diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm.c | 62 |
2 files changed, 52 insertions, 12 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1d6c3f757cb..82129437e87 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -358,6 +358,7 @@ struct kvm_vcpu_arch { unsigned int time_offset; struct page *time_page; + bool singlestep; /* guest is single stepped by KVM */ bool nmi_pending; bool nmi_injected; @@ -771,6 +772,7 @@ enum { #define HF_HIF_MASK (1 << 1) #define HF_VINTR_MASK (1 << 2) #define HF_NMI_MASK (1 << 3) +#define HF_IRET_MASK (1 << 4) /* * Hardware virtualization extension instructions may fault if a diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 377c4f17d17..71510e07e69 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -965,15 +965,16 @@ static void svm_set_segment(struct kvm_vcpu *vcpu, } -static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) +static void update_db_intercept(struct kvm_vcpu *vcpu) { - int old_debug = vcpu->guest_debug; struct vcpu_svm *svm = to_svm(vcpu); - vcpu->guest_debug = dbg->control; - svm->vmcb->control.intercept_exceptions &= ~((1 << DB_VECTOR) | (1 << BP_VECTOR)); + + if (vcpu->arch.singlestep) + svm->vmcb->control.intercept_exceptions |= (1 << DB_VECTOR); + if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) { if (vcpu->guest_debug & (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) @@ -984,6 +985,16 @@ static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) 1 << BP_VECTOR; } else vcpu->guest_debug = 0; +} + +static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) +{ + int old_debug = vcpu->guest_debug; + struct vcpu_svm *svm = to_svm(vcpu); + + vcpu->guest_debug = dbg->control; + + update_db_intercept(vcpu); if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) svm->vmcb->save.dr7 = dbg->arch.debugreg[7]; @@ -1133,14 +1144,30 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) static int db_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { if (!(svm->vcpu.guest_debug & - (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) { + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) && + !svm->vcpu.arch.singlestep) { kvm_queue_exception(&svm->vcpu, DB_VECTOR); return 1; } - kvm_run->exit_reason = KVM_EXIT_DEBUG; - kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip; - kvm_run->debug.arch.exception = DB_VECTOR; - return 0; + + if (svm->vcpu.arch.singlestep) { + svm->vcpu.arch.singlestep = false; + if (!(svm->vcpu.guest_debug & KVM_GUESTDBG_SINGLESTEP)) + svm->vmcb->save.rflags &= + ~(X86_EFLAGS_TF | X86_EFLAGS_RF); + update_db_intercept(&svm->vcpu); + } + + if (svm->vcpu.guest_debug & + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)){ + kvm_run->exit_reason = KVM_EXIT_DEBUG; + kvm_run->debug.arch.pc = + svm->vmcb->save.cs.base + svm->vmcb->save.rip; + kvm_run->debug.arch.exception = DB_VECTOR; + return 0; + } + + return 1; } static int bp_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) @@ -1887,7 +1914,7 @@ static int iret_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { ++svm->vcpu.stat.nmi_window_exits; svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET); - svm->vcpu.arch.hflags &= ~HF_NMI_MASK; + svm->vcpu.arch.hflags |= HF_IRET_MASK; return 1; } @@ -2357,8 +2384,16 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); - if (svm->vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) - enable_irq_window(vcpu); + if ((svm->vcpu.arch.hflags & (HF_NMI_MASK | HF_IRET_MASK)) + == HF_NMI_MASK) + return; /* IRET will cause a vm exit */ + + /* Something prevents NMI from been injected. Single step over + possible problem (IRET or exception injection or interrupt + shadow) */ + vcpu->arch.singlestep = true; + svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF); + update_db_intercept(vcpu); } static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr) @@ -2401,6 +2436,9 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) int type; u32 exitintinfo = svm->vmcb->control.exit_int_info; + if (svm->vcpu.arch.hflags & HF_IRET_MASK) + svm->vcpu.arch.hflags &= ~(HF_NMI_MASK | HF_IRET_MASK); + svm->vcpu.arch.nmi_injected = false; kvm_clear_exception_queue(&svm->vcpu); kvm_clear_interrupt_queue(&svm->vcpu); |