From 68f35500d733ed5cc3153c09f685e0abcfce4956 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Tue, 23 Feb 2010 17:47:53 +0100 Subject: [PATCH] KVM: VMX: Update instruction length on intercepted BP (Cherry-picked from commit c573cd22939e54fc1b8e672054a505048987a7cb) We intercept #BP while in guest debugging mode. As VM exits due to intercepted exceptions do not necessarily come with valid idt_vectoring, we have to update event_exit_inst_len explicitly in such cases. At least in the absence of migration, this ensures that re-injections of #BP will find and use the correct instruction length. Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8a8e1396507..85904fa41f0 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2719,6 +2719,12 @@ static int handle_rmode_exception(struct kvm_vcpu *vcpu, kvm_queue_exception(vcpu, vec); return 1; case BP_VECTOR: + /* + * Update instruction length as we may reinject the exception + * from user space while in guest debugging mode. + */ + to_vmx(vcpu)->vcpu.arch.event_exit_inst_len = + vmcs_read32(VM_EXIT_INSTRUCTION_LEN); if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) return 0; /* fall through */ @@ -2841,6 +2847,13 @@ static int handle_exception(struct kvm_vcpu *vcpu) kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7); /* fall through */ case BP_VECTOR: + /* + * Update instruction length as we may reinject #BP from + * user space while in guest debugging mode. Reading it for + * #DB as well causes no harm, it is not used in that case. + */ + vmx->vcpu.arch.event_exit_inst_len = + vmcs_read32(VM_EXIT_INSTRUCTION_LEN); kvm_run->exit_reason = KVM_EXIT_DEBUG; kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip; kvm_run->debug.arch.exception = ex_no; -- 2.11.4.GIT