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...@hitachi.com>
Cc: Avi Kivity <a...@redhat.com>
Cc: Marcelo Tosatti <mtosa...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@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 74fcb96..6899aaa 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -66,6 +66,7 @@
 #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
@@ -196,6 +197,7 @@ 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,
@@ -280,6 +282,7 @@ 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
 #define EXIT_REASON_INVPCID            58
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 6081be7..fc350f3 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 6dc59c8..2130cbd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4456,6 +4456,12 @@ 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;
@@ -5768,6 +5774,7 @@ 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,


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