summaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorNadav Amit <namit@cs.technion.ac.il>2014-09-30 20:49:14 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2014-11-03 12:07:23 +0100
commit6bdf06625d240361e92254143a123ab432e337f8 (patch)
tree4c3935eecde52126dd7fad88d3e4a5d3171fbcb1 /arch
parent394457a928e0f7ff121c375966f5ec1980dabc09 (diff)
downloadlinux-6bdf06625d240361e92254143a123ab432e337f8.tar.gz
linux-6bdf06625d240361e92254143a123ab432e337f8.tar.bz2
linux-6bdf06625d240361e92254143a123ab432e337f8.zip
KVM: x86: DR7.GD should be cleared upon any #DB exception
Intel SDM 17.2.4 (Debug Control Register (DR7)) says: "The processor clears the GD flag upon entering to the debug exception handler." This sentence may be misunderstood as if it happens only on #DB due to debug-register protection, but it happens regardless to the cause of the #DB. Fix the behavior to match both real hardware and Bochs. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/vmx.c2
-rw-r--r--arch/x86/kvm/x86.c6
2 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2627ffae919b..63e7cf18c1c8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5185,9 +5185,7 @@ static int handle_dr(struct kvm_vcpu *vcpu)
vcpu->run->exit_reason = KVM_EXIT_DEBUG;
return 0;
} else {
- vcpu->arch.dr7 &= ~DR7_GD;
vcpu->arch.dr6 |= DR6_BD | DR6_RTM;
- vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
kvm_queue_exception(vcpu, DB_VECTOR);
return 1;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0033df32a745..1ab7361594d5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5965,6 +5965,12 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
X86_EFLAGS_RF);
+ if (vcpu->arch.exception.nr == DB_VECTOR &&
+ (vcpu->arch.dr7 & DR7_GD)) {
+ vcpu->arch.dr7 &= ~DR7_GD;
+ kvm_update_dr7(vcpu);
+ }
+
kvm_x86_ops->queue_exception(vcpu, vcpu->arch.exception.nr,
vcpu->arch.exception.has_error_code,
vcpu->arch.exception.error_code,