diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e3b25dc6c367..9e6e8701933e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -441,6 +441,7 @@ struct kvm_vcpu_arch { #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */ #define KVM_ARM64_FP_FOREIGN_FPSTATE (1 << 14) #define KVM_ARM64_ON_UNSUPPORTED_CPU (1 << 15) /* Physical CPU not in supported_cpus */ +#define KVM_ARM64_WFIT (1 << 16) /* WFIT instruction trapped */ #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ KVM_GUESTDBG_USE_SW_BP | \ diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index c92a68190f6a..4e39ace073af 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -239,6 +239,20 @@ static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx) (ARCH_TIMER_CTRL_IT_MASK | ARCH_TIMER_CTRL_ENABLE)) == ARCH_TIMER_CTRL_ENABLE); } +static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu) +{ + return (cpus_have_final_cap(ARM64_HAS_WFXT) && + (vcpu->arch.flags & KVM_ARM64_WFIT)); +} + +static u64 wfit_delay_ns(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *ctx = vcpu_vtimer(vcpu); + u64 val = vcpu_get_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu)); + + return kvm_counter_compute_delta(ctx, val); +} + /* * Returns the earliest expiration time in ns among guest timers. * Note that it will return 0 if none of timers can fire. @@ -256,6 +270,9 @@ static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu) min_delta = min(min_delta, kvm_timer_compute_delta(ctx)); } + if (vcpu_has_wfit_active(vcpu)) + min_delta = min(min_delta, wfit_delay_ns(vcpu)); + /* If none of timers can fire, then return 0 */ if (min_delta == ULLONG_MAX) return 0; @@ -355,7 +372,7 @@ static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx) int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) { - return 0; + return vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu) == 0; } /* @@ -481,7 +498,8 @@ static void kvm_timer_blocking(struct kvm_vcpu *vcpu) */ if (!kvm_timer_irq_can_fire(map.direct_vtimer) && !kvm_timer_irq_can_fire(map.direct_ptimer) && - !kvm_timer_irq_can_fire(map.emul_ptimer)) + !kvm_timer_irq_can_fire(map.emul_ptimer) && + !vcpu_has_wfit_active(vcpu)) return; /* diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 2122c699af06..e7cb8a4d2e81 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -634,6 +634,7 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu) preempt_enable(); kvm_vcpu_halt(vcpu); + vcpu->arch.flags &= ~KVM_ARM64_WFIT; kvm_clear_request(KVM_REQ_UNHALT, vcpu); preempt_disable(); diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 97fe14aab1a3..4260f2cd1971 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -85,16 +85,21 @@ static int handle_no_fpsimd(struct kvm_vcpu *vcpu) * WFI: Simply call kvm_vcpu_halt(), which will halt execution of * world-switches and schedule other host processes until there is an * incoming IRQ or FIQ to the VM. + * WFIT: Same as WFI, with a timed wakeup implemented as a background timer */ static int kvm_handle_wfx(struct kvm_vcpu *vcpu) { - if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_WFx_ISS_WFE) { + u64 esr = kvm_vcpu_get_esr(vcpu); + + if (esr & ESR_ELx_WFx_ISS_WFE) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu)); } else { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; + if ((esr & (ESR_ELx_WFx_ISS_RV | ESR_ELx_WFx_ISS_WFxT)) == (ESR_ELx_WFx_ISS_RV | ESR_ELx_WFx_ISS_WFxT)) + vcpu->arch.flags |= KVM_ARM64_WFIT; kvm_vcpu_wfi(vcpu); }