From ab1264f459a1cabe3e4c929e9f0f434399b3ed5b Mon Sep 17 00:00:00 2001
From: Jan Kiszka <jan.kiszka@web.de>
Date: Sun, 18 Oct 2009 13:24:44 +0200
Subject: [PATCH] --- yaml --- r: 172311 b: refs/heads/master c:
 94fe45da48f921d01d8ff02a0ad54ee9c326d7f0 h: refs/heads/master i:   172309:
 db982c37be15145b973791ffa8440a8b686cdaa6   172307:
 b535cdbdb125b9c972e7c77c0835218019bdd017   172303:
 2cec686be969d4530fd124dbb299ea40a609809c v: v3

---
 [refs]                                |  2 +-
 trunk/arch/x86/include/asm/kvm_host.h |  4 +++
 trunk/arch/x86/kvm/x86.c              | 47 ++++++++++++++++-----------
 3 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/[refs] b/[refs]
index e140dc86dcdd..126f98e94653 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ffde22ac53b6d6b1d7206f1172176a667eead778
+refs/heads/master: 94fe45da48f921d01d8ff02a0ad54ee9c326d7f0
diff --git a/trunk/arch/x86/include/asm/kvm_host.h b/trunk/arch/x86/include/asm/kvm_host.h
index 36f3b53f5c27..2536fbd85b3a 100644
--- a/trunk/arch/x86/include/asm/kvm_host.h
+++ b/trunk/arch/x86/include/asm/kvm_host.h
@@ -371,6 +371,10 @@ struct kvm_vcpu_arch {
 	u64 mcg_status;
 	u64 mcg_ctl;
 	u64 *mce_banks;
+
+	/* used for guest single stepping over the given code position */
+	u16 singlestep_cs;
+	unsigned long singlestep_rip;
 };
 
 struct kvm_mem_alias {
diff --git a/trunk/arch/x86/kvm/x86.c b/trunk/arch/x86/kvm/x86.c
index bb842db3ee7c..13f30aac460b 100644
--- a/trunk/arch/x86/kvm/x86.c
+++ b/trunk/arch/x86/kvm/x86.c
@@ -235,25 +235,6 @@ bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
 }
 EXPORT_SYMBOL_GPL(kvm_require_cpl);
 
-unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu)
-{
-	unsigned long rflags;
-
-	rflags = kvm_x86_ops->get_rflags(vcpu);
-	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
-		rflags &= ~(unsigned long)(X86_EFLAGS_TF | X86_EFLAGS_RF);
-	return rflags;
-}
-EXPORT_SYMBOL_GPL(kvm_get_rflags);
-
-void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
-{
-	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
-		rflags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
-	kvm_x86_ops->set_rflags(vcpu, rflags);
-}
-EXPORT_SYMBOL_GPL(kvm_set_rflags);
-
 /*
  * Load the pae pdptrs.  Return true is they are all valid.
  */
@@ -4565,6 +4546,12 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 		vcpu->arch.switch_db_regs = (vcpu->arch.dr7 & DR7_BP_EN_MASK);
 	}
 
+	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
+		vcpu->arch.singlestep_cs =
+			get_segment_selector(vcpu, VCPU_SREG_CS);
+		vcpu->arch.singlestep_rip = kvm_rip_read(vcpu);
+	}
+
 	/*
 	 * Trigger an rflags update that will inject or remove the trace
 	 * flags.
@@ -5031,6 +5018,28 @@ int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
 	return kvm_x86_ops->interrupt_allowed(vcpu);
 }
 
+unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu)
+{
+	unsigned long rflags;
+
+	rflags = kvm_x86_ops->get_rflags(vcpu);
+	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
+		rflags &= ~(unsigned long)(X86_EFLAGS_TF | X86_EFLAGS_RF);
+	return rflags;
+}
+EXPORT_SYMBOL_GPL(kvm_get_rflags);
+
+void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
+{
+	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP &&
+	    vcpu->arch.singlestep_cs ==
+			get_segment_selector(vcpu, VCPU_SREG_CS) &&
+	    vcpu->arch.singlestep_rip == kvm_rip_read(vcpu))
+		rflags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
+	kvm_x86_ops->set_rflags(vcpu, rflags);
+}
+EXPORT_SYMBOL_GPL(kvm_set_rflags);
+
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);