KVM: x86: DR7.GD should be cleared upon any #DB exception
authorNadav Amit <namit@cs.technion.ac.il>
Tue, 30 Sep 2014 17:49:14 +0000 (20:49 +0300)
committerPaolo Bonzini <pbonzini@redhat.com>
Mon, 3 Nov 2014 11:07:23 +0000 (12:07 +0100)
commit6bdf06625d240361e92254143a123ab432e337f8
tree4c3935eecde52126dd7fad88d3e4a5d3171fbcb1
parent394457a928e0f7ff121c375966f5ec1980dabc09
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>
arch/x86/kvm/vmx.c
arch/x86/kvm/x86.c