KVM: VMX: Avoid exit when setting cr8 if the local apic is in the kernel

With apic in userspace, we must exit to userspace after a cr8 write in order
to update the tpr.  But if the apic is in the kernel, the exit is unnecessary.

Noticed by Joerg Roedel.

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 3b44573c326e..83084348581a 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1973,6 +1973,8 @@ static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                         vcpu_load_rsp_rip(vcpu);
                         set_cr8(vcpu, vcpu->regs[reg]);
                         skip_emulated_instruction(vcpu);
+                        if (irqchip_in_kernel(vcpu->kvm))
+                                return 1;
                         kvm_run->exit_reason = KVM_EXIT_SET_TPR;
                         return 0;
                 };