KVM: local APIC TPR access reporting facility
Add a facility to report on accesses to the local apic tpr even if the
local apic is emulated in the kernel. This is basically a hack that
allows userspace to patch Windows which tends to bang on the tpr a lot.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 513258c..c2b8088 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -684,6 +684,7 @@
case KVM_CAP_USER_MEMORY:
case KVM_CAP_SET_TSS_ADDR:
case KVM_CAP_EXT_CPUID:
+ case KVM_CAP_VAPIC:
r = 1;
break;
default:
@@ -1055,6 +1056,15 @@
return 0;
}
+static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
+ struct kvm_tpr_access_ctl *tac)
+{
+ if (tac->flags)
+ return -EINVAL;
+ vcpu->arch.tpr_access_reporting = !!tac->enabled;
+ return 0;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -1148,6 +1158,21 @@
case KVM_SET_MSRS:
r = msr_io(vcpu, argp, do_set_msr, 0);
break;
+ case KVM_TPR_ACCESS_REPORTING: {
+ struct kvm_tpr_access_ctl tac;
+
+ r = -EFAULT;
+ if (copy_from_user(&tac, argp, sizeof tac))
+ goto out;
+ r = vcpu_ioctl_tpr_access_reporting(vcpu, &tac);
+ if (r)
+ goto out;
+ r = -EFAULT;
+ if (copy_to_user(argp, &tac, sizeof tac))
+ goto out;
+ r = 0;
+ break;
+ };
default:
r = -EINVAL;
}
