On 19/04/2015 14:18, Nadav Amit wrote: > If the host sets hardware breakpoints to debug the guest, and a task-switch > occurs in the guest, the architectural DR7 will not be updated. The effective > DR7 would be updated instead. > > This fix uses the standard DR setting mechanism instead of the one that was > previously used. As a bonus, the update of DR7 will now be effective for AMD as > well. Is there a reason not to do it in emulate.c instead? Paolo > Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx> > --- > arch/x86/kvm/vmx.c | 3 --- > arch/x86/kvm/x86.c | 3 +++ > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index f7a0a7f..8f731c0 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -5703,9 +5703,6 @@ static int handle_task_switch(struct kvm_vcpu *vcpu) > return 0; > } > > - /* clear all local breakpoint enable flags */ > - vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~0x155); > - > /* > * TODO: What about debug traps on tss switch? > * Are we supposed to inject them and update dr6? > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 2046be4..a170c35 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6816,6 +6816,9 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index, > > kvm_rip_write(vcpu, ctxt->eip); > kvm_set_rflags(vcpu, ctxt->eflags); > + ret = __kvm_set_dr(vcpu, 7, vcpu->arch.dr7 & ~(DR_LOCAL_ENABLE_MASK | > + DR_LOCAL_SLOWDOWN)); > + WARN_ON(ret != 0); > kvm_make_request(KVM_REQ_EVENT, vcpu); > return EMULATE_DONE; > } > -- 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
