From 6f05485d3a161caebc0fc7a73d641fa42a0dd263 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Tue, 9 Feb 2016 20:15:18 +0100 Subject: [PATCH] KVM: VMX: Fix guest debugging while in L2 When we take a #DB or #BP vmexit while in guest mode, we first of all need to check if there is ongoing guest debugging that might be interested in the event. Currently, we unconditionally leave L2 and inject the event into L1 if it is intercepting the exceptions. That breaks things marvelously. Signed-off-by: Jan Kiszka Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 7852092b82ae..cb501d306416 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -968,6 +968,16 @@ static inline bool is_exception_n(u32 intr_info, u8 vector) (INTR_TYPE_HARD_EXCEPTION | vector | INTR_INFO_VALID_MASK); } +static inline bool is_debug(u32 intr_info) +{ + return is_exception_n(intr_info, DB_VECTOR); +} + +static inline bool is_breakpoint(u32 intr_info) +{ + return is_exception_n(intr_info, BP_VECTOR); +} + static inline bool is_page_fault(u32 intr_info) { return is_exception_n(intr_info, PF_VECTOR); @@ -7753,6 +7763,13 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) else if (is_no_device(intr_info) && !(vmcs12->guest_cr0 & X86_CR0_TS)) return false; + else if (is_debug(intr_info) && + vcpu->guest_debug & + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) + return false; + else if (is_breakpoint(intr_info) && + vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) + return false; return vmcs12->exception_bitmap & (1u << (intr_info & INTR_INFO_VECTOR_MASK)); case EXIT_REASON_EXTERNAL_INTERRUPT: -- 2.20.1