diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index 100df6f38d920759291e5b442f6f0995061e4f60..32023d1ac24b0bd9ae7bbacb33c1e33f2a2376d3 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -173,6 +173,7 @@ struct kvm_vcpu { struct mutex mutex; int cpu; int launched; + int interrupt_window_open; unsigned long irq_summary; /* bit vector: 1 per word in irq_pending */ #define NR_IRQ_WORDS KVM_IRQ_BITMAP_SIZE(unsigned long) unsigned long irq_pending[NR_IRQ_WORDS]; @@ -247,6 +248,9 @@ struct kvm_stat { u32 io_exits; u32 mmio_exits; u32 signal_exits; + u32 irq_window_exits; + u32 halt_exits; + u32 request_irq_exits; u32 irq_exits; }; diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index b54caf0ceeb1305a2129177234a745cf079897a5..aca14139a680649efd202db303a3f2258373f31b 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -58,6 +58,9 @@ static struct kvm_stats_debugfs_item { { "io_exits", &kvm_stat.io_exits }, { "mmio_exits", &kvm_stat.mmio_exits }, { "signal_exits", &kvm_stat.signal_exits }, + { "irq_window", &kvm_stat.irq_window_exits }, + { "halt_exits", &kvm_stat.halt_exits }, + { "request_irq", &kvm_stat.request_irq_exits }, { "irq_exits", &kvm_stat.irq_exits }, { 0, 0 } }; @@ -1693,12 +1696,12 @@ static long kvm_dev_ioctl(struct file *filp, if (copy_from_user(&kvm_run, (void *)arg, sizeof kvm_run)) goto out; r = kvm_dev_ioctl_run(kvm, &kvm_run); - if (r < 0) + if (r < 0 && r != -EINTR) goto out; - r = -EFAULT; - if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run)) + if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run)) { + r = -EFAULT; goto out; - r = 0; + } break; } case KVM_GET_REGS: { diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index fa042873571711b1f453489a881f46ce2723188c..855207a9b3962c12513648a7baf4601e0a26e432 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -235,6 +235,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) vcpu->rip = vcpu->svm->vmcb->save.rip = vcpu->svm->next_rip; vcpu->svm->vmcb->control.int_state &= ~SVM_INTERRUPT_SHADOW_MASK; + + vcpu->interrupt_window_open = 1; } static int has_svm(void) @@ -1031,10 +1033,11 @@ static int halt_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { vcpu->svm->next_rip = vcpu->svm->vmcb->save.rip + 1; skip_emulated_instruction(vcpu); - if (vcpu->irq_summary && (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF)) + if (vcpu->irq_summary) return 1; kvm_run->exit_reason = KVM_EXIT_HLT; + ++kvm_stat.halt_exits; return 0; } @@ -1186,6 +1189,24 @@ static int msr_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) return rdmsr_interception(vcpu, kvm_run); } +static int interrupt_window_interception(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) +{ + /* + * If the user space waits to inject interrupts, exit as soon as + * possible + */ + if (kvm_run->request_interrupt_window && + !vcpu->irq_summary && + (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF)) { + ++kvm_stat.irq_window_exits; + kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; + return 0; + } + + return 1; +} + static int (*svm_exit_handlers[])(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) = { [SVM_EXIT_READ_CR0] = emulate_on_interception, @@ -1210,6 +1231,7 @@ static int (*svm_exit_handlers[])(struct kvm_vcpu *vcpu, [SVM_EXIT_NMI] = nop_on_interception, [SVM_EXIT_SMI] = nop_on_interception, [SVM_EXIT_INIT] = nop_on_interception, + [SVM_EXIT_VINTR] = interrupt_window_interception, /* [SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception, */ [SVM_EXIT_CPUID] = cpuid_interception, [SVM_EXIT_HLT] = halt_interception, @@ -1278,15 +1300,11 @@ static void pre_svm_run(struct kvm_vcpu *vcpu) } -static inline void kvm_try_inject_irq(struct kvm_vcpu *vcpu) +static inline void kvm_do_inject_irq(struct kvm_vcpu *vcpu) { struct vmcb_control_area *control; - if (!vcpu->irq_summary) - return; - control = &vcpu->svm->vmcb->control; - control->int_vector = pop_irq(vcpu); control->int_ctl &= ~V_INTR_PRIO_MASK; control->int_ctl |= V_IRQ_MASK | @@ -1301,6 +1319,59 @@ static void kvm_reput_irq(struct kvm_vcpu *vcpu) control->int_ctl &= ~V_IRQ_MASK; push_irq(vcpu, control->int_vector); } + + vcpu->interrupt_window_open = + !