On Mon, Apr 12, 2021 at 07:00:16PM +0200, Siddharth Chandrasekaran wrote: > + > +static inline void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc) Do you really need inline here? The compiler should be smart enough to inline this function if necessary. > +{ > + int reg; > + > + kvm_fpu_get(); > + for (reg = 0; reg < KVM_HV_HYPERCALL_MAX_XMM_REGISTERS; reg++) > + _kvm_read_sse_reg(reg, &hc->xmm[reg]); > + kvm_fpu_put(); > + hc->xmm_dirty = false; There is no code that sets xmm_dirty to true? What am I missing? I guess that's because you haven't implemented the hypercalls that need writing back to guest? Wei.