From bc1a34f1bf354fabc03e3f465620c80e510d0e8f Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Thu, 1 May 2008 18:43:33 +0200 Subject: [PATCH] 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 Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 11 ++++++++++- include/asm-x86/kvm_host.h | 2 +- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bc224bba1e87..21338bdb28ff 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3703,10 +3703,19 @@ void fx_init(struct kvm_vcpu *vcpu) { 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(); diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index 4baa9c9e1f41..1d8cd01fa514 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -627,7 +627,7 @@ static inline void fx_restore(struct i387_fxsave_struct *image) asm("fxrstor (%0)":: "r" (image)); } -static inline void fpu_init(void) +static inline void fx_finit(void) { asm("finit"); }