From 9bd01506ee551689b90ba5822c28ef55207146af Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 30 Jul 2007 16:29:56 +1000 Subject: [PATCH] KVM: fx_init() needs preemption disabled while it plays with the FPU state Now that kvm generally runs with preemption enabled, we need to protect the fpu intialization sequence. Signed-off-by: Rusty Russell Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 7aeaaba79c54..5b42731beba4 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -693,10 +693,13 @@ void fx_init(struct kvm_vcpu *vcpu) } *fx_image; + /* Initialize guest FPU by resetting ours and saving into guest's */ + preempt_disable(); fx_save(vcpu->host_fx_image); fpu_init(); fx_save(vcpu->guest_fx_image); fx_restore(vcpu->host_fx_image); + preempt_enable(); fx_image = (struct fx_image_s *)vcpu->guest_fx_image; fx_image->mxcsr = 0x1f80;