From: Nadav Amit <namit@cs.technion.ac.il>
Date: Sun, 2 Nov 2014 09:54:43 +0000 (+0200)
Subject: KVM: x86: Emulator should set DR6 upon GD like real CPU
X-Git-Tag: v3.19-rc1~36^2~86
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6d2a0526b09e551d0f395cfb63e7cb965db825af;p=karo-tx-linux.git

KVM: x86: Emulator should set DR6 upon GD like real CPU

It should clear B0-B3 and set BD.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a4703eb9c1ed..736a49f218ff 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3588,8 +3588,15 @@ static int check_dr_read(struct x86_emulate_ctxt *ctxt)
 	if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
 		return emulate_ud(ctxt);
 
-	if (check_dr7_gd(ctxt))
+	if (check_dr7_gd(ctxt)) {
+		ulong dr6;
+
+		ctxt->ops->get_dr(ctxt, 6, &dr6);
+		dr6 &= ~15;
+		dr6 |= DR6_BD | DR6_RTM;
+		ctxt->ops->set_dr(ctxt, 6, dr6);
 		return emulate_db(ctxt);
+	}
 
 	return X86EMUL_CONTINUE;
 }