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authorRusty Russell <rusty@rustcorp.com.au>2007-07-30 16:29:56 +1000
committerAvi Kivity <avi@qumranet.com>2007-10-13 10:18:20 +0200
commit9bd01506ee551689b90ba5822c28ef55207146af (patch)
tree811e7ac5e8571e172fce8b7199830f9f511440ba /drivers/kvm
parent11ec2804711896546ee3c945f3786c7f9fdd175a (diff)
downloadblackbird-op-linux-9bd01506ee551689b90ba5822c28ef55207146af.tar.gz
blackbird-op-linux-9bd01506ee551689b90ba5822c28ef55207146af.zip
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 <rusty@rustcorp.com.au> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm')
-rw-r--r--drivers/kvm/kvm_main.c3
1 files changed, 3 insertions, 0 deletions
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;
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