KVM: In kernel PIT model

The patch moves the PIT model from userspace to kernel, and increases
the timer accuracy greatly.

[marcelo: make last_injected_time per-guest]

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-and-Acked-by: Alex Davis <alex14641@yahoo.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bf78d6522d3d..c33a4578132c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -17,6 +17,7 @@
 #include <linux/kvm_host.h>
 #include "irq.h"
 #include "mmu.h"
+#include "i8254.h"
 
 #include <linux/clocksource.h>
 #include <linux/kvm.h>
@@ -818,6 +819,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_SET_TSS_ADDR:
         case KVM_CAP_EXT_CPUID:
         case KVM_CAP_CLOCKSOURCE:
+        case KVM_CAP_PIT:
                 r = 1;
                 break;
         case KVM_CAP_VAPIC:
@@ -1594,6 +1596,12 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 } else
                         goto out;
                 break;
+        case KVM_CREATE_PIT:
+                r = -ENOMEM;
+                kvm->arch.vpit = kvm_create_pit(kvm);
+                if (kvm->arch.vpit)
+                        r = 0;
+                break;
         case KVM_IRQ_LINE: {
                 struct kvm_irq_level irq_event;
 
@@ -3372,6 +3380,7 @@ static void kvm_free_vcpus(struct kvm *kvm)
 
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
+        kvm_free_pit(kvm);
         kfree(kvm->arch.vpic);
         kfree(kvm->arch.vioapic);
         kvm_free_vcpus(kvm);