[RFC PATCH 15/18] KVM: vmx: Add definitions PIN_BASED_PREEMPTION_TIMER

[Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>]

Add some definitions to use PIN_BASED_PREEMPTION_TIMER.

When PIN_BASED_PREEMPTION_TIMER is enabled, the guest will exit
with reason=EXIT_REASON_PREEMPTION_TIMER when the counter specified in
VMX_PREEMPTION_TIMER_VALUE becomes 0.
This patch also adds a dummy handler for EXIT_REASON_PREEMPTION_TIMER,
which just goes back to VM execution soon.

These are currently intended only to be used with avoid entering the
guest on a slave CPU when vmx_prevent_run(vcpu, 1) is called.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---

 arch/x86/include/asm/vmx.h |    3 +++
 arch/x86/kvm/trace.h       |    1 +
 arch/x86/kvm/vmx.c         |    7 +++++++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 31f180c..5ff43b1 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -65,6 +65,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_PREEMPTION_TIMER              0x00000040
 
 #define VM_EXIT_SAVE_DEBUG_CONTROLS             0x00000002
 #define VM_EXIT_HOST_ADDR_SPACE_SIZE            0x00000200
@@ -195,6 +196,7 @@ enum vmcs_field {
 	GUEST_INTERRUPTIBILITY_INFO     = 0x00004824,
 	GUEST_ACTIVITY_STATE            = 0X00004826,
 	GUEST_SYSENTER_CS               = 0x0000482A,
+	VMX_PREEMPTION_TIMER_VALUE      = 0x0000482E,
 	HOST_IA32_SYSENTER_CS           = 0x00004c00,
 	CR0_GUEST_HOST_MASK             = 0x00006000,
 	CR4_GUEST_HOST_MASK             = 0x00006002,
@@ -279,6 +281,7 @@ enum vmcs_field {
 #define EXIT_REASON_APIC_ACCESS         44
 #define EXIT_REASON_EPT_VIOLATION       48
 #define EXIT_REASON_EPT_MISCONFIG       49
+#define EXIT_REASON_PREEMPTION_TIMER	52
 #define EXIT_REASON_WBINVD		54
 #define EXIT_REASON_XSETBV		55
 
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 911d264..28b4df8 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -218,6 +218,7 @@ TRACE_EVENT(kvm_apic,
 	{ EXIT_REASON_APIC_ACCESS,		"APIC_ACCESS" }, \
 	{ EXIT_REASON_EPT_VIOLATION,		"EPT_VIOLATION" }, \
 	{ EXIT_REASON_EPT_MISCONFIG,		"EPT_MISCONFIG" }, \
+	{ EXIT_REASON_PREEMPTION_TIMER,		"PREEMPTION_TIMER" }, \
 	{ EXIT_REASON_WBINVD,			"WBINVD" }
 
 #define SVM_EXIT_REASONS \
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3aea448..2c987d1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4347,6 +4347,12 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+static int handle_preemption_timer(struct kvm_vcpu *vcpu)
+{
+	/* Nothing */
+	return 1;
+}
+
 static int handle_triple_fault(struct kvm_vcpu *vcpu)
 {
 	vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
@@ -5645,6 +5651,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
 	[EXIT_REASON_VMON]                    = handle_vmon,
 	[EXIT_REASON_TPR_BELOW_THRESHOLD]     = handle_tpr_below_threshold,
 	[EXIT_REASON_APIC_ACCESS]             = handle_apic_access,
+	[EXIT_REASON_PREEMPTION_TIMER]        = handle_preemption_timer,
 	[EXIT_REASON_WBINVD]                  = handle_wbinvd,
 	[EXIT_REASON_XSETBV]                  = handle_xsetbv,
 	[EXIT_REASON_TASK_SWITCH]             = handle_task_switch,