[RFC: timer passthrough 9/9] KVM: vmx: query the state of timer-passth for vm

[Zhimin Feng <fengzhimin@xxxxxxxxxxxxx>]

query the state of timer passthrough of specific vm

Signed-off-by: Zhimin Feng <fengzhimin@xxxxxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/vmx/vmx.c          | 11 +++++++++++
 arch/x86/kvm/x86.c              |  6 ++++++
 include/uapi/linux/kvm.h        |  1 +
 tools/include/uapi/linux/kvm.h  |  1 +
 5 files changed, 20 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9855ef419793..189c4f6f9d5d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1306,6 +1306,7 @@ struct kvm_x86_ops {
 	void (*msr_filter_changed)(struct kvm_vcpu *vcpu);
 	void (*switch_to_sw_timer)(struct kvm_vcpu *vcpu);
 	int (*set_timer_passth_state)(struct kvm *kvm, void *argp);
+	int (*get_timer_passth_state)(struct kvm *kvm, void __user *argp);
 };
 
 struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b88f744478e9..b760aa7bc6d5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7883,6 +7883,16 @@ static int vmx_set_timer_passth_state(struct kvm *kvm, void *argp)
 	return r;
 }
 
+static int vmx_get_timer_passth_state(struct kvm *kvm, void __user *argp)
+{
+	int state = atomic_read(&kvm->timer_passth_state);
+
+	if (copy_to_user(argp, &state, sizeof(state)))
+		return -1;
+
+	return 0;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.hardware_unsetup = hardware_unsetup,
 
@@ -8013,6 +8023,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.msr_filter_changed = vmx_msr_filter_changed,
 	.switch_to_sw_timer = vmx_passth_switch_to_sw_timer,
 	.set_timer_passth_state = vmx_set_timer_passth_state,
+	.get_timer_passth_state = vmx_get_timer_passth_state,
 };
 
 static __init int hardware_setup(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7db74bd9d362..a32927697e82 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5698,6 +5698,12 @@ long kvm_arch_vm_ioctl(struct file *filp,
 			r = kvm_x86_ops.set_timer_passth_state(kvm, argp);
 		break;
 	}
+	case KVM_GET_TIMER_PASSTH_STATE: {
+		r = -EFAULT;
+		if (kvm_x86_ops.get_timer_passth_state)
+			r = kvm_x86_ops.get_timer_passth_state(kvm, argp);
+		break;
+	}
 	default:
 		r = -ENOTTY;
 	}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 6e26bc342599..2c0cefb8ffe2 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1558,6 +1558,7 @@ struct kvm_pv_cmd {
 #define KVM_X86_SET_MSR_FILTER	_IOW(KVMIO,  0xc6, struct kvm_msr_filter)
 
 #define KVM_SET_TIMER_PASSTH_STATE  _IO(KVMIO,   0xc7)
+#define KVM_GET_TIMER_PASSTH_STATE  _IO(KVMIO,   0xc8)
 
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index 6e26bc342599..2c0cefb8ffe2 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1558,6 +1558,7 @@ struct kvm_pv_cmd {
 #define KVM_X86_SET_MSR_FILTER	_IOW(KVMIO,  0xc6, struct kvm_msr_filter)
 
 #define KVM_SET_TIMER_PASSTH_STATE  _IO(KVMIO,   0xc7)
+#define KVM_GET_TIMER_PASSTH_STATE  _IO(KVMIO,   0xc8)
 
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {
-- 
2.11.0