From: Suresh Siddha Date: Fri, 24 Aug 2012 21:12:59 +0000 (-0700) Subject: x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=9c1c3fac53378c9782c18f80107965578d7b7167;p=deliverable%2Flinux.git x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() kvm's guest fpu save/restore should be wrapped around kernel_fpu_begin/end(). This will avoid for example taking a DNA in kvm_load_guest_fpu() when it tries to load the fpu immediately after doing unlazy_fpu() on the host side. More importantly this will prevent the host process fpu from being corrupted. Signed-off-by: Suresh Siddha Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com Cc: Avi Kivity Signed-off-by: H. Peter Anvin --- diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 148ed666e311..cf637f572bdd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5972,7 +5972,7 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) */ kvm_put_guest_xcr0(vcpu); vcpu->guest_fpu_loaded = 1; - unlazy_fpu(current); + kernel_fpu_begin(); fpu_restore_checking(&vcpu->arch.guest_fpu); trace_kvm_fpu(1); } @@ -5986,6 +5986,7 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) vcpu->guest_fpu_loaded = 0; fpu_save_init(&vcpu->arch.guest_fpu); + kernel_fpu_end(); ++vcpu->stat.fpu_reload; kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); trace_kvm_fpu(0);