diff options
| -rw-r--r-- | arch/x86/kvm/vmx.c | 174 |
1 files changed, 115 insertions, 59 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f16a62c7926..2180109d794 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -90,6 +90,11 @@ struct vcpu_vmx { } rmode; int vpid; bool emulation_required; + + /* Support for vnmi-less CPUs */ + int soft_vnmi_blocked; + ktime_t entry_time; + s64 vnmi_blocked_time; }; static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu) @@ -2230,6 +2235,8 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu) vmx->vcpu.arch.rmode.active = 0; + vmx->soft_vnmi_blocked = 0; + vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); kvm_set_cr8(&vmx->vcpu, 0); msr = 0xfee00000 | MSR_IA32_APICBASE_ENABLE; @@ -2335,6 +2342,29 @@ out: return ret; } +static void enable_irq_window(struct kvm_vcpu *vcpu) +{ + u32 cpu_based_vm_exec_control; + + cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); + cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; + vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); +} + +static void enable_nmi_window(struct kvm_vcpu *vcpu) +{ + u32 cpu_based_vm_exec_control; + + if (!cpu_has_virtual_nmis()) { + enable_irq_window(vcpu); + return; + } + + cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); + cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING; + vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); +} + static void vmx_inject_irq(struct kvm_vcpu *vcpu, int irq) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -2360,6 +2390,19 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); + if (!cpu_has_virtual_nmis()) { + /* + * Tracking the NMI-blocked state in software is built upon + * finding the next open IRQ window. This, in turn, depends on + * well-behaving guests: They have to keep IRQs disabled at + * least as long as the NMI handler runs. Otherwise we may + * cause NMI nesting, maybe breaking the guest. But as this is + * highly unlikely, we can live with the residual risk. + */ + vmx->soft_vnmi_blocked = 1; + vmx->vnmi_blocked_time = 0; + } + ++vcpu->stat.nmi_injections; if (vcpu->arch.rmode.active) { vmx->rmode.irq.pending = true; @@ -2384,6 +2427,8 @@ static void vmx_update_window_states(struct kvm_vcpu *vcpu) !(guest_intr & (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS | GUEST_INTR_STATE_NMI)); + if (!cpu_has_virtual_nmis() && to_vmx(vcpu)->soft_vnmi_blocked) + vcpu->arch.nmi_window_open = 0; vcpu->arch.interrupt_window_open = ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) && @@ -2403,55 +2448,31 @@ static void kvm_do_inject_irq(struct kvm_vcpu *vcpu) kvm_queue_interrupt(vcpu, irq); } -static void enable_irq_window(struct kvm_vcpu *vcpu) -{ - u32 cpu_based_vm_exec_control; - - cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); - cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; - vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); -} - -static void enable_nmi_window(struct kvm_vcpu *vcpu) -{ - u32 cpu_based_vm_exec_control; - - if (!cpu_has_virtual_nmis()) - return; - - cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); - cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING; - vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); -} - static void do_interrupt_requests(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { vmx_update_window_states(vcpu); - if (cpu_has_virtual_nmis()) { - if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) { - if (vcpu->arch.nmi_window_open) { - vcpu->arch.nmi_pending = false; - vcpu->arch.nmi_injected = true; - } else { - enable_nmi_window(vcpu); - return; - } - } - if (vcpu->arch.nmi_injected) { - vmx_inject_nmi(vcpu); - if (vcpu->arch.nmi_pending - || kvm_run->request_nmi_window) - enable_nmi_window(vcpu); - else if (vcpu->arch.irq_summary - || kvm_run->request_interrupt_window) - enable_irq_window(vcpu); + if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) { + if (vcpu->arch.nmi_window_open) { + vcpu->arch.nmi_pending = false; + vcpu->arch.nmi_injected = true; + } else { + enable_nmi_window(vcpu); return; } - if (!vcpu->arch.nmi_window_open || kvm_run->request_nmi_window) + } + if (vcpu->arch.nmi_injected) { + vmx_inject_nmi(vcpu); + if (vcpu->arch.nmi_pending || kvm_run->request_nmi_window) enable_nmi_window(vcpu); + else if (vcpu->arch.irq_summary + || kvm_run->request_interrupt_window) + enable_irq_window(vcpu); + return; } + if (!vcpu->arch.nmi_window_open || kvm_run->request_nmi_window) + enable_nmi_window(vcpu); if (vcpu->arch.interrupt_window_open) { if (vcpu->arch.irq_summary && !vcpu->arch.interrupt.pending) @@ -3097,6 +3118,37 @@ static int kvm_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) printk(KERN_WARNING "%s: unexpected, valid vectoring info " "(0x%x) and exit reason is 0x%x\n", __func__, vectoring_info, exit_reason); + + if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked)) { + if (vcpu->arch.interrupt_window_open) { + vmx->soft_vnmi_blocked = 0; + vcpu->arch.nmi_window_open = 1; + } else if (vmx->vnmi_blocked_time > 1000000000LL && + (kvm_run->request_nmi_window || vcpu->arch.nmi_pending)) { + /* + * This CPU don't support us in finding the end of an + * NMI-blocked window if the guest runs with IRQs + * disabled. So we pull the trigger after 1 s of + * futile waiting, but inform the user about this. + */ + printk(KERN_WARNING "%s: Breaking out of NMI-blocked " + "state on VCPU %d after 1 s timeout\n", + __func__, vcpu->vcpu_id); + vmx->soft_vnmi_blocked = 0; + vmx->vcpu.arch.nmi_window_open = 1; + } + + /* + * If the user space waits to inject an NNI, exit ASAP + */ + if (vcpu->arch.nmi_window_open && kvm_run->request_nmi_window + && !vcpu->arch.nmi_pending) { + kvm_run->exit_reason = KVM_EXIT_NMI_WINDOW_OPEN; + ++vcpu->stat.nmi_window_exits; + return 0; + } + } + if (exit_reason < kvm_vmx_max_exit_handlers && kvm_vmx_exit_handlers[exit_reason]) return kvm_vmx_exit_handlers[exit_reason](vcpu, kvm_run); @@ -3146,7 +3198,9 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx) if (unblock_nmi && vector != DF_VECTOR) vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); - } + } else if (unlikely(vmx->soft_vnmi_blocked)) + vmx->vnmi_blocked_time += + ktime_to_ns(ktime_sub(ktime_get(), vmx->entry_time)); idt_vectoring_info = vmx->idt_vectoring_info; idtv_info_valid = idt_vectoring_info & VECTORING_INFO_VALID_MASK; @@ -3186,27 +3240,25 @@ static void vmx_intr_assist(struct kvm_vcpu *vcpu) vmx_update_window_states(vcpu); - if (cpu_has_virtual_nmis()) { - if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) { - if (vcpu->arch.interrupt.pending) { - enable_nmi_window(vcpu); - } else if (vcpu->arch.nmi_window_open) { - vcpu->arch.nmi_pending = false; - vcpu->arch.nmi_injected = true; - } else { - enable_nmi_window(vcpu); - return; - } - } - if (vcpu->arch.nmi_injected) { - vmx_inject_nmi(vcpu); - if (vcpu->arch.nmi_pending) - enable_nmi_window(vcpu); - else if (kvm_cpu_has_interrupt(vcpu)) - enable_irq_window(vcpu); + if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) { + if (vcpu->arch.interrupt.pending) { + enable_nmi_window(vcpu); + } else if (vcpu->arch.nmi_window_open) { + vcpu->arch.nmi_pending = false; + vcpu->arch.nmi_injected = true; + } else { + enable_nmi_window(vcpu); return; } } + if (vcpu->arch.nmi_injected) { + vmx_inject_nmi(vcpu); + if (vcpu->arch.nmi_pending) + enable_nmi_window(vcpu); + else if (kvm_cpu_has_interrupt(vcpu)) + enable_irq_window(vcpu); + return; + } if (!vcpu->arch.interrupt.pending && kvm_cpu_has_interrupt(vcpu)) { if (vcpu->arch.interrupt_window_open) kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu)); @@ -3255,6 +3307,10 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) struct vcpu_vmx *vmx = to_vmx(vcpu); u32 intr_info; + /* Record the guest's net vcpu time for enforced NMI injections. */ + if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked)) + vmx->entry_time = ktime_get(); + /* Handle invalid guest state instead of entering VMX */ if (vmx->emulation_required && emulate_invalid_guest_state) { handle_invalid_guest_state(vcpu, kvm_run); |