Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
  KVM: Prevent guest fpu state from leaking into the host

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index da985b31b17e..8f1f07adb04e 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -253,6 +253,28 @@ int kvm_write_guest(struct kvm_vcpu *vcpu, gva_t addr, unsigned long size,
 }
 EXPORT_SYMBOL_GPL(kvm_write_guest);
 
+void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
+{
+        if (!vcpu->fpu_active || vcpu->guest_fpu_loaded)
+                return;
+
+        vcpu->guest_fpu_loaded = 1;
+        fx_save(vcpu->host_fx_image);
+        fx_restore(vcpu->guest_fx_image);
+}
+EXPORT_SYMBOL_GPL(kvm_load_guest_fpu);
+
+void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
+{
+        if (!vcpu->guest_fpu_loaded)
+                return;
+
+        vcpu->guest_fpu_loaded = 0;
+        fx_save(vcpu->guest_fx_image);
+        fx_restore(vcpu->host_fx_image);
+}
+EXPORT_SYMBOL_GPL(kvm_put_guest_fpu);
+
 /*
  * Switches to specified vcpu, until a matching vcpu_put()
  */