From: Jan Kiszka Date: Tue, 23 Feb 2010 16:47:53 +0000 (+0100) Subject: KVM: VMX: Update instruction length on intercepted BP X-Git-Tag: v2.6.33.3~11 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=68f35500d733ed5cc3153c09f685e0abcfce4956;p=karo-tx-linux.git 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 --- diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8a8e13965076..85904fa41f03 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;