From: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> 3.4.109-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 <suresh.b.siddha@xxxxxxxxx> Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@xxxxxxxxx Cc: Avi Kivity <avi@xxxxxxxxxx> Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> Cc: Rui Xiang <rui.xiang@xxxxxxxxxx> Signed-off-by: Zefan Li <lizefan@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 318a245..55ee4ca 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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html