diff options
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 6f21d389bed5..1a3a4a92dc60 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6007,13 +6007,26 @@ static fastpath_t handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu) if (vmx->req_immediate_exit) return EXIT_FASTPATH_EXIT_HANDLED; + /* + * If L2 is active, go down the slow path as emulating the guest timer + * expiration likely requires synthesizing a nested VM-Exit. + */ + if (is_guest_mode(vcpu)) + return EXIT_FASTPATH_NONE; + kvm_lapic_expired_hv_timer(vcpu); return EXIT_FASTPATH_REENTER_GUEST; } static int handle_preemption_timer(struct kvm_vcpu *vcpu) { - handle_fastpath_preemption_timer(vcpu); + /* + * This non-fastpath handler is reached if and only if the preemption + * timer was being used to emulate a guest timer while L2 is active. + * All other scenarios are supposed to be handled in the fastpath. + */ + WARN_ON_ONCE(!is_guest_mode(vcpu)); + kvm_lapic_expired_hv_timer(vcpu); return 1; } @@ -7214,7 +7227,12 @@ void noinstr vmx_spec_ctrl_restore_host(struct vcpu_vmx *vmx, static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) { - if (is_guest_mode(vcpu)) + /* + * If L2 is active, some VMX preemption timer exits can be handled in + * the fastpath even, all other exits must use the slow path. + */ + if (is_guest_mode(vcpu) && + to_vmx(vcpu)->exit_reason.basic != EXIT_REASON_PREEMPTION_TIMER) return EXIT_FASTPATH_NONE; switch (to_vmx(vcpu)->exit_reason.basic) { |