linux/arch/x86/kvm
Wanpeng Li 196f20ca52 KVM: vmx: fix missed cancellation of TSC deadline timer
INFO: rcu_sched detected stalls on CPUs/tasks:
 1-...: (11800 GPs behind) idle=45d/140000000000000/0 softirq=0/0 fqs=21663
 (detected by 0, t=65016 jiffies, g=11500, c=11499, q=719)
Task dump for CPU 1:
qemu-system-x86 R  running task        0  3529   3525 0x00080808
 ffff8802021791a0 ffff880212895040 0000000000000001 00007f1c2c00db40
 ffff8801dd20fcd3 ffffc90002b98000 ffff8801dd20fc88 ffff8801dd20fcf8
 0000000000000286 ffff8801dd2ac538 ffff8801dd20fcc0 ffffffffc06949c9
Call Trace:
? kvm_write_guest_cached+0xb9/0x160 [kvm]
? __delay+0xf/0x20
? wait_lapic_expire+0x14a/0x200 [kvm]
? kvm_arch_vcpu_ioctl_run+0xcbe/0x1b00 [kvm]
? kvm_arch_vcpu_ioctl_run+0xe34/0x1b00 [kvm]
? kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm]
? __fget+0x5/0x210
? do_vfs_ioctl+0x96/0x6a0
? __fget_light+0x2a/0x90
? SyS_ioctl+0x79/0x90
? do_syscall_64+0x7c/0x1e0
? entry_SYSCALL64_slow_path+0x25/0x25

This can be reproduced readily by running a full dynticks guest(since hrtimer
in guest is heavily used) w/ lapic_timer_advance disabled.

If fail to program hardware preemption timer, we will fallback to hrtimer based
method, however, a previous programmed preemption timer miss to cancel in this
scenario which results in one hardware preemption timer and one hrtimer emulated
tsc deadline timer run simultaneously. So sometimes the target guest deadline
tsc is earlier than guest tsc, which leads to the computation in vmx_set_hv_timer
can underflow and cause delta_tsc to be set a huge value, then host soft lockup
as above.

This patch fix it by cancelling the previous programmed preemption timer if there
is once we failed to program the new preemption timer and fallback to hrtimer
based method.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01 11:03:42 +02:00
..
assigned-dev.c KVM: x86: use list_for_each_entry* 2016-02-23 15:40:54 +01:00
assigned-dev.h KVM: x86: move device assignment out of kvm_host.h 2014-11-24 16:53:50 +01:00
cpuid.c KVM: x86: avoid vmalloc(0) in the KVM_SET_CPUID 2016-06-02 17:38:50 +02:00
cpuid.h KVM, pkeys: expose CPUID/CR4 to guest 2016-03-22 16:38:17 +01:00
emulate.c x86/kvm: Add stack frame dependency to fastop() inline asm 2016-05-10 18:16:50 +02:00
hyperv.c KVM: Hyper-V: do not do hypercall userspace exits if SynIC is disabled 2016-04-01 12:10:09 +02:00
hyperv.h kvm/x86: Hyper-V SynIC timers 2015-12-16 18:49:45 +01:00
i8254.c KVM: x86: protect KVM_CREATE_PIT/KVM_CREATE_PIT2 with kvm->lock 2016-06-03 15:28:19 +02:00
i8254.h KVM: i8254: turn kvm_kpit_state.reinject into atomic_t 2016-03-04 09:30:25 +01:00
i8259.c KVM: x86: clean/fix memory barriers in irqchip_in_kernel 2015-07-30 16:02:56 +02:00
ioapic.c KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg 2016-05-18 18:04:25 +02:00
ioapic.h kvm: x86: Track irq vectors in ioapic->rtc_status.dest_map 2016-03-03 14:36:18 +01:00
iommu.c kvm/x86: remove unnecessary header file inclusion 2016-06-03 15:28:19 +02:00
irq_comm.c KVM: add missing memory barrier in kvm_{make,check}_request 2016-04-20 15:29:17 +02:00
irq.c KVM: x86: consolidate "has lapic" checks into irq.c 2016-02-09 16:57:39 +01:00
irq.h KVM: x86: consolidate different ways to test for in-kernel LAPIC 2016-02-09 16:57:45 +01:00
Kconfig KVM: remove kvm_vcpu_compatible 2016-06-16 00:05:00 +02:00
kvm_cache_regs.h KVM, pkeys: add pkeys support for permission_fault 2016-03-22 16:23:37 +01:00
lapic.c KVM: vmx: fix missed cancellation of TSC deadline timer 2016-07-01 11:03:42 +02:00
lapic.h KVM: x86: support using the vmx preemption timer for tsc deadline timer 2016-06-16 10:07:48 +02:00
Makefile KVM: page track: add the framework of guest page tracking 2016-03-03 14:36:20 +01:00
mmu_audit.c kvm: rename pfn_t to kvm_pfn_t 2016-01-15 17:56:32 -08:00
mmu.c KVM: x86: Fix typos 2016-06-14 11:16:28 +02:00
mmu.h KVM: MMU: fix permission_fault() 2016-04-10 21:53:49 +02:00
mmutrace.h tracing: Rename ftrace_event.h to trace_events.h 2015-05-13 14:05:12 -04:00
mtrr.c KVM: MTRR: remove MSR 0x2f8 2016-05-18 18:04:32 +02:00
page_track.c KVM: page_track: fix access to NULL slot 2016-03-22 17:27:28 +01:00
paging_tmpl.h KVM: MMU: fix permission_fault() 2016-04-10 21:53:49 +02:00
pmu_amd.c KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn 2015-08-11 15:19:41 +02:00
pmu_intel.c KVM: x86: Fix typos 2016-06-14 11:16:28 +02:00
pmu.c KVM: x86: consolidate different ways to test for in-kernel LAPIC 2016-02-09 16:57:45 +01:00
pmu.h KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch 2015-06-23 14:12:14 +02:00
svm.c KVM: x86: use guest_exit_irqoff 2016-07-01 11:03:38 +02:00
trace.h KVM: x86: support using the vmx preemption timer for tsc deadline timer 2016-06-16 10:07:48 +02:00
tss.h
vmx.c KVM: vmx: fix underflow in TSC deadline calculation 2016-07-01 11:03:39 +02:00
x86.c KVM: x86: use guest_exit_irqoff 2016-07-01 11:03:38 +02:00
x86.h KVM, pkeys: add pkeys support for xsave state 2016-03-22 16:21:05 +01:00