diff options
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 5 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmcs.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 60 |
3 files changed, 41 insertions, 25 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 22e02f10ece9..990e543f4531 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2012,9 +2012,8 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) * PIN CONTROLS */ exec_control = vmx_pin_based_exec_ctrl(vmx); - exec_control |= vmcs12->pin_based_vm_exec_control; - /* Preemption timer setting is computed directly in vmx_vcpu_run. */ - exec_control &= ~PIN_BASED_VMX_PREEMPTION_TIMER; + exec_control |= (vmcs12->pin_based_vm_exec_control & + ~PIN_BASED_VMX_PREEMPTION_TIMER); /* Posted interrupts setting is only taken from vmcs12. */ if (nested_cpu_has_posted_intr(vmcs12)) { diff --git a/arch/x86/kvm/vmx/vmcs.h b/arch/x86/kvm/vmx/vmcs.h index 9a87a2482e3e..481ad879197b 100644 --- a/arch/x86/kvm/vmx/vmcs.h +++ b/arch/x86/kvm/vmx/vmcs.h @@ -61,6 +61,7 @@ struct loaded_vmcs { int cpu; bool launched; bool nmi_known_unmasked; + bool hv_timer_soft_disabled; /* Support for vnmi-less CPUs */ int soft_vnmi_blocked; ktime_t entry_time; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 09f1e0b70316..b939a688ae83 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2465,6 +2465,7 @@ int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs) return -ENOMEM; loaded_vmcs->shadow_vmcs = NULL; + loaded_vmcs->hv_timer_soft_disabled = false; loaded_vmcs_init(loaded_vmcs); if (cpu_has_vmx_msr_bitmap()) { @@ -3835,8 +3836,9 @@ u32 vmx_pin_based_exec_ctrl(struct vcpu_vmx *vmx) if (!enable_vnmi) pin_based_exec_ctrl &= ~PIN_BASED_VIRTUAL_NMIS; - /* Enable the preemption timer dynamically */ - pin_based_exec_ctrl &= ~PIN_BASED_VMX_PREEMPTION_TIMER; + if (!enable_preemption_timer) + pin_based_exec_ctrl &= ~PIN_BASED_VMX_PREEMPTION_TIMER; + return pin_based_exec_ctrl; } @@ -5455,8 +5457,12 @@ static int handle_pml_full(struct kvm_vcpu *vcpu) static int handle_preemption_timer(struct kvm_vcpu *vcpu) { - if (!to_vmx(vcpu)->req_immediate_exit) + struct vcpu_vmx *vmx = to_vmx(vcpu); + + if (!vmx->req_immediate_exit && + !unlikely(vmx->loaded_vmcs->hv_timer_soft_disabled)) kvm_lapic_expired_hv_timer(vcpu); + return 1; } @@ -6356,12 +6362,6 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx) msrs[i].host, false); } -static void vmx_arm_hv_timer(struct vcpu_vmx *vmx, u32 val) -{ - vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, val); - pin_controls_setbit(vmx, PIN_BASED_VMX_PREEMPTION_TIMER); -} - static void vmx_update_hv_timer(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -6369,11 +6369,9 @@ static void vmx_update_hv_timer(struct kvm_vcpu *vcpu) u32 delta_tsc; if (vmx->req_immediate_exit) { - vmx_arm_hv_timer(vmx, 0); - return; - } - - if (vmx->hv_deadline_tsc != -1) { + vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, 0); + vmx->loaded_vmcs->hv_timer_soft_disabled = false; + } else if (vmx->hv_deadline_tsc != -1) { tscl = rdtsc(); if (vmx->hv_deadline_tsc > tscl) /* set_hv_timer ensures the delta fits in 32-bits */ @@ -6382,11 +6380,12 @@ static void vmx_update_hv_timer(struct kvm_vcpu *vcpu) else delta_tsc = 0; - vmx_arm_hv_timer(vmx, delta_tsc); - return; + vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, delta_tsc); + vmx->loaded_vmcs->hv_timer_soft_disabled = false; + } else if (!vmx->loaded_vmcs->hv_timer_soft_disabled) { + vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, -1); + vmx->loaded_vmcs->hv_timer_soft_disabled = true; } - - pin_controls_clearbit(vmx, PIN_BASED_VMX_PREEMPTION_TIMER); } void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp) @@ -6458,7 +6457,8 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu) atomic_switch_perf_msrs(vmx); - vmx_update_hv_timer(vcpu); + if (enable_preemption_timer) + vmx_update_hv_timer(vcpu); if (lapic_in_kernel(vcpu) && vcpu->arch.apic->lapic_timer.timer_advance_ns) @@ -7565,17 +7565,33 @@ static __init int hardware_setup(void) } if (!cpu_has_vmx_preemption_timer()) - kvm_x86_ops->request_immediate_exit = __kvm_request_immediate_exit; + enable_preemption_timer = false; - if (cpu_has_vmx_preemption_timer() && enable_preemption_timer) { + if (enable_preemption_timer) { + u64 use_timer_freq = 5000ULL * 1000 * 1000; u64 vmx_msr; rdmsrl(MSR_IA32_VMX_MISC, vmx_msr); cpu_preemption_timer_multi = vmx_msr & VMX_MISC_PREEMPTION_TIMER_RATE_MASK; - } else { + + if (tsc_khz) + use_timer_freq = (u64)tsc_khz * 1000; + use_timer_freq >>= cpu_preemption_timer_multi; + + /* + * KVM "disables" the preemption timer by setting it to its max + * value. Don't use the timer if it might cause spurious exits + * at a rate faster than 0.1 Hz (of uninterrupted guest time). + */ + if (use_timer_freq > 0xffffffffu / 10) + enable_preemption_timer = false; + } + + if (!enable_preemption_timer) { kvm_x86_ops->set_hv_timer = NULL; kvm_x86_ops->cancel_hv_timer = NULL; + kvm_x86_ops->request_immediate_exit = __kvm_request_immediate_exit; } kvm_set_posted_intr_wakeup_handler(wakeup_handler); |