If the RFLAGS.RF is set, then no #DB should occur on instruction breakpoints. However, the KVM emulator injects #DB regardless to RFLAGS.RF. This patch fixes this behavior. KVM, however, still appears not to update RFLAGS.RF correctly, regardless of this patch.
Signed-off-by: Nadav Amit <na...@cs.technion.ac.il> --- arch/x86/kvm/x86.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fae064f..e341a81 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5168,7 +5168,8 @@ static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r) } } - if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK)) { + if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK) && + !(kvm_get_rflags(vcpu) & X86_EFLAGS_RF)) { dr6 = kvm_vcpu_check_hw_bp(eip, 0, vcpu->arch.dr7, vcpu->arch.db); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html