[PATCH 2/2] KVM: x86: Emulator should set DR6 upon GD like real CPU
Seyeong Kim
seyeong.kim at canonical.com
Tue Jan 31 13:32:04 UTC 2017
From: Nadav Amit <namit at cs.technion.ac.il>
It should clear B0-B3 and set BD.
Signed-off-by: Nadav Amit <namit at cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/emulate.c | 9 ++++++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 70427d1..4d2cfd8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -157,6 +157,7 @@ enum {
#define DR6_BD (1 << 13)
#define DR6_BS (1 << 14)
+#define DR6_RTM (1 << 16)
#define DR6_FIXED_1 0xffff0ff0
#define DR6_VOLATILE 0x0000e00f
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index f8eea19..46d0145 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3533,8 +3533,15 @@ 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;
}
--
2.7.4
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