KVM: in-kernel LAPIC save and restore support

This patch adds a new vcpu-based IOCTL to save and restore the local
apic registers for a single vcpu. The kernel only copies the apic page as
a whole, extraction of registers is left to userspace side. On restore, the
APIC timer is restarted from the initial count, this introduces a little
delay, but works fine.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 42d15150d7a3..30a83696906c 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -208,6 +208,12 @@ struct kvm_fpu {
         __u32 pad2;
 };
 
+/* for KVM_GET_LAPIC and KVM_SET_LAPIC */
+#define KVM_APIC_REG_SIZE 0x400
+struct kvm_lapic_state {
+        char regs[KVM_APIC_REG_SIZE];
+};
+
 struct kvm_segment {
         __u64 base;
         __u32 limit;
@@ -380,5 +386,7 @@ struct kvm_signal_mask {
 #define KVM_SET_SIGNAL_MASK       _IOW(KVMIO,  0x8b, struct kvm_signal_mask)
 #define KVM_GET_FPU               _IOR(KVMIO,  0x8c, struct kvm_fpu)
 #define KVM_SET_FPU               _IOW(KVMIO,  0x8d, struct kvm_fpu)
+#define KVM_GET_LAPIC             _IOR(KVMIO,  0x8e, struct kvm_lapic_state)
+#define KVM_SET_LAPIC             _IOW(KVMIO,  0x8f, struct kvm_lapic_state)
 
 #endif