On Sat, Feb 13, 2010 at 10:31:12AM +0100, Jan Kiszka wrote: > From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > > We intercept #BP while in guest debugging mode. As VM exists 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. > event_exit_inst_len is only used for event reinjection. Since event intercepted here will not be reinjected why updating event_exit_inst_len is needed here? > Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > --- > > Please consider for stable, this fixes guest debugging scenarios. > > arch/x86/kvm/vmx.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index f82b072..e9f64e8 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2775,6 +2775,8 @@ static int handle_rmode_exception(struct kvm_vcpu *vcpu, > kvm_queue_exception(vcpu, vec); > return 1; > case BP_VECTOR: > + 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 */ > @@ -2897,6 +2899,8 @@ static int handle_exception(struct kvm_vcpu *vcpu) > kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7); > /* fall through */ > case BP_VECTOR: > + 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; > -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
