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Wanpeng Li
e751732486
The idea before commit240c35a37(which has just been reverted) was that we have the following FPU states: userspace (QEMU) guest --------------------------------------------------------------------------- processor vcpu->arch.guest_fpu >>> KVM_RUN: kvm_load_guest_fpu vcpu->arch.user_fpu processor >>> preempt out vcpu->arch.user_fpu current->thread.fpu >>> preempt in vcpu->arch.user_fpu processor >>> back to userspace >>> kvm_put_guest_fpu processor vcpu->arch.guest_fpu --------------------------------------------------------------------------- With the new lazy model we want to get the state back to the processor when schedule in from current->thread.fpu. Reported-by: Thomas Lambertz <mail@thomaslambertz.de> Reported-by: anthony <antdev66@gmail.com> Tested-by: anthony <antdev66@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Lambertz <mail@thomaslambertz.de> Cc: anthony <antdev66@gmail.com> Cc: stable@vger.kernel.org Fixes:5f409e20b(x86/fpu: Defer FPU state load until return to userspace) Signed-off-by: Wanpeng Li <wanpengli@tencent.com> [Add a comment in front of the warning. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
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