[PATCH v10 21/81] KVM: x86: add kvm_x86_ops.control_singlestep()

[Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>]

From: Nicușor Cîțu <nicu.citu@xxxxxxxxxx>

This function is needed for KVMI_VCPU_CONTROL_SINGLESTEP.

Signed-off-by: Nicușor Cîțu <nicu.citu@xxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/vmx/vmx.c          | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 45c72af05fa2..c2da5c24e825 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1305,6 +1305,7 @@ struct kvm_x86_ops {
 	void (*msr_filter_changed)(struct kvm_vcpu *vcpu);
 
 	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
+	void (*control_singlestep)(struct kvm_vcpu *vcpu, bool enable);
 };
 
 struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 41ea1ee9d419..1c8fbd6209ce 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7648,6 +7648,16 @@ static u64 vmx_fault_gla(struct kvm_vcpu *vcpu)
 	return ~0ull;
 }
 
+static void vmx_control_singlestep(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (enable)
+		exec_controls_setbit(to_vmx(vcpu),
+			      CPU_BASED_MONITOR_TRAP_FLAG);
+	else
+		exec_controls_clearbit(to_vmx(vcpu),
+				CPU_BASED_MONITOR_TRAP_FLAG);
+}
+
 static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.hardware_unsetup = hardware_unsetup,
 
@@ -7788,6 +7798,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.cpu_dirty_log_size = vmx_cpu_dirty_log_size,
 
 	.fault_gla = vmx_fault_gla,
+	.control_singlestep = vmx_control_singlestep,
 };
 
 static __init int hardware_setup(void)