KVM: avoid fx_init() schedule in atomic
This make sure not to schedule in atomic during fx_init. I also
changed the name of fpu_init to fx_finit to avoid duplicating the name
with fpu_init that is already used in the kernel, this makes grep
simpler if nothing else.
Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bc224bb..21338bd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3703,10 +3703,19 @@
{
unsigned after_mxcsr_mask;
+ /*
+ * Touch the fpu the first time in non atomic context as if
+ * this is the first fpu instruction the exception handler
+ * will fire before the instruction returns and it'll have to
+ * allocate ram with GFP_KERNEL.
+ */
+ if (!used_math())
+ fx_save(&vcpu->arch.host_fx_image);
+
/* Initialize guest FPU by resetting ours and saving into guest's */
preempt_disable();
fx_save(&vcpu->arch.host_fx_image);
- fpu_init();
+ fx_finit();
fx_save(&vcpu->arch.guest_fx_image);
fx_restore(&vcpu->arch.host_fx_image);
preempt_enable();