linux/arch/x86/kvm/vmx
Sean Christopherson 39497d7660 KVM: lapic: Track lapic timer advance per vCPU
Automatically adjusting the globally-shared timer advancement could
corrupt the timer, e.g. if multiple vCPUs are concurrently adjusting
the advancement value.  That could be partially fixed by using a local
variable for the arithmetic, but it would still be susceptible to a
race when setting timer_advance_adjust_done.

And because virtual_tsc_khz and tsc_scaling_ratio are per-vCPU, the
correct calibration for a given vCPU may not apply to all vCPUs.

Furthermore, lapic_timer_advance_ns is marked __read_mostly, which is
effectively violated when finding a stable advancement takes an extended
amount of timer.

Opportunistically change the definition of lapic_timer_advance_ns to
a u32 so that it matches the style of struct kvm_timer.  Explicitly
pass the param to kvm_create_lapic() so that it doesn't have to be
exposed to lapic.c, thus reducing the probability of unintentionally
using the global value instead of the per-vCPU value.

Cc: Liran Alon <liran.alon@oracle.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 3b8a5df6c4 ("KVM: LAPIC: Tune lapic_timer_advance_ns automatically")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-18 18:55:41 +02:00
..
capabilities.h
evmcs.c x86/kvm/hyper-v: nested_enable_evmcs() sets vmcs_version incorrectly 2019-01-25 19:11:37 +01:00
evmcs.h
nested.c KVM: nVMX: always use early vmcs check when EPT is disabled 2019-04-16 15:37:12 +02:00
nested.h
ops.h
pmu_intel.c
vmcs12.c
vmcs12.h
vmcs_shadow_fields.h
vmcs.h KVM: nVMX: Cache host_rsp on a per-VMCS basis 2019-02-12 13:12:22 +01:00
vmenter.S KVM: VMX: Reorder clearing of registers in the vCPU-run assembly flow 2019-02-20 22:48:18 +01:00
vmx.c KVM: lapic: Track lapic timer advance per vCPU 2019-04-18 18:55:41 +02:00
vmx.h KVM: nVMX: allow tests to use bad virtual-APIC page address 2019-04-16 10:59:07 +02:00