(control->int_state & SVM_INTERRUPT_SHADOW_MASK); +} + +static void do_interrupt_requests(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) +{ + struct vmcb_control_area *control = &vcpu->svm->vmcb->control; + + vcpu->interrupt_window_open = + (!(control->int_state & SVM_INTERRUPT_SHADOW_MASK) && + (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF)); + + if (vcpu->interrupt_window_open && vcpu->irq_summary) + /* + * If interrupts enabled, and not blocked by sti or mov ss. Good. + */ + kvm_do_inject_irq(vcpu); + + /* + * Interrupts blocked. Wait for unblock. + */ + if (!vcpu->interrupt_window_open && + (vcpu->irq_summary || kvm_run->request_interrupt_window)) { + control->intercept |= 1ULL << INTERCEPT_VINTR; + } else + control->intercept &= ~(1ULL << INTERCEPT_VINTR); +} + +static void post_kvm_run_save(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) +{ + kvm_run->ready_for_interrupt_injection = (vcpu->interrupt_window_open && + vcpu->irq_summary == 0); + kvm_run->if_flag = (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF) != 0; + kvm_run->cr8 = vcpu->cr8; + kvm_run->apic_base = vcpu->apic_base; +} + +/* + * Check if userspace requested an interrupt window, and that the + * interrupt window is open. + * + * No need to exit to userspace if we already have an interrupt queued. + */ +static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) +{ + return (!vcpu->irq_summary && + kvm_run->request_interrupt_window && + vcpu->interrupt_window_open && + (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF)); } static void save_db_regs(unsigned long *db_regs) @@ -1326,7 +1397,7 @@ static int svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) u16 ldt_selector; again: - kvm_try_inject_irq(vcpu); + do_interrupt_requests(vcpu, kvm_run); clgi(); @@ -1487,17 +1558,26 @@ static int svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) if (vcpu->svm->vmcb->control.exit_code == SVM_EXIT_ERR) { kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY; kvm_run->exit_reason = vcpu->svm->vmcb->control.exit_code; + post_kvm_run_save(vcpu, kvm_run); return 0; } if (handle_exit(vcpu, kvm_run)) { if (signal_pending(current)) { ++kvm_stat.signal_exits; + post_kvm_run_save(vcpu, kvm_run); + return -EINTR; + } + + if (dm_request_for_irq_injection(vcpu, kvm_run)) { + ++kvm_stat.request_irq_exits; + post_kvm_run_save(vcpu, kvm_run); return -EINTR; } kvm_resched(vcpu); goto again; } + post_kvm_run_save(vcpu, kvm_run); return 0; } diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index 2d204fd45972aca650caf415ff263bf13137a17f..c55635ddf426057ede5e11570f975fcc1fa93aea 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -263,6 +263,7 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) if (interruptibility & 3) vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, interruptibility & ~3); + vcpu->interrupt_window_open = 1; } static void vmx_inject_gp(struct kvm_vcpu *vcpu, unsigned error_code) @@ -1214,21 +1215,34 @@ static void kvm_do_inject_irq(struct kvm_vcpu *vcpu) irq | INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK); } -static void kvm_try_inject_irq(struct kvm_vcpu *vcpu) + +static void do_interrupt_requests(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) { - if ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) - && (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0) + u32 cpu_based_vm_exec_control; + + vcpu->interrupt_window_open = + ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) && + (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0); + + if (vcpu->interrupt_window_open && + vcpu->irq_summary && + !(vmcs_read32(VM_ENTRY_INTR_INFO_FIELD) & INTR_INFO_VALID_MASK)) /* - * Interrupts enabled, and not blocked by sti or mov ss. Good. + * If interrupts enabled, and not blocked by sti or mov ss. Good. */ kvm_do_inject_irq(vcpu); - else + + cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); + if (!vcpu->interrupt_window_open && + (vcpu->irq_summary || kvm_run->request_interrupt_window)) /* * Interrupts blocked. Wait for unblock. */ - vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, - vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) - | CPU_BASED_VIRTUAL_INTR_PENDING); + cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; + else + cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING; + vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); } static void kvm_guest_debug_pre(struct kvm_vcpu *vcpu) @@ -1565,23 +1579,41 @@ static int handle_wrmsr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) return 1; } +static void post_kvm_run_save(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) +{ + kvm_run->if_flag = (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) != 0; + kvm_run->cr8 = vcpu->cr8; + kvm_run->apic_base = vcpu->apic_base; + kvm_run->ready_for_interrupt_injection = (vcpu->interrupt_window_open && + vcpu->irq_summary == 0); +} + static int handle_interrupt_window(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { - /* Turn off interrupt window reporting. */ - vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, - vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) - & ~CPU_BASED_VIRTUAL_INTR_PENDING); + /* + * If the user space waits to inject interrupts, exit as soon as + * possible + */ + if (kvm_run->request_interrupt_window && + !vcpu->irq_summary && + (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF)) { + kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; + ++kvm_stat.irq_window_exits; + return 0; + } return 1; } static int handle_halt(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { skip_emulated_instruction(vcpu); - if (vcpu->irq_summary && (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF)) + if (vcpu->irq_summary) return 1; kvm_run->exit_reason = KVM_EXIT_HLT; + ++kvm_stat.halt_exits; return 0; } @@ -1632,6 +1664,21 @@ static int kvm_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) return 0; } +/* + * Check if userspace requested an interrupt window, and that the + * interrupt window is open. + * + * No need to exit to userspace if we already have an interrupt queued. + */ +static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu, + struct kvm_run *kvm_run) +{ + return (!vcpu->irq_summary && + kvm_run->request_interrupt_window && + vcpu->interrupt_window_open && + (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF)); +} + static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { u8 fail; @@ -1663,9 +1710,7 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) vmcs_writel(HOST_GS_BASE, segment_base(gs_sel)); #endif - if (vcpu->irq_summary && - !(vmcs_read32(VM_ENTRY_INTR_INFO_FIELD) & INTR_INFO_VALID_MASK)) - kvm_try_inject_irq(vcpu); + do_interrupt_requests(vcpu, kvm_run); if (vcpu->guest_debug.enabled) kvm_guest_debug_pre(vcpu); @@ -1802,6 +1847,7 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) fx_save(vcpu->guest_fx_image); fx_restore(vcpu->host_fx_image); + vcpu->interrupt_window_open = (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0; #ifndef CONFIG_X86_64 asm ("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS)); @@ -1834,12 +1880,22 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) /* Give scheduler a change to reschedule. */ if (signal_pending(current)) { ++kvm_stat.signal_exits; + post_kvm_run_save(vcpu, kvm_run); + return -EINTR; + } + + if (dm_request_for_irq_injection(vcpu, kvm_run)) { + ++kvm_stat.request_irq_exits; + post_kvm_run_save(vcpu, kvm_run); return -EINTR; } + kvm_resched(vcpu); goto again; } } + + post_kvm_run_save(vcpu, kvm_run); return 0; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 28fdce1ac1db3e6c4d3db845989ec5f502ad25a3..bc8b4616bad702f073b49fbb60d3b3c833e3076c 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -11,7 +11,7 @@ #include #include -#define KVM_API_VERSION 1 +#define KVM_API_VERSION 2 /* * Architectural interrupt line count, and the size of the bitmap needed @@ -45,6 +45,7 @@ enum kvm_exit_reason { KVM_EXIT_DEBUG = 4, KVM_EXIT_HLT = 5, KVM_EXIT_MMIO = 6, + KVM_EXIT_IRQ_WINDOW_OPEN = 7, }; /* for KVM_RUN */ @@ -53,11 +54,19 @@ struct kvm_run { __u32 vcpu; __u32 emulated; /* skip current instruction */ __u32 mmio_completed; /* mmio request completed */ + __u8 request_interrupt_window; + __u8 padding1[3]; /* out */ __u32 exit_type; __u32 exit_reason; __u32 instruction_length; + __u8 ready_for_interrupt_injection; + __u8 if_flag; + __u16 padding2; + __u64 cr8; + __u64 apic_base; + union { /* KVM_EXIT_UNKNOWN */ struct {