From: Jan Kiszka <[email protected]> According to the SDM, only bits 0-3 of DR6 "may" be cleared by "certain" debug exception. So do update them on #DB exception in KVM, but leave the rest alone, only setting BD and BS in addition to already set bits in DR6. This also aligns us with kvm_vcpu_check_singlestep.
Signed-off-by: Jan Kiszka <[email protected]> --- arch/x86/kvm/vmx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 55cb4b6..2a95ce0 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4869,7 +4869,8 @@ static int handle_exception(struct kvm_vcpu *vcpu) dr6 = vmcs_readl(EXIT_QUALIFICATION); if (!(vcpu->guest_debug & (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) { - vcpu->arch.dr6 = dr6 | DR6_FIXED_1; + vcpu->arch.dr6 &= ~15; + vcpu->arch.dr6 |= dr6; kvm_queue_exception(vcpu, DB_VECTOR); return 1; } -- 1.8.1.1.298.ge7eed54 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
