linux-stable/arch/x86/kvm
Wanpeng Li 6550c4df7e KVM: nVMX: Fix interrupt window request with "Acknowledge interrupt on exit"
------------[ cut here ]------------
 WARNING: CPU: 5 PID: 2288 at arch/x86/kvm/vmx.c:11124 nested_vmx_vmexit+0xd64/0xd70 [kvm_intel]
 CPU: 5 PID: 2288 Comm: qemu-system-x86 Not tainted 4.13.0-rc2+ #7
 RIP: 0010:nested_vmx_vmexit+0xd64/0xd70 [kvm_intel]
Call Trace:
  vmx_check_nested_events+0x131/0x1f0 [kvm_intel]
  ? vmx_check_nested_events+0x131/0x1f0 [kvm_intel]
  kvm_arch_vcpu_ioctl_run+0x5dd/0x1be0 [kvm]
  ? vmx_vcpu_load+0x1be/0x220 [kvm_intel]
  ? kvm_arch_vcpu_load+0x62/0x230 [kvm]
  kvm_vcpu_ioctl+0x340/0x700 [kvm]
  ? kvm_vcpu_ioctl+0x340/0x700 [kvm]
  ? __fget+0xfc/0x210
  do_vfs_ioctl+0xa4/0x6a0
  ? __fget+0x11d/0x210
  SyS_ioctl+0x79/0x90
  do_syscall_64+0x8f/0x750
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL64_slow_path+0x25/0x25

This can be reproduced by booting L1 guest w/ 'noapic' grub parameter, which
means that tells the kernel to not make use of any IOAPICs that may be present
in the system.

Actually external_intr variable in nested_vmx_vmexit() is the req_int_win
variable passed from vcpu_enter_guest() which means that the L0's userspace
requests an irq window. I observed the scenario (!kvm_cpu_has_interrupt(vcpu) &&
L0's userspace reqeusts an irq window) is true, so there is no interrupt which
L1 requires to inject to L2, we should not attempt to emualte "Acknowledge
interrupt on exit" for the irq window requirement in this scenario.

This patch fixes it by not attempt to emulate "Acknowledge interrupt on exit"
if there is no L1 requirement to inject an interrupt to L2.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Added code comment to make it obvious that the behavior is not correct.
 We should do a userspace exit with open interrupt window instead of the
 nested VM exit.  This patch still improves the behavior, so it was
 accepted as a (temporary) workaround.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-03 15:38:11 +02:00
..
cpuid.c KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulation 2017-06-08 15:38:21 +02:00
cpuid.h kvm: x86: Guest BNDCFGS requires guest MPX support 2017-06-07 16:28:15 +02:00
debugfs.c kvm: x86: export TSC information to user-space 2016-09-16 16:57:48 +02:00
emulate.c PPC: 2017-07-06 18:38:31 -07:00
hyperv.c kvm: x86: hyperv: avoid livelock in oneshot SynIC timers 2017-07-20 17:00:00 +02:00
hyperv.h kvm: x86: hyperv: make VP_INDEX managed by userspace 2017-07-14 16:28:18 +02:00
i8254.c KVM: x86: take slots_lock in kvm_free_pit 2017-07-12 22:38:26 +02:00
i8254.h KVM: x86: Handle the kthread worker using the new API 2016-12-08 15:31:11 +01:00
i8259.c KVM: x86: simplify pic_ioport_read() 2017-04-12 20:17:15 +02:00
ioapic.c KVM: x86: rename kvm_vcpu_request_scan_ioapic() 2017-04-12 20:17:14 +02:00
ioapic.h KVM: x86: convert kvm_(set|get)_ioapic() into void 2017-04-12 20:17:14 +02:00
irq.c KVM: x86: get rid of pic_irqchip() 2017-04-12 20:17:13 +02:00
irq.h KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING 2017-05-02 14:45:45 +02:00
irq_comm.c KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING 2017-05-02 14:45:45 +02:00
Kconfig x86: add MULTIUSER dependency for KVM 2017-07-19 16:19:14 +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: LAPIC: Fix reentrancy issues with preempt notifiers 2017-07-26 19:04:53 +02:00
lapic.h KVM: lapic: reorganize restart_apic_timer 2017-06-29 18:18:52 +02:00
Makefile KVM: x86: drop legacy device assignment 2017-04-07 16:49:00 +02:00
mmu.c KVM: async_pf: Let guest support delivery of async_pf from guest mode 2017-07-14 14:26:16 +02:00
mmu.h KVM: async_pf: Add L1 guest async_pf #PF vmexit handler 2017-07-14 14:25:24 +02:00
mmu_audit.c kvm: rename pfn_t to kvm_pfn_t 2016-01-15 17:56:32 -08:00
mmutrace.h kvm: x86: mmu: allow A/D bits to be disabled in an mmu 2017-07-03 11:19:54 +02:00
mtrr.c KVM: MTRR: fix kvm_mtrr_check_gfn_range_consistency page fault 2016-07-05 16:14:43 +02:00
page_track.c mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
paging_tmpl.h KVM: nVMX: fix EPT permissions as reported in exit qualification 2017-05-15 18:22:40 +02:00
pmu.c KVM: x86: never specify a sample period for virtualized in_tx_cp counters 2017-03-01 14:19:46 +01:00
pmu.h
pmu_amd.c perf/x86/amd: Make HW_CACHE_REFERENCES and HW_CACHE_MISSES measure L2 2016-09-16 16:19:49 +02:00
pmu_intel.c KVM: x86/vPMU: fix undefined shift in intel_pmu_refresh() 2017-05-19 19:59:27 +02:00
svm.c KVM: nVMX: fixes to nested virt interrupt injection 2017-08-01 22:24:17 +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: nVMX: Fix interrupt window request with "Acknowledge interrupt on exit" 2017-08-03 15:38:11 +02:00
x86.c KVM: X86: init irq->level in kvm_pv_kick_cpu_op 2017-08-02 22:41:01 +02:00
x86.h kvm: better MWAIT emulation for guests 2017-04-21 12:50:28 +02:00