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-Tag: v3.4.109~10 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac573c10cbf023a905dc15c5a2f91887b56ae5a7;p=thirdparty%2Fkernel%2Fstable.git x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() commit 9c1c3fac53378c9782c18f80107965578d7b7167 upstream. 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 Cc: Rui Xiang Signed-off-by: Zefan Li --- diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 318a2454366f0..55ee4ca517f22 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5907,7 +5907,7 @@ 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); } @@ -5921,6 +5921,7 @@ 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);