00
h8300 mm, arch: remove empty_bad_page* 2017-11-15 18:21:03 -08:00
hexagon A couple of dma-mapping updates: 2017-11-14 16:54:12 -08:00
ia64 pci-v4.15-changes 2017-11-15 15:01:28 -08:00
m32r m32r: fix endianness constraints 2017-11-15 18:21:00 -08:00
m68k A couple of dma-mapping updates: 2017-11-14 16:54:12 -08:00
metag DeviceTree for 4.15: 2017-11-14 18:25:40 -08:00
microblaze DeviceTree for 4.15: 2017-11-14 18:25:40 -08:00
mips AFS development 2017-11-16 11:41:22 -08:00
mn10300 Merge branch 'akpm' (patches from Andrew) 2017-11-15 19:42:40 -08:00
nios2 DeviceTree for 4.15: 2017-11-14 18:25:40 -08:00
openrisc kmemcheck: remove annotations 2017-11-15 18:21:04 -08:00
parisc pci-v4.15-changes 2017-11-15 15:01:28 -08:00
powerpc First batch of KVM changes for 4.15 2017-11-16 13:00:24 -08:00
riscv RISC-V Port for Linux 4.15 v9 2017-11-15 10:49:15 -08:00
s390 First batch of KVM changes for 4.15 2017-11-16 13:00:24 -08:00
score License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
sh Merge branch 'akpm' (patches from Andrew) 2017-11-15 19:42:40 -08:00
sparc Merge branch 'akpm' (patches from Andrew) 2017-11-15 19:42:40 -08:00
tile mm: remove cold parameter from free_hot_cold_page* 2017-11-15 18:21:06 -08:00
um Merge branch 'akpm' (patches from Andrew) 2017-11-15 19:42:40 -08:00
unicore32 kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2017-11-15 18:21:04 -08:00
x86 KVM: X86: Fix softlockup when get the current kvmclock 2017-11-27 17:32:53 +01:00
xtensa pci-v4.15-changes 2017-11-15 15:01:28 -08:00
.gitignore
Kconfig bpf: Revert bpf_overrid_function() helper changes. 2017-11-11 18:24:55 +09:00